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Shinjyo N, Hikosaka K, Kido Y, Yoshida H, Norose K. Toxoplasma Infection Induces Sustained Up-Regulation of Complement Factor B and C5a Receptor in the Mouse Brain via Microglial Activation: Implication for the Alternative Complement Pathway Activation and Anaphylatoxin Signaling in Cerebral Toxoplasmosis. Front Immunol 2021; 11:603924. [PMID: 33613523 PMCID: PMC7892429 DOI: 10.3389/fimmu.2020.603924] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2020] [Accepted: 12/21/2020] [Indexed: 01/01/2023] Open
Abstract
Toxoplasma gondii is a neurotropic protozoan parasite, which is linked to neurological manifestations in immunocompromised individuals as well as severe neurodevelopmental sequelae in congenital toxoplasmosis. While the complement system is the first line of host defense that plays a significant role in the prevention of parasite dissemination, Toxoplasma artfully evades complement-mediated clearance via recruiting complement regulatory proteins to their surface. On the other hand, the details of Toxoplasma and the complement system interaction in the brain parenchyma remain elusive. In this study, infection-induced changes in the mRNA levels of complement components were analyzed by quantitative PCR using a murine Toxoplasma infection model in vivo and primary glial cells in vitro. In addition to the core components C3 and C1q, anaphylatoxin C3a and C5a receptors (C3aR and C5aR1), as well as alternative complement pathway components properdin (CFP) and factor B (CFB), were significantly upregulated 2 weeks after inoculation. Two months post-infection, CFB, C3, C3aR, and C5aR1 expression remained higher than in controls, while CFP upregulation was transient. Furthermore, Toxoplasma infection induced significant increase in CFP, CFB, C3, and C5aR1 in mixed glial culture, which was abrogated when microglial activation was inhibited by pre-treatment with minocycline. This study sheds new light on the roles for the complement system in the brain parenchyma during Toxoplasma infection, which may lead to the development of novel therapeutic approaches to Toxoplasma infection-induced neurological disorders.
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MESH Headings
- Animals
- Brain/immunology
- Brain/metabolism
- Brain/parasitology
- Cells, Cultured
- Complement Factor B/genetics
- Complement Factor B/metabolism
- Complement Pathway, Alternative
- Disease Models, Animal
- Host-Parasite Interactions
- Male
- Mice, Inbred C57BL
- Microglia/immunology
- Microglia/metabolism
- Microglia/parasitology
- Receptor, Anaphylatoxin C5a/genetics
- Receptor, Anaphylatoxin C5a/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Signal Transduction
- Time Factors
- Toxoplasma/immunology
- Toxoplasma/pathogenicity
- Toxoplasmosis, Animal/genetics
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/metabolism
- Toxoplasmosis, Animal/parasitology
- Toxoplasmosis, Cerebral/genetics
- Toxoplasmosis, Cerebral/immunology
- Toxoplasmosis, Cerebral/metabolism
- Toxoplasmosis, Cerebral/parasitology
- Up-Regulation
- Mice
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Affiliation(s)
- Noriko Shinjyo
- Department of Infection and Host Defense, Graduate School of Medicine, Chiba University, Chiba, Japan
- School of Tropical Medicine and Global Health, Nagasaki University, Nagasaki, Japan
- Department of Parasitology & Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Kenji Hikosaka
- Department of Infection and Host Defense, Graduate School of Medicine, Chiba University, Chiba, Japan
| | - Yasutoshi Kido
- Department of Parasitology & Research Center for Infectious Disease Sciences, Graduate School of Medicine, Osaka City University, Osaka, Japan
| | - Hiroki Yoshida
- Division of Molecular and Cellular Immunoscience, Department of Biomolecular Sciences, Faculty of Medicine, Saga University, Saga, Japan
| | - Kazumi Norose
- Department of Infection and Host Defense, Graduate School of Medicine, Chiba University, Chiba, Japan
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2
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Tao Q, Wang X, Liu L, Ji Y, Luo Q, Du J, Yu L, Shen J, Chu D. Toxoplasma gondii Chinese I genotype Wh6 strain infection induces tau phosphorylation via activating GSK3β and causes hippocampal neuron apoptosis. Acta Trop 2020; 210:105560. [PMID: 32492398 DOI: 10.1016/j.actatropica.2020.105560] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2020] [Revised: 04/10/2020] [Accepted: 05/24/2020] [Indexed: 11/30/2022]
Abstract
Toxoplasma gondii (T. gondii) is a neurophilic and intracellular parasite that can affect plenty of vertebrate animals, including humans. Recent researches indicate that T. gondii infection is associated with neurodegenerative diseases such as Alzheimer's disease(AD). In addition, tau hyper-phosphorylation is a crucial event leading to the formation of nerve fiber tangles in AD. Despite the efforts to understand the interactions between T. gondii and AD, there are no clear results available so far. Here, we infected mice with the T. gondii of the Chinese 1 genotype Wh6 strain (TgCtwh6) for 60 days. Then we observed the formation of tissue cysts in the brain, the damage of neuron and the increased expression of phosphorylated tau (p-tau) in the hippocampal tissue of the mice. Similarly, we also found that p-tau, glycogen synthase kinase 3 beta (GSK3β), and phosphorylated GSK3β (p-GSK3β) were upregulated in vitro in TgCtwh6 challenged hippocampal neuron cell strain, HT22 cells. We noted a down-regulated expression of GSK3β,p-GSK3β, and p-tau in HT22 cells, which were pretreated with LiCl, an inhibitor of GSK3β. These data suggested that p-GSK3β may mediate tau phosphorylation after TgCtwh6 infection. Furthermore, TgCtwh6 infection also caused the increased expression of Bax and Caspase3, the decreased expression of Bcl-XL in HT22 cells, which had both early and late apoptosis. In all, our results indicated that TgCtwh6 infection not only led to phosphorylation of tau via activating GSK3β but also promoted hippocampal neuron apoptosis. Our research may partially reveal the mechanism with which TgCtwh6 induce neurofibrillary pathology.
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Affiliation(s)
- Qing Tao
- Anhui Provincial Laboratory of Microbiology and Parasitology, Anhui Medical University, Hefei, China
| | - Xianhe Wang
- Department of Pediatrics, First Affiliated Hospital of Anhui Medical University, Heifei, China
| | - Lei Liu
- Department of Parasitology, Medical College of Soochow University, Suzhou, China
| | - Yongsheng Ji
- Anhui Provincial Laboratory of Microbiology and Parasitology, Anhui Medical University, Hefei, China
| | - Qingli Luo
- Anhui Provincial Laboratory of Microbiology and Parasitology, Anhui Medical University, Hefei, China
| | - Jian Du
- Anhui Provincial Laboratory of Microbiology and Parasitology, Anhui Medical University, Hefei, China
| | - Li Yu
- Anhui Provincial Laboratory of Microbiology and Parasitology, Anhui Medical University, Hefei, China
| | - Jilong Shen
- Anhui Provincial Laboratory of Zoonoses of High Institutions, Anhui Medical University, Hefei, China
| | - Deyong Chu
- Anhui Provincial Laboratory of Microbiology and Parasitology, Anhui Medical University, Hefei, China.
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Nadipuram SM, Thind AC, Rayatpisheh S, Wohlschlegel JA, Bradley PJ. Proximity biotinylation reveals novel secreted dense granule proteins of Toxoplasma gondii bradyzoites. PLoS One 2020; 15:e0232552. [PMID: 32374791 PMCID: PMC7202600 DOI: 10.1371/journal.pone.0232552] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2019] [Accepted: 04/16/2020] [Indexed: 02/06/2023] Open
Abstract
Toxoplasma gondii is an obligate intracellular parasite which is capable of establishing life-long chronic infection in any mammalian host. During the intracellular life cycle, the parasite secretes an array of proteins into the parasitophorous vacuole (PV) where it resides. Specialized organelles called the dense granules secrete GRA proteins that are known to participate in nutrient acquisition, immune evasion, and host cell-cycle manipulation. Although many GRAs have been discovered which are expressed during the acute infection mediated by tachyzoites, little is known about those that participate in the chronic infection mediated by the bradyzoite form of the parasite. In this study, we sought to uncover novel bradyzoite-upregulated GRA proteins using proximity biotinylation, which we previously used to examine the secreted proteome of the tachyzoites. Using a fusion of the bradyzoite upregulated protein MAG1 to BirA* as bait and a strain with improved switch efficiency, we identified a number of novel GRA proteins which are expressed in bradyzoites. After using the CRISPR/Cas9 system to characterize these proteins by gene knockout, we focused on one of these GRAs (GRA55) and found it was important for the establishment or maintenance of cysts in the mouse brain. These findings highlight new components of the GRA proteome of the tissue-cyst life stage of T. gondii and identify potential targets that are important for maintenance of parasite persistence in vivo.
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Affiliation(s)
- Santhosh Mukund Nadipuram
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, United States of America
- Division of Pediatric Infectious Diseases, Department of Pediatrics, Cedar-Sinai Medical Center, Los Angeles, California, United States of America
| | - Amara Cervantes Thind
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California, Los Angeles, California, United States of America
| | - Shima Rayatpisheh
- Department of Biological Chemistry and Institute of Genomics and Proteomics, University of California, Los Angeles, California, United States of America
| | - James Akira Wohlschlegel
- Molecular Biology Institute, University of California, Los Angeles, California, United States of America
- Department of Biological Chemistry and Institute of Genomics and Proteomics, University of California, Los Angeles, California, United States of America
| | - Peter John Bradley
- Department of Microbiology, Immunology and Molecular Genetics, University of California, Los Angeles, California, United States of America
- Molecular Biology Institute, University of California, Los Angeles, California, United States of America
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4
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Ryffel B, Huang F, Robinet P, Panek C, Couillin I, Erard F, Piotet J, Le Bert M, Mackowiak C, Torres Arias M, Dimier-Poisson I, Zheng SG. Blockade of IL-33R/ST2 Signaling Attenuates Toxoplasma gondii Ileitis Depending on IL-22 Expression. Front Immunol 2019; 10:702. [PMID: 31057534 PMCID: PMC6482336 DOI: 10.3389/fimmu.2019.00702] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2018] [Accepted: 03/14/2019] [Indexed: 12/30/2022] Open
Abstract
Oral T. gondii infection (30 cysts of 76K strain) induces acute lethal ileitis in sensitive C57BL/6 (B6) mice with increased expression of IL-33 and its receptor ST2 in the ileum. Here we show that IL-33 is involved in ileitis, since absence of IL-33R/ST2 attenuated neutrophilic inflammation and Th1 cytokines upon T. gondii infection with enhanced survival. Blockade of ST2 by neutralizing ST2 antibody in B6 mice conferred partial protection, while rmIL-33 aggravated ileitis. Since IL-22 expression further increased in absence of ST2, we blocked IL-22 by neutralizing antibody, which abrogated protection from acute ileitis in ST2 deficient mice. In conclusion, severe lethal ileitis induced by oral T. gondii infection is attenuated by blockade of ST2 signaling and may be mediated in part by endogenous IL-22.
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Affiliation(s)
- Bernhard Ryffel
- Department of Clinical Immunology, Sun Yat-sen University Third Affiliated Hospital, Guangzhou, China
- INEM UMR 7355 CNRS and University of Orleans, Orléans, France
| | - Feng Huang
- Department of Clinical Immunology, Sun Yat-sen University Third Affiliated Hospital, Guangzhou, China
| | - Pauline Robinet
- INEM UMR 7355 CNRS and University of Orleans, Orléans, France
| | - Corine Panek
- INEM UMR 7355 CNRS and University of Orleans, Orléans, France
| | | | - François Erard
- INEM UMR 7355 CNRS and University of Orleans, Orléans, France
| | - Julie Piotet
- INEM UMR 7355 CNRS and University of Orleans, Orléans, France
| | - Marc Le Bert
- INEM UMR 7355 CNRS and University of Orleans, Orléans, France
| | | | - Marbel Torres Arias
- Immunology and Virology Laboratory, Nanoscience and Nanotechnology Center, Universidad de las Fuerzas Armadas, ESPE, Sangolquí, Ecuador
| | | | - Song Guo Zheng
- Department of Internal Medicine, Ohio State College of Medicine, Columbus, OH, United States
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5
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Milovanović I, Busarčević M, Trbovich A, Ivović V, Uzelac A, Djurković-Djaković O. Evidence for host genetic regulation of altered lipid metabolism in experimental toxoplasmosis supported with gene data mining results. PLoS One 2017; 12:e0176700. [PMID: 28459857 PMCID: PMC5411058 DOI: 10.1371/journal.pone.0176700] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2017] [Accepted: 04/14/2017] [Indexed: 12/23/2022] Open
Abstract
Toxoplasma gondii is one of the most successful parasites on Earth, infecting a wide array of mammals including one third of the global human population. The obligate intracellular protozoon is not capable of synthesizing cholesterol (Chl), and thus depends on uptake of host Chl for its own development. To explore the genetic regulation of previously observed lipid metabolism alterations during acute murine T. gondii infection, we here assessed total Chl and its fractions in serum and selected tissues at the pathophysiological and molecular level, and integrated the observed gene expression of selected molecules relevant for Chl metabolism, including its biosynthetic and export KEGG pathways, with the results of published transcriptomes obtained in similar murine models of T. gondii infection. The serum lipid status as well as the transcript levels of relevant genes in the brain and the liver were assessed in experimental models of acute and chronic toxoplasmosis in wild-type mice. The results showed that acute infection was associated with a decrease in Chl content in both the liver and periphery (brain, peripheral lymphocytes), and a decrease in Chl reverse transport. In contrast, in chronic infection, a return to normal levels of Chl metabolism has been noted. These changes corresponded to the brain and liver gene expression results as well as to data obtained via mining. We propose that the observed changes in Chl metabolism are part of the host defense response. Further insight into the lipid metabolism in T. gondii infection may provide novel targets for therapeutic agents.
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Affiliation(s)
- Ivan Milovanović
- Institute for Pathologic Physiology, School of Medicine, University of Belgrade, Belgrade, Serbia
| | - Miloš Busarčević
- National Reference Laboratory for Toxoplasmosis, Center of Excellence for Food- and Vector-borne Zoonoses, Institute for Medical Research, University of Belgrade, Belgrade, Serbia
| | - Alexander Trbovich
- Institute for Pathologic Physiology, School of Medicine, University of Belgrade, Belgrade, Serbia
- National Reference Laboratory for Toxoplasmosis, Center of Excellence for Food- and Vector-borne Zoonoses, Institute for Medical Research, University of Belgrade, Belgrade, Serbia
| | - Vladimir Ivović
- National Reference Laboratory for Toxoplasmosis, Center of Excellence for Food- and Vector-borne Zoonoses, Institute for Medical Research, University of Belgrade, Belgrade, Serbia
| | - Aleksandra Uzelac
- National Reference Laboratory for Toxoplasmosis, Center of Excellence for Food- and Vector-borne Zoonoses, Institute for Medical Research, University of Belgrade, Belgrade, Serbia
| | - Olgica Djurković-Djaković
- National Reference Laboratory for Toxoplasmosis, Center of Excellence for Food- and Vector-borne Zoonoses, Institute for Medical Research, University of Belgrade, Belgrade, Serbia
- * E-mail:
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6
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McConkey GA, Peers C, Prandovszky E. Reproducing increased dopamine with infection to evaluate the role of parasite-encoded tyrosine hydroxylase activity. Infect Immun 2015; 83:3334-5. [PMID: 26157085 PMCID: PMC4496599 DOI: 10.1128/iai.00605-15] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Affiliation(s)
- Glenn A McConkey
- Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
| | - Chris Peers
- Division of Cardiovascular and Diabetes Research, LIGHT, Faculty of Medicine and Health, University of Leeds, Leeds, United Kingdom
| | - Emese Prandovszky
- Stanley Division of Developmental Neurovirology, Department of Pediatrics, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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Wagage S, Harms Pritchard G, Dawson L, Buza EL, Sonnenberg GF, Hunter CA. The Group 3 Innate Lymphoid Cell Defect in Aryl Hydrocarbon Receptor Deficient Mice Is Associated with T Cell Hyperactivation during Intestinal Infection. PLoS One 2015; 10:e0128335. [PMID: 26010337 PMCID: PMC4444139 DOI: 10.1371/journal.pone.0128335] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 04/24/2015] [Indexed: 12/20/2022] Open
Abstract
Intestinal infection with the intracellular parasite Toxoplasma gondii results in the translocation of commensal bacteria to peripheral organs and the development of a T cell response specific to the microbiota. In naïve mice, the recently described RORγt+ group 3 innate lymphoid cell (ILC) population plays a critical role in promoting intestinal barrier function and limiting responses to gut-resident commensal bacteria. Given this role for group 3 ILCs, studies were performed to evaluate whether these cells might influence the immune response to mucosal infection with T. gondii. Phenotypic characterization of RORγt+ ILCs in T. gondii infected mice revealed that this population decreased following challenge but the population that remained expressed costimulatory molecules and IL-22. One factor that influences the maintenance of RORγt+ ILCs is the aryl hydrocarbon receptor (AHR), a ligand-activated transcription factor, and Ahr-/- mice have a marked defect in the lamina propria group 3 ILC population. When Ahr-/- mice were challenged with T. gondii, they lost more weight than wild type controls. This disease course in Ahr-/- animals was associated with increased T cell responses to Toxoplasma antigen and crude commensal antigen preparations. Together, these data suggest that group 3 ILCs have a role in limiting T cell activation during intestinal infection.
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Affiliation(s)
- Sagie Wagage
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Gretchen Harms Pritchard
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Lucas Dawson
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Elizabeth L. Buza
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Gregory F. Sonnenberg
- Department of Medicine and Institute for Immunology, Perelman School of Medicine, Division of Gastroenterology, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
| | - Christopher A. Hunter
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, United States of America
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Dvorakova-Hortova K, Sidlova A, Ded L, Hladovcova D, Vieweg M, Weidner W, Steger K, Stopka P, Paradowska-Dogan A. Toxoplasma gondii decreases the reproductive fitness in mice. PLoS One 2014; 9:e96770. [PMID: 24940596 PMCID: PMC4062421 DOI: 10.1371/journal.pone.0096770] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2013] [Accepted: 04/11/2014] [Indexed: 12/28/2022] Open
Abstract
Toxoplasma gondii is a common protozoan parasite that infects warm-blooded animals throughout the world, including mice and humans. During infection, both, the parasite and the host, utilize various mechanisms to maximize their own reproductive success. Mice and humans are both the intermediate hosts for Toxoplasma gondii, which forms specialized vacuoles containing reproductive cysts in the formers' tissue. As half of the human population is infected, developing a disease called toxoplasmosis, along with an ever-growing number of couples suffering with idiopathic infertility, it is therefore surprising that there is a lack of research on how Toxoplasma gondii can alter reproductive parameters. In this study, a detailed histometric screening of the testicular function along with the levels of the pituitary luteinizing hormone (LH) were analysed in infected mice. Data on relative testis and epididymis weight, and sperm count were also collected. Based on the results obtained, the level of LH in the urine of Toxoplasma gondii infected mice was lower compared to the control. In direct correlation with the hormone level, testicular function and sperm production was also significantly lower in Toxoplasma gondii positive group using sperm count and histometric analysis as a marker. Not only were the number of leptotene primary spermatocytes and spermatids lowered, but the number of Sertoli cells and the tubule diameter were elevated. In parallel, a pilot epigenetic study on global testicular methylation, and specific methylation of Crem, Creb1 and Hspa1genes essential for successfully ongoing spermatogenesis was performed. Global methylation was elevated in Toxoplasma infected mice, and differences in the DNA methylation of selected genes were detected between the Toxoplasma positive and control group. These findings demonstrate a direct relation between Toxoplasma gondii infection and the decrease of male reproductive fitness in mice, which may contribute to an increase of idiopathic infertility in humans.
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Affiliation(s)
- Katerina Dvorakova-Hortova
- Biocev Group, Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Adela Sidlova
- Biocev Group, Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Lukas Ded
- Laboratory of Reproductive Biology, Institute of Biotechnology, Academy of Science, Prague, Czech Republic
| | - Denisa Hladovcova
- Biocev Group, Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Markus Vieweg
- Department of Urology, Pediatric Urology and Andrology, Justus Liebig University of Giessen, Giessen, Germany
| | - Wolfgang Weidner
- Department of Urology, Pediatric Urology and Andrology, Justus Liebig University of Giessen, Giessen, Germany
| | - Klaus Steger
- Department of Urology, Pediatric Urology and Andrology, Justus Liebig University of Giessen, Giessen, Germany
| | - Pavel Stopka
- Biocev Group, Department of Zoology, Faculty of Science, Charles University in Prague, Prague, Czech Republic
| | - Agnieszka Paradowska-Dogan
- Department of Urology, Pediatric Urology and Andrology, Justus Liebig University of Giessen, Giessen, Germany
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MacRae JI, Sheiner L, Nahid A, Tonkin C, Striepen B, McConville MJ. Mitochondrial metabolism of glucose and glutamine is required for intracellular growth of Toxoplasma gondii. Cell Host Microbe 2013; 12:682-92. [PMID: 23159057 DOI: 10.1016/j.chom.2012.09.013] [Citation(s) in RCA: 166] [Impact Index Per Article: 15.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2012] [Revised: 07/07/2012] [Accepted: 09/20/2012] [Indexed: 12/23/2022]
Abstract
Toxoplasma gondii proliferates within host cell vacuoles where the parasite relies on host carbon and nutrients for replication. To assess how T. gondii utilizes these resources, we mapped the carbon metabolism pathways in intracellular and egressed parasite stages. We determined that intracellular T. gondii stages actively catabolize host glucose via a canonical, oxidative tricarboxylic acid (TCA) cycle, a mitochondrial pathway in which organic molecules are broken down to generate energy. These stages also catabolize glutamine via the TCA cycle and an unanticipated γ-aminobutyric acid (GABA) shunt, which generates GABA and additional molecules that enter the TCA cycle. Chemically inhibiting the TCA cycle completely prevents intracellular parasite replication. Parasites lacking the GABA shunt exhibit attenuated growth and are unable to sustain motility under nutrient-limited conditions, suggesting that GABA functions as a short-term energy reserve. Thus, T. gondii tachyzoites have metabolic flexibility that likely allows the parasite to infect diverse cell types.
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Affiliation(s)
- James I MacRae
- Department of Biochemistry and Molecular Biology, Bio21 Institute of Molecular Science and Biotechnology, University of Melbourne, Parkville, VIC 3010, Australia
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10
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Zhou YH, Huang YZ, Tao YH, Wang J, Xu YL, Gao Q. [Preliminary study on serum proteomics in mice with acute toxoplasma gondii infection by using functionalized magnetic beads and MALDI-TOF-MS technique]. Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi 2012; 24:311-314. [PMID: 23012956] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
OBJECTIVE To detect and analyze the serum protein biomarkers in mice with acute Toxoplasma gondii infection. METHODS The serum samples from 8 C57BL/6J mice with acute Toxoplasma gondii infection and 8 normal healthy paired mice were prepared with WCX magnetic beads, and then analyzed on PBS II -C mass spectrometer reader. The protein spectra of the serum samples were normalized by the Ciphergen Protein Chip software. The peak labeling was performed by the Biomarker Wizard software. The specific protein biomarkers were screened by the Biomarker Pattern software to construct a diagnostic model for acute Toxoplasma gondii infection. RESULTS A total of 13 distinguished proteomic peaks were detected. Nine peaks were of up-regulated expressions including m/z values of 1 932.76, 1 976.85, 2 090.53, 5 004.5, 5 776.01, 5 803.05, 5 847.99, 5 877.51 and 7 501.58, respectively; and four peaks were of down-regulated expressions including m/z values of 1 866.40,4 063.71, 8 120.31 and 8 203.83, respectively. CONCLUSION The potential protein biomarkers for acute Toxoplasma gondii infection are discovered in mouse serum by MALDI-TOF-MS combined with WCX magnetic beads.
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Affiliation(s)
- Yong-Hua Zhou
- Jiangsu Institute of Parasitic Diseases, Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health, Jiangsu Provincial Key Laboratory on Molecular Biology of Parasites, Jiangsu Provincial Key Subject on Parasitic Diseases, Wuxi 214064, China
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11
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Tato CM, Joyce-Shaikh B, Banerjee A, Chen Y, Sathe M, Ewald SE, Liu MR, Gorman D, McClanahan TK, Phillips JH, Heyworth PG, Cua DJ. The myeloid receptor PILRβ mediates the balance of inflammatory responses through regulation of IL-27 production. PLoS One 2012; 7:e31680. [PMID: 22479310 PMCID: PMC3313972 DOI: 10.1371/journal.pone.0031680] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2011] [Accepted: 01/16/2012] [Indexed: 11/21/2022] Open
Abstract
Paired immunoglobulin-like receptors beta, PILRβ, and alpha, PILRα, are related to the Siglec family of receptors and are expressed primarily on cells of the myeloid lineage. PILRβ is a DAP12 binding partner expressed on both human and mouse myeloid cells. The potential ligand, CD99, is found on many cell types, such as epithelial cells where it plays a role in migration of immune cells to sites of inflammation. Pilrb deficient mice were challenged with the parasite Toxoplasma gondii in two different models of infection induced inflammation; one involving the establishment of chronic encephalitis and a second mimicking inflammatory bowel disease in order to understand the potential role of this receptor in persistent inflammatory responses. It was found that in the absence of activating signals from PILRβ, antigen-presenting cells (APCs) produced increased amounts of IL-27, p28 and promoted IL-10 production in effector T cells. The sustained production of IL-27 led ultimately to enhanced survival after challenge due to dampened immune pathology in the gut. Similar protection was also observed in the CNS during chronic T. gondii infection after i.p. challenge again providing evidence that PILRβ is important for regulating aberrant inflammatory responses.
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MESH Headings
- Animals
- Cells, Cultured
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Encephalitis/genetics
- Encephalitis/immunology
- Encephalitis/metabolism
- Female
- Gene Expression
- Inflammation/genetics
- Inflammation/immunology
- Inflammation/metabolism
- Interferon-gamma/genetics
- Interferon-gamma/immunology
- Interferon-gamma/metabolism
- Interleukins/genetics
- Interleukins/immunology
- Interleukins/metabolism
- Macrophages/immunology
- Macrophages/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred CBA
- Mice, Knockout
- Microglia/immunology
- Microglia/metabolism
- Receptors, Immunologic/deficiency
- Receptors, Immunologic/genetics
- Receptors, Immunologic/immunology
- Reverse Transcriptase Polymerase Chain Reaction
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Toxoplasma/immunology
- Toxoplasmosis, Animal/genetics
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/metabolism
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Affiliation(s)
- Cristina M. Tato
- Merck Research Laboratories, Palo Alto, California, United States of America
- Institute for Immunity, Transplantation and Infection, School of Medicine, Stanford University, Stanford, California, United States of America
| | | | - Antara Banerjee
- Merck Research Laboratories, Palo Alto, California, United States of America
| | - Yi Chen
- Merck Research Laboratories, Palo Alto, California, United States of America
| | - Manjiri Sathe
- Merck Research Laboratories, Palo Alto, California, United States of America
| | - Sarah E. Ewald
- Department of Microbiology and Immunology, School of Medicine, Stanford University, Stanford, California, United States of America
| | - Man-Ru Liu
- Merck Research Laboratories, Palo Alto, California, United States of America
| | - Daniel Gorman
- Merck Research Laboratories, Palo Alto, California, United States of America
| | | | - Joseph H. Phillips
- Merck Research Laboratories, Palo Alto, California, United States of America
| | - Paul G. Heyworth
- Merck Research Laboratories, Palo Alto, California, United States of America
| | - Daniel J. Cua
- Merck Research Laboratories, Palo Alto, California, United States of America
- * E-mail:
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12
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Zhou YH, Wang SS, Yang J, Tao JP, Xu YL, Huang YZ, Gao Q. [Expression of Toll-like receptor 4 in brain tissue of chronic Toxoplasma gondii infection rats and its effect on brain injury]. Zhongguo Xue Xi Chong Bing Fang Zhi Za Zhi 2012; 24:58-61. [PMID: 22590866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To explore the expression of Toll-like receptor 4 (TLR4) in brain tissue of chronic Toxoplasma infection rats and its effect on brain injury. METHODS Ten male SD rats were randomly divided into 2 groups, namely control and infection groups. Each rat in the infection group was intraperitoneal injected with Toxoplasma gondii tachyzoites 10(7)/ml x 2 ml, and that in the control group was injected with 2 ml sterile normal sodium. After 10 weeks, the expression of TLR4 mRNA in the brain was determined by RT-PCR, and the levels of IL-1beta and IL-4 in peripheral blood sera were detected by ELISA. RESULTS Compared with the control group, the expression of TLR4 gene and the peripheral blood serum level of IL-1beta of rats in the Toxoplasma gondii infection group were both significantly increased, with all P values were less than 0.05, and the level of IL-4 was also increased, but the difference had no statistically significance (P > 0.05). CONCLUSION TLR4 might be involved in inflammatory reactions of brain injury for chronic Toxoplasma gondii infection rats.
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Affiliation(s)
- Yong-Hua Zhou
- Jiangsu Institute of Parasitic Diseases, Key Laboratory on Technology for Parasitic Disease Prevention and Control, Ministry of Health, Wuxi 214064, China
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13
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Yang R. [Effect of Toxoplasma gondii infection on cytokines and spermatogenic cells in rats]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2011; 29:274-278. [PMID: 21972602] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
OBJECTIVE To study on the fluctuation of cytokines of T helper type 1 (Th1) and T helper type 2 (Th2) after Toxoplasma gondii infection, as well as pathological damage of testis and apoptosis of spermatogenic cells in male rats. METHODS Eighty-eight SD male rats (9-10 week old) were randomly and equally divided into normal control group and infection group. Rats in infection group were infected with 1x10(4) tachyzoites by intraperitoneal injection, while those in normal control group received same volume of PBS. On the day before infection and at the 3rd, 6th, 9th, 12th, ......, and 30th day post infection, four rats from each group were sacrificed for sera and testes. gamma-interferon (IFN-gamma) and interleukin 4 (IL-4) levels in sera were measured by ELISA. The testes were sliced and observed by microscope. The levels of apoptosis relative proteins Bcl-2 and Bax in seminiferous tubules were detected by immunohistochemistry. RESULTS IFN-gamma in sera of infected rats increased rapidly with the peak [(518.3 +/- 83.6) pg/ml] at the 6th day post infection, and then decreased rapidly. IL-4 increased slowly with the peak [(325.0 +/- 38.6) pg/ml] at the 12th day, and then decreased. Both cytokines were significantly higher than the control, (P<0.01) in the 30-day period. Pathological examination at the 6th day post infection showed that the cell levels of testicular seminiferous tubule disturbed. The number of primary and secondary spermatocytes decreased significantly. There were few sperms within the lumen or cavity which even closed. All the changes did not recover during 30 days. Bax expression in infected rats significantly increased in spermatogenic cells especially in spermatocytes at the 3rd day (P<0.05), reached a peak (0.547 +/- 0.037) at the 6th day, and then gradually decreased to normal after 15 days. The expression of Bcl-2 in infected rats did not change significantly (P>0.05). CONCLUSION T. gondii causes severe pathological damage in spermatogenic cells of the host. During the acute phase there appears Th1 cytokine polarization accompanied by high expression of apoptosis protein Bax, which is mainly expressed in spermatocytes. After re-balance of Th1/Th2, Bax protein expression decreases without noticeable recovery of spermatogenesis.
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Affiliation(s)
- Rui Yang
- Department of Immunology and Pathogen Biology, Zhuhai Campus, Zunyi Medical College, Zhuhai 519041, China
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14
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Yang JF, Yue HP, Hou YY, Liu ZS, Rao HX, He YX, Zhang TT, Huang CY, Guo LN. [Acute infection of Toxoplasma gondii affects the level of oxygen free radicals in serum and testes of mice]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2010; 28:364-367. [PMID: 21351550] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
OBJECTIVE To observe the impact of Toxoplasma gondii infection on the level of oxygen free radicals and antioxidant enzyme in serum and testes of mice. METHODS 40 BALB/c male mice were randomly divided into four groups. Five mice from each group were injected intraperitoneally with 2.5 x 10(3) tachyzoites of T. gondii, the others received PBS. Mice were sacrificed on the 1st, 3rd, 5th, and 7th day after inoculation. Samples of serum and testes were collected to determine the content of oxygen free radicals and superoxide dismutase (SOD). RESULTS The concentration of the oxygen free radicals (NO, *OH, O2-) in serum and testes of the mice increased along with the days of infection. The concentration of SOD reached a peak on the 3rd day after the injection and then decreased. Both of oxygen free radicals and SOD showed a statistical difference with the control (P < 0.01). CONCLUSION Acute infection of T. gondii leads to n increase of oxygen free radicals and SOD in the serum and testes of mice.
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Affiliation(s)
- Jun-Feng Yang
- Institute of Medical Parasitology, Shanxi Medical University, Taiyuan 030001, China
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15
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Goncharov DB, Mezentseva MV, Surgucheva IM, Kobets NV, Ignatova NG, Sherbenko VE, Narovlianskiĭ AN. [Production of cytokines in experimental toxoplasmosis]. Med Parazitol (Mosk) 2008:16-19. [PMID: 18365467] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/26/2023]
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16
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Thomas NJ, Dubey JP, Lindsay DS, Cole RA, Meteyer CU. Protozoal meningoencephalitis in sea otters (Enhydra lutris): a histopathological and immunohistochemical study of naturally occurring cases. J Comp Pathol 2007; 137:102-21. [PMID: 17692867 DOI: 10.1016/j.jcpa.2007.05.001] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2006] [Accepted: 05/04/2007] [Indexed: 10/23/2022]
Abstract
Protozoal meningoencephalitis is considered to be an important cause of mortality in the California sea otter (Enhydra lutris). Thirty nine of 344 (11.3%) California (CA) and Washington state (WA) sea otters examined from 1985 to 2004 had histopathological evidence of significant protozoal meningoencephalitis. The aetiological agents and histopathological changes associated with these protozoal infections are described. The morphology of the actively multiplicative life stages of the organisms (tachyzoites for Toxoplasma gondii and merozoites for Sarcocystis neurona) and immunohistochemical labelling were used to identify infection with S. neurona (n=22, 56.4%), T. gondii (n=5, 12.8%) or dual infection with both organisms (n=12, 30.8%). Active S. neurona was present in all dual infections, while most had only the latent form of T. gondii. In S. neurona meningoencephalitis, multifocal to diffuse gliosis was widespread in grey matter and consistently present in the molecular layer of the cerebellum. In T. gondii meningoencephalitis, discrete foci of gliosis and malacia were more widely separated, sometimes incorporated pigment-laden macrophages and mineral, and were found predominantly in the cerebral cortex. Quiescent tissue cysts of T. gondii were considered to be incidental and not a cause of clinical disease and mortality. Protozoal meningoencephalitis was diagnosed more frequently in the expanding population of WA sea otters (10 of 31, 32.3%) than in the declining CA population (29 of 313, 9.3%). Among sea otters with protozoal meningoencephalitis, those that had displayed neurological signs prior to death had active S. neurona encephalitis, supporting the conclusion that S. neurona is the most significant protozoal pathogen in the central nervous system of sea otters.
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Affiliation(s)
- N J Thomas
- Department of the Interior, US Geological Survey, National Wildlife Health Center, Madison, WI, USA.
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17
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Bhatnagar S, Shinagawa K, Castellino FJ, Schorey JS. Exosomes released from macrophages infected with intracellular pathogens stimulate a proinflammatory response in vitro and in vivo. Blood 2007; 110:3234-44. [PMID: 17666571 PMCID: PMC2200902 DOI: 10.1182/blood-2007-03-079152] [Citation(s) in RCA: 464] [Impact Index Per Article: 27.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Intracellular pathogens and the molecules they express have limited contact with the immune system. Here, we show that macrophages infected with intracellular pathogens Mycobacterium tuberculosis, M bovis BCG, Salmonella typhimurium, or Toxoplasma gondii release from cells small vesicles known as exosomes which contain pathogen-associated molecular patterns (PAMPs). These exosomes, when exposed to uninfected macrophages, stimulate a proinflammatory response in a Toll-like receptor- and myeloid differentiation factor 88-dependent manner. Further, exosomes isolated from the bronchoalveolar lavage fluid (BALF) of M bovis BCG-infected mice contain the mycobacteria components lipoarabinomannan and the 19-kDa lipoprotein and can stimulate TNF-alpha production in naive macrophages. Moreover, exosomes isolated from M bovis BCG- and M tuberculosis-infected macrophages, when injected intranasally into mice, stimulate TNF-alpha and IL-12 production as well as neutrophil and macrophage recruitment in the lung. These studies identify a previously unknown function for exosomes in promoting intercellular communication during an immune response to intracellular pathogens, and we hypothesize that extracellular release of exosomes containing PAMPs is an important mechanism of immune surveillance.
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Affiliation(s)
- Sanchita Bhatnagar
- Department of Biological Sciences, Center for Global Health and Infectious Diseases, University of Notre Dame, 130 Galvin Life Science Center, Notre Dame, IN 46556, USA
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18
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Abstract
PURPOSE Surface antigen 3 (SAG3) of Toxoplasma gondii is very similar in structure to the major surface antigen 1 (SAG1). Although numerous studies have supported the importance of SAG1 in protection against T. gondii infection, few reports exist on SAG3. MATERIALS AND METHODS Glutathione-S-transferase (GST)-fused SAG3 of T. gondii (rSAG3) were immunized into BALB/c mice alone or in combination with Quil A (rSAG3/Quil A), and then evaluated the protective immunity in vivo and in vitro against murine toxoplasmosis. RESULTS Immunization with rSAG3 or rSAG3/Quil A resulted in significantly more survival days and fewer brain cysts after challenge with T. gondii compared to an infected control group. Mice immunized with rSAG3 alone or in combination with Quil A produced significantly more specific IgG2a antibody, whereas specific IgG1 antibody titers did not increase. The percentage of CD8+ T cells, IFN-gamma mRNA expression, and nitric oxide production significantly increased in rSAG3- and rSAG3/Quil A-immunized mice. CONCLUSION These results indicate that vaccination with Toxoplasma rSAG3 results in partial protective immunity against T. gondii infection through induction of a Th1-type immune response, and that protective immunity is accelerated by the modulating effects of Quil A.
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Affiliation(s)
- Young-Ha Lee
- Department of Infection Biology, College of Medicine, Chungnam National University, 6 Munwha-dong, Jung-gu, Daejeon 301-131, Korea.
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19
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Arsenijevic D, Clavel S, Sanchis D, Plamondon J, Huang Q, Ricquier D, Rouger L, Richard D. Induction of Ucp2 expression in brain phagocytes and neurons following murine toxoplasmosis: an essential role of IFN-gamma and an association with negative energy balance. J Neuroimmunol 2007; 186:121-32. [PMID: 17467814 DOI: 10.1016/j.jneuroim.2007.03.013] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2006] [Revised: 03/12/2007] [Accepted: 03/14/2007] [Indexed: 01/22/2023]
Abstract
A model of murine toxoplasmosis was used to study cellular and temporal expression of uncoupling protein-2 (Ucp2) in the brain. In situ hybridization indicated that Ucp2 was located in neurons. Nuclei structures involved in energy balance, in particular the nucleus of the solitary tract (NST), was shown to have a positive association between negative energy balance and Ucp2 levels. Infection-induced Ucp2 expression colocalized mainly with microglial cells, but also with infiltrating macrophages and neutrophils in the brain, which was evident from day 9 post-infection. Using cytokine knockout mice we demonstrate that microglial Ucp2 induction in the brain was largely dependant on interferon-gamma, but not interleukin-6 or tumour-necrosis-factor-alpha in response to infection. In summary, this study shows that Ucp2 is regulated in a different manner in neurons than in microglia/phagocytes following infection. Our study indicates that an association exists between negative energy balance and neuronal Ucp2 levels in the NST, in particular.
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Affiliation(s)
- Denis Arsenijevic
- Department of Medicine, Division of Physiology, University of Fribourg, Ch. Du Musée 5, Fribourg, Switzerland
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20
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Masek KS, Fiore J, Leitges M, Yan SF, Freedman BD, Hunter CA. Host cell Ca2+ and protein kinase C regulate innate recognition of Toxoplasma gondii. J Cell Sci 2007; 119:4565-73. [PMID: 17074836 DOI: 10.1242/jcs.03206] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
In healthy hosts, acute infection with the opportunistic pathogen Toxoplasma gondii is controlled by innate production of IL-12, a key cytokine crucial for the development of protective immunity. Previous work has established that the mitogen-activated protein kinases (MAPK), particularly p38 and ERK1/2, are important regulators of T. gondii-induced IL-12 synthesis. Here we report that host cell Ca(2+) is required for activation of MAPK by T. gondii, as well as LPS and CpG, and for parasite-induced synthesis of IL-12. In addition, pharmacological mobilization of Ca(2+) stores in macrophages treated with parasites or LPS enhanced MAPK phosphorylation initiated by these stimuli. Investigation of the upstream mechanism by which Ca(2+) regulates MAPK activation revealed that T. gondii induced acute activation of conventional, Ca(2+)-dependent PKCalpha and PKCbeta, which are required for infection-induced MAPK activation and production of IL-12. Despite these findings, neither acute parasite infection nor LPS initiated a measurable Ca(2+) response in macrophages, suggesting that low levels of Ca(2+) are permissive for initiation of pro-inflammatory signaling. Together these data identify host cell Ca(2+) and PKC as crucial regulators of the innate immune response to microbial stimuli, including T. gondii.
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Affiliation(s)
- Katherine S Masek
- Department of Pathobiology, School of Veterinary Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
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21
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Dalton JE, Cruickshank SM, Egan CE, Mears R, Newton DJ, Andrew EM, Lawrence B, Howell G, Else KJ, Gubbels MJ, Striepen B, Smith JE, White SJ, Carding SR. Intraepithelial gammadelta+ lymphocytes maintain the integrity of intestinal epithelial tight junctions in response to infection. Gastroenterology 2006; 131:818-29. [PMID: 16952551 DOI: 10.1053/j.gastro.2006.06.003] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2006] [Accepted: 05/18/2006] [Indexed: 02/07/2023]
Abstract
BACKGROUND & AIMS Intestinal epithelial integrity and permeability is dependent on intercellular tight junction (TJ) complexes. How TJ integrity is regulated remains unclear, although phosphorylation and dephosphorylation of the integral membrane protein occludin is an important determinant of TJ formation and epithelial permeability. We have investigated the role intestinal intraepithelial lymphocytes (iIELs) play in regulating epithelial permeability in response to infection. METHODS Recombinant strains of Toxoplasma gondii were used to assess intestinal epithelial barrier function and TJ integrity in mice with intact or depleted populations of iIELs. Alterations in epithelial permeability were correlated with TJ structure and the state of phosphorylation of occludin. iIEL in vivo reconstitution experiments were used to identify the iIELs required to maintain epithelial permeability and TJ integrity. RESULTS In the absence of gammadelta+ iIELs, intestinal epithelial barrier function and the ability to restrict epithelial transmigration of Toxoplasma and the unrelated intracellular bacterial pathogen Salmonella typhimurium was severely compromised. Leaky epithelium in gammadelta+ iIEL-deficient mice was associated with the absence of phosphorylation of serine residues of occludin and lack of claudin 3 and zona occludens-1 proteins in TJ complexes. These deficiencies were attributable to the absence of a single subset of gammadelta T-cell receptor (TCR-Vgamma7+) iIELs that, after reconstituting gammadelta iIEL-deficient mice, restored epithelial barrier function and TJ complexes, resulting in increased resistance to infection. CONCLUSIONS These findings identify a novel role for gammadelta+ iIELs in maintaining TJ integrity and epithelial barrier function that have implications for understanding the pathogenesis of intestinal inflammatory diseases associated with disruption of TJ complexes.
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MESH Headings
- Animals
- Blotting, Western
- Cell Membrane Permeability/immunology
- Disease Models, Animal
- Immunohistochemistry
- Immunoprecipitation
- Intercellular Junctions/metabolism
- Intestinal Mucosa/immunology
- Intestinal Mucosa/metabolism
- Intestinal Mucosa/parasitology
- Male
- Membrane Proteins/metabolism
- Mice
- Mice, Inbred C57BL
- Occludin
- Phosphorylation
- RNA/genetics
- Receptors, Antigen, T-Cell, gamma-delta/genetics
- Receptors, Antigen, T-Cell, gamma-delta/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- T-Lymphocytes/immunology
- T-Lymphocytes/metabolism
- Toxoplasma/isolation & purification
- Toxoplasma/pathogenicity
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/metabolism
- Toxoplasmosis, Animal/pathology
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Affiliation(s)
- Jane E Dalton
- Institute of Molecular and Cellular Biology, Faculty of Biological Sciences, University of Leeds, Leeds, United Kingdom
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Minns LA, Menard LC, Foureau DM, Darche S, Ronet C, Mielcarz DW, Buzoni-Gatel D, Kasper LH. TLR9 is required for the gut-associated lymphoid tissue response following oral infection of Toxoplasma gondii. J Immunol 2006; 176:7589-97. [PMID: 16751405 DOI: 10.4049/jimmunol.176.12.7589] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
TLRs expressed by a variety of cells, including epithelial cells, B cells, and dendritic cells, are important initiators of the immune response following stimulation with various microbial products. Several of the TLRs require the adaptor protein, MyD88, which is an important mediator for the immune response following Toxoplasma gondii infection. Previously, TLR9-mediated innate immune responses were predominantly associated with ligation of unmethylated bacterial CpG DNA. In this study, we show that TLR9 is required for the Th1-type inflammatory response that ensues following oral infection with T. gondii. After oral infection with T. gondii, susceptible wild-type (WT; C57BL/6) but not TLR9(-/-) (B6 background) mice develop a Th1-dependent acute lethal ileitis; TLR9(-/-) mice have higher parasite burdens than control WT mice, consistent with depressed IFN-gamma-dependent parasite killing. A reduction in the total T cell and IFN-gamma-producing T cell frequencies was observed in the lamina propria of the TLR9(-/-) parasite-infected mice. TLR9 and type I IFN production was observed by cells from infected intestines in WT mice. TLR9 expression by dendritic cell populations is essential for their expansion in the mesenteric lymph nodes of infected mice. Infection of chimeric mice deleted of TLR9 in either the hemopoietic or nonhemopoietic compartments demonstrated that TLR9 expression by cells from both compartments is important for efficient T cell responses to oral infection. These observations demonstrate that TLR9 mediates the innate response to oral parasite infection and is involved in the development of an effective Th1-type immune response.
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Affiliation(s)
- Laurie A Minns
- Department of Medicine, Dartmouth Medical School, Lebanon, NH 03756, USA
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23
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Bernardes ES, Silva NM, Ruas LP, Mineo JR, Loyola AM, Hsu DK, Liu FT, Chammas R, Roque-Barreira MC. Toxoplasma gondii infection reveals a novel regulatory role for galectin-3 in the interface of innate and adaptive immunity. Am J Pathol 2006; 168:1910-20. [PMID: 16723706 PMCID: PMC1606628 DOI: 10.2353/ajpath.2006.050636] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
In attempts to investigate the role of galectin-3 in innate immunity, we studied galectin-3-deficient (gal3-/-) mice with regard to their response to Toxoplasma gondii infection, which is characterized by inflammation in affected organs, Th-1-polarized immune response, and accumulation of cysts in the central nervous system. In wild-type (gal3+/+) mice, infected orally, galectin-3 was highly expressed in the leukocytes infiltrating the intestines, liver, lungs, and brain. Compared with gal3+/+, infected gal3-/- mice developed reduced inflammatory response in all of these organs but the lungs. Brain of gal3-/- mice displayed a significantly reduced number of infiltrating monocytes/macrophages and CD8+ cells and a higher parasite burden. Furthermore, gal3-/- mice mounted a higher Th1-polarized response and had comparable survival rates on peroral T. gondii infection, even though they were more susceptible to intraperitoneal infection. Interestingly, splenic cells and purified CD11c+ dendritic cells from gal3-/- mice produced higher amounts of interleukin-12 than cells from gal3+/+ mice, possibly explaining the higher Th1 response verified in the gal3-/- mice. We conclude that galectin-3 exerts an important role in innate immunity, including not only a pro-inflammatory effect but also a regulatory role on dendritic cells, capable of interfering in the adaptive immune response.
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Affiliation(s)
- Emerson Soares Bernardes
- Departamento de Biologia Celular e Molecular e Bioagentes Patogênicos, Faculdade de Medicina de Ribeirão Preto-USP, Av. dos Bandeirantes, 3900, Ribeirão Preto-SP, Brazil-CEP 14049-900
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Shrestha SP, Tomita T, Weiss LM, Orlofsky A. Proliferation of Toxoplasma gondii in inflammatory macrophages in vivo is associated with diminished oxygen radical production in the host cell. Int J Parasitol 2006; 36:433-41. [PMID: 16516217 PMCID: PMC3109651 DOI: 10.1016/j.ijpara.2006.01.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2005] [Revised: 12/02/2005] [Accepted: 01/13/2006] [Indexed: 11/24/2022]
Abstract
While reactive oxygen species (ROS) can kill Toxoplasma gondii in vitro the role these molecules play in vivo is not known. We used a flow cytometry-based assay to investigate the relationship between intracellular infection and ROS production during acute peritoneal toxoplasmosis in mice. A distinct population of ROS(+) inflammatory macrophages, detected by the oxidation of hydroethidine, was observed to increase progressively in frequency during the course of infection, and to be inversely correlated with the degree of cell parasitization. These data imply that either intracellular parasites inhibit ROS synthesis or, alternatively, ROS-producing cells contain anti-Toxoplasma activity. The latter interpretation was supported by the finding that uninfected ROS-producing inflammatory macrophages were resistant to infection in vivo. However, in the same animals, ROS-producing macrophages that had previously been parasitized could readily be infected with additional parasites, suggesting that the difference in ROS production between highly infected and less infected cells was not due to ROS-associated killing of parasites within these cells. In addition, macrophages infected with T. gondii in vitro and then briefly transferred to acutely infected mice upregulated ROS production in a manner that was again inversely correlated with the degree of intracellular parasitization. Taken together, these findings suggest that both ROS-associated anti-Toxoplasma activity and parasite-driven inhibition of ROS production underlie the observed pattern of ROS production. ROS function and parasite evasion of this function may contribute significantly to the balance between host defense and disease progression during acute infection.
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Affiliation(s)
- Sunder P. Shrestha
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, G704, Bronx, NY 10461, USA
| | - Tadakimi Tomita
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, G704, Bronx, NY 10461, USA
| | - Louis M. Weiss
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, G704, Bronx, NY 10461, USA
- Division of Infectious Diseases, Department of Medicine, Albert Einstein College of Medicine, 1300 Marris Park Avenue, G704 Bronx, NY 10461, USA
| | - Amos Orlofsky
- Department of Pathology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, G704, Bronx, NY 10461, USA
- Corresponding author. Tel.: +718 430 2674; fax: +718 430 8867. (A. Orlofsky)
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Mayer KD, Mohrs K, Crowe SR, Johnson LL, Rhyne P, Woodland DL, Mohrs M. The functional heterogeneity of type 1 effector T cells in response to infection is related to the potential for IFN-gamma production. J Immunol 2005; 174:7732-9. [PMID: 15944275 DOI: 10.4049/jimmunol.174.12.7732] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The expression of IFN-gamma is a hallmark of Th1 cells and CD8(+) effector T cells and is the signature cytokine of type 1 responses. However, it is not known whether T cells are homogeneous in their capacity to produce IFN-gamma, whether this potential varies between tissues, and how it relates to the production of other effector molecules. In the present study we used bicistronic IFN-gamma-enhanced yellow fluorescent protein (IFN-gamma-eYFP) reporter mice (Yeti) and MHC class I tetramers to directly quantify IFN-gamma expression at the single cell level. The eYFP fluorescence of Th1 cells and CD8(+) effector T cells was broadly heterogeneous even before cell division and correlated with both the abundance of IFN-gamma transcripts and the secretion of IFN-gamma upon stimulation. CD4(+) and CD8(+) T cells of influenza-infected mice revealed a similarly heterogeneous IFN-gamma expression, and eYFP(high) cells were only found in the infected lung. Ag-specific T cells were in all examined tissues eYFP(+), but also heterogeneous in their reporter fluorescence, and eYFP(high) cells were also restricted to the infected lung. A similar heterogeneity was observed in Toxoplasma gondii-infected animals, but eYFP(high) cells were restricted to different tissues. Highly eYFP fluorescent cells produced elevated levels of proinflammatory cytokines and chemokines in addition to IFN-gamma, suggesting their coregulated expression as a functional unit in highly differentiated effector T cells.
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MESH Headings
- Animals
- Antigens, Differentiation, T-Lymphocyte/biosynthesis
- Bacterial Proteins/biosynthesis
- Bacterial Proteins/genetics
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/parasitology
- CD8-Positive T-Lymphocytes/virology
- Cells, Cultured
- Chemokines/biosynthesis
- Chemokines/physiology
- Cytokines/biosynthesis
- Cytokines/physiology
- Dose-Response Relationship, Immunologic
- Genes, Reporter/immunology
- Interferon-gamma/biosynthesis
- Interferon-gamma/genetics
- Luminescent Proteins/biosynthesis
- Luminescent Proteins/genetics
- Lung/immunology
- Lung/metabolism
- Lung/virology
- Lymphocyte Activation/genetics
- Lymphocyte Activation/immunology
- Mice
- Mice, Inbred C57BL
- Mice, Mutant Strains
- Organ Specificity/genetics
- Organ Specificity/immunology
- Orthomyxoviridae Infections/genetics
- Orthomyxoviridae Infections/immunology
- Orthomyxoviridae Infections/metabolism
- Th1 Cells/immunology
- Th1 Cells/metabolism
- Th1 Cells/parasitology
- Th1 Cells/virology
- Toxoplasmosis, Animal/genetics
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/metabolism
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26
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Ferguson DJP, Henriquez FL, Kirisits MJ, Muench SP, Prigge ST, Rice DW, Roberts CW, McLeod RL. Maternal inheritance and stage-specific variation of the apicoplast in Toxoplasma gondii during development in the intermediate and definitive host. Eukaryot Cell 2005; 4:814-26. [PMID: 15821140 PMCID: PMC1087807 DOI: 10.1128/ec.4.4.814-826.2005] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The structure and location of Toxoplasma gondii apicoplasts were examined in intermediate and definitive hosts and shown to vary in a stage-specific manner. Immunocytochemistry and electron microscopy studies were used to identify changes in the morphology of apicoplasts and in their enoyl reductase (ENR) content during asexual and sexual development. Apicoplasts in tachyzoites were small, multimembraned organelles anterior to nuclei that divided and segregated with the nuclei during endodyogeny. In nonproliferating bradyzoites within mature tissue cysts (1 to 24 months), apicoplasts had high levels of ENR. During coccidian development, asexual multiplication (endopolygeny), resulting in simultaneous formation of up to 30 daughters (merozoites), involved an initial growth phase associated with repeated nuclear divisions during which apicoplasts appeared as single, elongated, branched structures with increased levels of ENR. At initiation of merozoite formation, enlarged apicoplasts divided simultaneously, with constrictions, into portions that segregated to developing daughters. In sexual stages, apicoplast division did not occur during microgametogony, and apicoplasts were absent from the microgametes that were formed. In contrast, during macrogametogony, the apicoplast appeared as a large, branched, perinuclear structure that had very high levels of ENR in the absence of nuclear division. Marked increases in the size of apicoplasts and levels of ENR may be related to requirements of the macrogametocytes to synthesize and store all components necessary for oocyst formation and subsequent extracellular sporulation. Thus, it is shown that apicoplasts are present and contain ENR in all T. gondii life cycle stages except microgametes, which will result in maternal inheritance of the organelle.
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Affiliation(s)
- David J P Ferguson
- Department of Pathology, University of Oxford, John Radcliffe Hospital, United Kingdom
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27
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Patrón S A, Mondragón M, González S, Ambrosio JR, Guerrero B AL, Mondragón R. Identification and purification of actin from the subpellicular network of Toxoplasma gondii tachyzoites. Int J Parasitol 2005; 35:883-94. [PMID: 15970197 DOI: 10.1016/j.ijpara.2005.03.016] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2005] [Revised: 03/22/2005] [Accepted: 03/31/2005] [Indexed: 11/16/2022]
Abstract
Toxoplasma gondii infects cells through dynamic events dependent on actin. Although the presence of cortical actin has been widely suggested, visualisation and localisation of actin filaments has not been reported. The subpellicular cytoskeleton network is a recently described structure possibly involved in the dynamic events. Using non-ionic detergent extractions, the cortical cytoskeleton network was enriched and used for the isolation and identification of actin. Actin was detected by Western blots in extracts of cytoskeleton networks, and it was localised by gold staining in the network and in both the apical end and the posterior polar ring. Actin was isolated from subpellicular cytoskeleton extracts by binding to DNase I, and it polymerised in vitro as filaments that were gold-decorated by a monoclonal anti-actin antibody. Filaments bound the subfragment 1 of heavy meromyosin, although with atypical arrangements in comparison with the arrowheads observed in muscle actin filaments. Treatment with cytochalasin D and colchicine altered the structural organisation of the subpellicular network indicating the participation of actin filaments and microtubules in the maintenance of its structure. Actin filaments and microtubules, in the subpellicular network, participate reciprocally in the maintaining of the parasite's shape and the gliding motility.
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Affiliation(s)
- Araceli Patrón S
- Departamento de Bioquímica, Centro de Investigación y Estudios Avanzados del IPN. Av. Instituto Politécnico Nacional No 2508. Col. Sn Pedro Zacatenco, Del. Gustavo A. Madero., México
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28
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Abstract
Toxoplasma gondii infects many warm-blooded animals, including chickens. However, little is known about how this protozoan behaves within chicken macrophages. Thus, the microbicidal biology of HD11 and MQ-NCSU (available chicken macrophage cell lines) and the escaping mechanism of T. gondii were investigated. After infection, both cell lines were activated with lipopolysaccharide (LPS) and nitric oxide (NO), and reactive oxygen intermediates (ROI) were evaluated. T. gondii infected both cell lines, and 30 and 60% inhibition of NO production was detected in MQ-NCSU and HD11, respectively. In HD11, NO inhibition was not dependent on cyclooxygenase products. Although NO was partially inhibited, it did control T. gondii multiplication, showing the importance of this microbicidal molecule. Production of ROI was not detected in either cell line after T. gondii or yeast interaction. NADPH diaphorase (NADPH-d) activity, a histochemical marker of inducible NO synthase (iNOS), was detected at various levels in the HD11 population activated with LPS. The HD11 population infected with T. gondii showed a decrease in NADPH-d, indicating that NO production inhibition was related to iNOS disappearance in infected macrophages. These results demonstrate that in chicken macrophages T. gondii can also inhibit NO production, which suggests that an iNOS suppression mechanism might be used for better survival in macrophages.
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Affiliation(s)
- L V C Guillermo
- Laboratório de Biologia Celular e Tecidual, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense, Avenida Alberto Lamego 2000, 28013-600, Campos dos Goytacazes, RJ, Brazil
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29
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Stenzel W, Soltek S, Schlüter D, Deckert M. The intermediate filament GFAP is important for the control of experimental murine Staphylococcus aureus-induced brain abscess and Toxoplasma encephalitis. J Neuropathol Exp Neurol 2004; 63:631-40. [PMID: 15217091 DOI: 10.1093/jnen/63.6.631] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The functional role of astrocytes exerted via their intermediate protein glial fibrillary acidic protein (GFAP) in CNS infections was studied in Staphylococcus aureus-induced brain abscess. Compared to wild type (WT) mice, GFAP(0/0) mice developed larger and more poorly demarcated inflammatory lesions paralleled by a significantly increased intracerebral bacterial load, a diffuse leukocytic infiltration of the contralateral hemisphere, purulent ventriculitis, vasculitis, and severe brain edema. These observations were correlated with the lack of a bordering function of activated astrocytes that strongly upregulated their GFAP expression in the abscess surrounding of WT mice. Clinically important, this lack of restriction of inflammation markedly aggravated the course of disease with manifestation of seizures and a severe weight loss in GFAP(0/0) mice. These data were paralleled by observations in the model of Toxoplasma encephalitis (TE) during which the intracerebral parasitic load was significantly increased. Moreover, tachyzoite-induced tissue necrosis was exclusively found in the brains of GFAP(0/0) mice in chronic TE. Collectively, these findings delineate a host defense function of astrocytes via restricting pathogenic spread and multiplication within the CNS, thereby contributing to the protection of the highly vulnerable brain parenchyma.
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Affiliation(s)
- Werner Stenzel
- Abteilung für Neuropathologie, Universität zu Köln, Köln, Germany
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30
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Ferguson DJP. Use of molecular and ultrastructural markers to evaluate stage conversion of Toxoplasma gondii in both the intermediate and definitive host. Int J Parasitol 2004; 34:347-60. [PMID: 15003495 DOI: 10.1016/j.ijpara.2003.11.024] [Citation(s) in RCA: 101] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2003] [Revised: 11/12/2003] [Accepted: 11/17/2003] [Indexed: 11/18/2022]
Abstract
Toxoplasma gondii has a complex life cycle involving definite (cat) and intermediate (all warm blooded animals) hosts. This gives rise to four infectious forms each of which has a distinctive biological role. Two (tachyzoite and merozoite) are involved in propagation within a host and two (bradyzoite and sporozoite) are involved in transmission to new hosts. The various forms can be identified by their structure, host parasite relationship and distinctive developmental processes. In the present in vivo study, the various stages have been evaluated by electron microscopy and immunocytochemistry using a panel of molecular markers relating to surface and cytoplasmic molecules, metabolic iso-enzymes and secreted proteins that can differentiate between tachyzoite, bradyzoite and coccidian development. Tachyzoites were characterised as being positive for surface antigen 1, enolase isoenzyme 2, lactic dehydrogenase isoenzyme 1 and negative for bradyzoite antigen 1. In contrast, bradyzoites were negative for SAG1 but positive for BAG1, ENO1 and LDH2. When stage conversion was followed in brain lesion at 10 and 15 days post-infection, tachyzoites were predominant but a number of single intermediate organisms displaying tachyzoite and certain bradyzoite markers were observed. At later time points, small groups of organisms displaying only bradyzoite markers were also present. A number (9) of dense granule proteins (GRA1-8, NTPase) have also been identified in both tachyzoites and bradyzoites but there were differences in their location during parasite development. All the dense granule proteins extensively label the parasitophorous vacuole during tachyzoite development. In contrast the tissue cyst wall displays variable staining for the dense granule proteins, which also expresses an additional unique cyst wall protein. The molecular differences could be identified at the single cell stage consistent with conversion occurring at the time of entry into a new cell. These molecular differences were reflected in the structural differences in the parasitophorous vacuoles observed by electron microscopy. Stage conversion to enteric (coccidian) development was limited to the enterocytes of the cat small intestine. Although no specific markers were available, this form of development can be identified by the absence of specific tachyzoite (SAG1) and bradyzoite (BAG1) markers although the isoenzymes ENO2 and LHD1 were expressed. There was also a significant difference in the expression of the dense granule proteins. The coccidian stages and merozoites only expressed two (GRA7 and NTPase) of the nine dense granule proteins and this was reflected in significant differences in the structure of the parasitophorous vacuole. The coccidian stages also undergo conversion from asexual to sexual development. The mechanism controlling this process is unknown but does not involve any change in the host cell type or parasitophorous vacuole and may be pre-programmed, since the number of asexual cycles was self-limiting. In conclusion, it was possible using a combination of molecular markers to identify tachyzoite, bradyzoite and coccidian development in tissue sections.
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Affiliation(s)
- D J P Ferguson
- Nuffield Department of Pathology, Oxford University, John Radcliffe Hospital, Oxford OX3 9DU, UK.
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31
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Geng ZH, Fang YQ, Liu L, Shi Y, Li SH. [Determination of T lymphocytes and trace elements in spleen from rats infected with Toxoplasma gondii]. Zhongguo Ji Sheng Chong Xue Yu Ji Sheng Chong Bing Za Zhi 2003; 19:357-9. [PMID: 12572072] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVE To determine the level of five trace elements(Fe2+, Cu2+, Zn2+, Ca2+, Mg2+) in the spleen and changes of T lymphocyte and its subtype variations in peripheral blood from the rats infected with Toxoplasma gondii. METHODS Twenty rats were randomly and equally divided into two groups: control group and experiment group. Each rat in the experiment group received an i.p. injection of 2 ml normal saline containing 1.5 x 10(6) tachyzoites of T. gondii. On the 64th day after injection of T. gondii, the changes in T lymphocytes (TL) and their subgroups, the helper T lymphocytes (Th) and the suppressor T lymphocytes(Ts) in the peripheral blood of the rats with T. gondii were determined by the assay of the lymphocytes labeled with intercellular acid alpha-naphthyl acetate esterase. All the rats were killed and the atomic absorption method were used for detecting the level of trace elements in the spleen tissue. RESULTS The number of TL and Th in experiment group was significantly lower than that of control (P < 0.01, P < 0.01). The ratio of Th/Ts showed a significant difference between the two groups. The level of Fe2+, Cu2+ in experiment group was significantly reduced (P < 0.01). The amount of Mg2+ in infected rats was higher than that of the control(P < 0.01). No statistical difference in the content of Zn2+, Ca2+ was found between the two groups. CONCLUSION T. gondii infection might cause the changes in the TL and Th in peripheral blood and the changes in trace elements in spleen of the rats.
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Affiliation(s)
- Z H Geng
- Department of the Third Centre, Norman Bethune University of Medical Sciences, Changchun 130021
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32
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King MD, Lindsay DS, Holladay S, Ehrich M. Neurotoxicity and immunotoxicity assessment in CBA/J mice with chronic Toxoplasma gondii infection and multiple oral exposures to methylmercury. J Parasitol 2003; 89:856-9. [PMID: 14533705 DOI: 10.1645/ge-79r] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
The present study was conducted to determine the effect of multiple low doses of methylmercury (MeHg) on the course of a chronic Toxoplasma gondii infection. Four groups of 6-wk-old female CBA/J mice either were fed 25 T. gondii tissue cysts of the ME-49 strain or were vehicle control. Six weeks later, half of each group was orally gavaged with 8-mg/kg body weight doses of MeHg on days 0, 2, 4, 7, 10, and 13, totaling 4 experimental groups. Mice were killed on day 17 or 18 after MeHg exposure. Flow cytometric analysis of lymphocyte subpopulations in the thymus demonstrated a significant increase in the percentage of CD4- CD8+ T-cells in mice exposed to MeHg with a concurrent T. gondii infection. Groups of mice exposed to MeHg showed a decrease in total thymic cellularity and cellularity of all T-cell subpopulations when compared with control mice, but viability of these cells was unaffected. Splenic cell viability was decreased in mice exposed to MeHg, but alterations in T-cell subpopulations were not noted. These data indicate that multiple low doses of MeHg may not exacerbate chronic toxoplasmosis, but MeHg-induced effects on the immune system were evident.
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Affiliation(s)
- Marquea D King
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia 24061, USA
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33
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Robbins SH, Terrizzi SC, Sydora BC, Mikayama T, Brossay L. Differential regulation of killer cell lectin-like receptor G1 expression on T cells. J Immunol 2003; 170:5876-85. [PMID: 12794113 DOI: 10.4049/jimmunol.170.12.5876] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The killer cell lectin-like receptor G1 (KLRG1) is the mouse homologue of the rat mast cell function-associated Ag and contains a tyrosine-based inhibitory motif in its cytoplasmic domain. It has been demonstrated that KLRG1 is induced on activated NK cells and that KLRG1 can inhibit NK cell effector functions. In this study, we show that in naive C57BL/6 mice KLRG1 is expressed on a subset of CD44(high)CD62L(low) T cells. KLRG1 expression can be detected on a small number of V(alpha)14i NK T cells but not on CD8alphaalpha(+) intraepithelial T cells that are either TCRgammadelta(+) or TCRalphabeta(+). We also show that KLRG1 expression is dramatically induced on approximately 50% of the CD8(+) T cells during both a viral and a parasitic infection. Interestingly, during Toxoplasma gondii infection, KLRG1 is up-regulated on CD4(+) T cells. Although KLRG1 expression can be induced on both NK cells and T cells, the molecular mechanism leading to the induction of KLRG1 differs in these two subsets of cells. Indeed, the up-regulation of KLRG1 on NK cells can be driven in vivo by cytokines, whereas KLRG1 cannot be induced on CD8(+) T cells by cytokines. In addition, although induction of KLRG1 on T cells appears to require TCR engagement in vivo, TCR engagement is not sufficient for KLRG1 induction in vitro. Taken together, these data suggest that the expression and induction of KLRG1 on T cells are tightly regulated. This could have important biological consequences on T cell activation and homeostasis.
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MESH Headings
- Acute Disease
- Animals
- CD4-Positive T-Lymphocytes/immunology
- CD4-Positive T-Lymphocytes/metabolism
- CD8 Antigens/biosynthesis
- CD8-Positive T-Lymphocytes/immunology
- CD8-Positive T-Lymphocytes/metabolism
- CD8-Positive T-Lymphocytes/pathology
- CD8-Positive T-Lymphocytes/virology
- Cell Division/immunology
- Cell Separation
- Cytokines/physiology
- Cytomegalovirus Infections/immunology
- Cytomegalovirus Infections/metabolism
- Cytomegalovirus Infections/pathology
- Hyaluronan Receptors/biosynthesis
- Immunologic Memory
- Interferon-gamma/biosynthesis
- Intestinal Mucosa/cytology
- Intestinal Mucosa/immunology
- Intestinal Mucosa/metabolism
- Killer Cells, Natural/immunology
- Killer Cells, Natural/metabolism
- L-Selectin/biosynthesis
- Lectins, C-Type/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Transgenic
- Receptors, Antigen, T-Cell, alpha-beta/biosynthesis
- Receptors, Antigen, T-Cell, alpha-beta/immunology
- Receptors, Antigen, T-Cell, alpha-beta/metabolism
- Receptors, Immunologic/biosynthesis
- T-Lymphocyte Subsets/immunology
- T-Lymphocyte Subsets/metabolism
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/metabolism
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Affiliation(s)
- Scott H Robbins
- Department of Molecular Microbiology and Immunology and Graduate Program in Pathobiology, Division of Biology and Medicine, Brown University, Providence, RI 02912, USA
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34
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Straw AD, MacDonald AS, Denkers EY, Pearce EJ. CD154 plays a central role in regulating dendritic cell activation during infections that induce Th1 or Th2 responses. J Immunol 2003; 170:727-34. [PMID: 12517934 DOI: 10.4049/jimmunol.170.2.727] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
We compared splenic DC activation during infection with either the Th2 response-inducing parasite Schistosoma mansoni or with the Th1 response-inducing parasite Toxoplasma gondii. CD8alpha(+) DC from schistosome-infected mice exhibited a 2- to 3-fold increase in the expression of MHC class II, CD80, and CD40 (but not CD86) compared with DC from uninfected control animals, while CD8alpha(-) DC exhibited a 2- to 3-fold increase in the expression of MHC class II and CD80 and no alteration, compared with DC from uninfected mice, in the expression of CD86 or CD40. Intracellular staining revealed that DC did not produce IL-12 during infection with S. mansoni. In contrast, infection with T. gondii resulted in a more pronounced increase in the expression of activation-associated molecules (MHC class II, CD80, CD86, and CD40) on both CD8alpha(-) and CD8alpha(+) splenic DC and promoted elevated IL-12 production by DC. Analysis of MHC class I and of additional costimulatory molecules (ICOSL, ICAM-1, OX40L, 4-1BBL, and B7-DC) revealed a generally similar pattern, with greater indication of activation in T. gondii-infected mice compared with S. mansoni-infected animals. Strikingly, the activation of DC observed during infection with either parasite was not apparent in DC from infected CD154(-/-) mice, indicating that CD40/CD154 interactions are essential for maintaining DC activation during infection regardless of whether the outcome is a Th1 or a Th2 response. However, the ability of this activation pathway to induce IL-12 production by DC is restrained in S. mansoni-infected, but not T. gondii-infected, mice by Ag-responsive CD11c(-) cells.
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Affiliation(s)
- Amy D Straw
- Department of Pathobiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia 19104, USA
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35
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Fujigaki S, Takemura M, Hamakawa H, Seishima M, Saito K. The Mechanism of Interferon-Gamma Induced Anti Toxoplasma Gondh By Indoleamine 2,3-Dioxygenase And/Or Inducible Nitric Oxide Synthase Vary Among Tissues. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2003; 527:97-103. [PMID: 15206721 DOI: 10.1007/978-1-4615-0135-0_11] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
L-Tryptophan degradation by indoleamine 2,3-dioxygenase (IDO) induction and reactive nitrogen intermediates produced by inducible nitric oxide synthase (iNOS) induction are important factors for IFN-gamma-induced anti-toxoplasma activities. In the present study, the effects of acute Toxoplasma gondii (T. gondii) infection on IDO and iNOS were investigated using wild-type (WT) and IFN-gamma gene-deficient (IFN-gamma KO) mice. In the WT C57BL/6J mice, enzyme activities and mRNA levels of IDO in both lung and brain were markedly increased, and lung L-tryptophan concentrations were dramatically decreased following infection. In contrast, these metabolic changes did not occur in infected IFN-gamma KO mice. The level of iNOS induction in the infected IFN-gamma KO mice was high in lung and low in brain compared to that in infected WT mice. The extent of increased mRNA expression of T. gondii surface antigen gene 2 (SAG2) in lung and brain induced by infection was significantly enhanced in the IFN-gamma KO mice compared to that in WT mice. Treatment with N-nitro-L-arginine methyl ester, an iNOS inhibitor, increased the levels of SAG2 mRNA in brain, but not in lung following infection. This in vivo study provides evidence that L-tryptophan depletion caused by T. gondii is directly mediated by IFN-gamma in the lung, where iNOS is not induced by IFN-gamma. This study suggests that there is an anti-toxoplasma mechanism of cross-regulation between iNOS and IDO and that the expression of main anti-parasite effector mechanisms of iNOS and/or IDO may vary among tissues.
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MESH Headings
- Animals
- Brain/immunology
- Brain/metabolism
- Brain/parasitology
- Female
- Indoleamine-Pyrrole 2,3,-Dioxygenase
- Interferon-gamma/deficiency
- Interferon-gamma/genetics
- Interferon-gamma/metabolism
- Kynurenine/metabolism
- Lung/immunology
- Lung/metabolism
- Lung/parasitology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Nitric Oxide Synthase/metabolism
- Nitric Oxide Synthase Type II
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Tissue Distribution
- Toxoplasma/immunology
- Toxoplasma/pathogenicity
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/metabolism
- Toxoplasmosis, Animal/parasitology
- Toxoplasmosis, Cerebral/immunology
- Toxoplasmosis, Cerebral/metabolism
- Toxoplasmosis, Cerebral/parasitology
- Tryptophan/metabolism
- Tryptophan Oxygenase/genetics
- Tryptophan Oxygenase/metabolism
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Affiliation(s)
- Suwako Fujigaki
- Department of Laboratory Medicine, Gifu University School of Medicine, 40 Tsukasa-machi, Gifu 500-8705, Japan.
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36
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Długońska H, Dytnerska K. [Toxoplasma gondii proteome]. Wiad Parazytol 2003; 49:3-10. [PMID: 16889012] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/11/2023]
Abstract
The article presents data concerning methods of proteomics and main achievements of studies on Toxoplasma gondii proteom.
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37
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Dobbin CA, Smith NC, Johnson AM. Heat shock protein 70 is a potential virulence factor in murine toxoplasma infection via immunomodulation of host NF-kappa B and nitric oxide. J Immunol 2002; 169:958-65. [PMID: 12097402 DOI: 10.4049/jimmunol.169.2.958] [Citation(s) in RCA: 82] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
We propose that the 70-kDa heat shock protein (HSP70) protects virulent Toxoplasma gondii from the effects of the host by immunomodulation. This hypothesis was tested using quercetin and antisense oligonucleotides targeting the start codon of the virulent T. gondii HSP70 gene. Oligonucleotides were transiently transfected into two virulent (RH, ENT) and two avirulent (ME49, C) strains of T. gondii, significantly reducing HSP70 expression in treated parasites. Virulent parasites with reduced HSP70 expression displayed reduced proliferation in vivo, as measured by the number of tachyzoites present in spleens of infected mice. They also exhibited an enhanced rate of conversion from tachyzoites to bradyzoites in vitro. Our results implicate HSP70 as a means by which virulent strains of T. gondii evade host proinflammatory responses: when RAW 264.7 cells were exposed to parasites with reduced HSP70 expression, differential expression of inducible NO synthase (iNOS) and cell NO production were observed between infections with normal and HSP70-deficient T. gondii. iNOS message levels were significantly increased when host cells were infected with HSP70 reduced virulent tachyzoites and HSP70-related inhibition of iNOS transcription resulted in altered host NO production by virulent T. gondii infection. Virulent parasites expressing reduced levels of HSP70 initiated significantly more NF-kappa B activation in host splenocytes than infections with untreated parasites. Neither proliferative ability nor conversion from tachyzoites to bradyzoites was affected by lack of HSP70 in avirulent strains of T. gondii. Furthermore, avirulent T. gondii strains induced high levels of host iNOS expression and NO production, regardless of HSP70 expression in these parasites, and inhibition of HSP70 had no significant effects on translocation of NF-kappa B to the nucleus. Therefore, the 70-kDa parasite stress protein may be part of an important survival strategy by which virulent strains down-regulate host parasiticidal mechanisms.
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Affiliation(s)
- Caroline A Dobbin
- Institute for the Biotechnology of Infectious Diseases, University of Technology, Sydney, New South Wales, Australia
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38
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Shen DF, Matteson DM, Tuaillon N, Suedekum BK, Buggage RR, Chan CC. Involvement of apoptosis and interferon-gamma in murine toxoplasmosis. Invest Ophthalmol Vis Sci 2001; 42:2031-6. [PMID: 11481268] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/20/2023] Open
Abstract
PURPOSE A murine toxoplasmosis model has been developed that results in central nervous system (CNS) and ocular inflammation characterized by encephalitis with numerous brain tissue cysts and milder inflammation with rare tissue cysts in the eye after 4 weeks of Toxoplasma gondii infection. In this model IFN gamma and inducible nitric oxide (iNO) are protective against T. gondii infection. In this study, the role of apoptosis in the pathogenesis of toxoplasmosis was investigated. METHODS C57BL/6 (wild-type mice), B6MRL/lpr, and B6MRL/gld (defective Fas or FasL expression, respectively) mice were infected intraperitoneally with 20 to 30 tissue cysts of the ME-49 strain of T. gondii. Mice were killed at days 0, 14, or 28 after infection. The eyes and brains were harvested for histologic, immunohistochemical, and molecular studies. Analysis included immunostaining for Fas, FasL, Bcl-2, and Bax; in situ apoptosis detection (TUNEL assay); RT-PCR amplification for IFN gamma; and measurement of ocular nitrite levels. The control mice were naïve mice of each strain that received no inoculation or injection. RESULTS Wild-type mice appeared to constitutively express apoptotic molecules at higher levels in the eye than in the brain. Consequently, during T. gondii infection, apoptosis was greater in the eyes than in the brain. Untreated naïve lpr and gld mice showed no expression of Fas and FasL, respectively. After infection, a slightly higher number of tissue cysts (lpr, 11.8 +/- 2.4; gld, 10.3 +/- 3.4) were found in the brains of the mutants than in the control animals (8.8 +/- 2.9). However, no significant differences between the number of apoptotic cells, inflammatory scores, or number of tissue cysts were noted in the eyes. IFN gamma mRNA in control mice was detected at day 28 after infection, whereas in both mutants, mRNA production occurred earlier, at day 14. Ocular nitrite levels were higher in lpr and gld mice than in wild-type mice. CONCLUSIONS No significant difference in the degree of ocular inflammation and apoptosis was detected between the wild-type and Fas or FasL mutant mice. However, there was an earlier and subjectively greater expression of IFN gamma in the brain and eye and a higher level of nitrite in the ocular tissue of mutant strains than in the wild type. Multiple factors are likely to be involved in the pathogenesis of ocular toxoplasmosis.
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MESH Headings
- Animals
- Apoptosis
- Brain/metabolism
- Brain/parasitology
- Brain/pathology
- Fas Ligand Protein
- Immunoenzyme Techniques
- In Situ Nick-End Labeling
- Interferon-gamma/biosynthesis
- Interferon-gamma/genetics
- Membrane Glycoproteins/metabolism
- Mice
- Mice, Inbred BALB C
- Mice, Inbred MRL lpr
- Nitrites/metabolism
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-bcl-2/metabolism
- RNA, Messenger/metabolism
- Retina/metabolism
- Retina/parasitology
- Retina/pathology
- Reverse Transcriptase Polymerase Chain Reaction
- Toxoplasma/pathogenicity
- Toxoplasmosis, Animal/etiology
- Toxoplasmosis, Animal/metabolism
- Toxoplasmosis, Animal/pathology
- Toxoplasmosis, Cerebral/etiology
- Toxoplasmosis, Cerebral/metabolism
- Toxoplasmosis, Cerebral/pathology
- Toxoplasmosis, Ocular/etiology
- Toxoplasmosis, Ocular/metabolism
- Toxoplasmosis, Ocular/pathology
- bcl-2-Associated X Protein
- fas Receptor/metabolism
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Affiliation(s)
- D F Shen
- Section of Immunopathology, Laboratory of Immunology, National Eye Institute, National Institutes of Health, Bethesda, Maryland 20892-1857, USA
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39
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Arsenijevic D, Bilbao FD, Giannakopoulos P, Girardier L, Samec S, Richard D. A role for interferon-gamma in the hypermetabolic response to murine toxoplasmosis. Eur Cytokine Netw 2001; 12:518-27. [PMID: 11566633] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/21/2023]
Abstract
Toxoplasma gondii (Me49 strain) infection into Swiss Webster mice is followed by hypermetabolism and weight loss in the acute phase lasting 14 days. In the subsequent chronic phase of infection, mice showed either a resolution of hypermetabolism and partial weight recovery (Gainers) or persistent hypermetabolism, with stable weight loss (Non-Gainers). The hypermetabolic response was not associated with an augmentation in the thermogenic uncoupling protein 1 (UCP1) mRNA expression in interscapular brown adipose tissue (BAT), but rather UCP1 expression was reduced. Hypermetabolism is associated with high lipid oxidation as attested by a low respiratory quotient (RQ). Neither BAT nor sympathetic nervous system appear to be involved in the increased lipid utilization, since propranolol did not increase the lower RQ in infected mice. The mitochondrial lipid oxidation blocker mercaptoacetate did not reestablish the respiratory quotient RQ in acute infection (on day 4) and in chronically infected Non-Gainer mice. This suggests an important extra-mitochondrial mechanism of lipid oxidation. Increased lipid peroxidation was detected especially in serum, lung, spleen and liver, which are rich in macrophage-type cells. Following infection peritoneal macrophages exhibited an enhanced capacity to produce reactive oxygen species (ROS). Using IFN-gamma knockout mice we observed that not only the hypermetabolic response was ablated in these mice but there was not a marked increase in ROS production or preferential oxidation/peroxidation of lipids in the acute phase of infection prior to the cachectic phase. The present study described a novel hypermetabolic mechanism involving enhanced lipid peroxidation dependent on IFN-gamma, especially associated with tissues rich in macrophages.
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Affiliation(s)
- D Arsenijevic
- Physiology and Animal Husbandary, Institute of Physiology and Animal Science, Swiss Federal Institute of Technology Zurich, Schorenstrasse 16, Schwerzenbach 8603, Switzerland.
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40
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Abstract
A prominent neuropathological change observed in a murine model of congenital toxoplasmosis is cerebral cortical hypoplasia. In the early embryonic life of toxoplasmosis mice, the number of apoptotic cell observed in cerebral cortex is increased, indicating that increased number of apoptotic cells might relate to the pathogenetic mechanism of the cortical hypoplasia. Immunohistochemical expression of apoptosis-related factors, Bcl-2 and Bax has been studied in fetal murine brains infected with toxoplasma and in controls. Paraffin sections of the fetal brains on embryonic day (ED) 10, 12, 14, 16 and 18 were applied for the immunostains of Bcl-2 and Bax. Totally, 47 experimental animals (ED10: n=8, ED12: n=6, ED14: n=12, ED16: n=6, ED18: n=15) and 48 control animals (ED10: n=6, ED12: n=8, ED14: n=9, ED16: n=9, ED18: n=16) were examined. Bcl-2 positive cells were detected on ED10, whereas Bax positive cells appeared on ED14. No difference of Bcl-2 and Bax expression between toxoplasmosis and control groups was detected, suggesting that there is no clear relation between Bax-induced apoptosis and cortical dysplasia in congenital toxoplasmosis.
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MESH Headings
- Animals
- Apoptosis/physiology
- Body Patterning/physiology
- Cerebral Cortex/abnormalities
- Cerebral Cortex/pathology
- Cerebral Cortex/physiopathology
- Female
- Fetus
- Mice
- Mice, Inbred C57BL
- Nervous System Malformations/parasitology
- Nervous System Malformations/pathology
- Nervous System Malformations/physiopathology
- Neurons/metabolism
- Neurons/pathology
- Proto-Oncogene Proteins/metabolism
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Toxoplasma/pathogenicity
- Toxoplasma/physiology
- Toxoplasmosis, Animal/metabolism
- Toxoplasmosis, Animal/pathology
- Toxoplasmosis, Animal/physiopathology
- Toxoplasmosis, Cerebral/metabolism
- Toxoplasmosis, Cerebral/pathology
- Toxoplasmosis, Cerebral/physiopathology
- Toxoplasmosis, Congenital/metabolism
- Toxoplasmosis, Congenital/pathology
- Toxoplasmosis, Congenital/physiopathology
- bcl-2-Associated X Protein
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Affiliation(s)
- J Takahashi
- Division of Neuropathology, Jikei University School of Medicine, 3-25-8, Nishi-shim bashi, Minato-Ku, 105-8461, Tokyo, Japan.
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41
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Abstract
Microglia subpopulations were studied in mouse experimental autoimmune encephalomyelitis and toxoplasmic encephalitis. CNS inflammation was associated with the proliferation of CD11b(+) brain cells that exhibited the dendritic cell (DC) marker CD11c. These cells constituted up to 30% of the total CD11b(+) brain cell population. In both diseases CD11c(+) brain cells displayed the surface phenotype of myeloid DC and resided at perivascular and intraparenchymatic inflammatory sites. By lacking prominent phagocytic organelles, CD11c(+) cells from inflamed brain proved distinct from other microglia, but strikingly resembled bone marrow-derived DC and thus were identified as DC. This brain DC population comprised cells strongly secreting IL-12p70, whereas coisolated CD11c(-) microglia/brain macrophages predominantly produced TNF-alpha, GM-CSF, and NO. In comparison, the DC were more potent stimulators of naive or allogeneic T cell proliferation. Both DC and CD11c(-) microglia/macrophages from inflamed brain primed naive T cells from DO11.10 TCR transgenic mice for production of Th1 cytokines IFN-gamma and IL-2. Resting microglia that had been purified from normal adult brain generated immature DC upon exposure to GM-CSF, while CD40 ligation triggered terminal maturation. Consistently, a functional maturation of brain DC was observed to occur following the onset of encephalitis. In conclusion, these findings indicate that in addition to inflammatory macrophage-like brain cells, intraparenchymatical DC exist in autoimmune and infectious encephalitis. These DC functionally mature upon disease onset and can differentiate from resident microglia. Their emergence, maturation, and prolonged activity within the brain might contribute to the chronicity of intracerebral Th1 responses.
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MESH Headings
- Animals
- Brain/immunology
- Brain/metabolism
- Brain/pathology
- Brain/ultrastructure
- CD40 Ligand/immunology
- CD40 Ligand/metabolism
- CD40 Ligand/pharmacology
- Cell Differentiation/immunology
- Cells, Cultured
- Cellular Senescence/immunology
- Coculture Techniques
- Cytokines/biosynthesis
- Dendritic Cells/immunology
- Dendritic Cells/metabolism
- Dendritic Cells/pathology
- Dendritic Cells/ultrastructure
- Encephalomyelitis, Autoimmune, Experimental/immunology
- Encephalomyelitis, Autoimmune, Experimental/metabolism
- Encephalomyelitis, Autoimmune, Experimental/pathology
- Female
- Granulocyte-Macrophage Colony-Stimulating Factor/pharmacology
- Immunophenotyping
- Integrin alphaXbeta2/biosynthesis
- Interphase/immunology
- Leukocyte Count
- Leukocytes, Mononuclear/immunology
- Leukocytes, Mononuclear/metabolism
- Lymphocyte Activation
- Macrophage-1 Antigen/biosynthesis
- Macrophages/immunology
- Macrophages/metabolism
- Macrophages/pathology
- Macrophages/ultrastructure
- Mice
- Mice, Inbred BALB C
- Mice, Inbred C57BL
- Mice, Transgenic
- Microglia/immunology
- Microglia/metabolism
- Microglia/pathology
- Microglia/ultrastructure
- Nitric Oxide/biosynthesis
- T-Lymphocyte Subsets/immunology
- Th1 Cells/immunology
- Th1 Cells/metabolism
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/metabolism
- Toxoplasmosis, Animal/pathology
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Affiliation(s)
- H G Fischer
- Institute for Medical Microbiology and Virology, Heinrich Heine University, Duesseldorf, Germany.
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42
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Rutschman R, Lang R, Hesse M, Ihle JN, Wynn TA, Murray PJ. Cutting edge: Stat6-dependent substrate depletion regulates nitric oxide production. J Immunol 2001; 166:2173-7. [PMID: 11160269 DOI: 10.4049/jimmunol.166.4.2173] [Citation(s) in RCA: 244] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The cytokines IL-4 and IL-13 inhibit the production of NO from activated macrophages through an unresolved molecular mechanism. We show here that IL-4 and IL-13 regulate NO production through depletion of arginine, the substrate of inducible NO synthase (iNOS). Inhibition of NO production from murine macrophages stimulated with LPS and IFN-gamma by IL-4 or IL-13 was dependent on Stat6, cell density in the cultures, and pretreatment for at least 6 h. IL-4/IL-13 did not interfere with the expression or activity of iNOS but up-regulated arginase I (the liver isoform of arginase) in a Stat6-dependent manner. Addition of exogenous arginine completely restored NO production in IL-4-treated macrophages. Furthermore, impaired killing of the intracellular pathogen Toxoplasma gondii in IL-4-treated macrophages was overcome by supplementing L-arginine. The simple system of regulated substrate competition between arginase and iNOS has implications for understanding the physiological regulation of NO production.
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MESH Headings
- Animals
- Arginase/biosynthesis
- Arginine/deficiency
- Cells, Cultured
- Down-Regulation/immunology
- Interleukin-13/physiology
- Interleukin-4/physiology
- Macrophage Activation
- Macrophages, Peritoneal/enzymology
- Macrophages, Peritoneal/immunology
- Macrophages, Peritoneal/metabolism
- Macrophages, Peritoneal/parasitology
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Nitric Oxide/antagonists & inhibitors
- Nitric Oxide/biosynthesis
- Nitric Oxide Synthase/metabolism
- Nitric Oxide Synthase Type II
- STAT6 Transcription Factor
- Substrate Specificity/immunology
- Toxoplasmosis, Animal/enzymology
- Toxoplasmosis, Animal/immunology
- Toxoplasmosis, Animal/metabolism
- Trans-Activators/deficiency
- Trans-Activators/genetics
- Trans-Activators/physiology
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Affiliation(s)
- R Rutschman
- Department of Infectious Diseases, Howard Hughes Medical Institute, St. Jude Children's Research Hospital, Memphis, TN 38105, USA
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43
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Arsenijevic D, Onuma H, Pecqueur C, Raimbault S, Manning BS, Miroux B, Couplan E, Alves-Guerra MC, Goubern M, Surwit R, Bouillaud F, Richard D, Collins S, Ricquier D. Disruption of the uncoupling protein-2 gene in mice reveals a role in immunity and reactive oxygen species production. Nat Genet 2000; 26:435-9. [PMID: 11101840 DOI: 10.1038/82565] [Citation(s) in RCA: 830] [Impact Index Per Article: 34.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The gene Ucp2 is a member of a family of genes found in animals and plants, encoding a protein homologous to the brown fat uncoupling protein Ucp1 (refs 1-3). As Ucp2 is widely expressed in mammalian tissues, uncouples respiration and resides within a region of genetic linkage to obesity, a role in energy dissipation has been proposed. We demonstrate here, however, that mice lacking Ucp2 following targeted gene disruption are not obese and have a normal response to cold exposure or high-fat diet. Expression of Ucp2 is robust in spleen, lung and isolated macrophages, suggesting a role for Ucp2 in immunity or inflammatory responsiveness. We investigated the response to infection with Toxoplasma gondii in Ucp2-/- mice, and found that they are completely resistant to infection, in contrast with the lethality observed in wild-type littermates. Parasitic cysts and inflammation sites in brain were significantly reduced in Ucp2-/- mice (63% decrease, P<0.04). Macrophages from Ucp2-/- mice generated more reactive oxygen species than wild-type mice (80% increase, P<0.001) in response to T. gondii, and had a fivefold greater toxoplasmacidal activity in vitro compared with wild-type mice (P<0.001 ), which was absent in the presence of a quencher of reactive oxygen species (ROS). Our results indicate a role for Ucp2 in the limitation of ROS and macrophage-mediated immunity.
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Affiliation(s)
- D Arsenijevic
- Centre de Recherche de Hôpital Laval et Centre de Recherche sur le Métabolisme Energétique, Université Laval, Québec, Canada
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44
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Fischer HG, Bonifas U, Reichmann G. Phenotype and functions of brain dendritic cells emerging during chronic infection of mice with Toxoplasma gondii. J Immunol 2000; 164:4826-34. [PMID: 10779791 DOI: 10.4049/jimmunol.164.9.4826] [Citation(s) in RCA: 130] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
During chronic infection of mice with Toxoplasma gondii, gene message for IL-12p40, CD86, and the potassium channel Kv1.3 was detected in brain mononuclear cells, suggesting the presence of dendritic cells (DC) in the CNS. Consistently, cells bearing the DC markers CD11c and 33D1 were localized at inflammatory sites in the infected brain. The number of isolated CD11c+ brain cells increased until peak inflammation. The cells exhibited the surface phenotype of myeloid DC by coexpressing 33D1 and F4/80, little DEC-205, and no CD8alpha. These brain DC were mature, as indicated by high-level expression of MHC class II, CD40, CD54, CD80, and CD86. They triggered Ag-specific and primary allogeneic T cell responses at very low APC/T cell ratios. Among mononuclear cells from encephalitic brain, DC were the main producers of IL-12. Evidence for a parasite-dependent development of DC from CNS progenitors was obtained in vitro: after inoculation of primary brain cell culture with T. gondii, IL-12-secreting dendriform cells emerged, and DC marker genes were expressed. Different stimuli elicited the generation and maturation of brain DC: neutralization of parasite-induced GM-CSF prevented outgrowth of dendriform cells and concomitant release of IL-12. IL-12 production was up-regulated by external IFN-gamma but was stopped by inhibiting parasite replication. Consistently, DC isolated from GM-CSF-treated brain cell culture were activated to secrete IL-12 by exposure to parasite lysate. In sum, these results demonstrate T. gondii-induced expansion and functional maturation of DC in the CNS and, thus, highlight a mechanism that may contribute to the chronicity of the host response.
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Affiliation(s)
- H G Fischer
- Institute for Medical Microbiology and Virology, Heinrich-Heine University, Duesseldorf, Germany.
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45
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46
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Abstract
There is considerable controversy as to the roles of parasite proliferation and the inflammatory response in destruction of the retina during Toxoplasma gondii infection. A murine model was used to investigate the role of nitric oxide in pathogenesis of chronic ocular toxoplasmosis. Increased quantities of messenger RNA (mRNA) transcripts for iNOS were detected in the eyes of chronically infected C57BL/6 mice compared with noninfected control mice. Inhibition of nitric oxide (NO) by the addition of Lomega-nitro-L-arginine methyl ester (L-NAME) to the drinking water of infected mice between weeks 4-6 of infection, exacerbated ocular inflammation. The amount of inflammation was assessed semiquantitatively in histological sections of the eye. Eyes from L-NAME treated mice showed a significant increase in inflammation of the retina (P = 0.02), choroid (P = 0.03), and vitreous (P = 0.02) compared with control mice. These results demonstrate a protective role for NO in the control of chronic, ocular toxoplasmosis.
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Affiliation(s)
- F Roberts
- Michael Reese Hospital and Medical Center and University of Chicago, Chicago, IL 60637, USA
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47
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Jungersen G, Jensen L, Riber U, Heegaard PM, Petersen E, Poulsen JS, Bille-Hansen V, Lind P. Pathogenicity of selected Toxoplasma gondii isolates in young pigs. Int J Parasitol 1999; 29:1307-19. [PMID: 10576580 DOI: 10.1016/s0020-7519(99)00078-8] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
The pathogenicity in 7-week-old pigs to five different Toxoplasma gondii strains of various host species origin was compared after i.v. inoculation of 10(4) tachyzoites. Additionally, one group of pigs was inoculated i.v. with 10(6) tachyzoites of the reference strain, SSI 119. In response to the infection a significant effect of T. gondii tachyzoite inoculation dose as well as differences among strains could be observed in several parameters. The 10(6)-dose inoculated pigs showed variable degrees of clinical illness and recurrent episodes of fever 4-17 days p.i., while pigs of four of the 10(4) tachyzoite inoculated groups experienced a short-lived rise in body temperature from day 6-8 p.i. without any apparent illness or inappetence. Control pigs and pigs infected with the least pathogenic strain had normal body temperature throughout the experiment. In all inoculated pigs, T. gondii-specific IgM and IgG antibodies appeared from day 8-10 and 10-17 p.i., respectively. Serum levels of alkaline phosphatase and the acute phase protein haptoglobin were decreased or increased, respectively, in response to the infection. Differential leukocyte count on peripheral blood revealed a significant lymphocytopenia on day 6 p.i. equal to both CD4+ and CD8+ T-cells, but shifting towards a reduced ratio of CD4+/CD8+ T-cells from day 8-14 p.i. In the 10(6)-dose inoculated pigs a considerable increase in zymosan induced and spontaneous oxidative burst capacity of peripheral blood leukocytes was observed from 6 days p.i. compared with control pigs. Oxidative burst capacity was not examined for other pigs. In conclusion, several useful parameters to identify differences in T. gondii pathogenicity other than mortality were identified. Furthermore, even at low doses, significant differences between recently collected Danish T. gondii field isolates were demonstrated after i.v. inoculation in young pigs.
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Affiliation(s)
- G Jungersen
- Danish Veterinary Laboratory, Copenhagen, Denmark.
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48
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Deckert-Schlüter M, Buck C, Schlüter D. Kinetics and differential expression of heat-stable antigen and GL7 in the normal and Toxoplasma gondii-infected murine brain. Acta Neuropathol 1999; 98:97-106. [PMID: 10412806 DOI: 10.1007/s004010051056] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The co-expression of various cell surface molecules by cells of the nervous system and the immune system is a remarkable feature. To identify novel molecules that are shared between cells of the neural and hematopoietic lineage, the expression and regulation of heat-stable antigen (HSA, CD24, nectadrin) and GL7, two hematolymphoid differentiation antigens that are involved in antigen presentation, cell adhesion, signal transduction and activation, was studied in the adult normal and Toxoplasma gondii-infected murine brain by immunohistochemistry and flow cytometry of isolated cerebral leukocytes. In the normal brain ependymal cells, plexus macrophages and a fraction of blood vessel endothelial cells were HSA positive (+), whereas the choroid plexus epithelium was GL7+. This basal expression of HSA and GL7 was not further modified on these cell populations in Toxoplasma encephalitis (TE). In acute and chronic TE, HSA and GL7 were strongly induced on resident brain cells, and activated astrocytes were the predominant HSA+ and GL7+ cell type. FACS analysis additionally identified a minor fraction of HSA+ microglia in the normal brain with a small, but significant increase in TE. The differential expression pattern of HSA and GL7 on distinct resident cell populations in various anatomic compartments of the normal adult brain and their up-regulation in TE may indicate that their intracerebral role is diverse and may include both immunological as well as non-immunological functions.
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49
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Orlofsky A, Somogyi RD, Weiss LM, Prystowsky MB. The murine antiapoptotic protein A1 is induced in inflammatory macrophages and constitutively expressed in neutrophils. J Immunol 1999; 163:412-9. [PMID: 10384143] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Subscribe] [Scholar Register] [Indexed: 02/13/2023]
Abstract
Myeloid leukocytes are thought to regulate their susceptibility to apoptosis upon migration to a site of inflammation. However, factors that determine survival have not been well characterized in these cells. We have examined the expression of murine A1, an antiapoptotic Bcl-2 relative found in activated myeloid cells, during the course of an acute inflammatory response. Intraperitoneal infection of mice with the virulent RH strain of Toxoplasma gondii led to a 5- to 10-fold increase in A1 mRNA levels in peritoneal cells after several days. Bcl-2 expression was unchanged. The increase in A1 expression depended on the dose of the organism and coincided with a sharp increase in peritoneal cellularity. A1 protein levels were also increased as determined by Western blot analysis and immunohistochemical studies. All neutrophils and approximately half of the macrophages in the inflammatory exudate contained high levels of A1 in cytoplasm. A1 expression did not correlate with intracellular parasitization. Peripheral blood neutrophils from normal mice strongly expressed A1 protein, whereas normal monocytes showed only weak staining. Bax mRNA was induced in parallel with A1 in macrophages. Exudate macrophages and granulocytes that were apoptotic by TUNEL staining occasionally appeared to display A1 throughout the cell nucleus. These studies identify A1 as a potential regulator of apoptosis during acute inflammation.
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Affiliation(s)
- A Orlofsky
- Department of Pathology, Albert Einstein College of Medicine, Bronx, NY 10461, USA.
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50
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Neyer LE, Kang H, Remington JS, Suzuki Y. Mesenteric lymph node T cells but not splenic T cells maintain their proliferative response to concanavalin-A following peroral infection with Toxoplasma gondii. Parasite Immunol 1998; 20:573-81. [PMID: 9990642 DOI: 10.1046/j.1365-3024.1998.00162.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The suppression of T cell responsiveness which occurs after infection with Toxoplasma gondii in mice has been widely studied using spleen cells. Because the natural route of infection with T. gondii is the peroral route, we examined the proliferative responses of mesenteric lymph node (MLN) cells, in addition to spleen cells, to Concanavalin-A (Con-A) in mice perorally infected with T. gondii. Proliferative responses of spleen cells were significantly suppressed seven and ten days after infection when compared with spleen cells from uninfected mice (62% and 91% reduction, respectively). In contrast, proliferative responses of MLN cells from these infected mice did not differ from those of normal MLN cells. Since IFN-gamma-induced reactive nitrogen intermediate (RNI) production has been reported to play a major role in suppression of proliferative responses in spleen cells of infected mice, we compared production of IFN-gamma and RNI by spleen and MLN cells following infection. MLN cells produced as much IFN-gamma as did spleen cells, but produced 70% less nitrite (as a measure of RNI) after Con-A stimulation. Proliferative responses of MLN cells were suppressed when co-cultured with spleen cells from infected mice, and addition of an inhibitor of RNI to these co-culture inhibited this suppression, suggesting that reduced RNI production by MLN cells contributes to their maintenance of higher proliferative responses. These results demonstrated a clear difference in activity of T cells in the MLN and spleen during the acute stage of the infection.
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Affiliation(s)
- L E Neyer
- Department of Immunology and Infectious Diseases, Palo Alto Medical Foundation, California 94301, USA
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