References of "Antoine, Nadine"
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See detailGerminal centre innervation of bovine and human tonsils related to prion diseases.
Defaweux, Valérie ULg; Dorban, Gauthier; Antoine, Nadine ULg et al

in Brain, Behavior & Immunity (2009), 23(1), 10

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See detailVascularisation of the equine menisci
De Busscher, V.; Maitre, D.; Busoni, Valeria ULg et al

Poster (2009)

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See detailIn vitro modelisation of prions neuroinvasion mediated by dendritic cells
Dorban, G.; Defaweux, Valérie ULg; Heinen, Ernst ULg et al

Poster (2008, October)

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See detail. Do innervation of germinal centre and contacts between FDC and nerve fibers be keys to understand the susceptibility difference between bovines and humans to the BSE agent?
Defaweux, Valérie ULg; Dorban, G.; Antoine, Nadine ULg et al

Poster (2008, October)

Background: In regard to BSE and vCJD, the agent tropism for lymphoid tissues is completely different even if the infectious strain responsible and the way of inoculation are identical. During vCJD, the ... [more ▼]

Background: In regard to BSE and vCJD, the agent tropism for lymphoid tissues is completely different even if the infectious strain responsible and the way of inoculation are identical. During vCJD, the infectious agent crosses the digestive barrier and multiplies in lymphoid organs, before progressively reaching the brain. Indeed, in vCJD, it accumulates in the ileum, tonsils, spleen and appendix of infected individuals. In contrast, in cattle, the BSE agent has a low affinity for lymphoid tissues and mainly accumulates in the nervous system. During preclinical stages, infectivity, other than that in the peripheral nervous system or central nervous system, is confined in the distal ileum of orally infected cattle. So, it appears that, at least in the case of BSE and vCJD, host properties can influence the accumulation of the infectious agent in lymphoid organs. Objectives and methods: In this study, we analysed by confocale microscopy the mucosal innervation and the interface between nerve fibres and FDC in bovine and human tonsils using a panel of antibodies. Since differences in the innervation of lymphoid organs depending on species and on age have been reported, we analysed two categories of bovines (calves less than 12 months old and bovines older than 24 months) and two categories of humans (patients less than 5 years old and patients older than 25 years). Results: In both species, ways of innervation by-passing germinal centres could be postulated: nerve fibres are widely distributed in antigen/cell traffic area: the lamina propria, the interfollicular zone and the lymphoepithelial area. We pointed out that, only in tonsils of bovines older than 24 months, nerve fibres are observed to be in contact with FDC. In contrast, in human tonsils, no nerve fibres established contacts with FDC, whatever the age. Discussion: Innervation of germinal centres can be said to be an age-dependent dynamic process in bovines. The weak innervation of the secondary lymphoid organs could thus be a rate-limiting step to neuroinvasion in humans. This species difference could influence the way of neuroinvasion and thus, the susceptibility of bovines and humans to the BSE agent. [less ▲]

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See detailInteraction between dendritic cells and nerve fibres in lymphoid organs after oral scrapie exposure
Dorban, Gauthier ULg; Defaweux, Valérie ULg; Demonceau, Christine ULg et al

in Virchows Archiv (2007), 451(6), 1057-1065

In transmissible spongiform encephalopathies (TSEs), the infectious agent, called PrPsc, an abnormal isoform of the cellular prion protein, accumulates and replicates in lymphoid organs before affecting ... [more ▼]

In transmissible spongiform encephalopathies (TSEs), the infectious agent, called PrPsc, an abnormal isoform of the cellular prion protein, accumulates and replicates in lymphoid organs before affecting the nervous system. To clarify the cellular requirements for the neuro-invasion of the scrapie agent from the lymphoid organs to the central nervous system, we have studied, by confocal microscopy, the innervations within Peyer's patches, mesenteric lymph nodes and the spleen of mice in physiological conditions and after oral exposure to prion. Contacts between nerve fibres and PrPsc-associated cells, dendritic cells (DCs) and follicular dendritic cells (FDCs), were evaluated in preclinical prion-infected mice. Using a double immunolabelling strategy, we demonstrated the lack of innervation of PrPsc-accumulating cells (FDCs). Contacts between nerve fibers and PrPsc-propagating cells (DCs) were detected in T-cell zones and cell-trafficking areas. This supports, for the first time, the possible implication of dendritic cells in the prion neuroinvasion process. [less ▲]

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See detailDo tonsilar FDCs express PrPc in sheep?
Toppets, Vinciane ULg; Piret,J; Minne,M et al

Poster (2007, October)

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See detailOral scrapie infection modifies the homeostasis of Peyer's patches' dendritic cells
Dorban, Gauthier ULg; Defaweux, Valérie ULg; Levavasseur, Etienne et al

in Histochemistry & Cell Biology (2007), 128(3), 243-251

In transmitted prion diseases the immune system supports the replication and the propagation of the pathogenic agent (PrPSc). DCs, which are mobile cells present in large numbers within lymph organs, are ... [more ▼]

In transmitted prion diseases the immune system supports the replication and the propagation of the pathogenic agent (PrPSc). DCs, which are mobile cells present in large numbers within lymph organs, are suspected to carry prions through the lymphoid system and to transfer them towards the peripheral nervous system. In this study, C57Bl/6 mice were orally inoculated with PrPSc (scrapie strain 139A) and sacrificed at the preclinical stages of the disease. Immunolabelled cryosections of Peyer's patches were analysed by confocal microscopy. Membrane prion protein expression was studied by flow cytometry. In Peyer's patches (PP), dissected at day one and day 105 after oral exposure to scrapie, we observed an increased population of DCs localised in the follicular-associated epithelium. On day 105, PrPSc was found in the follicles inside the PP of prion-infected mice. A subset of Peyer's patches DCs, which did not express cellular prion protein on their surface in non-infected mice conditions, was prion-positive in scrapie conditions. Within Peyer's patches oral scrapie exposure thus induced modifications of the homeostasis of DCs at the preclinical stages of the disease. These results give new arguments in favour of the implication of DCs in prion diseases. [less ▲]

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See detailNeuroimmune connections in jejunal and ileal Peyer's patches at various bovine ages: potential sites for prion neuroinvasion
Defaweux, Valérie ULg; Dorban, Gauthier ULg; Antoine, Nadine ULg et al

in Cell & Tissue Research (2007), 329(1), 35-44

During preclinical stages of cattle orally infected with bovine spongiform encephalopathy (BSE), the responsible agent is confined to ileal Peyer's patches (IPP), namely in nerve fibers and in lymph ... [more ▼]

During preclinical stages of cattle orally infected with bovine spongiform encephalopathy (BSE), the responsible agent is confined to ileal Peyer's patches (IPP), namely in nerve fibers and in lymph follicles, before reaching the peripheral and central nervous systems. No infectivity has been reported in other bovine lymphoid organs, including jejunal Peyer's patches (JPP). To determine the potential sites for prion neuroinvasion in IPP, we analyzed the mucosal innervation and the interface between nerve fibers and follicular dendritic cells (FDC), two dramatic influences on neuroinvasion. Bovine IPP were studied at three ages, viz., newborn calves, calves less than 12 months old, and bovines older than 24 months, and the parameters obtained were compared with those of JPP. No differences in innervation patterns between IPP and JPP were found. The major difference observed was that, in calves of less than 12 months, IPP were the major mucosal-associated lymphoid organ that possessed a large number of follicles with extended FDC networks. Using a panel of antibodies, we showed that PP in 24-month-old bovines were highly innervated at various strategic sites assumed to be involved in the invasion and replication of the BSE pathogen: the suprafollicular dome, T cell area, and germinal centers. In PP in calves of less than 12 months old, no nerve fibers positive for the neurofilament markers NF-L (70 kDa) and NF-H (200 kDa) were observed in contact with FDC. Thus, in view of the proportion of these protein subunits present in neurofilaments, the innervation of the germinal centers can be said to be an age-dependent dynamic process. This variation in innervation might influence the path of neuroinvasion and, thus, the susceptibility of bovines to the BSE agent. [less ▲]

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See detailMorphological alterations in oxidative muscles and mitochondrial structure associated with equine atypical myopathy
Cassart, Dominique ULg; Baise, Etienne ULg; Cherel, Yann et al

in Equine Veterinary Journal (2007), 39(1), 26-32

REASONS FOR PERFORMING STUDY: There is a lack of well documented studies about muscular lesions in equine atypical myopathy (EAM). <br /> <br />OBJECTIVES: To characterise morphopathological changes of ... [more ▼]

REASONS FOR PERFORMING STUDY: There is a lack of well documented studies about muscular lesions in equine atypical myopathy (EAM). <br /> <br />OBJECTIVES: To characterise morphopathological changes of striated muscles and myocardium, to progress understanding of this disease. <br /> <br />METHODS: Thirty-two horses age 0.5-7 years kept on pasture were referred for a sudden ataxia/myoglobinuria syndrome. Clinical examination (stiffness, muscle pain, muscle fasciculations, abnormal gait, recumbency, myoglobinuria, tachycardia, sweating) and plasma CPK, LDH and AST levels were consistent with extensive myonecrosis and, together with anamnestic data, with so-called 'equine atypical myopathy' (EAM), a disease of unknown aetiology reported since 1939. Macroscopic and microscopic (histology, histoenzymology, ultrastructure) lesions were evaluated. <br /> <br />RESULTS: Necropsic examination revealed large areas of muscle necrosis, the extent and severity of which varied between cases and muscles, but which were clearly more constant and severe in respiratory and postural muscles and in the myocardium. Histology highlighted a multifocal and monophasic process compatible with Zenker degeneration/necrosis that mostly and segmentally affected type 1 fibres. Histochemical evaluation revealed a weak and disorganised pattern of NADH tetrazolium reductase staining, the absence of calcium salts precipitates and a dramatic accumulation of lipid droplets. Ultrastructural examination often revealed fibres of which the sole modifications were altered mitochondria and sarcoplasmic lipidosis. <br /> <br />CONCLUSIONS: Taken together, the data suggest that a primary alteration of mitochondria should be considered, although secondary mitochondrial abnormalities have yet to be ruled out. <br /> <br />POTENTIAL RELEVANCE: The morphological features gathered here reveal that EAM shares most of the characteristics of toxic myopathies. [less ▲]

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See detailUltrasonography and histology of equine menisci; a comparative study of the medial
De Busscher,V; Gabriel, Annick ULg; Cassart, Dominique ULg et al

Poster (2007, January)

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See detailMorphology of the stifle menisci in dogs: preliminary study
De Busscher, Virginie; Letesson, Julien; Busoni, Valeria ULg et al

in Slovenian Veterinary Research (2007), 44

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See detailComparative ultrasonographic and morphologic appearance of femorotibial menisci in horses: a preliminary study
De Busscher, V.; Busoni, Valeria ULg; Schreder, A. et al

in Canifelis Hippos Proceedings (2007)

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See detailAre CNA42 and FDC-B1 directed against ovine follicular dendritic cells?
Toppets, Vinciane ULg; Piret,J; Minne , M et al

Poster (2006, October)

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See detailDistribution of nerve fibres in bovine and human mucosal associated lymphoid tissues
Defaweux, Valérie ULg; Dorban, G.; Antoine, Nadine ULg et al

Poster (2006, October)

Prion cell tropism varies significantly among animal species, depending on both the agent strain and host-specific factors. For example, prions show high lymphotropism in scrapie infected sheep and vCJD ... [more ▼]

Prion cell tropism varies significantly among animal species, depending on both the agent strain and host-specific factors. For example, prions show high lymphotropism in scrapie infected sheep and vCJD, but little, if any, in sCJD or BSE. In particular, the BSE strain is associated with significant PrP-res accumulation in tonsils, spleen and appendix in humans, whereas it is largely confined to the nervous system in infected cattle. Therefore, at least in the case of BSE and vCJD, it appears that host properties can influence the accumulation of the infectious agent in lymphoid organs. Mature FDC play an important role in prion pathogenesis, since neuroinvasion following peripheral challenge is significantly impaired in their absence. The proximity between these FDC and sympathetic nerve endings is known to affect the speed of prion neuroinvasion. In this study, we analysed the mucosal innervation and the interface between nerve fibres and FDC in bovine and human tonsils and in ileal and jejunal bovine Peyer’s patches using a panel of antibodies observed by confocal microscopy. Since differences in the innervation of lymphoid organs depending on age have been reported, we analysed three categories of bovine ages (new born calves, calves less than 12 months old and bovines older than 24 months) and two categories of human ages (patients less than 5 years old and patients older than 25 years). In both species, hypothetical ways of innervation by-passing germinal centre could be postulated: nerve fibres are widely distributed in antigens/cells traffic area (the lamina propria, the interfollicular zone, the suprafollicular dome in Peyer’s patches and the lymphoepithelial area in tonsils). We pointed out that, only in ileal and jejunal Peyer’s patches and in tonsils of bovines older than 24 months, nerve fibres are observed to be in contact with FDC. In contrast, in human tonsils, no nerve fibres established contact with FDC, whatever the age. Thus, innervation of germinal centres can be said to be an age-dependent dynamic process in bovines and a weak innervation of the secondary lymphoid organs could thus be a rate-limiting step to neuroinvasion in humans. This variation could influence the way of neuroinvasion and thus, the differences of susceptibility of bovines and humans to the BSE agent. [less ▲]

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See detailDendritic cells: potential actors in prion neuroinvasion.
Dorban, G.; Lallemand, C.; Defaweux, Valérie ULg et al

Poster (2006, September)

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See detailBiological characterization of bovine herpesvirus 1 recombinants possessing the vaccine glycoprotein E negative phenotype
Muylkens, Benoît ULg; Meurens, F.; Schynts, F. et al

in Veterinary Microbiology (2006), 113(3-4), 283-291

Intramolecular recombination is a frequent event during the replication cycle of bovine herpesvirus 1 (BoHV-1). Recombinant viruses frequently arise and survive in cattle after concomitant nasal ... [more ▼]

Intramolecular recombination is a frequent event during the replication cycle of bovine herpesvirus 1 (BoHV-1). Recombinant viruses frequently arise and survive in cattle after concomitant nasal infections with two BoHV-1 mutants. The consequences of this process, related to herpesvirus evolution, have to be assessed in the context of large use of live marker vaccines based on glycoprotein E (gE) gene deletion. In natural conditions, double nasal infections by vaccine and wild-type strains are likely to occur. This situation might generate virulent recombinant viruses inducing a serological response indistinguishable from the vaccine one. This question was addressed by generating in vitro BoHV-1 recombinants deleted in the gE gene from seven wild-type BoHV-1 strains and one mutant strain deleted in the genes encoding gC and gE. In vitro growth properties were assessed by virus production, one step growth kinetics and plaque size assay. Heterogeneity in the biological properties was shown among the investigated recombinant viruses. The results demonstrated that some recombinants. in spite of their gE minus phenotype, have biological characteristics close to wild-type BoHV-1. (c) 2005 Elsevier B.V. All rights reserved. [less ▲]

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