References of "Thellin, Olivier"
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See detailDecontamination of Prions by the Flowing Afterglow of a Reduced-Pressure N2-O2 Cold-Plasma
Elmoualij, Benaïssa ULg; Thellin, Olivier ULg; GOFFLOT, Stéphanie ULg et al

in Plasma Processes and Polymers (2012), 9(6), 612618

Transmissible spongiform encephalopathies, also called prion diseases, represent a family of neurodegenerative disorders that affect various animal species. Since the infectious forms of prions are ... [more ▼]

Transmissible spongiform encephalopathies, also called prion diseases, represent a family of neurodegenerative disorders that affect various animal species. Since the infectious forms of prions are transmissible and highly resistant to chemical and physical decontamination methods routinely used in healthcare, they represent a challenge for science, medicine, and public health/food systems. Suitable decontamination procedures have been proposed, but they are generally incompatible with the materials from which medical devices are made. In this study, we evaluate a cold gaseous-plasma treatment, based on the outflow from a N2[BOND]O2 microwave discharge, as an alternative decontamination tool against both the non-infectious (PrPC) and infectious (PrPSc) forms of prion proteins. The efficiency of the plasma treatment on these proteins is assessed using an in vitro assay as well as an in vivo bioassay. We showed by Enzyme-Linked Immuno-Sorbent Assay (ELISA) that the N2[BOND]O2 discharge afterglow reduces the immunoreactivity of both non-infectious recombinant and pathogenic prion proteins deposited on polystyrene substrates. Tests done in vivo demonstrate that exposure to the cold-plasma flowing afterglow achieves significant decontamination of stainless steel sutures inoculated with infectious forms of prions to be implanted in mice. [less ▲]

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See detailSterilization/disinfection of medical devices using plasma: the reduced-pressure flowing-afterglow of the N2-O2 discharge as the inactivating medium
Michel Moisan; Jean Barbeau; Karim Boudama et al

in European journal of Applied Physics (2012)

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See detailPre-Mortem Diagnostic Screening for Transmissible Spongiform Encephalopathies by Proteomic Approaches
Falisse-Poirrier, Nandini; Thellin, Olivier ULg; Dupiereux-Fettweis, Ingrid ULg et al

Book published by Nova Publishers (2012)

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See detailA decade of improvements in quantification of gene expression and internal standard selection.
Thellin, Olivier ULg; Elmoualij, Benaïssa ULg; Heinen, Ernst ULg et al

in Biotechnology Advances (2009)

Major improvements have been made in mRNA quantification and internal standard selection over the last decade. Our aim in this paper is to present the main developments that are of interest for practical ... [more ▼]

Major improvements have been made in mRNA quantification and internal standard selection over the last decade. Our aim in this paper is to present the main developments that are of interest for practical laboratory work, contrasting the situation as it is now with the one of ten years ago, and presenting some excellent examples of what can be done today. Specifically, we will mainly discuss Real-Time RT-PCR major improvements that have been performed in the following areas: the most commonly used quantification techniques, the mathematical and software tools created to help researchers in their work on internal standard selection, the availability of detection chemistries and technical information and of commercial tools and services. In addition to mRNA quantification, we will also discuss some aspects of non-coding RNA and protein quantification. In addition to technical improvements, the development of international cooperation and the creation of technical databases are likely to represent a major tool for the future in the standardization of gene expression quantification. [less ▲]

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See detailProtective effect of prion protein via the N-terminal region in mediating a protective effect on paraquat-induced oxidative injury in neuronal cells.
Dupiereux-Fettweis, Ingrid ULg; Falisse-Poirier, Nandini; Zorzi, Willy ULg et al

in Journal of Neuroscience Research (2008), 86(3), 653-9

Transmissible spongiform encephalopathies are a group of neurodegenerative disorders caused by a posttranslational, conformational change in the cellular isoform of the prion protein (PrP(C)) into an ... [more ▼]

Transmissible spongiform encephalopathies are a group of neurodegenerative disorders caused by a posttranslational, conformational change in the cellular isoform of the prion protein (PrP(C)) into an infectious, disease-associated form (PrP(Sc)). Increasing evidence supports a role for PrP(C) in the cellular response to oxidative stress. We investigated the effect of oxidative stress mediated by paraquat exposure on SH-SY5Y neuroblastoma cells. A loss of mitochondrial membrane potential and subsequent reduction in ATP production were demonstrated in untransfected SH-SY5Y cells, an effect that was ameliorated by the expression of PrP(C). Cells expressing either PrP-DeltaOct, which lacks the octapeptide repeats, or PrP-DA, in which the N-terminus is tethered to the membrane, showed increased sensitivity to paraquat compared with cells expressing wild-type PrP(C) as shown by reduced viability, loss of their membrane integrity, and reduced mitochondrial bioenergetic measurements. Exposure of prion-infected mouse SMB15S cells to paraquat resulted in a reduction in viability to levels similar to those seen in the untransfected SH-SY5Y cells. However, "curing" the cells with pentosan sulfate restored the viability to the level observed in the SH-SY5Y cells expressing PrP(C). These data would indicate that the molecular mechanism promoting cellular resistance to oxidative stress had been compromised in the infected SMB15S cells, which could be reinstated upon curing. Our study supports the hypothesis that PrP(C) expression protects cells against paraquat-induced oxidative injury, demonstrates the significance of the N-terminal region of the protein in mediating this protective effect, and also shows that the biochemical consequences of prion infection may be reversed with therapeutic intervention. [less ▲]

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See detailInfluence of the Ixodes ricinus tick blood-feeding on the antigen-specific antibody response in vivo.
Menten-Dedoyart, Catherine ULg; Couvreur, B.; Thellin, Olivier ULg et al

in Vaccine (2008), 26(52), 6956-64

The blood meal of hard ticks such as Ixodes ricinus lasts several days. This is made possible by tick salivary factors that inhibit inflammation, haemostasis and the host immune response. We assessed the ... [more ▼]

The blood meal of hard ticks such as Ixodes ricinus lasts several days. This is made possible by tick salivary factors that inhibit inflammation, haemostasis and the host immune response. We assessed the latter on a model of immune response in vivo. A significant reduction of specific IgM and IgG levels was observed in BALB/c mice infested 5 days before injection with bovine serum albumin (BSA) and QuilA but not in mice infested 5 days after the immunization. This effect was not observed in mock-infested mice and could not be attributed to the use of anesthetics. The antibody response was not merely delayed and the Th(1)/Th(2) balance appeared not altered. T-dependent zones and germinal centers in lymph nodes draining the tick bite site showed no apparent morphological alterations or shift in T cell subpopulations. However, the spleens of tick-infested mice had also an enlarged red pulp, indicating an increased extramedullary haematopoietic activity. [less ▲]

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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 detailLa tremblante du mouton influence-t-elle le système immunitaire lors d’une réponse vis-à-vis d’un antigène
Defaweux, Valérie ULg; Dorban, G.; Demonceau, C. et al

Conference (2005, November)

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See detailL'infection par les prions pathogènes modifie l'expression menbranaire de la PrPc par les cellules dendritiques
Dorban, G; Demonceau,C; Levavasseur, E et al

Poster (2005, October)

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See detailInterfaces between dendritic cells, other immune cells, and nerve fibres in mouse Peyer's patches: Potential sites for neuroinvasion in prion diseases
Defaweux, Valérie ULg; Dorban, Gauthier ULg; Demonceau, Christine ULg et al

in Microscopy Research and Technique (2005), 66(1), 1-9

In this study, we examined where immune cells and nerve fibres are located in mouse Peyer's patches, with a view to identifying potential sites for neuroinvasion by prions. Special attention was paid to ... [more ▼]

In this study, we examined where immune cells and nerve fibres are located in mouse Peyer's patches, with a view to identifying potential sites for neuroinvasion by prions. Special attention was paid to dendritic cells, viewed as candidate transporters of infectious prion. Double immunofluorescence labellings with anti-CD11c antibody and marker for other immune cells (B cells, T cells, follicular dendritic cells) were carried out and analysed by confocal microscopy on Peyer's patch cryosections. To reveal the extensive ganglionated networks of the myenteric and submucosal plexi and the sparse meshworks of nerve strands, we used antibodies directed against different neurofilament subunits or against glial fibrillary acidic protein. In the suprafollicular dome, dendritic cells connect, via their cytoplasmic extensions, enterocytes with M cells of the follicle-associated epithelium. They are also close to B and T cells. Nerve fibres are detected in the suprafollicular dome, notably in contact with dendritic cells. Similar connections between dendritic cells, T cells, and nerve fibres are seen in the interfollicular region. Germinal centres are not innervated; inside them dendritic cells establish contacts with follicular dendritic cells and with B cells. After immunolabelling of normal prion protein, dendritic cells of the suprafollicular dome are intensely positive labelled. (c) 2005 Wiley-Liss, Inc. [less ▲]

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See detailPregnancy and the immune system: between tolerance and rejection
Thellin, Olivier ULg; Heinen, Ernst ULg

in Toxicology (2003), 185(3), 179-184

Interactions between the conceptus and the mother are bi-directional: the feto-placental tissues need nutrition and a suitable environment in homeostatic condition whereas the mother influenced by the ... [more ▼]

Interactions between the conceptus and the mother are bi-directional: the feto-placental tissues need nutrition and a suitable environment in homeostatic condition whereas the mother influenced by the placental factors adapts her metabolism and immune system. Many different mechanisms acting locally or at distance ensure tolerance of the semi-allogeneic graft by the maternal natural and adaptive immune defences. In front of this tolerance, mechanisms exist ensuring rejection of the conceptus by the mother (spontaneous abortion) through rupture of one or more tolerance mechanisms, notably in stress situations endangering the mother. Thus outcome of a pregnancy is dependent on efficiently working tolerance mechanisms, and rupture of such mechanisms can lead to rejection. The balance of influence leading either to tolerance or rejection is under control of internal (maternal and fetal) and external (environmental) factors. Rejection, if triggered, mainly occurs through immune-induced inflammation, tissue degradation and coagulation. (C) 2002 Elsevier Science Ireland Ltd. All rights reserved. [less ▲]

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See detailTolerance to the Foeto-Placental 'Graft': Ten Ways to Support a Child for Nine Months
Thellin, Olivier ULg; Coumans, Bernard ULg; Zorzi, Willy ULg et al

in Current Opinion in Immunology (2000), 12(6), 731-7

Tolerance to the foetal 'allograft' has been extensively studied in the past few years, providing interesting new insights. In addition to a potential role for HLA-G, which has been widely discussed ... [more ▼]

Tolerance to the foetal 'allograft' has been extensively studied in the past few years, providing interesting new insights. In addition to a potential role for HLA-G, which has been widely discussed, there are hypotheses suggesting roles for several other molecules or cells: leukemia inhibitory factor and its receptor; indoleamine 2. 3-dioxygenase; the Th1/Th2 balance; suppressor macrophages; hormones such as progesterone or the placental growth hormone; CD95 and its ligand; and, as recently proposed, annexin II. Tolerance of the foetal allograft is probably the consequence of a wide panel of mechanisms that may or may not be pregnancy-specific, that are of major or secondary importance and that may be interconnected. [less ▲]

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See detailLimited effects of placental and pituitary growth hormone on cytokine expression in vitro
Thellin, Olivier ULg; Coumans, Bernard ULg; Devos, Sébastien ULg et al

in European Cytokine Network (2000), 11(3), 452-455

The hypothesis that growth hormone (GH) can affect immune responses in man has been evaluated by monitoring cytokine expression in cultures from peripheral blood mononuclear cells, by enzyme-linked ... [more ▼]

The hypothesis that growth hormone (GH) can affect immune responses in man has been evaluated by monitoring cytokine expression in cultures from peripheral blood mononuclear cells, by enzyme-linked immunosorbent assay (ELISA) and ribonuclease protection assay, and in tonsillar cells by ELISA. In addition to pituitary GH (GH-N), the placental form (GH-V), differing from pituitary GH by 13 amino acids has also been tested. Only few effects reached statistical significance and were in no case greater than 15%. Pituitary GH slightly reduced IL-5 production and stimulated IFN-gamma production. The latter effect was also observed with prolactin and could thus be induced through the prolactin receptor. It is proposed that GH has no strong effects on the parameters investigated, possibly as a result of redundancy in the cytokine network. Alternatively, effects on leukocytes are mediated by other tissues such as the liver or are clear only in response to stronger challenges. [less ▲]

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See detailLymphoid cell apoptosis induced by trophoblastic cells: a model of active foeto-placental tolerance
Coumans, Bernard ULg; Thellin, Olivier ULg; Zorzi, Willy ULg et al

in Journal of Immunological Methods (1999), 224(1-2), 185-196

To test the hypothesis that CD95-L (Fas-L) present on trophoblastic cells plays a part in establishing foeto-placental tolerance by inducing apoptosis of immune defence cells, we cocultured trophoblasts ... [more ▼]

To test the hypothesis that CD95-L (Fas-L) present on trophoblastic cells plays a part in establishing foeto-placental tolerance by inducing apoptosis of immune defence cells, we cocultured trophoblasts with lymphoid cells and scored the frequency of cell death in these cultures. We prepared human trophoblastic cells from term placentas removed by C-section and placed them in culture for 48 h before introducing the lymphoid cells. We added Jurkat cells, a CD3 + lymphoid cell line, or purified T cells from human blood to the cultured trophoblasts and monitored apoptosis by electron microscopy and flow cytometry after TUNEL or annexin V labelling. The frequency of cell death in the CD3 + cell population was higher when the lymphoid cells were cocultured with trophoblastic cells than when they were cultured alone. This frequency increased with time but was reduced when anti-CD95-L antibodies were added to the culture medium. Cell death was less frequent in the lymphoid cell population when trophoblasts were replaced with human fibroblasts not expressing CD95-L. (C) 1999 Elsevier Science B.V. All rights reserved. [less ▲]

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See detailHousekeeping Genes as Internal Standards: Use and Limits
Thellin, Olivier ULg; Zorzi, Willy ULg; Lakaye, Bernard ULg et al

in Journal of Biotechnology (1999), 75(2-3), 291-5

Quantitative studies are commonly realised in the biomedical research to compare RNA expression in different experimental or clinical conditions. These quantifications are performed through their ... [more ▼]

Quantitative studies are commonly realised in the biomedical research to compare RNA expression in different experimental or clinical conditions. These quantifications are performed through their comparison to the expression of the housekeeping gene transcripts like glyceraldehyde-3-phosphate dehydrogenase (G3PDH), albumin, actins, tubulins, cyclophilin, hypoxantine phsophoribosyltransferase (HRPT), L32. 28S, and 18S rRNAs are also used as internal standards. In this paper, it is recalled that the commonly used internal standards can quantitatively vary in response to various factors. Possible variations are illustrated using three experimental examples. Preferred types of internal standards are then proposed for each of these samples and thereafter the general procedure concerning the choice of an internal standard and the way to manage its uses are discussed. [less ▲]

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See detailExpression of Growth Hormone Receptors by Lymphocyte Subpopulations in the Human Tonsil
Thellin, Olivier ULg; Coumans, Bernard ULg; Zorzi, Willy ULg et al

in Developmental Immunology (1998), 6(3-4), 295-304

The ability of human tonsillar lymphoid cells to express growth hormone receptor (hGH-N-R) was analyzed by flow cytometry. FITC-coupled recombinant human growth hormone (hGH-N) was used to reveal the ... [more ▼]

The ability of human tonsillar lymphoid cells to express growth hormone receptor (hGH-N-R) was analyzed by flow cytometry. FITC-coupled recombinant human growth hormone (hGH-N) was used to reveal the receptors, in combination with phenotype markers. Unlike T cells, tonsillar B cells constitutively express the hGH-N receptor. Quiescent cells separated from activated cells by Percoll-gradient centrifugation bear fewer receptors than activated ones. Activated T cells express hGH-N-R, but the typical germinal centre CD4+ CD57+ T cells do not. These latter thus appear not to be fully activated. Inside the lymph follicles, the germinal centre CD38+ B-cell population and the mantle-zone CD39+ B-cell population display similar levels of hGH-N-R expression, but receptor density is lower on dividing dark-zone CD38+ CD10+ B cells. Different lymphoid-cell populations thus differ markedly in their ability to express the growth hormone receptor, in relation notably to their activation status. This highlights the link between the neuroendocrine system and the active immune defense. [less ▲]

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See detailDemonstration of the expression of CD95 ligand transcript and protein in human placenta
Zorzi, Willy ULg; Thellin, Olivier ULg; Coumans, Bernard ULg et al

in Placenta (1998), 19(4), 269-277

Tolerance of the fetal allograft enables the human conceptus to implant itself into the maternal uterus and survive and grow there. This tolerance phenomenon remains largely obscure, notably because it ... [more ▼]

Tolerance of the fetal allograft enables the human conceptus to implant itself into the maternal uterus and survive and grow there. This tolerance phenomenon remains largely obscure, notably because it appears to be controlled by multiple mechanisms. CD95 ligand (CD95-L), which can trigger death of CD95-positive cells by apoptosis, may participate in inducing anti-fetus-sensitized CD95-positive T lymphocytes to enter apoptosis. Using immunohistochemistry (first trimester and term placentae), FAGS assays (term placenta) and RT-PCR assays (term placenta), the presence of CD95-L protein and mRNA has been shown in crude placental tissue preparations and isolated placental cells. Among the latter, CD95-L expression was detected in trophoblastic cells, fetal blood cells (mRNA only) and also the Hofbauer macrophages. No CD95-L was detected in fibroblasts or fetal endothelial cells. Thus trophoblastic cells, Hofbauer macrophages, and perhaps also fetal blood cells could form a sequential barrier blocking maternal activated defence cells bearing CD95 molecules. (C) 1998 W. B. Saunders Company Ltd. [less ▲]

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