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Infection of mice with oocysts of Toxoplasma gondii by oral route showed differences of virulence from Brazilian RFLP genotypes BrI and BrIII. Res Vet Sci 2016; 107:257-260. [DOI: 10.1016/j.rvsc.2016.06.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2016] [Accepted: 06/18/2016] [Indexed: 11/21/2022]
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Phenotypes Associated with Knockouts of Eight Dense Granule Gene Loci (GRA2-9) in Virulent Toxoplasma gondii. PLoS One 2016; 11:e0159306. [PMID: 27458822 PMCID: PMC4961421 DOI: 10.1371/journal.pone.0159306] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2016] [Accepted: 06/30/2016] [Indexed: 11/19/2022] Open
Abstract
Toxoplasma gondii actively invades host cells and establishes a parasitophorous vacuole (PV) that accumulates many proteins secreted by the dense granules (GRA proteins). To date, at least 23 GRA proteins have been reported, though the function(s) of most of these proteins still remains unknown. We targeted gene knockouts at ten GRA gene loci (GRA1-10) to investigate the cellular roles and essentiality of these classical GRA proteins during acute infection in the virulent type I RH strain. While eight of these genes (GRA2-9) were successfully knocked out, targeted knockouts at the GRA1 and GRA10 loci were not obtained, suggesting these GRA proteins may be essential. As expected, the Δgra2 and Δgra6 knockouts failed to form an intravacuolar network (IVN). Surprisingly, Δgra7 exhibited hyper-formation of the IVN in both normal and lipid-free growth conditions. No morphological alterations were identified in parasite or PV structures in the Δgra3, Δgra4, Δgra5, Δgra8, or Δgra9 knockouts. With the exception of the Δgra3 and Δgra8 knockouts, all of the GRA knockouts exhibited defects in their infection rate in vitro. While the single GRA knockouts did not exhibit reduced replication rates in vitro, replication rate defects were observed in three double GRA knockout strains (Δgra4Δgra6, Δgra3Δgra5 and Δgra3Δgra7). However, the virulence of single or double GRA knockout strains in CD1 mice was not affected. Collectively, our results suggest that while the eight individual GRA proteins investigated in this study (GRA2-9) are not essential, several GRA proteins may provide redundant and potentially important functions during acute infection.
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Fox BA, Sanders KL, Rommereim LM, Guevara RB, Bzik DJ. Secretion of Rhoptry and Dense Granule Effector Proteins by Nonreplicating Toxoplasma gondii Uracil Auxotrophs Controls the Development of Antitumor Immunity. PLoS Genet 2016; 12:e1006189. [PMID: 27447180 PMCID: PMC4957766 DOI: 10.1371/journal.pgen.1006189] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Accepted: 06/22/2016] [Indexed: 12/19/2022] Open
Abstract
Nonreplicating type I uracil auxotrophic mutants of Toxoplasma gondii possess a potent ability to activate therapeutic immunity to established solid tumors by reversing immune suppression in the tumor microenvironment. Here we engineered targeted deletions of parasite secreted effector proteins using a genetically tractable Δku80 vaccine strain to show that the secretion of specific rhoptry (ROP) and dense granule (GRA) proteins by uracil auxotrophic mutants of T. gondii in conjunction with host cell invasion activates antitumor immunity through host responses involving CD8α+ dendritic cells, the IL-12/interferon-gamma (IFN-γ) TH1 axis, as well as CD4+ and CD8+ T cells. Deletion of parasitophorous vacuole membrane (PVM) associated proteins ROP5, ROP17, ROP18, ROP35 or ROP38, intravacuolar network associated dense granule proteins GRA2 or GRA12, and GRA24 which traffics past the PVM to the host cell nucleus severely abrogated the antitumor response. In contrast, deletion of other secreted effector molecules such as GRA15, GRA16, or ROP16 that manipulate host cell signaling and transcriptional pathways, or deletion of PVM associated ROP21 or GRA3 molecules did not affect the antitumor activity. Association of ROP18 with the PVM was found to be essential for the development of the antitumor responses. Surprisingly, the ROP18 kinase activity required for resistance to IFN-γ activated host innate immunity related GTPases and virulence was not essential for the antitumor response. These data show that PVM functions of parasite secreted effector molecules, including ROP18, manipulate host cell responses through ROP18 kinase virulence independent mechanisms to activate potent antitumor responses. Our results demonstrate that PVM associated rhoptry effector proteins secreted prior to host cell invasion and dense granule effector proteins localized to the intravacuolar network and host nucleus that are secreted after host cell invasion coordinately control the development of host immune responses that provide effective antitumor immunity against established ovarian cancer.
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Affiliation(s)
- Barbara A. Fox
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
| | - Kiah L. Sanders
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
| | - Leah M. Rommereim
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
| | - Rebekah B. Guevara
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
| | - David J. Bzik
- Department of Microbiology and Immunology, Geisel School of Medicine at Dartmouth, Lebanon, New Hampshire, United States of America
- * E-mail:
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104
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Fernández C, Jaimes J, Ortiz MC, Ramírez JD. Host and Toxoplasma gondii genetic and non-genetic factors influencing the development of ocular toxoplasmosis: A systematic review. INFECTION GENETICS AND EVOLUTION 2016; 44:199-209. [PMID: 27389360 DOI: 10.1016/j.meegid.2016.06.053] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Revised: 06/29/2016] [Accepted: 06/30/2016] [Indexed: 12/13/2022]
Abstract
Toxoplasmosis is a cosmopolitan infection caused by the apicomplexan parasite Toxoplasma gondii. This infectious disease is widely distributed across the world where cats play an important role in its spread. The symptomatology caused by this parasite is diverse but the ocular affectation emerges as the most important clinical phenotype. Therefore, we conducted a systematic review of the current knowledge of ocular toxoplasmosis from the genetic diversity of the pathogen towards the treatment available for this infection. This review represents an update to the scientific community regarding the genetic diversity of the parasite, the genetic factors of the host, the molecular pathogenesis and its association with disease, the available diagnostic tools and the available treatment of patients undergoing ocular toxoplamosis. This review will be an update for the scientific community in order to encourage researchers to deploy cutting-edge investigation across this field.
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Affiliation(s)
- Carolina Fernández
- Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia; Grupo de Investigaciones Microbiológicas - UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - Jesús Jaimes
- Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia; Grupo de Investigaciones Microbiológicas - UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - María Camila Ortiz
- Escuela de Medicina y Ciencias de la Salud, Universidad del Rosario, Bogotá, Colombia; Grupo de Investigaciones Microbiológicas - UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia
| | - Juan David Ramírez
- Grupo de Investigaciones Microbiológicas - UR (GIMUR), Programa de Biología, Facultad de Ciencias Naturales y Matemáticas, Universidad del Rosario, Bogotá, Colombia.
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Teshima T, Onoe H, Tottori S, Aonuma H, Mizutani T, Kamiya K, Ishihara H, Kanuka H, Takeuchi S. High-Resolution Vertical Observation of Intracellular Structure Using Magnetically Responsive Microplates. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2016; 12:3366-3373. [PMID: 27185344 DOI: 10.1002/smll.201600339] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Revised: 02/09/2016] [Indexed: 06/05/2023]
Abstract
A vertical confocal observation system capable of high-resolution observation of intracellular structure is demonstrated. The system consists of magnet-active microplates to rotate, incline, and translate single adherent cells in the applied magnetic field. Appended to conventional confocal microscopes, this system enables high-resolution cross-sectional imaging with single-molecule sensitivity in single scanning.
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Affiliation(s)
- Tetsuhiko Teshima
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
| | - Hiroaki Onoe
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
| | - Soichiro Tottori
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
| | - Hiroka Aonuma
- Department of Tropical Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shinbashi, Minato-ku, Tokyo, 105-8461, Japan
| | - Takeomi Mizutani
- Graduate School of Science, Hokkaido University, Kita 10 Nishi 8, Kita-ku, Sapporo, Hokkaido, 060-0810, Japan
| | - Koki Kamiya
- Kanagawa Academy of Science and Technology, 3-2-1 Sakado, Takatsu-ku, Kawasaki, Kanagawa, 213-0012, Japan
| | - Hirotaka Ishihara
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
| | - Hirotaka Kanuka
- Department of Tropical Medicine, The Jikei University School of Medicine, 3-25-8 Nishi-Shinbashi, Minato-ku, Tokyo, 105-8461, Japan
| | - Shoji Takeuchi
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
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106
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Morse D, Webster W, Kalanon M, Langsley G, McFadden GI. Plasmodium falciparum Rab1A Localizes to Rhoptries in Schizonts. PLoS One 2016; 11:e0158174. [PMID: 27348424 PMCID: PMC4922565 DOI: 10.1371/journal.pone.0158174] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/11/2016] [Indexed: 12/17/2022] Open
Abstract
Over-expression of a GFP-PfRab1A fusion protein in Plasmodium falciparum schizonts produces a punctate pattern of fluorescence typical of rhoptries, secretory organelles involved in host cell invasion. The GFP-positive bodies were purified by a combination of differential and density gradient centrifugation and their protein content determined by MS/MS sequencing. Consistent with the GFP rhoptry-like pattern of transgenic parasites, four of the 19 proteins identified have been previously described to be rhoptry-associated and another four are ER or ER-associated proteins. Confirmation that GFP-PfRab1A decorates rhoptries was obtained by its co-localization with Rap1 and Ron4 in late phase schizonts. We conclude that PfRab1A potentially regulates vesicular traffic from the endoplasmic reticulum to the rhoptries in Apicomplexa parasites.
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Affiliation(s)
- David Morse
- School of BioSciences, University of Melbourne, Melbourne, VIC, 3010, Australia
- * E-mail:
| | - Wesley Webster
- School of BioSciences, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Ming Kalanon
- School of BioSciences, University of Melbourne, Melbourne, VIC, 3010, Australia
| | - Gordon Langsley
- Laboratoire de Biologie Cellulaire Comparative des Apicomplexes, Institut Cochin, INSERM U1016, CNRS UMR 8104, Université Paris Descartes, 75014, Paris, France
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107
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Schrével J, Valigurová A, Prensier G, Chambouvet A, Florent I, Guillou L. Ultrastructure of Selenidium pendula, the Type Species of Archigregarines, and Phylogenetic Relations to Other Marine Apicomplexa. Protist 2016; 167:339-368. [PMID: 27423403 DOI: 10.1016/j.protis.2016.06.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2016] [Revised: 05/30/2016] [Accepted: 06/12/2016] [Indexed: 01/16/2023]
Abstract
Archigregarines, an early branching lineage within Apicomplexa, are a poorly-known group of invertebrate parasites. By their phylogenetic position, archigregarines are an important lineage to understand the functional transition that occurred between free-living flagellated predators to obligatory parasites in Apicomplexa. In this study, we provide new ultrastructural data and phylogenies based on SSU rDNA sequences using the type species of archigregarines, the Selenidiidae Selenidium pendulaGiard, 1884. We describe for the first time the syzygy and early gamogony at the ultrastructural level, revealing a characteristic nuclear multiplication with centrocones, cryptomitosis, filamentous network of chromatin, a cyst wall secretion and a 9+0 flagellar axoneme of the male gamete. S. pendula belongs to a monophyletic lineage that includes several other related species, all infecting Sedentaria Polychaeta (Spionidae, Sabellaridae, Sabellidae and Cirratulidae). All of these Selenidium species exhibit similar biological characters: a cell cortex with the plasma membrane - inner membrane complex - subpellicular microtubule sets, an apical complex with the conoid, numerous rhoptries and micronemes, a myzocytosis with large food vacuoles, a nuclear multiplication during syzygy and young gamonts. Two other distantly related Selenidium-like lineages infect Terebellidae and Sipunculida, underlying the ability of archigregarines to parasite a wide range of marine hosts.
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Affiliation(s)
- Joseph Schrével
- Unité Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR 7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005 Paris, France.
| | - Andrea Valigurová
- Department of Botany and Zoology, Faculty of Science, Masaryk University, Kotlářská 2, 611 37 Brno, Czech Republic
| | - Gérard Prensier
- Cell Biology and Electron Microscopy Laboratory, François Rabelais University, 10 Boulevard Tonnellé, BP 3223, 37032 Tours Cedex, France
| | - Aurélie Chambouvet
- Laboratoire des Sciences de l'Environnement Marin (LEMAR), UMR6539 UBO/CNRS/IRD/IFREMER, Institut Universitaire Européen de la Mer (IUEM), Technopole Brest Iroise, 29280 Plouzané, France
| | - Isabelle Florent
- Unité Molécules de Communication et Adaptation des Microorganismes, (MCAM, UMR 7245), Muséum National Histoire Naturelle, Sorbonne Universités, CNRS, CP 52, 57 Rue Cuvier, 75005 Paris, France
| | - Laure Guillou
- Sorbonne Universités, Université Pierre et Marie Curie - Paris 6, CNRS, UMR 7144, Station Biologique de Roscoff, Place Georges Teissier, CS90074, 29688 Roscoff cedex, France
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108
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Tahara M, Andrabi SBA, Matsubara R, Aonuma H, Nagamune K. A host cell membrane microdomain is a critical factor for organelle discharge by Toxoplasma gondii. Parasitol Int 2016; 65:378-88. [PMID: 27217289 DOI: 10.1016/j.parint.2016.05.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 05/18/2016] [Accepted: 05/19/2016] [Indexed: 11/18/2022]
Abstract
Host cell microdomains are involved in the attachment, entry, and replication of intracellular microbial pathogens. Entry into the host cell of Toxoplasma gondii and the subsequent survival of this protozoan parasite are tightly coupled with the proteins secreted from organelle called rhoptry. The rhoptry proteins are rapidly discharged into clusters of vesicles, called evacuoles, which are then delivered to parasitophorous vacuoles (PVs) or nucleus. In this study, we examined the roles of two host cell microdomain components, cholesterol and glycosylphosphatidylinositol (GPI), in evacuole formation. The acute depletion of cholesterol from the host cell plasma membrane blocked evacuole formation but not invasion. Whereas the lack of host cell GPI also altered evacuole formation but not invasion, instead inducing excess evacuole formation. The latter effect was not influenced by the evacuole-inhibiting effects of host cell cholesterol depletion, indicating the independent roles of host GPI and cholesterol in evacuole formation. In addition, the excess formation of evacuoles resulted in the enhanced recruitment of host mitochondria and endoplasmic reticulum to PVs, which in turn stimulated the growth of the parasite.
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Affiliation(s)
- Michiru Tahara
- Department of Parasitology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Syed Bilal Ahmad Andrabi
- Department of Parasitology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo, Japan; Department of Biochemistry, School of Medicine, Keio University, Shinanomachi, Shinjuku-ku, Tokyo, Japan
| | - Ryuma Matsubara
- Department of Parasitology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo, Japan; Graduate School of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan
| | - Hiroka Aonuma
- Department of Parasitology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo, Japan; Department of Tropical Medicine, The Jikei University School of Medicine, Nishi-shinbashi, Minato-ku, Tokyo, Japan
| | - Kisaburo Nagamune
- Department of Parasitology, National Institute of Infectious Diseases, Toyama, Shinjuku-ku, Tokyo, Japan; Faculty of Life and Environmental Sciences, University of Tsukuba, Tennodai, Tsukuba, Ibaraki, Japan.
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109
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Abstract
Ingestion of the obligate intracellular protozoan parasite Toxoplasma gondii causes an acute infection that leads to chronic infection of the host. To facilitate the acute phase of the infection, T. gondii manipulates the host response by secreting rhoptry organelle proteins (ROPs) into host cells during its invasion. A few key ROP proteins with signatures of kinases or pseudokinases (ROPKs) act as virulence factors that enhance parasite survival against host gamma interferon-stimulated innate immunity. However, the roles of these and other ROPK proteins in establishing chronic infection have not been tested. Here, we deleted 26 ROPK gene loci encoding 31 unique ROPK proteins of type II T. gondii and show that numerous ROPK proteins influence the development of chronic infection. Cyst burdens were increased in the Δrop16 knockout strain or moderately reduced in 11 ROPK knockout strains. In contrast, deletion of ROP5, ROP17, ROP18, ROP35, or ROP38/29/19 (ROP38, ROP29, and ROP19) severely reduced cyst burdens. Δrop5 and Δrop18 knockout strains were less resistant to host immunity-related GTPases (IRGs) and exhibited >100-fold-reduced virulence. ROP18 kinase activity and association with the parasitophorous vacuole membrane were necessary for resistance to host IRGs. The Δrop17 strain exhibited a >12-fold defect in virulence; however, virulence was not affected in the Δrop35 or Δrop38/29/19 strain. Resistance to host IRGs was not affected in the Δrop17, Δrop35, or Δrop38/29/19 strain. Collectively, these findings provide the first definitive evidence that the type II T. gondii ROPK proteome functions as virulence factors and facilitates additional mechanisms of host manipulation that are essential for chronic infection and transmission of T. gondii. Reactivation of chronic Toxoplasma gondii infection in individuals with weakened immune systems causes severe toxoplasmosis. Existing treatments for toxoplasmosis are complicated by adverse reactions to chemotherapy. Understanding key parasite molecules required for chronic infection provides new insights into potential mechanisms that can interrupt parasite survival or persistence in the host. This study reveals that key secreted rhoptry molecules are used by the parasite to establish chronic infection of the host. Certain rhoptry proteins were found to be critical virulence factors that resist innate immunity, while other rhoptry proteins were found to influence chronic infection without affecting virulence. This study reveals that rhoptry proteins utilize multiple mechanisms of host manipulation to establish chronic infection of the host. Targeted disruption of parasite rhoptry proteins involved in these biological processes opens new avenues to interfere with chronic infection with the goal to either eliminate chronic infection or to prevent recrudescent infections.
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110
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The Rhoptry Pseudokinase ROP54 Modulates Toxoplasma gondii Virulence and Host GBP2 Loading. mSphere 2016; 1:mSphere00045-16. [PMID: 27303719 PMCID: PMC4863586 DOI: 10.1128/msphere.00045-16] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2016] [Accepted: 02/29/2016] [Indexed: 12/02/2022] Open
Abstract
The interactions between intracellular microbes and their host cells can lead to the discovery of novel drug targets. During Toxoplasma infections, host cells express an array of immunity-related GTPases (IRGs) and guanylate binding proteins (GBPs) that load onto the parasite-containing vacuole to clear the parasite. To counter this mechanism, the parasite secretes effector proteins that traffic to the vacuole to disarm the immunity-related loading proteins and evade the immune response. While the interplay between host IRGs and Toxoplasma effector proteins is well understood, little is known about how Toxoplasma neutralizes the GBP response. We describe here a T. gondii pseudokinase effector, ROP54, that localizes to the vacuole upon invasion and is critical for parasite virulence. Toxoplasma vacuoles lacking ROP54 display an increased loading of the host immune factor GBP2, but not IRGb6, indicating that ROP54 plays a distinct role in immune evasion. Toxoplasma gondii uses unique secretory organelles called rhoptries to inject an array of effector proteins into the host cytoplasm that hijack host cell functions. We have discovered a novel rhoptry pseudokinase effector, ROP54, which is injected into the host cell upon invasion and traffics to the cytoplasmic face of the parasitophorous vacuole membrane (PVM). Disruption of ROP54 in a type II strain of T. gondii does not affect growth in vitro but results in a 100-fold decrease in virulence in vivo, suggesting that ROP54 modulates some aspect of the host immune response. We show that parasites lacking ROP54 are more susceptible to macrophage-dependent clearance, further suggesting that ROP54 is involved in evasion of innate immunity. To determine how ROP54 modulates parasite virulence, we examined the loading of two known innate immune effectors, immunity-related GTPase b6 (IRGb6) and guanylate binding protein 2 (GBP2), in wild-type and ∆rop54II mutant parasites. While no difference in IRGb6 loading was seen, we observed a substantial increase in GBP2 loading on the parasitophorous vacuole (PV) of ROP54-disrupted parasites. These results demonstrate that ROP54 is a novel rhoptry effector protein that promotes Toxoplasma infections by modulating GBP2 loading onto parasite-containing vacuoles. IMPORTANCE The interactions between intracellular microbes and their host cells can lead to the discovery of novel drug targets. During Toxoplasma infections, host cells express an array of immunity-related GTPases (IRGs) and guanylate binding proteins (GBPs) that load onto the parasite-containing vacuole to clear the parasite. To counter this mechanism, the parasite secretes effector proteins that traffic to the vacuole to disarm the immunity-related loading proteins and evade the immune response. While the interplay between host IRGs and Toxoplasma effector proteins is well understood, little is known about how Toxoplasma neutralizes the GBP response. We describe here a T. gondii pseudokinase effector, ROP54, that localizes to the vacuole upon invasion and is critical for parasite virulence. Toxoplasma vacuoles lacking ROP54 display an increased loading of the host immune factor GBP2, but not IRGb6, indicating that ROP54 plays a distinct role in immune evasion.
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111
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Wang K, Peng ED, Huang AS, Xia D, Vermont SJ, Lentini G, Lebrun M, Wastling JM, Bradley PJ. Identification of Novel O-Linked Glycosylated Toxoplasma Proteins by Vicia villosa Lectin Chromatography. PLoS One 2016; 11:e0150561. [PMID: 26950937 PMCID: PMC4780768 DOI: 10.1371/journal.pone.0150561] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 02/15/2016] [Indexed: 12/31/2022] Open
Abstract
Toxoplasma gondii maintains its intracellular life cycle using an extraordinary arsenal of parasite-specific organelles including the inner membrane complex (IMC), rhoptries, micronemes, and dense granules. While these unique compartments play critical roles in pathogenesis, many of their protein constituents have yet to be identified. We exploited the Vicia villosa lectin (VVL) to identify new glycosylated proteins that are present in these organelles. Purification of VVL-binding proteins by lectin affinity chromatography yielded a number of novel proteins that were subjected to further study, resulting in the identification of proteins from the dense granules, micronemes, rhoptries and IMC. We then chose to focus on three proteins identified by this approach, the SAG1 repeat containing protein SRS44, the rhoptry neck protein RON11 as well as a novel IMC protein we named IMC25. To assess function, we disrupted their genes by homologous recombination or CRISPR/Cas9. The knockouts were all successful, demonstrating that these proteins are not essential for invasion or intracellular survival. We also show that IMC25 undergoes substantial proteolytic processing that separates the C-terminal domain from the predicted glycosylation site. Together, we have demonstrated that lectin affinity chromatography is an efficient method of identifying new glycosylated parasite-specific proteins.
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Affiliation(s)
- Kevin Wang
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, California, 90095–1489, United States of America
| | - Eric D. Peng
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, California, 90095–1489, United States of America
| | - Amy S. Huang
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, California, 90095–1489, United States of America
| | - Dong Xia
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Sarah J. Vermont
- Institute of Infection and Global Health, University of Liverpool, Liverpool, United Kingdom
| | - Gaelle Lentini
- UMR 5235 CNRS, Université de Montpellier 1 and 2, 34095, Montpellier, France
| | - Maryse Lebrun
- UMR 5235 CNRS, Université de Montpellier 1 and 2, 34095, Montpellier, France
| | | | - Peter J. Bradley
- Department of Microbiology, Immunology and Molecular Genetics, University of California Los Angeles, Los Angeles, California, 90095–1489, United States of America
- * E-mail:
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112
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Host Mitochondrial Association Evolved in the Human Parasite Toxoplasma gondii via Neofunctionalization of a Gene Duplicate. Genetics 2016; 203:283-98. [PMID: 26920761 PMCID: PMC4858780 DOI: 10.1534/genetics.115.186270] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 02/14/2016] [Indexed: 01/30/2023] Open
Abstract
In Toxoplasma gondii, an intracellular parasite of humans and other animals, host mitochondrial association (HMA) is driven by a gene family that encodes multiple mitochondrial association factor 1 (MAF1) proteins. However, the importance of MAF1 gene duplication in the evolution of HMA is not understood, nor is the impact of HMA on parasite biology. Here we used within- and between-species comparative analysis to determine that the MAF1 locus is duplicated in T. gondii and its nearest extant relative Hammondia hammondi, but not another close relative, Neospora caninum. Using cross-species complementation, we determined that the MAF1 locus harbors multiple distinct paralogs that differ in their ability to mediate HMA, and that only T. gondii and H. hammondi harbor HMA+ paralogs. Additionally, we found that exogenous expression of an HMA+ paralog in T. gondii strains that do not normally exhibit HMA provides a competitive advantage over their wild-type counterparts during a mouse infection. These data indicate that HMA likely evolved by neofunctionalization of a duplicate MAF1 copy in the common ancestor of T. gondii and H. hammondi, and that the neofunctionalized gene duplicate is selectively advantageous.
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Mueller C, Samoo A, Hammoudi PM, Klages N, Kallio JP, Kursula I, Soldati-Favre D. Structural and functional dissection of Toxoplasma gondii armadillo repeats only protein (TgARO). J Cell Sci 2016; 129:1031-45. [DOI: 10.1242/jcs.177386] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 01/07/2016] [Indexed: 02/03/2023] Open
Abstract
Rhoptries are club-shaped, regulated secretory organelles that cluster at the apical pole of apicomplexan parasites. Their discharge is essential for invasion and the establishment of an intracellular lifestyle. Little is known about rhoptry biogenesis and recycling during parasite division. In Toxoplasma gondii, positioning of rhoptries involves the armadillo repeats only protein (TgARO) and myosin F (TgMyoF). Here, we show that two TgARO partners, ARO interacting protein (TgAIP) and adenylate cyclase β (TgACβ) localize to a rhoptry subcompartment. In absence of TgAIP, TgACβ disappears from the rhoptries. By assessing the contribution of each TgARO armadillo (ARM) repeat, we provide evidence that TgARO is multifunctional, participating not only in positioning but also in clustering of rhoptries. Structural analyses show that TgARO resembles the myosin-binding domain of the myosin chaperone UNC-45. A conserved patch of aromatic and acidic residues denotes the putative TgMyoF-binding site, and the overall arrangement of the ARM repeats explains the dramatic consequences of deleting each of them. Lastly, Plasmodium falciparum ARO functionally complements TgARO depletion and interacts with the same partners, highlighting the conservation of rhoptry biogenesis in Apicomplexa.
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Affiliation(s)
- Christina Mueller
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1 Rue Michel-Servet, CH-1211 Geneva 4, Switzerland
| | - Atta Samoo
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, P.O. Box 5400, 90014 Oulu, Finland
- Helmholtz Centre for Infection Research, Notkestrasse 85, 22607 Hamburg, Germany
- German Electron Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany
| | - Pierre-Mehdi Hammoudi
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1 Rue Michel-Servet, CH-1211 Geneva 4, Switzerland
| | - Natacha Klages
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1 Rue Michel-Servet, CH-1211 Geneva 4, Switzerland
| | - Juha Pekka Kallio
- Helmholtz Centre for Infection Research, Notkestrasse 85, 22607 Hamburg, Germany
- German Electron Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Inari Kursula
- Faculty of Biochemistry and Molecular Medicine, University of Oulu, P.O. Box 5400, 90014 Oulu, Finland
- Helmholtz Centre for Infection Research, Notkestrasse 85, 22607 Hamburg, Germany
- German Electron Synchrotron (DESY), Notkestrasse 85, 22607 Hamburg, Germany
- Department of Biomedicine, University of Bergen, Jonas Lies vei 91, 5009 Bergen, Norway
| | - Dominique Soldati-Favre
- Department of Microbiology and Molecular Medicine, CMU, University of Geneva, 1 Rue Michel-Servet, CH-1211 Geneva 4, Switzerland
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114
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Extracellular Toxoplasma gondii tachyzoites metabolize and incorporate unnatural sugars into cellular proteins. Microbes Infect 2015; 18:199-210. [PMID: 26687036 DOI: 10.1016/j.micinf.2015.11.004] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2014] [Revised: 11/12/2015] [Accepted: 11/13/2015] [Indexed: 11/20/2022]
Abstract
Toxoplasma gondii is an obligate intracellular parasite that infects all nucleated cell types in diverse warm-blooded organisms. Many of the surface antigens and effector molecules secreted by the parasite during invasion and intracellular growth are modified by glycans. Glycosylated proteins in the nucleus and cytoplasm have also been reported. Despite their prevalence, the complete inventory and biological significance of glycosylated proteins in Toxoplasma remain unknown. In this study, we aimed to globally profile parasite glycoproteins using a bioorthogonal chemical reporter strategy. This strategy involves the metabolic incorporation of unnatural functional groups (i.e., "chemical reporters") into Toxoplasma glycans, followed by covalent labeling with visual probes or affinity tags. The two-step approach enables the visualization and identification of newly biosynthesized glycoconjugates in the parasite. Using a buffer that mimics intracellular conditions, extracellular Toxoplasma tachyzoites were found to metabolize and incorporate unnatural sugars (equipped with bioorthogonal functional groups) into diverse proteins. Covalent chemistries were used to visualize and retrieve these labeled structures. Subsequent mass spectrometry analysis revealed 89 unique proteins. This survey identified novel proteins as well as previously characterized proteins from lectin affinity analyses.
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115
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Coffey MJ, Sleebs BE, Uboldi AD, Garnham A, Franco M, Marino ND, Panas MW, Ferguson DJP, Enciso M, O'Neill MT, Lopaticki S, Stewart RJ, Dewson G, Smyth GK, Smith BJ, Masters SL, Boothroyd JC, Boddey JA, Tonkin CJ. An aspartyl protease defines a novel pathway for export of Toxoplasma proteins into the host cell. eLife 2015; 4:e10809. [PMID: 26576949 PMCID: PMC4764566 DOI: 10.7554/elife.10809] [Citation(s) in RCA: 78] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2015] [Accepted: 11/18/2015] [Indexed: 02/03/2023] Open
Abstract
Infection by Toxoplasma gondii leads to massive changes to the host cell. Here, we identify a novel host cell effector export pathway that requires the Golgi-resident aspartyl protease 5 (ASP5). We demonstrate that ASP5 cleaves a highly constrained amino acid motif that has similarity to the PEXEL-motif of Plasmodium parasites. We show that ASP5 matures substrates at both the N- and C-terminal ends of proteins and also controls trafficking of effectors without this motif. Furthermore, ASP5 controls establishment of the nanotubular network and is required for the efficient recruitment of host mitochondria to the vacuole. Assessment of host gene expression reveals that the ASP5-dependent pathway influences thousands of the transcriptional changes that Toxoplasma imparts on its host cell. All these changes result in attenuation of virulence of Δasp5 tachyzoites in vivo. This work characterizes the first identified machinery required for export of Toxoplasma effectors into the infected host cell.
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Affiliation(s)
- Michael J Coffey
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Brad E Sleebs
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Alessandro D Uboldi
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Alexandra Garnham
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Magdalena Franco
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Nicole D Marino
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Michael W Panas
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - David JP Ferguson
- Nuffield Department of Clinical Laboratory Science, Oxford University, John Radcliffe Hospital, Oxford, United Kingdom
| | - Marta Enciso
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Matthew T O'Neill
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Sash Lopaticki
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
| | - Rebecca J Stewart
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Grant Dewson
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Gordon K Smyth
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Mathematics and Statistics, The University of Melbourne, Melbourne, Australia
| | - Brian J Smith
- La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Australia
| | - Seth L Masters
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - John C Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, United States
| | - Justin A Boddey
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
| | - Christopher J Tonkin
- The Walter and Eliza Hall Institute of Medical Research, Melbourne, Australia
- Department of Medical Biology, The University of Melbourne, Melbourne, Australia
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116
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Characterization of the Neospora caninum NcROP40 and NcROP2Fam-1 rhoptry proteins during the tachyzoite lytic cycle. Parasitology 2015; 143:97-113. [DOI: 10.1017/s0031182015001511] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
SUMMARYVirulence factors from the ROP2-family have been extensively studied in Toxoplasma gondii, but in the closely related Neospora caninum only NcROP2Fam-1 has been partially characterized to date. NcROP40 is a member of this family and was found to be more abundantly expressed in virulent isolates. Both NcROP2Fam-1 and NcROP40 were evaluated as vaccine candidates and exerted a synergistic effect in terms of protection against vertical transmission in mouse models, which suggests that they may be relevant for parasite pathogenicity. NcROP40 is localized in the rhoptry bulbs of tachyzoites and bradyzoites, but in contrast to NcROP2Fam-1, the protein does not associate with the parasitophorous vacuole membrane due to the lack of arginine-rich amphipathic helix in its sequence. Similarly to NcROP2Fam-1, NcROP40 mRNA levels are highly increased during tachyzoite egress and invasion. However, NcROP40 up-regulation does not appear to be linked to the mechanisms triggering egress. In contrast to NcROP2Fam-1, phosphorylation of NcROP40 was not observed during egress. Besides, NcROP40 secretion into the host cell was not successfully detected by immunofluorescence techniques. These findings indicate that NcROP40 and NcROP2Fam-1 carry out different functions, and highlight the need to elucidate the role of NcROP40 within the lytic cycle and to explain its relative abundance in tachyzoites.
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117
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Gliding motility in apicomplexan parasites. Semin Cell Dev Biol 2015; 46:135-42. [DOI: 10.1016/j.semcdb.2015.09.020] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 09/25/2015] [Indexed: 11/22/2022]
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118
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Chang S, Shan X, Li X, Fan W, Zhang SQ, Zhang J, Jiang N, Ma D, Mao Z. Toxoplasma gondii Rhoptry Protein ROP16 Mediates Partially SH-SY5Y Cells Apoptosis and Cell Cycle Arrest by Directing Ser15/37 Phosphorylation of p53. Int J Biol Sci 2015; 11:1215-25. [PMID: 26327815 PMCID: PMC4551757 DOI: 10.7150/ijbs.10516] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 07/11/2015] [Indexed: 02/04/2023] Open
Abstract
Toxoplasma rhoptries, an unusual set of apical organelles that are associated with Toxoplasma infection may cause subversion of the host cell functions. Parasite rhoptry protein 16 (ROP16) is a regulator of host cell transcription during cell invasion in which it migrates into the host cell cytoplasm and subsequently localizes to the nucleus. In the present study, we found that overexpression of ROP16 could partially mediate human neuroblastoma SH-SY5Y apoptosis (12.47%) and cell cycle arrest in G1 phase (60.77%) in a p53 dependent manner by influencing the expression of Bax/Bcl-2 and p21/CDKs. ROP16 was identified to co-localize with p53, a novel direct interaction partner in the nucleus of SH-SY5Y. Furthermore, SH-SY5Y apoptosis via the mitochondria-dependent p53 pathway and cell cycle arrest caused by ROP16 dealt with direct serine 15/37 phosphorylation of p53. Our studies provide a new mechanism by which ROP16 interacts with the nucleus proteins which subsequently subverts the host cells functions.
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Affiliation(s)
- Shuang Chang
- 1. Department of Parasitology and Microbiology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Xiumei Shan
- 1. Department of Parasitology and Microbiology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Xingliang Li
- 1. Department of Parasitology and Microbiology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Weiwei Fan
- 1. Department of Parasitology and Microbiology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Steven Qian Zhang
- 1. Department of Parasitology and Microbiology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Jin Zhang
- 2. Key Laboratory of Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Nan Jiang
- 2. Key Laboratory of Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Duan Ma
- 2. Key Laboratory of Molecular Medicine, Ministry of Education, Department of Biochemistry and Molecular Biology, Institutes of Biomedical Sciences, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
| | - Zuohua Mao
- 1. Department of Parasitology and Microbiology, School of Basic Medical Sciences, Fudan University, Shanghai, 200032, China
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119
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Xu Y, Zhang NZ, Wang M, Dong H, Feng SY, Guo HC, Zhu XQ. A long-lasting protective immunity against chronic toxoplasmosis in mice induced by recombinant rhoptry proteins encapsulated in poly (lactide-co-glycolide) microparticles. Parasitol Res 2015; 114:4195-203. [PMID: 26243574 DOI: 10.1007/s00436-015-4652-3] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2015] [Accepted: 07/23/2015] [Indexed: 12/31/2022]
Abstract
Toxoplasma gondii infection in humans and animals is a worldwide zoonosis. Prevention and control of toxoplasmosis based on vaccination is one of the promising strategies. In the present study, recombinant T. gondii rhoptry proteins 38 and 18 (TgROP38 and TgROP18) were encapsulated into poly (lactide-co-glycolide) (PLG) (1:1), respectively, to obtain the stable water-in-oil-in-water double emulsion. Female Kunming mice were then immunized with the protein vaccines twice at a 2-week interval. Eight weeks after the second immunization, 10 mice from each group were challenged with T. gondii PRU strain (genotype II). The entrapment rates of PLG-rROP38 and PLG-rROP18 ranged from 65.5 to 77.7% and 58.1 to 72.3%, respectively. Immunization of mice with rROP38 and rROP18 proteins encapsulated into PLG microparticles elicited strongly humoral and cell-mediated responses against T. gondii, associated with relatively high levels of total IgG, IgG2a isotype, and IFN-γ, as well as the mixed Th1/Th2 immunity responses. Immunization with various protein vaccines induced significant reduction of the brain cysts after chronic infection with the T. gondii PRU strain, and the most effective protection was achieved in the PLG-rROP38-rROP18-immunized mice, with a cyst reduction of 81.3%. The findings of the present study indicated that recombinant rhoptry antigens encapsulated in PLG could maintain the protein immunogenicity in an extended period and elicit effective protection against chronic T. gondii infection, which has implications for the development of long-lasting vaccines against chronic toxoplasmosis in animals.
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Affiliation(s)
- Ying Xu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China.,Key Laboratory of Animal Epidemiology and Zoonosis, Ministry of Agriculture, National Animal Protozoa Laboratory, College of Veterinary Medicine, China Agricultural University, Beijing, 100193, People's Republic of China
| | - Nian-Zhang Zhang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China
| | - Meng Wang
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China
| | - Hu Dong
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China
| | - Sheng-Yong Feng
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China
| | - Hui-Chen Guo
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China.
| | - Xing-Quan Zhu
- State Key Laboratory of Veterinary Etiological Biology, Key Laboratory of Veterinary Parasitology of Gansu Province, Lanzhou Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Lanzhou, Gansu Province, 730046, People's Republic of China. .,Jiangsu Co-innovation Center for the Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou University College of Veterinary Medicine, Yangzhou, Jiangsu Province, 225009, People's Republic of China.
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120
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Maindola P, Jamal S, Grover A. Cheminformatics Based Machine Learning Models for AMA1-RON2 Abrogators for Inhibiting Plasmodium falciparum Erythrocyte Invasion. Mol Inform 2015; 34:655-64. [PMID: 27490966 DOI: 10.1002/minf.201400139] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 02/21/2015] [Indexed: 01/15/2023]
Abstract
Malaria remains a dreadful disease by putting every year about 3.4 billion people at risk and resulting into mortality of 627 thousand people worldwide. Existing therapies based upon Quinines and Artemisinin-based combination therapies have started showing resistance, pressing the need for search of anti-malarials with different mechanisms of action. In this respect erythrocyte invasion by Plasmodium is immensely crucial, as being obligate intracellular parasite it must invade host cells. This process is mediated by interaction between conserved Apical Membrane Antigen (AMA1) and Rhoptry Neck (RON2) protein, which is compulsory for successful invasion of erythrocyte by Plasmodium and manifestation of the disease Malaria. Here, using the physicochemical properties of the compounds available from a confirmatory high throughput screening, which were tested for their disruption capability of this crucial molecular interaction, we trained supervised classifiers and validated their robustness by various statistical parameters. Best model was used for screening new compounds from Traditional Chinese Medicine Database. Some of the best hits already find their use as anti-malarials and the model predicts that an essential part of their effectiveness is likely due to inhibition of AMA1-RON2 interaction. Pharmacophoric features have also been identified to ease further designing of possible leads in an effective way.
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Affiliation(s)
- Priyank Maindola
- School of Biotechnology, Jawaharlal Nehru University, New Delhi-110067, India phone/fax: +91-11-26738728; fax: +91-11-26702040
| | - Salma Jamal
- School of Biotechnology, Jawaharlal Nehru University, New Delhi-110067, India phone/fax: +91-11-26738728; fax: +91-11-26702040
| | - Abhinav Grover
- School of Biotechnology, Jawaharlal Nehru University, New Delhi-110067, India phone/fax: +91-11-26738728; fax: +91-11-26702040.
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121
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English ED, Adomako-Ankomah Y, Boyle JP. Secreted effectors in Toxoplasma gondii and related species: determinants of host range and pathogenesis? Parasite Immunol 2015; 37:127-40. [PMID: 25655311 PMCID: PMC4359005 DOI: 10.1111/pim.12166] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Accepted: 11/26/2014] [Indexed: 12/20/2022]
Abstract
Recent years have witnessed the discovery of a number of secreted proteins in Toxoplasma gondii that play important roles in host-pathogen interactions and parasite virulence, particularly in the mouse model. However, the role that these proteins play in driving the unique features of T. gondii compared to some of its nearest apicomplexan relatives (Hammondia hammondi and Neospora caninum) is unknown. These unique features include distinct dissemination characteristics in vivo and a vast host range. In this review we comprehensively survey what is known about disease outcome, the host response and host range for T. gondii, H. hammondi, and N. caninum. We then review what is presently known about recently identified secreted virulence effectors in these three genetically related, but phenotypically distinct, species. Finally we exploit the existence of genome sequences for these three organisms and discuss what is known about the presence, and functionality, of key T. gondii effectors in these three species.
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Affiliation(s)
- E D English
- Department of Biological Sciences, Dietrich School of Arts and Sciences, University of Pittsburgh, Pittsburgh, PA, USA
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122
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Cheng Y, Li J, Ito D, Kong DH, Ha KS, Lu F, Wang B, Sattabongkot J, Lim CS, Tsuboi T, Han ET. Antigenicity and immunogenicity of PvRALP1, a novel Plasmodium vivax rhoptry neck protein. Malar J 2015; 14:186. [PMID: 25925592 PMCID: PMC4435652 DOI: 10.1186/s12936-015-0698-z] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2014] [Accepted: 04/12/2015] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Proteins secreted from the rhoptry in Plasmodium merozoites are associated with the formation of tight junctions and parasitophorous vacuoles during invasion of erythrocytes and are sorted within the rhoptry neck or bulb. Very little information has been obtained to date about Plasmodium vivax rhoptry-associated leucine (Leu) zipper-like protein 1 (PvRALP1; PVX_096245), a putative rhoptry protein. PvRALP1 contains a signal peptide, a glycine (Gly)/glutamate (Glu)-rich domain, and a Leu-rich domain, all of which are conserved in other Plasmodium species. METHODS Recombinant PvRALP1s were expressed as full-length protein without the signal peptide (PvRALP1-Ecto) and as truncated protein consisting of the Gly/Glu- and Leu-rich domains (PvRALP1-Tr) using the wheat germ cell-free expression system. The immunoreactivity to these two fragments of recombinant PvRALP1 protein in serum samples from P. vivax-infected patients and immunized mice, including analysis of immunoglobulin G (IgG) subclasses, was evaluated by enzyme-linked immunosorbent assay or protein microarray technology. The subcellular localization of PvRALP1 in blood stage parasites was also determined. RESULTS Recombinant PvRALP1-Ecto and PvRALP1-Tr proteins were successfully expressed, and in serum samples from P. vivax patients from the Republic of Korea, the observed immunoreactivities to these proteins had 58.9% and 55.4% sensitivity and 95.0% and 92.5% specificity, respectively. The response to PvRALP1 in humans was predominantly cytophilic antibodies (IgG1 and IgG3), but a balanced Th1/Th2 response was observed in mice. Unexpectedly, there was no significant inverse correlation between levels of parasitaemia and levels of antibody against either PvRALP1-Ecto (R2=0.11) or PvRALP1-Tr (R2=0.14) antigens. PvRALP1 was localized in the rhoptry neck of merozoites, and this was the first demonstration of the localization of this protein in P. vivax. CONCLUSIONS This study analysed the antigenicity and immunogenicity of PvRALP1 and suggested that PvRALP1 may be immunogenic in humans during parasite infection and might play an important role during invasion of P. vivax parasites.
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Affiliation(s)
- Yang Cheng
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Hyoja2-dong, Chuncheon, Gangwon-do, 200-701, Republic of Korea. .,Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Rockville, MD, 20852, USA.
| | - Jian Li
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Hyoja2-dong, Chuncheon, Gangwon-do, 200-701, Republic of Korea. .,Department of Parasitology, College of Basic Medicine, Hubei University of Medicine, Hubei, 442000, China.
| | - Daisuke Ito
- Laboratory of Malaria and Vector Research, National Institute of Allergy and Infectious Diseases (NIAID), National Institutes of Health (NIH), Rockville, MD, 20852, USA. .,Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime, 790-8577, Japan.
| | - Deok-Hoon Kong
- Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-701, Republic of Korea.
| | - Kwon-Soo Ha
- Department of Molecular and Cellular Biochemistry, School of Medicine, Kangwon National University, Chuncheon, Gangwon-do, 200-701, Republic of Korea.
| | - Feng Lu
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Hyoja2-dong, Chuncheon, Gangwon-do, 200-701, Republic of Korea. .,Key Laboratory of Parasitic Disease Control and Prevention (Ministry of Health), and Jiangsu Provincial Key Laboratory of Parasite Molecular Biology, Jiangsu Institute of Parasitic Diseases, Wuxi, Jiangsu Province, People's Republic of China.
| | - Bo Wang
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Hyoja2-dong, Chuncheon, Gangwon-do, 200-701, Republic of Korea. .,Department of Clinical Laboratory, The First Affiliated Hospital of Anhui Medical University, Hefei, Anhui, People's Republic of China.
| | - Jetsumon Sattabongkot
- Mahidol Vivax Research Unit, Faculty of Tropical Medicine, Mahidol University, Bangkok, 10400, Thailand.
| | - Chae Seung Lim
- Department of Laboratory Medicine, College of Medicine, Korea University Guro Hospital, Seoul, 152-703, Republic of Korea.
| | - Takafumi Tsuboi
- Division of Malaria Research, Proteo-Science Center, Ehime University, Matsuyama, Ehime, 790-8577, Japan.
| | - Eun-Taek Han
- Department of Medical Environmental Biology and Tropical Medicine, Kangwon National University School of Medicine, Hyoja2-dong, Chuncheon, Gangwon-do, 200-701, Republic of Korea.
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Sloves PJ, Mouveaux T, Ait-Yahia S, Vorng H, Everaere L, Sangare LO, Tsicopoulos A, Tomavo S. Apical Organelle Secretion by Toxoplasma Controls Innate and Adaptive Immunity and Mediates Long-Term Protection. J Infect Dis 2015; 212:1449-58. [PMID: 25910629 DOI: 10.1093/infdis/jiv250] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2015] [Accepted: 04/10/2015] [Indexed: 01/06/2023] Open
Abstract
Apicomplexan parasites have unique apical rhoptry and microneme secretory organelles that are crucial for host infection, although their role in protection against Toxoplasma gondii infection is not thoroughly understood. Here, we report a novel function of the endolysosomal T. gondii sortilin-like receptor (TgSORTLR), which mediates trafficking to functional apical organelles and their subsequent secretion of virulence factors that are critical to the induction of sterile immunity against parasite reinfection. We further demonstrate that the T. gondii armadillo repeats-only protein (TgARO) mutant, which is deficient only in apical secretion of rhoptries, is also critical in mounting protective immunity. The lack of TgSORTLR and TgARO proteins completely inhibited T-helper 1-dependent adaptive immunity and compromised the function of natural killer T-cell-mediated innate immunity. Our findings reveal an essential role for apical secretion in promoting sterile protection against T. gondii and provide strong evidence for rhoptry-regulated discharge of antigens as a key effector for inducing protective immunity.
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Affiliation(s)
| | | | - Saliha Ait-Yahia
- Laboratory of Pulmonary Immunity, Center for Infection and Immunity of Lille, Centre National de la Recherche Scientfique (CNRS) Unité Mixte de Recherche (UMR) 8204, Institut National de la Santé et de la Recherche Médicale (NSERM), Unité ( U) 1019, Université de Lille, Institut Pasteur de Lille, France
| | - Han Vorng
- Laboratory of Pulmonary Immunity, Center for Infection and Immunity of Lille, Centre National de la Recherche Scientfique (CNRS) Unité Mixte de Recherche (UMR) 8204, Institut National de la Santé et de la Recherche Médicale (NSERM), Unité ( U) 1019, Université de Lille, Institut Pasteur de Lille, France
| | - Laetitia Everaere
- Laboratory of Pulmonary Immunity, Center for Infection and Immunity of Lille, Centre National de la Recherche Scientfique (CNRS) Unité Mixte de Recherche (UMR) 8204, Institut National de la Santé et de la Recherche Médicale (NSERM), Unité ( U) 1019, Université de Lille, Institut Pasteur de Lille, France
| | | | - Anne Tsicopoulos
- Laboratory of Pulmonary Immunity, Center for Infection and Immunity of Lille, Centre National de la Recherche Scientfique (CNRS) Unité Mixte de Recherche (UMR) 8204, Institut National de la Santé et de la Recherche Médicale (NSERM), Unité ( U) 1019, Université de Lille, Institut Pasteur de Lille, France
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Leroux LP, Dasanayake D, Rommereim LM, Fox BA, Bzik DJ, Jardim A, Dzierszinski FS. Secreted Toxoplasma gondii molecules interfere with expression of MHC-II in interferon gamma-activated macrophages. Int J Parasitol 2015; 45:319-32. [PMID: 25720921 DOI: 10.1016/j.ijpara.2015.01.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2014] [Revised: 01/16/2015] [Accepted: 01/18/2015] [Indexed: 11/15/2022]
Abstract
The obligate intracellular protozoan parasite Toxoplasma gondii interferes with major histocompatibility complex class II antigen presentation to dampen host CD4(+) T cell responses. While it is known that T. gondii inhibits major histocompatibility complex class II gene transcription and expression in infected host cells, the mechanism of this host manipulation is unknown. Here, we show that soluble parasite proteins inhibit IFNγ-induced expression of major histocompatibility complex class II on the surface of the infected cell in a dose-dependent response that was abolished by protease treatment. Subcellular fractionation of T. gondii tachyzoites revealed that the major histocompatibility complex class II inhibitory activity co-partitioned with rhoptries and/or dense granules. However, parasite mutants deleted for single rhoptries or dense granules genes (ROP1, 4/7, 14, 16 and 18 or GRA 2-9 and 12 knock-out strains) retained the ability to inhibit expression of major histocompatibility complex class II. In addition, excreted/secreted antigens released by extracellular tachyzoites displayed immunomodulatory activity characterized by an inhibition of major histocompatibility complex class II expression, and reduced expression and release of TNFα by macrophages. Tandem MS analysis of parasite excreted/secreted antigens generated a list of T. gondii secreted proteins that may participate in major histocompatibility complex class II inhibition and the modulation of host immune functions.
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Affiliation(s)
- Louis-Philippe Leroux
- Institute of Parasitology, McGill University, Parasitology Building, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada; Centre for Host-Parasite Interaction, McGill University, Parasitology Building, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Dayal Dasanayake
- Institute of Parasitology, McGill University, Parasitology Building, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada; Centre for Host-Parasite Interaction, McGill University, Parasitology Building, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada
| | - Leah M Rommereim
- Geisel School of Medicine at Dartmouth, Borwell Research Building, 1 Medical Center Drive, Lebanon, NH 03756, USA
| | - Barbara A Fox
- Geisel School of Medicine at Dartmouth, Borwell Research Building, 1 Medical Center Drive, Lebanon, NH 03756, USA
| | - David J Bzik
- Geisel School of Medicine at Dartmouth, Borwell Research Building, 1 Medical Center Drive, Lebanon, NH 03756, USA
| | - Armando Jardim
- Institute of Parasitology, McGill University, Parasitology Building, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada; Centre for Host-Parasite Interaction, McGill University, Parasitology Building, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada.
| | - Florence S Dzierszinski
- Institute of Parasitology, McGill University, Parasitology Building, 21,111 Lakeshore Road, Sainte-Anne-de-Bellevue, QC H9X 3V9, Canada; Carleton University Research Office, Dunton Tower, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada
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125
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Systems-based analysis of the Sarcocystis neurona genome identifies pathways that contribute to a heteroxenous life cycle. mBio 2015; 6:mBio.02445-14. [PMID: 25670772 PMCID: PMC4337577 DOI: 10.1128/mbio.02445-14] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Sarcocystis neurona is a member of the coccidia, a clade of single-celled parasites of medical and veterinary importance including Eimeria, Sarcocystis, Neospora, and Toxoplasma. Unlike Eimeria, a single-host enteric pathogen, Sarcocystis, Neospora, and Toxoplasma are two-host parasites that infect and produce infectious tissue cysts in a wide range of intermediate hosts. As a genus, Sarcocystis is one of the most successful protozoan parasites; all vertebrates, including birds, reptiles, fish, and mammals are hosts to at least one Sarcocystis species. Here we sequenced Sarcocystis neurona, the causal agent of fatal equine protozoal myeloencephalitis. The S. neurona genome is 127 Mbp, more than twice the size of other sequenced coccidian genomes. Comparative analyses identified conservation of the invasion machinery among the coccidia. However, many dense-granule and rhoptry kinase genes, responsible for altering host effector pathways in Toxoplasma and Neospora, are absent from S. neurona. Further, S. neurona has a divergent repertoire of SRS proteins, previously implicated in tissue cyst formation in Toxoplasma. Systems-based analyses identified a series of metabolic innovations, including the ability to exploit alternative sources of energy. Finally, we present an S. neurona model detailing conserved molecular innovations that promote the transition from a purely enteric lifestyle (Eimeria) to a heteroxenous parasite capable of infecting a wide range of intermediate hosts. Sarcocystis neurona is a member of the coccidia, a clade of single-celled apicomplexan parasites responsible for major economic and health care burdens worldwide. A cousin of Plasmodium, Cryptosporidium, Theileria, and Eimeria, Sarcocystis is one of the most successful parasite genera; it is capable of infecting all vertebrates (fish, reptiles, birds, and mammals—including humans). The past decade has witnessed an increasing number of human outbreaks of clinical significance associated with acute sarcocystosis. Among Sarcocystis species, S. neurona has a wide host range and causes fatal encephalitis in horses, marine mammals, and several other mammals. To provide insights into the transition from a purely enteric parasite (e.g., Eimeria) to one that forms tissue cysts (Toxoplasma), we present the first genome sequence of S. neurona. Comparisons with other coccidian genomes highlight the molecular innovations that drive its distinct life cycle strategies.
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Tonkin ML, Boulanger MJ. The shear stress of host cell invasion: exploring the role of biomolecular complexes. PLoS Pathog 2015; 11:e1004539. [PMID: 25629317 PMCID: PMC4309608 DOI: 10.1371/journal.ppat.1004539] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Affiliation(s)
- Michelle L. Tonkin
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
| | - Martin J. Boulanger
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
- * E-mail:
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127
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A vaccine formulation combining rhoptry proteins NcROP40 and NcROP2 improves pup survival in a pregnant mouse model of neosporosis. Vet Parasitol 2015; 207:203-15. [DOI: 10.1016/j.vetpar.2014.12.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Revised: 12/11/2014] [Accepted: 12/12/2014] [Indexed: 11/23/2022]
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128
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Tyler BM, Kale SD, Wang Q, Tao K, Clark HR, Drews K, Antignani V, Rumore A, Hayes T, Plett JM, Fudal I, Gu B, Chen Q, Affeldt KJ, Berthier E, Fischer GJ, Dou D, Shan W, Keller NP, Martin F, Rouxel T, Lawrence CB. Microbe-Independent Entry of Oomycete RxLR Effectors and Fungal RxLR-Like Effectors Into Plant and Animal Cells Is Specific and Reproducible. MOLECULAR PLANT-MICROBE INTERACTIONS : MPMI 2015; 2015:51-56. [PMID: 27839069 DOI: 10.1094/mpmi-99-99-0002.testissue] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Affiliation(s)
- Brett M Tyler
- 1 Center for Genome Research and Biocomputing, and Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Shiv D Kale
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Qunqing Wang
- 1 Center for Genome Research and Biocomputing, and Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Kai Tao
- 1 Center for Genome Research and Biocomputing, and Department of Botany and Plant Pathology, Oregon State University, Corvallis, OR 97331, U.S.A
| | - Helen R Clark
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Kelly Drews
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Vincenzo Antignani
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Amanda Rumore
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Tristan Hayes
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Jonathan M Plett
- 3 Lab of Excellence ARBRE, UMR INRA/UHP 1136, Interactions Arbres/Micro-organismes, Centre INRA de Nancy, 54280 Champenoux, France
| | - Isabelle Fudal
- 4 INRA-Bioger, Campus AgroParisTech, 78850 Thiverval-Grignon, France
| | - Biao Gu
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
- 5 College of Plant Protection and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Qinghe Chen
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
| | - Katharyn J Affeldt
- 6 Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, U.S.A
| | - Erwin Berthier
- 6 Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, U.S.A
| | - Gregory J Fischer
- 6 Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, U.S.A
| | - Daolong Dou
- 2 Virginia Bioinformatics Institute, Virginia Tech, Blacksburg, VA 24061, U.S.A
- 7 Department of Plant Pathology, Nanjing Agricultural University, Nanjing 210095, China
| | - Weixing Shan
- 5 College of Plant Protection and State Key Laboratory of Crop Stress Biology in Arid Areas, Northwest A&F University, Yangling, Shaanxi 712100, China
| | - Nancy P Keller
- 6 Department of Medical Microbiology and Immunology, University of Wisconsin, Madison, WI 53706, U.S.A
| | - Francis Martin
- 3 Lab of Excellence ARBRE, UMR INRA/UHP 1136, Interactions Arbres/Micro-organismes, Centre INRA de Nancy, 54280 Champenoux, France
| | - Thierry Rouxel
- 4 INRA-Bioger, Campus AgroParisTech, 78850 Thiverval-Grignon, France
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129
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Lee WK, Ahn HJ, Baek JH, Lee CH, Yu YG, Nam HW. Comprehensive Proteome Analysis of the Excretory/Secretory Proteins of Toxoplasma gondii. B KOREAN CHEM SOC 2014. [DOI: 10.5012/bkcs.2014.35.10.3071] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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130
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Fletcher J, Leach JE, Eversole K, Tauxe R. Human Pathogens on Plants: Designing a Multidisciplinary Strategy for Research. PHYTOPATHOLOGY 2014:PHYTO09120236RVWtest. [PMID: 27454683 PMCID: PMC10962904 DOI: 10.1094/phyto-09-12-0236-rvw.test] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Recent efforts to address concerns about microbial contamination of food plants and resulting foodborne illness have prompted new collaboration and interactions between the scientific communities of plant pathology and food safety. This article provides perspectives from scientists of both disciplines and presents selected research results and concepts that highlight existing and possible future synergisms for audiences of both disciplines. Plant pathology is a complex discipline that encompasses studies of the dissemination, colonization, and infection of plants by microbes such as bacteria, viruses, fungi, and oomycetes. Plant pathologists study plant diseases as well as host plant defense responses and disease management strategies with the goal of minimizing disease occurrences and impacts. Repeated outbreaks of human illness attributed to the contamination of fresh produce, nuts and seeds, and other plant-derived foods by human enteric pathogens such as Shiga toxin-producing Escherichia coli and Salmonella spp. have led some plant pathologists to broaden the application of their science in the past two decades, to address problems of human pathogens on plants (HPOPs). Food microbiology, which began with the study of microbes that spoil foods and those that are critical to produce food, now also focuses study on how foods become contaminated with pathogens and how this can be controlled or prevented. Thus, at the same time, public health researchers and food microbiologists have become more concerned about plant-microbe interactions before and after harvest. New collaborations are forming between members of the plant pathology and food safety communities, leading to enhanced research capacity and greater understanding of the issues for which research is needed. The two communities use somewhat different vocabularies and conceptual models. For example, traditional plant pathology concepts such as the disease triangle and the disease cycle can help to define cross-over issues that pertain also to HPOP research, and can suggest logical strategies for minimizing the risk of microbial contamination. Continued interactions and communication among these two disciplinary communities is essential and can be achieved by the creation of an interdisciplinary research coordination network. We hope that this article, an introduction to the multidisciplinary HPOP arena, will be useful to researchers in many related fields.
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Affiliation(s)
- Jacqueline Fletcher
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Jan E Leach
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Kellye Eversole
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Robert Tauxe
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
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131
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Fletcher J, Leach JE, Eversole K, Tauxe R. Human Pathogens on Plants: Designing a Multidisciplinary Strategy for Research. PHYTOPATHOLOGY 2014:PHYTO09120236IAtest. [PMID: 27454682 DOI: 10.1094/phyto-09-12-0236-ia.test] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Recent efforts to address concerns about microbial contamination of food plants and resulting foodborne illness have prompted new collaboration and interactions between the scientific communities of plant pathology and food safety. This article provides perspectives from scientists of both disciplines and presents selected research results and concepts that highlight existing and possible future synergisms for audiences of both disciplines. Plant pathology is a complex discipline that encompasses studies of the dissemination, colonization, and infection of plants by microbes such as bacteria, viruses, fungi, and oomycetes. Plant pathologists study plant diseases as well as host plant defense responses and disease management strategies with the goal of minimizing disease occurrences and impacts. Repeated outbreaks of human illness attributed to the contamination of fresh produce, nuts and seeds, and other plant-derived foods by human enteric pathogens such as Shiga toxin-producing Escherichia coli and Salmonella spp. have led some plant pathologists to broaden the application of their science in the past two decades, to address problems of human pathogens on plants (HPOPs). Food microbiology, which began with the study of microbes that spoil foods and those that are critical to produce food, now also focuses study on how foods become contaminated with pathogens and how this can be controlled or prevented. Thus, at the same time, public health researchers and food microbiologists have become more concerned about plant-microbe interactions before and after harvest. New collaborations are forming between members of the plant pathology and food safety communities, leading to enhanced research capacity and greater understanding of the issues for which research is needed. The two communities use somewhat different vocabularies and conceptual models. For example, traditional plant pathology concepts such as the disease triangle and the disease cycle can help to define cross-over issues that pertain also to HPOP research, and can suggest logical strategies for minimizing the risk of microbial contamination. Continued interactions and communication among these two disciplinary communities is essential and can be achieved by the creation of an interdisciplinary research coordination network. We hope that this article, an introduction to the multidisciplinary HPOP arena, will be useful to researchers in many related fields.
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Affiliation(s)
- Jacqueline Fletcher
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Jan E Leach
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Kellye Eversole
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
| | - Robert Tauxe
- First author: National Institute for Microbial Forensics & Food and Agricultural Biosecurity, Department of Entomology & Plant Pathology, Oklahoma State University, Stillwater, OK; second author: Bioagricultural Sciences and Pest Management, Colorado State University, Ft. Collins, CO; third author: Eversole Associates, Bethesda, MD; and fourth author: Centers for Disease Control & Prevention, Atlanta, GA
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132
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Lee IP, Evans AK, Yang C, Works MG, Kumar V, De Miguel Z, Manley NC, Sapolsky RM. Toxoplasma gondii is dependent on glutamine and alters migratory profile of infected host bone marrow derived immune cells through SNAT2 and CXCR4 pathways. PLoS One 2014; 9:e109803. [PMID: 25299045 PMCID: PMC4192591 DOI: 10.1371/journal.pone.0109803] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2014] [Accepted: 09/12/2014] [Indexed: 01/16/2023] Open
Abstract
The obligate intracellular parasite, Toxoplasma gondii, disseminates through its host inside infected immune cells. We hypothesize that parasite nutrient requirements lead to manipulation of migratory properties of the immune cell. We demonstrate that 1) T. gondii relies on glutamine for optimal infection, replication and viability, and 2) T. gondii-infected bone marrow-derived dendritic cells (DCs) display both “hypermotility” and “enhanced migration” to an elevated glutamine gradient in vitro. We show that glutamine uptake by the sodium-dependent neutral amino acid transporter 2 (SNAT2) is required for this enhanced migration. SNAT2 transport of glutamine is also a significant factor in the induction of migration by the small cytokine stromal cell-derived factor-1 (SDF-1) in uninfected DCs. Blocking both SNAT2 and C-X-C chemokine receptor 4 (CXCR4; the unique receptor for SDF-1) blocks hypermotility and the enhanced migration in T. gondii-infected DCs. Changes in host cell protein expression following T. gondii infection may explain the altered migratory phenotype; we observed an increase of CD80 and unchanged protein level of CXCR4 in both T. gondii-infected and lipopolysaccharide (LPS)-stimulated DCs. However, unlike activated DCs, SNAT2 expression in the cytosol of infected cells was also unchanged. Thus, our results suggest an important role of glutamine transport via SNAT2 in immune cell migration and a possible interaction between SNAT2 and CXCR4, by which T. gondii manipulates host cell motility.
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Affiliation(s)
- I-Ping Lee
- Department of Biology, Stanford University, Stanford, California, United States of America
- * E-mail:
| | - Andrew K. Evans
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Cissy Yang
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Melissa G. Works
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Vineet Kumar
- School of Biological Sciences, Nanyang Technological University, Singapore, Republic of Singapore
| | - Zurine De Miguel
- Department of Biology, Stanford University, Stanford, California, United States of America
| | - Nathan C. Manley
- Department of Biology, Stanford University, Stanford, California, United States of America
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, United States of America
- Stanford Stroke Center and Stanford Institute for Neuro-Innovation and Translational Neurosciences, Stanford University School of Medicine, Stanford, California, United States of America
| | - Robert M. Sapolsky
- Department of Biology, Stanford University, Stanford, California, United States of America
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, California, United States of America
- Stanford Stroke Center and Stanford Institute for Neuro-Innovation and Translational Neurosciences, Stanford University School of Medicine, Stanford, California, United States of America
- Department of Neurology and Neurological Sciences, Stanford University School of Medicine, Stanford, California, United States of America
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133
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Nunney L, Elfekih S, Stouthamer R. The Importance of Multilocus Sequence Typing: Cautionary Tales from the Bacterium Xylella fastidiosa. PHYTOPATHOLOGY 2014:PHYTO10110298Rtest. [PMID: 27454684 DOI: 10.1094/phyto-10-11-0298-r.test] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Microbial identification methods have evolved rapidly over the last few decades. One such method is multilocus sequence typing (MLST). MLST is a powerful tool for understanding the evolutionary dynamics of pathogens and to gain insight into their genetic diversity. We illustrate the importance of accurate typing by reporting on three problems that have arisen in the study of a single bacterial species, the plant pathogen Xylella fastidiosa. Two of these were particularly serious since they concerned contamination of important research material that has had detrimental consequences for Xylella research: the contamination of DNA used in the sequencing of an X. fastidiosa genome (Ann-1) with DNA from another X. fastidiosa strain, and the unrecognized mislabeling of a strain (Temecula1) distributed from a culture collection (ATCC). We advocate the routine use of MLST to define strains maintained in culture collections and emphasize the importance of confirming the purity of DNA submitted for sequencing. We also present a third example that illustrates the value of MLST in guiding the choice of taxonomic types. Beyond these situations, there is a strong case for MLST whenever an isolate is used experimentally, especially where genotypic differences are suspected to influence the outcome.
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Affiliation(s)
- L Nunney
- First and second authors: Department of Biology, University of California, Riverside 92521; and third author: Department of Entomology, University of California, Riverside 92521
| | - S Elfekih
- First and second authors: Department of Biology, University of California, Riverside 92521; and third author: Department of Entomology, University of California, Riverside 92521
| | - R Stouthamer
- First and second authors: Department of Biology, University of California, Riverside 92521; and third author: Department of Entomology, University of California, Riverside 92521
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134
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Wang HL, Zhang TE, Yin LT, Pang M, Guan L, Liu HL, Zhang JH, Meng XL, Bai JZ, Zheng GP, Yin GR. Partial protective effect of intranasal immunization with recombinant Toxoplasma gondii rhoptry protein 17 against toxoplasmosis in mice. PLoS One 2014; 9:e108377. [PMID: 25255141 PMCID: PMC4177930 DOI: 10.1371/journal.pone.0108377] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2014] [Accepted: 07/21/2014] [Indexed: 11/18/2022] Open
Abstract
Toxoplasma gondii (T. gondii) is an obligate intracellular protozoan parasite that infects a variety of mammals, including humans. An effective vaccine for this parasite is therefore needed. In this study, RH strain T. gondii rhoptry protein 17 was expressed in bacteria as a fusion with glutathione S-transferase (GST) and the recombinant proteins (rTgROP17) were purified via GST-affinity chromatography. BALB/c mice were nasally immunised with rTgROP17, and induction of immune responses and protection against chronic and lethal T. gondii infections were investigated. The results revealed that mice immunised with rTgROP17 produced high levels of specific anti-rTgROP17 IgGs and a mixed IgG1/IgG2a response of IgG2a predominance. The systemic immune response was associated with increased production of Th1 (IFN-γand IL-2) and Th2 (IL-4) cytokines, and enhanced lymphoproliferation (stimulation index, SI) in the mice immunised with rTgROP17. Strong mucosal immune responses with increased secretion of TgROP17-specific secretory IgA (SIgA) in nasal, vaginal and intestinal washes were also observed in these mice. The vaccinated mice displayed apparent protection against chronic RH strain infection as evidenced by their lower liver and brain parasite burdens (59.17% and 49.08%, respectively) than those of the controls. The vaccinated mice also exhibited significant protection against lethal infection of the virulent RH strain (survival increased by 50%) compared to the controls. Our data demonstrate that rTgROP17 can trigger strong systemic and mucosal immune responses against T. gondii and that ROP17 is a promising candidate vaccine for toxoplasmosis.
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Affiliation(s)
- Hai-Long Wang
- Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China
- * E-mail: (GRY); (HLW)
| | - Tie-E Zhang
- Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China
| | - Li-Tian Yin
- Department of Physiology, Key Laboratory of Cellular Physiology Co-constructed by Province and Ministry of Education, Shanxi Medical University, Taiyuan, Shanxi, PR China
| | - Min Pang
- Department of Respiratory, the First Affiliated Hospital, Shanxi Medical University, Taiyuan, Shanxi, PR China
| | - Li Guan
- Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China
| | - Hong-Li Liu
- Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China
| | - Jian-Hong Zhang
- Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China
| | - Xiao-Li Meng
- Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China
| | - Ji-Zhong Bai
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Guo-Ping Zheng
- Department of Biochemistry and Molecular Biology, Shanxi Medical University, Taiyuan, Shanxi, PR China
| | - Guo-Rong Yin
- Research Institute of Medical Parasitology, Shanxi Medical University, Taiyuan, Shanxi, PR China
- * E-mail: (GRY); (HLW)
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Ma JS, Sasai M, Ohshima J, Lee Y, Bando H, Takeda K, Yamamoto M. Selective and strain-specific NFAT4 activation by the Toxoplasma gondii polymorphic dense granule protein GRA6. ACTA ACUST UNITED AC 2014; 211:2013-32. [PMID: 25225460 PMCID: PMC4172224 DOI: 10.1084/jem.20131272] [Citation(s) in RCA: 87] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Ma et al. show that the Toxoplasma gondii polymorphic dense granule protein GRA6 triggers the activation of the host transcription factor NFAT4, thus affecting the host immune response and maximizing parasite virulence. Toxoplasma gondii infection results in co-option and subversion of host cellular signaling pathways. This process involves discharge of T. gondii effector molecules from parasite secretory organelles such as rhoptries and dense granules. We report that the T. gondii polymorphic dense granule protein GRA6 regulates activation of the host transcription factor nuclear factor of activated T cells 4 (NFAT4). GRA6 overexpression robustly and selectively activated NFAT4 via calcium modulating ligand (CAMLG). Infection with wild-type (WT) but not GRA6-deficient parasites induced NFAT4 activation. Moreover, GRA6-deficient parasites failed to exhibit full virulence in local infection, and the treatment of WT mice with an NFAT inhibitor mitigated virulence of WT parasites. Notably, NFAT4-deficient mice displayed prolonged survival, decreased recruitment of CD11b+ Ly6G+ cells to the site of infection, and impaired expression of chemokines such as Cxcl2 and Ccl2. In addition, infection with type I parasites culminated in significantly higher NFAT4 activation than type II parasites due to a polymorphism in the C terminus of GRA6. Collectively, our data suggest that GRA6-dependent NFAT4 activation is required for T. gondii manipulation of host immune responses to maximize the parasite virulence in a strain-dependent manner.
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Affiliation(s)
- Ji Su Ma
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Miwa Sasai
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Jun Ohshima
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Youngae Lee
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Hironori Bando
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
| | - Kiyoshi Takeda
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Core Research for Evolutional Science and Technology, Japan Science and Technology Agency, Saitama 332-0012, Japan
| | - Masahiro Yamamoto
- Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan Department of Immunoparasitology, Research Institute for Microbial Diseases, Laboratory of Immunoparasitology, Laboratory of Mucosal Immunology, WPI Immunology Frontier Research Center, Department of Microbiology and Immunology, Graduate School of Medicine, and Department of Restorative Dentistry and Endodontology, Osaka University Graduate School of Dentistry, Suita, Osaka 565-0871, Japan
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Use of transgenic parasites and host reporters to dissect events that promote interleukin-12 production during toxoplasmosis. Infect Immun 2014; 82:4056-67. [PMID: 25024368 DOI: 10.1128/iai.01643-14] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
The intracellular parasite Toxoplasma gondii has multiple strategies to alter host cell function, including the injection of rhoptry proteins into the cytosol of host cells as well as bystander populations, but the consequence of these events is unclear. Here, a reporter system using fluorescent parasite strains that inject Cre recombinase with their rhoptry proteins (Toxoplasma-Cre) was combined with Ai6 Cre reporter mice to identify cells that have been productively infected, that have been rhoptry injected but lack the parasite, or that have phagocytosed T. gondii. The ability to distinguish these host-parasite interactions was then utilized to dissect the events that lead to the production of interleukin-12 p40 (IL-12p40), which is required for resistance to T. gondii. In vivo, the use of invasion-competent or invasion-inhibited (phagocytosed) parasites with IL-12p40 (YET40) reporter mice revealed that dendritic cell (DC) and macrophage populations that phagocytose the parasite or are infected can express IL-12p40 but are not the major source, as larger numbers of uninfected cells secrete this cytokine. Similarly, the use of Toxoplasma-Cre parasite strains indicated that dendritic cells and inflammatory monocytes untouched by the parasite and not cells injected by the parasite are the primary source of IL-12p40. These results imply that a soluble host or parasite factor is responsible for the bulk of IL-12p40 production in vivo, rather than cellular interactions with T. gondii that result in infection, infection and clearance, injection of rhoptry proteins, or phagocytosis of the parasite.
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137
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Toxoplasma gondii development of its replicative niche: in its host cell and beyond. EUKARYOTIC CELL 2014; 13:965-76. [PMID: 24951442 DOI: 10.1128/ec.00081-14] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Intracellular pathogens can replicate efficiently only after they manipulate and modify their host cells to create an environment conducive to replication. While diverse cellular pathways are targeted by different pathogens, metabolism, membrane and cytoskeletal architecture formation, and cell death are the three primary cellular processes that are modified by infections. Toxoplasma gondii is an obligate intracellular protozoan that infects ∼30% of the world's population and causes severe and life-threatening disease in developing fetuses, in immune-comprised patients, and in certain otherwise healthy individuals who are primarily found in South America. The high prevalence of Toxoplasma in humans is in large part a result of its ability to modulate these three host cell processes. Here, we highlight recent work defining the mechanisms by which Toxoplasma interacts with these processes. In addition, we hypothesize why some processes are modified not only in the infected host cell but also in neighboring uninfected cells.
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138
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Grover HS, Chu HH, Kelly FD, Yang SJ, Reese ML, Blanchard N, Gonzalez F, Chan SW, Boothroyd JC, Shastri N, Robey EA. Impact of regulated secretion on antiparasitic CD8 T cell responses. Cell Rep 2014; 7:1716-1728. [PMID: 24857659 DOI: 10.1016/j.celrep.2014.04.031] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2013] [Revised: 02/21/2014] [Accepted: 04/16/2014] [Indexed: 10/25/2022] Open
Abstract
CD8 T cells play a key role in defense against the intracellular parasite Toxoplasma, but why certain CD8 responses are more potent than others is not well understood. Here, we describe a parasite antigen, ROP5, that elicits a CD8 T cell response in genetically susceptible mice. ROP5 is secreted via parasite organelles termed rhoptries that are injected directly into host cells during invasion, whereas the protective, dense-granule antigen GRA6 is constitutively secreted into the parasitophorous vacuole. Transgenic parasites in which the ROP5 antigenic epitope was targeted for secretion through dense granules led to enhanced CD8 T cell responses, whereas targeting the GRA6 epitope to rhoptries led to reduced CD8 responses. CD8 T cell responses to the dense-granule-targeted ROP5 epitope resulted in reduced parasite load in the brain. These data suggest that the mode of secretion affects the efficacy of parasite-specific CD8 T cell responses.
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Affiliation(s)
- Harshita Satija Grover
- Division of Immunology and Pathogenesis, Department of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | - H Hamlet Chu
- Division of Immunology and Pathogenesis, Department of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | - Felice D Kelly
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5124, USA
| | - Soo Jung Yang
- Division of Immunology and Pathogenesis, Department of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | - Michael L Reese
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5124, USA
| | - Nicolas Blanchard
- Center of Pathophysiology of Toulouse-Purpan, INSERM UMR1043-CNRS UMR5282, University of Toulouse, 31024 Toulouse Cedex 3, France
| | - Federico Gonzalez
- Division of Immunology and Pathogenesis, Department of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | - Shiao Wei Chan
- Division of Immunology and Pathogenesis, Department of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA
| | - John C Boothroyd
- Department of Microbiology and Immunology, Stanford University School of Medicine, Stanford, CA 94305-5124, USA
| | - Nilabh Shastri
- Division of Immunology and Pathogenesis, Department of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA.
| | - Ellen A Robey
- Division of Immunology and Pathogenesis, Department of Molecular and Cellular Biology, University of California, Berkeley, Berkeley, CA 94720-3200, USA.
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139
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Daryani A, Sharif M, Dadimoghaddam Y, Souteh MBH, Ahmadpour E, Khalilian A, Sarvi S, Farazmand T, Kalani H, Rasouli M. Determination of parasitic load in different tissues of murine toxoplasmosis after immunization by excretory-secretory antigens using Real time QPCR. Exp Parasitol 2014; 143:55-9. [PMID: 24852216 DOI: 10.1016/j.exppara.2014.05.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2013] [Revised: 04/14/2014] [Accepted: 05/13/2014] [Indexed: 01/06/2023]
Abstract
Excretory-secretory antigens (ESAs) of Toxoplasma gondii are one of the candidates for immunization against toxoplasmosis. For evaluation of immunization, we determined the kinetics of the distribution of Toxoplasma and parasite load in different tissues of mice immunized by ESAs. In this experimental study, 36 mice in case (n=18) and control (n=18) groups were immunized with ESAs and PBS, respectively. After 2weeks, mice were challenged intraperitoneally with Toxoplasma virulent RH strain. Blood and different tissues (brain, spleen, liver, heart, kidney, and muscle) were collected daily after challenge (1, 2, 3 and last day before death). Parasite load was calculated using Real time QPCR targeted at the B1 gene. ESAs as vaccine in different tissues showed various effects. However, infected mice which received the vaccine in comparison with control group, displayed a drastically decreasing in parasite burden, in their blood and tissues (P=0.000). These results indicated that ESAs with reduction of parasite load in different tissues of host could be evaluable candidate for the development of immunization strategies against toxoplasmosis.
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Affiliation(s)
- Ahmad Daryani
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran; Parasitology and Mycology Department, Sari Medical School, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mehdi Sharif
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran; Parasitology and Mycology Department, Sari Medical School, Mazandaran University of Medical Sciences, Sari, Iran.
| | - Yousef Dadimoghaddam
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran; Parasitology and Mycology Department, Sari Medical School, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mohammad Bagher Hashemi Souteh
- Department of Biochemistry, Biophysics & Genetics, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
| | - Ehsan Ahmadpour
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran; Parasitology and Mycology Department, Sari Medical School, Mazandaran University of Medical Sciences, Sari, Iran
| | - Alireza Khalilian
- Biostatistics Department, Mazandaran University of Medical Sciences, Sari, Iran
| | - Shahabeddin Sarvi
- Toxoplasmosis Research Center, Mazandaran University of Medical Sciences, Sari, Iran; Parasitology and Mycology Department, Sari Medical School, Mazandaran University of Medical Sciences, Sari, Iran
| | - Touraj Farazmand
- Molecular and Cell Biology Research Center, Mazandaran University of Medical Sciences, Sari, Iran
| | - Hamed Kalani
- Parasitology and Mycology Department, Sari Medical School, Mazandaran University of Medical Sciences, Sari, Iran
| | - Mehdi Rasouli
- Department of Biochemistry, Biophysics & Genetics, Faculty of Medicine, Mazandaran University of Medical Sciences, Sari, Iran
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Teshima T, Onoe H, Aonuma H, Kuribayashi-Shigetomi K, Kamiya K, Tonooka T, Kanuka H, Takeuchi S. Magnetically responsive microflaps reveal cell membrane boundaries from multiple angles. ADVANCED MATERIALS (DEERFIELD BEACH, FLA.) 2014; 26:2850-2856. [PMID: 24677083 DOI: 10.1002/adma.201305494] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/05/2013] [Revised: 12/13/2013] [Indexed: 06/03/2023]
Abstract
A microflap system to incline adherent cells in the desired orientation is described. Inclination angles of cell-laden microflaps are precisely controlled by the applied magnetic field, enabling us to observe cell-membrane boundaries from multiple angles. This system is equipped with conventional microscopes, allowing clear focused images of cell-membrane boundaries to be obtained with high magnification.
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Affiliation(s)
- Tetsuhiko Teshima
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
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141
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Teshima T, Onoe H, Kuribayashi-Shigetomi K, Aonuma H, Kamiya K, Ishihara H, Kanuka H, Takeuchi S. Parylene mobile microplates integrated with an enzymatic release for handling of single adherent cells. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2014; 10:912-921. [PMID: 24123995 DOI: 10.1002/smll.201301993] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 08/25/2013] [Indexed: 06/02/2023]
Abstract
An approach for manipulating single adherent cells is developed that is integrated with an enzymatic batch release. This strategy uses an array of releasable microfabricated mobile substrates, termed microplates, formed from a biocompatible polymer, parylene. A parylene microplate array of 10-70 μm in diameter can be formed on an alginate hydrogel sacrificial layer by using a standard photolithographic process. The parylene surfaces are modified with fibronectin to enhance cell attachment, growth, and stretching. To load single cells onto these microplates, cells are initially placed in suspension at an optimized seeding density and are allowed to settle, stretch, and grow on individual microplates. The sacrificial layer underneath the microplate array can be dissolved on a time-scale of several seconds without cytotoxicity. This system allows the inspection of selected single adherent cells. The ability to assess single cells while maintaining their adhesive properties will broaden the examination of a variety of attributes, such as cell shape and cytoskeletal properties.
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Affiliation(s)
- Tetsuhiko Teshima
- Institute of Industrial Science, The University of Tokyo, 4-6-1 Komaba, Meguro-ku, Tokyo, 153-8505, Japan
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Chapman HD, Barta JR, Blake D, Gruber A, Jenkins M, Smith NC, Suo X, Tomley FM. A selective review of advances in coccidiosis research. ADVANCES IN PARASITOLOGY 2014; 83:93-171. [PMID: 23876872 DOI: 10.1016/b978-0-12-407705-8.00002-1] [Citation(s) in RCA: 161] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Coccidiosis is a widespread and economically significant disease of livestock caused by protozoan parasites of the genus Eimeria. This disease is worldwide in occurrence and costs the animal agricultural industry many millions of dollars to control. In recent years, the modern tools of molecular biology, biochemistry, cell biology and immunology have been used to expand greatly our knowledge of these parasites and the disease they cause. Such studies are essential if we are to develop new means for the control of coccidiosis. In this chapter, selective aspects of the biology of these organisms, with emphasis on recent research in poultry, are reviewed. Topics considered include taxonomy, systematics, genetics, genomics, transcriptomics, proteomics, transfection, oocyst biogenesis, host cell invasion, immunobiology, diagnostics and control.
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Affiliation(s)
- H David Chapman
- Department of Poultry Science, University of Arkansas, Fayetteville, Arkansas, USA.
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143
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Differential locus expansion distinguishes Toxoplasmatinae species and closely related strains of Toxoplasma gondii. mBio 2014; 5:e01003-13. [PMID: 24496792 PMCID: PMC3950507 DOI: 10.1128/mbio.01003-13] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Toxoplasma gondii is a human obligate intracellular parasite that has infected over 20% of the world population and has a vast intermediate host range compared to those of its nearest relatives Neospora caninum and Hammondia hammondi. While these 3 species have highly syntenic genomes (80 to 99%), in this study we examined and compared species-specific structural variations, specifically at loci that have undergone local (i.e., tandem) duplication and expansion. To do so, we used genomic sequence coverage analysis to identify and curate T. gondii and N. caninum loci that have undergone duplication and expansion (expanded loci [ELs]). The 53 T. gondii ELs are significantly enriched for genes with predicted signal sequences and single-exon genes and genes that are developmentally regulated at the transcriptional level. We validated 24 T. gondii ELs using comparative genomic hybridization; these data suggested significant copy number variation at these loci. High-molecular-weight Southern blotting for 3 T. gondii ELs revealed that copy number varies across T. gondii lineages and also between members of the same clonal lineage. Using similar methods, we identified 64 N. caninum ELs which were significantly enriched genes belonging to the SAG-related surface (SRS) antigen family. Moreover, there is significantly less overlap (30%) between the expanded gene sets in T. gondii and N. caninum than would be predicted by overall genomic synteny (81%). Consistent with this finding, only 59% of queried T. gondii ELs are similarly duplicated/expanded in H. hammondi despite over 99% genomic synteny between these species. Gene duplication, expansion, and diversification are a basis for phenotypic differences both within and between species. This study represents the first characterization of both the extent and degree of overlap in gene duplication and locus expansion across multiple apicomplexan parasite species. The most important finding of this study is that the locus duplications/expansions are quantitatively and qualitatively distinct, despite the high degree of genetic relatedness between the species. Given that these differential expansions are prominent species-specific genetic differences, they may also contribute to some of the more striking phenotypic differences between these species. More broadly, this work is important in providing further support for the idea that postspeciation selection events may have a dramatic impact on locus structure and copy number that overshadows selection on single-copy genes.
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Evolutionary repurposing of endosomal systems for apical organelle biogenesis in Toxoplasma gondii. Int J Parasitol 2014; 44:133-8. [DOI: 10.1016/j.ijpara.2013.10.003] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2013] [Revised: 10/09/2013] [Accepted: 10/10/2013] [Indexed: 12/20/2022]
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Molecular cloning and characterization of NcROP2Fam-1, a member of the ROP2 family of rhoptry proteins in Neospora caninum that is targeted by antibodies neutralizing host cell invasion in vitro. Parasitology 2014; 140:1033-50. [PMID: 23743240 DOI: 10.1017/s0031182013000383] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Recent publications demonstrated that a fragment of a Neospora caninum ROP2 family member antigen represents a promising vaccine candidate. We here report on the cloning of the cDNA encoding this protein, N. caninum ROP2 family member 1 (NcROP2Fam-1), its molecular characterization and localization. The protein possesses the hallmarks of ROP2 family members and is apparently devoid of catalytic activity. NcROP2Fam-1 is synthesized as a pre-pro-protein that is matured to 2 proteins of 49 and 55 kDa that localize to rhoptry bulbs. Upon invasion the protein is associated with the nascent parasitophorous vacuole membrane (PVM), evacuoles surrounding the host cell nucleus and, in some instances, the surface of intracellular parasites. Staining was also observed within the cyst wall of 'cysts' produced in vitro. Interestingly, NcROP2Fam-1 was also detected on the surface of extracellular parasites entering the host cells and antibodies directed against NcROP2Fam-1-specific peptides partially neutralized invasion in vitro. We conclude that, in spite of the general belief that ROP2 family proteins are intracellular antigens, NcROP2Fam-1 can also be considered as an extracellular antigen, a property that should be taken into account in further experiments employing ROP2 family proteins as vaccines.
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Muniz-Feliciano L, Van Grol J, Portillo JAC, Liew L, Liu B, Carlin CR, Carruthers VB, Matthews S, Subauste CS. Toxoplasma gondii-induced activation of EGFR prevents autophagy protein-mediated killing of the parasite. PLoS Pathog 2013; 9:e1003809. [PMID: 24367261 PMCID: PMC3868508 DOI: 10.1371/journal.ppat.1003809] [Citation(s) in RCA: 94] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 10/19/2013] [Indexed: 12/24/2022] Open
Abstract
Toxoplasma gondii resides in an intracellular compartment (parasitophorous vacuole) that excludes transmembrane molecules required for endosome-lysosome recruitment. Thus, the parasite survives by avoiding lysosomal degradation. However, autophagy can re-route the parasitophorous vacuole to the lysosomes and cause parasite killing. This raises the possibility that T. gondii may deploy a strategy to prevent autophagic targeting to maintain the non-fusogenic nature of the vacuole. We report that T. gondii activated EGFR in endothelial cells, retinal pigment epithelial cells and microglia. Blockade of EGFR or its downstream molecule, Akt, caused targeting of the parasite by LC3(+) structures, vacuole-lysosomal fusion, lysosomal degradation and killing of the parasite that were dependent on the autophagy proteins Atg7 and Beclin 1. Disassembly of GPCR or inhibition of metalloproteinases did not prevent EGFR-Akt activation. T. gondii micronemal proteins (MICs) containing EGF domains (EGF-MICs; MIC3 and MIC6) appeared to promote EGFR activation. Parasites defective in EGF-MICs (MIC1 ko, deficient in MIC1 and secretion of MIC6; MIC3 ko, deficient in MIC3; and MIC1-3 ko, deficient in MIC1, MIC3 and secretion of MIC6) caused impaired EGFR-Akt activation and recombinant EGF-MICs (MIC3 and MIC6) caused EGFR-Akt activation. In cells treated with autophagy stimulators (CD154, rapamycin) EGFR signaling inhibited LC3 accumulation around the parasite. Moreover, increased LC3 accumulation and parasite killing were noted in CD154-activated cells infected with MIC1-3 ko parasites. Finally, recombinant MIC3 and MIC6 inhibited parasite killing triggered by CD154 particularly against MIC1-3 ko parasites. Thus, our findings identified EGFR activation as a strategy used by T. gondii to maintain the non-fusogenic nature of the parasitophorous vacuole and suggest that EGF-MICs have a novel role in affecting signaling in host cells to promote parasite survival.
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Affiliation(s)
- Luis Muniz-Feliciano
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, United States of America
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Jennifer Van Grol
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, United States of America
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Jose-Andres C. Portillo
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Lloyd Liew
- Division of Molecular Biosciences, Imperial College London, London, United Kingdom
| | - Bing Liu
- Division of Molecular Biosciences, Imperial College London, London, United Kingdom
| | - Cathleen R. Carlin
- Department of Molecular Biology and Microbiology, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
| | - Vern B. Carruthers
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, United States of America
| | - Stephen Matthews
- Division of Molecular Biosciences, Imperial College London, London, United Kingdom
| | - Carlos S. Subauste
- Department of Pathology, Case Western Reserve University, Cleveland, Ohio, United States of America
- Division of Infectious Diseases and HIV Medicine, Department of Medicine, Case Western Reserve University School of Medicine, Cleveland, Ohio, United States of America
- Department of Ophthalmology and Visual Sciences, Case Western Reserve University, Cleveland, Ohio, United States of America
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147
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Zhang W, Blackman LM, Hardham AR. Transient fusion and selective secretion of vesicle proteins in Phytophthora nicotianae zoospores. PeerJ 2013; 1:e221. [PMID: 24392285 PMCID: PMC3869178 DOI: 10.7717/peerj.221] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 11/13/2013] [Indexed: 12/25/2022] Open
Abstract
Secretion of pathogen proteins is crucial for the establishment of disease in animals and plants. Typically, early interactions between host and pathogen trigger regulated secretion of pathogenicity factors that function in pathogen adhesion and host penetration. During the onset of plant infection by spores of the Oomycete, Phytophthora nicotianae, proteins are secreted from three types of cortical vesicles. Following induction of spore encystment, two vesicle types undergo full fusion, releasing their entire contents onto the cell surface. However, the third vesicle type, so-called large peripheral vesicles, selectively secretes a small Sushi domain-containing protein, PnCcp, while retaining a large glycoprotein, PnLpv, before moving away from the plasma membrane. Selective secretion of PnCcp is associated with its compartmentalization within the vesicle periphery. Pharmacological inhibition of dynamin function, purportedly in vesicle fission, by dynasore treatment provides evidence that selective secretion of PnCcp requires transient fusion of the large peripheral vesicles. This is the first report of selective protein secretion via transient fusion outside mammalian cells. Selective secretion is likely to be an important aspect of plant infection by this destructive pathogen.
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Affiliation(s)
- Weiwei Zhang
- Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University , Canberra, ACT , Australia
| | - Leila M Blackman
- Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University , Canberra, ACT , Australia
| | - Adrienne R Hardham
- Plant Science Division, Research School of Biology, College of Medicine, Biology and Environment, The Australian National University , Canberra, ACT , Australia
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148
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Lim D, Gold DA, Julien L, Rosowski EE, Niedelman W, Yaffe MB, Saeij JPJ. Structure of the Toxoplasma gondii ROP18 kinase domain reveals a second ligand binding pocket required for acute virulence. J Biol Chem 2013; 288:34968-80. [PMID: 24129568 PMCID: PMC3843107 DOI: 10.1074/jbc.m113.523266] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Revised: 10/13/2013] [Indexed: 12/27/2022] Open
Abstract
At least a third of the human population is infected with the intracellular parasite Toxoplasma gondii, which contributes significantly to the disease burden in immunocompromised and neutropenic hosts and causes serious congenital complications when vertically transmitted to the fetus. Genetic analyses have identified the Toxoplasma ROP18 Ser/Thr protein kinase as a major factor mediating acute virulence in mice. ROP18 is secreted into the host cell during the invasion process, and its catalytic activity is required for the acute virulence phenotype. However, its precise molecular function and regulation are not fully understood. We have determined the crystal structure of the ROP18 kinase domain, which is inconsistent with a previously proposed autoinhibitory mechanism of regulation. Furthermore, a sucrose molecule bound to our structure identifies an additional ligand-binding pocket outside of the active site cleft. Mutational analysis confirms an important role for this pocket in virulence.
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Affiliation(s)
- Daniel Lim
- From the Department of Biology and
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
| | | | | | | | | | - Michael B. Yaffe
- From the Department of Biology and
- Koch Institute for Integrative Cancer Research, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139
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149
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Toxoplasma gondii Inhibits gamma interferon (IFN-γ)- and IFN-β-induced host cell STAT1 transcriptional activity by increasing the association of STAT1 with DNA. Infect Immun 2013; 82:706-19. [PMID: 24478085 DOI: 10.1128/iai.01291-13] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
The gamma interferon (IFN-γ) response, mediated by the STAT1 transcription factor, is crucial for host defense against the intracellular pathogen Toxoplasma gondii, but prior infection with Toxoplasma can inhibit this response. Recently, it was reported that the Toxoplasma type II NTE strain prevents the recruitment of chromatin remodeling complexes containing Brahma-related gene 1 (BRG-1) to promoters of IFN-γ-induced secondary response genes such as Ciita and major histocompatibility complex class II genes in murine macrophages, thereby inhibiting their expression. We report here that a type I strain of Toxoplasma inhibits the expression of primary IFN-γ response genes such as IRF1 through a distinct mechanism not dependent on the activity of histone deacetylases. Instead, infection with a type I, II, or III strain of Toxoplasma inhibits the dissociation of STAT1 from DNA, preventing its recycling and further rounds of STAT1-mediated transcriptional activation. This leads to increased IFN-γ-induced binding of STAT1 at the IRF1 promoter in host cells and increased global IFN-γ-induced association of STAT1 with chromatin. Toxoplasma type I infection also inhibits IFN-β-induced interferon-stimulated gene factor 3-mediated gene expression, and this inhibition is also linked to increased association of STAT1 with chromatin. The secretion of proteins into the host cell by a type I strain of Toxoplasma without complete parasite invasion is not sufficient to block STAT1-mediated expression, suggesting that the effector protein responsible for this inhibition is not derived from the rhoptries.
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150
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Lilue J, Müller UB, Steinfeldt T, Howard JC. Reciprocal virulence and resistance polymorphism in the relationship between Toxoplasma gondii and the house mouse. eLife 2013; 2:e01298. [PMID: 24175088 PMCID: PMC3810784 DOI: 10.7554/elife.01298] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2013] [Accepted: 09/13/2013] [Indexed: 01/08/2023] Open
Abstract
Virulence in the ubiquitous intracellular protozoon Toxoplasma gondii for its natural intermediate host, the mouse, appears paradoxical from an evolutionary standpoint because death of the mouse before encystment interrupts the parasite life cycle. Virulent T. gondii strains secrete kinases and pseudokinases that inactivate the immunity-related GTPases (IRG proteins) responsible for mouse resistance to avirulent strains. Such considerations stimulated a search for IRG alleles unknown in laboratory mice that might confer resistance to virulent strains of T. gondii. We report that the mouse IRG system shows extraordinary polymorphic complexity in the wild. We describe an IRG haplotype from a wild-derived mouse strain that confers resistance against virulent parasites by interference with the virulent kinase complex. In such hosts virulent strains can encyst, hinting at an explanation for the evolution of virulence polymorphism in T. gondii. DOI:http://dx.doi.org/10.7554/eLife.01298.001 The parasite Toxoplasma gondii is one of the most common parasites worldwide and is known for its unusual life cycle. It reproduces sexually inside its primary host—the cat—and produces eggs that are released in faeces. Other animals, most often rodents, can then become infected when they unknowingly eat the eggs while foraging. Once inside its new host, the parasite reproduces asexually until the rodent’s immune system begins to fight back. It then becomes semi-dormant and forms cysts within the brain and muscle cells of its host. In an added twist, the parasite also causes rodents to lose their fear of cats. This increases their chances of being caught and eaten, thereby helping the parasite to return to its primary host and complete its life cycle. Previous work has shown that virulent strains of T. gondii can evade the host immune system in mice by secreting enzymes that inactivate immune-related proteins called IRG proteins. This prevents the infection being cleared and leads to death of the host within a few days. The existence of these virulent strains is intriguing because parasites that kill their host, and thus prevent their own reproduction, should be eliminated from the population. The fact that they are fairly common suggests that there must be a hitherto unknown mechanism that allows rodents to survive these virulent strains. Lilue et al. now report the existence of such a mechanism in strains of mice found in the wild. In contrast to laboratory mice, wild mice produce IRG proteins that inhibit the enzymes secreted by the virulent strains of T. gondii. Moreover, the IRG genes in wild mice are highly variable, whereas laboratory mice all have virtually identical IRG genes. By uncovering the complexity and variability of IRG genes in wild mice—complexity that has been lost from laboratory strains—Lilue et al. solve the conundrum of how highly virulent T. gondii strains can persist in the mouse population, and offer an explanation for the evolution of parasitic strains with differing levels of virulence. DOI:http://dx.doi.org/10.7554/eLife.01298.002
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Affiliation(s)
- Jingtao Lilue
- Institute for Genetics , University of Cologne , Cologne , Germany
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