References of "Drion, Pierre"
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See detailStudy of thromboxane modulators in a murine model of atherosclerosis
Cherdon, Céline ULg; Rolin, Stéphanie; de Leval, Laurence ULg et al

(2008, July 04)

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See detailLung interstitial macrophages prevent lipopolysaccharide-triggered T helper type 2 responses to harmless inhaled antigens
Bedoret, D.; Wallemacq, Hugues ULg; Marichal, Thomas ULg et al

in Proceedings of the Annual BIS-meeting (2008)

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See detailCloning of the koi herpesvirus genome as an infectious bacterial artificial chromosome demonstrates that disruption of the thymidine kinase locus induces partial attenuation in Cyprinus carpio koi.
Costes, Bérénice ULg; Fournier, Guillaume ULg; Michel, Benjamin ULg et al

in Journal of Virology (2008), 82(10), 4955-4964

Koi herpesvirus (KHV) is the causative agent of a lethal disease in koi and common carp. In the present study, we describe the cloning of the KHV genome as a stable and infectious bacterial artificial ... [more ▼]

Koi herpesvirus (KHV) is the causative agent of a lethal disease in koi and common carp. In the present study, we describe the cloning of the KHV genome as a stable and infectious bacterial artificial chromosome (BAC) clone that can be used to produce KHV recombinant strains. This goal was achieved by the insertion of a loxP-flanked BAC cassette into the thymidine kinase (TK) locus. This insertion led to a BAC plasmid that was stably maintained in bacteria and was able to regenerate virions when permissive cells were transfected with the plasmid. Reconstituted virions free of the BAC cassette but carrying a disrupted TK locus (the FL BAC-excised strain) were produced by the transfection of Cre recombinase-expressing cells with the BAC. Similarly, virions with a wild-type revertant TK sequence (the FL BAC revertant strain) were produced by the cotransfection of cells with the BAC and a DNA fragment encoding the wild-type TK sequence. Reconstituted recombinant viruses were compared to the wild-type parental virus in vitro and in vivo. The FL BAC revertant strain and the FL BAC-excised strain replicated comparably to the parental FL strain. The FL BAC revertant strain induced KHV infection in koi carp that was indistinguishable from that induced by the parental strain, while the FL BAC-excised strain exhibited a partially attenuated phenotype. Finally, the usefulness of the KHV BAC for recombination studies was demonstrated by the production of an ORF16-deleted strain by using prokaryotic recombination technology. The availability of the KHV BAC is an important advance that will allow the study of viral genes involved in KHV pathogenesis, as well as the production of attenuated recombinant candidate vaccines. [less ▲]

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See detailMalignant catarrhal fever induced by alcelaphine herpesvirus 1 is associated with proliferation of CD8+ T cells supporting a latent infection.
Dewals, Benjamin G ULg; Boudry, Christel ULg; Farnir, Frédéric ULg et al

in PLoS ONE (2008), 3(2), 1627

Alcelaphine herpesvirus 1 (AlHV-1), carried by wildebeest asymptomatically, causes malignant catarrhal fever (WD-MCF) when cross-species transmitted to a variety of susceptible species of the Artiodactyla ... [more ▼]

Alcelaphine herpesvirus 1 (AlHV-1), carried by wildebeest asymptomatically, causes malignant catarrhal fever (WD-MCF) when cross-species transmitted to a variety of susceptible species of the Artiodactyla order. Experimentally, WD-MCF can be induced in rabbits. The lesions observed are very similar to those described in natural host species. Here, we used the rabbit model and in vivo 5-Bromo-29-Deoxyuridine (BrdU) incorporation to study WD-MCF pathogenesis. The results obtained can be summarized as follows. (i) AlHV-1 infection induces CD8+ T cell proliferation detectable as early as 15 days postinoculation. (ii) While the viral load in peripheral blood mononuclear cells remains below the detection level during most of the incubation period, it increases drastically few days before death. At that time, at least 10% of CD8+ cells carry the viral genome; while CD11b+, IgM+ and CD4+ cells do not. (iii) RT-PCR analyses of mononuclear cells isolated from the spleen and the popliteal lymph node of infected rabbits revealed no expression of ORF25 and ORF9, low or no expression of ORF50, and high or no expression of ORF73. Based on these data, we propose a new model for the pathogenesis of WD-MCF. This model relies on proliferation of infected CD8+ cells supporting a predominantly latent infection. [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 detailIn vivo administration of a PKA type I inhibitor (Rp-8-Br-cAMPS) restores T-cell responses in retrovirus-infected mice
Nayjib, Btissam ULg; Zeddou, Mustapha ULg; Drion, Pierre ULg et al

in Open Immunol journal (2008), 1

Murine AIDS (MAIDS) is caused by infection with the murine leukemia retrovirus RadLV-Rs and is characterized by T-cell anergy and severe immunodeficiency with increased susceptibilty to several ... [more ▼]

Murine AIDS (MAIDS) is caused by infection with the murine leukemia retrovirus RadLV-Rs and is characterized by T-cell anergy and severe immunodeficiency with increased susceptibilty to several experimental opportunistic infections as observed in HIV infection. T cell anergy is associated with an increase of intracellular cAMP level, triggering a multistep pathway involving activation of PKA type I and resulting in inhibition of proximal TCR signaling. We have reviously demonstrated that blocking PKA type I using the selective inhibitor Rp-8-Br-cAMPS, restores T-cell function in vitro in MAIDS as well as in HIV infection. In the present report, we investigated the effect of parenteral administration of Rp-8-Br-cAMPS in mice with MAIDS. We show that the compound is not toxic and partially restores the ex vivo proliferative responses to anti-CD3 mAb, but that it has no effect on the lymphadenopathy and splenomegaly characterizing the MAIDS syndrome. [less ▲]

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See detailEvolution of anti-eCG antibodies in response to eCG doses and number of injections. Relation with rabbit does productivity
Theau-Clément, M.; Lebas, F.; Beckers, J. F. et al

in Animal (2008), 2(5), 746-751

The aim of this experiment was to study the kinetics of anti-eCG (equine chorionic gonadotrophin) antibodies in relation to eCG dose (8 or 25 IU) and number of injections (n = 11) in comparison with a ... [more ▼]

The aim of this experiment was to study the kinetics of anti-eCG (equine chorionic gonadotrophin) antibodies in relation to eCG dose (8 or 25 IU) and number of injections (n = 11) in comparison with a control group (no injection), and to relate antibody production to sexual receptivity and productivity of rabbit does. In all, 124 lactating primiparous rabbit does were inseminated every 35 days for a year. Just before eCG injection (48 h before insemination), blood samples were collected from all the does to assay anti-eCG antibodies. The anti-eCG antibody binding rate, regardless of the injected dose, shows that none of the does developed detectable anti-eCG antibodies before the 7th injection. The level of detectable anti-eCG antibodies began to show an increase at the 7th injection and was significant only for the 25 IU dose at the 11th injection. At the end of the experiment, 15% and 39% of does treated with 8 and 25 IU, respectively, developed immunity to eCG (binding rate >6%: higher binding rate of the control group). Consequently, the immune response depends on the eCG dose and on the number of injections. Moreover, productivity of does estimated from the number of weaned rabbits produced per insemination is not influenced by the level of eCG antibodies (7.0 and 6.9 for binding rate <6% and binding rate 6%, respectively). Only 19 inseminations (n = 6 and n = 13 for 8 and 25 IU, respectively) were made on hyperimmune does. Consequently, the immune response to eCG seems to be marginal for rabbit does. Moreover, under the described experimental conditions, reproductive performances of hyperimmune does were not affected [less ▲]

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See detailRépertoire commenté des Médicaments à Usage vétérinaire
Drion, Pierre ULg

in Livre Substances hormonales. Partim Hormones. Médicaments du système hormonal – hormones sexuelles et autres médicaments du système reproducteur (2008)

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See detailBm-573, an original thromboxane receptor antagonist, reduces development of atherosclerosis in apoe–deficient (apo e-/-) mice
Cherdon, Céline ULg; Rolin, Stéphanie; Hanson, Julien ULg et al

Poster (2007, October 11)

To test the efficacy of BM-573 in atherogenesis, the effect of 10 weeks of treatment with BM573 (10 mg/l) on early aortic atherosclerotic lesions of apo E deficient mice was assessed. These mice were fed ... [more ▼]

To test the efficacy of BM-573 in atherogenesis, the effect of 10 weeks of treatment with BM573 (10 mg/l) on early aortic atherosclerotic lesions of apo E deficient mice was assessed. These mice were fed with chow diet, with spontaneous increase of total plasma cholesterol and triglycerides. In this experiment, while BM-573 did not affect body weight, it significantly decreases early atherogenesis lesions confirmed by macroscopic, microscopic and biochemical analysis. These results confirm that selective antagonism of TP receptor is effective in reducing atherosclerotic lesion in apo E deficient mice. Consequently, BM-573 could be a potential drug for prevention of atherosclerosis [less ▲]

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See detailBm-573, a thromboxane receptor antagonist, reduces development of atherosclerosis in apoe–deficient mice
Cherdon, Céline ULg; Rolin, Stéphanie; Hanson, Julien ULg et al

Poster (2007, June 22)

Atherosclerotic cardiovascular disease, according to World Health Organization, is the primary cause of heart disease and stroke. Atherosclerosis is a chronic vascular disease whose development is ... [more ▼]

Atherosclerotic cardiovascular disease, according to World Health Organization, is the primary cause of heart disease and stroke. Atherosclerosis is a chronic vascular disease whose development is influenced by several mediators. Among them, the action of eicosanoïds such as thromboxane A2 and 8-iso-PGF2a have recently received a lot of attention. The aim of our study was the evaluation of benefits of original molecules, synthesised in our lab, targeting the thromboxane receptor (TP) in an apo E deficient mouse. We previously demonstrated in several in vitro and in vivo pharmacological experiments that our original sulfonylurea derivate, BM-573 was a potent combined inhibitor of the thromboxane synthase and antagonist of TP. Since TP is implied in atherosclerosis development, such antagonist could have a great therapeutic impact in atherogenesis.To test the efficacy of BM-573 in atherogenesis, the effect of 10 weeks of treatment with BM573 (10 mg/kg) on early aortic atherosclerotic lesions of apo E deficient mice was assessed. These mice were fed with chow diet, with spontaneous increase of total plasma cholesterol and triglycerides. In this experiment, while BM-573 did not affect body weight, it significantly decreased early atherogenesis lesions confirmed by macroscopic, microscopic and biochemical analysis. These results confirm that selective antagonism of TP receptor is effective in reducing atherosclerotic lesion in apo E deficient mice. Consequently, BM-573 could be a potential drug for prevention of atherosclerosis. [less ▲]

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See detailLe bm-573, un antagoniste original de récepteur au thromboxane a2, réduit le développement des lesions atheromateuses chez des souris deficientes en apolipoproteine e (apo e-/-)
Cherdon, Céline ULg; Rolin, Stéphanie; Hanson, Julien ULg et al

Poster (2007, May 10)

Afin d’examiner l'efficacité du BM-573 dans l'athérogenèse, des souris apo E-/- ont été traitées durant 10 semaines avec le BM573 (10mg/kg). Au cours de cette expérience, le traitement des animaux par le ... [more ▼]

Afin d’examiner l'efficacité du BM-573 dans l'athérogenèse, des souris apo E-/- ont été traitées durant 10 semaines avec le BM573 (10mg/kg). Au cours de cette expérience, le traitement des animaux par le BM-573, a eu pour effet de diminuer les lésions athéromateuses précoces de manière significative. Ces données ont été confirmées par des analyses histopathologiques et biochimiques. Ces résultats confirment que l'antagonisme sélectif des récepteurs TP associé à une inhibition de la thromboxane synthase réduit significativement les lésions athéromateuses chez les souris apoE-/-.. Le BM-573 est, par conséquent, un agent thérapeutique potentiel pour la prévention de l'athérosclérose [less ▲]

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See detailThe A5 gene of alcelaphine herpesvirus 1 encodes a constitutively active G-protei n-coupled receptor that is non-essential for the induction of malignant catarrhal fever in rabbits
Boudry, Christel ULg; Markine-Goriaynoff, Nicolas ULg; Delforge, Cédric ULg et al

in Journal of General Virology (2007), 88(Pt 12), 3224-3233

Many gammaherpesviruses encode G-protein-coupled receptors (GPCRs). Several in vivo studies have revealed that gammaherpesvirus GPCRs are important for viral replication and for virus-induced pathogenesis ... [more ▼]

Many gammaherpesviruses encode G-protein-coupled receptors (GPCRs). Several in vivo studies have revealed that gammaherpesvirus GPCRs are important for viral replication and for virus-induced pathogenesis. The gammaherpesvirus alcelaphine herpesvirus 1 (AlHV-1) is carried asymptomatically by wildebeest, but causes malignant catarrhal fever (MCF) following cross-species transmission to a variety of susceptible species. The A5 ORF of the AlHV-1 genome encodes a putative GPCR. In the present study, we investigated whether A5 encodes a functional GPCR and addressed its role in viral replication and in the pathogenesis of MCF. In silico analysis supported the hypothesis that A5 could encode a functional GPCR as its expression product contained several hallmark features of GPCRs. Expression of A5 as tagged proteins in various cell lines revealed that A5 localizes in cell membranes, including the plasma membrane. Using [35S]GTPgammaS and reporter gene assays, we found that A5 is able to constitutively couple to alpha i-type G-proteins in transfected cells, and that this interaction is able to inhibit forskolin-triggered cAMP response element-binding protein (CREB) activation. Finally, using an AlHV-1 BAC clone, we produced a strain deleted for A5 and a revertant strain. Interestingly, the strain deleted for A5 replicated comparably to the wild-type parental strain and induced MCF in rabbits that was indistinguishable from that of the parental strain. The present study is the first to investigate the role of an individual gene of AlHV-1 in MCF pathogenesis. [less ▲]

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See detailA thromboxane receptor antagonist, reduces development of atherosclerosis in apoE-deficient mice.
Cherdon, Céline ULg; Rolin, S.; Hanson, S. et al

in Journal of Molecular and Cellular Cardiology (2007), 42

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See detailBM-573, a thromboxane receptor antagonist, reduces development of atherosclerosis in apoE–deficient mice
Cherdon, Céline ULg; Rolin, Stéphanie; Hanson, Julien ULg et al

in Journal of Molecular and Cellular Cardiology (2007), 42(suppl 1.), 33-34

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See detailNatural antibody--complement dependent neutralization of bovine herpesvirus 4 by human serum
Machiels, Bénédicte ULg; Gillet, Laurent ULg; Brito, Sieberth Do Nascimento et al

in Microbes & Infection (2007), 9(14-15), 1530-1537

In contrast to most gammaherpesviruses, Bovine herpesvirus 4 (BoHV-4) has a broad range of host species both in vitro and in vivo. Several in vitro studies demonstrated that some human cell lines are ... [more ▼]

In contrast to most gammaherpesviruses, Bovine herpesvirus 4 (BoHV-4) has a broad range of host species both in vitro and in vivo. Several in vitro studies demonstrated that some human cell lines are sensitive or even permissive to BoHV-4. These observations led to the hypothesis that cross-species transmission of BoHV-4 could lead to human infections. In the present study, we investigate the sensitivity of BoHV-4 to neutralization by naïve human sera in order to determine if humans exhibit innate anti-viral activities against this virus. Our results demonstrate that human sera from naïve individuals, in contrast to the sera of naïve subjects from various animal species, neutralize BoHV-4 efficiently. A series of complementary experiments were performed to unravel the mechanism(s) of this neutralization. The data obtained in this study demonstrates that human serum neutralizes BoHV-4 in a complement dependent manner activated by natural antibodies raised against the Galalpha1-3Galbeta1-4GlcNAc-R epitope expressed by bovine cells [less ▲]

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See detailEstablishment and characterisation of two novel human KSHV- and EBV-negative Burkitt cell lines, GAL-01 and GAL-02, from a primary lymphomatous effusion
Thielen, Caroline ULg; Herens, Christian ULg; Fassotte, Marie-France ULg et al

in European Journal of Haematology (2006), 77(4), 318-326

Objectives: Burkitt's lymphoma (BL) is a highly aggressive mature B-cell neoplasm comprising endemic, sporadic and immunodeficiency-associated variants. Human cell lines constitute a very useful tool to ... [more ▼]

Objectives: Burkitt's lymphoma (BL) is a highly aggressive mature B-cell neoplasm comprising endemic, sporadic and immunodeficiency-associated variants. Human cell lines constitute a very useful tool to investigate the biology of lymphoid neoplasia. In this study, we succeeded in establishing two human cell lines, GAL-01 and GAL-02, from a HIV-negative patient with Epstein-Barr virus (EBV) -negative sporadic BL presenting as an effusion. GAL-01 and GAL-02 were established at diagnosis and after one course of polychemotherapy, respectively. The in vivo effusion occurred in a very peculiar clinical setting; the patient having a previous history of intestinal diffuse large B-cell lymphoma. Methods: The morphologic, immunophenotypic and molecular genetic features of GAL cell lines are reported and compared with those of the parental tumour. The findings clearly demonstrated that the Burkitt effusion did not represent disease progression of the intestinal tumour, but represented a second primary haematological malignancy. The in vivo tumorigenic properties of the cells were tested by subcutaneous injection to NOD/SCID mice. Results: Both cell lines were composed of medium-sized lymphoid cells with clumped chromatin, multiple medium-sized nucleoli and moderate amounts of vacuolated cytoplasm. GAL cells display the phenotype and genotype of a B-cell lineage (positive for CD20, CD79a and clonal rearrangement of Ig heavy chain), carry the c-MYC rearrangement by t(8;22)(q24;q11) translocation and are characterised by the expression of the germinal centre-associated antigens CD10, BCL6, CD38 and absent to low BCL2 expression. EBV and HHV8 were not identified within parental tumour or in cultured cells. Subcutaneous injection of both cell lines to NOD/SCID mice induced tumour formation. Conclusions: GAL-01 and GAL-02, two novel EBV-negative human BL cell lines represent a potentially useful experimental model to study the biology of BL possibly including the resistance to chemotherapy. [less ▲]

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See detailThe use of an apoE–deficient (apoE-/-) mice model to characterize the therapeutic benefits of original thromboxane modulators
Cherdon, Céline ULg; Rolin, stephanie; Hanson, Julien ULg et al

Poster (2006, May 17)

The aim of our study was to use an apoE–deficient mouse model to test drugs acting as thromboxane A2 antagonist. Presented here is the “en face” method 6 which allows the evaluation of atherosclerosis ... [more ▼]

The aim of our study was to use an apoE–deficient mouse model to test drugs acting as thromboxane A2 antagonist. Presented here is the “en face” method 6 which allows the evaluation of atherosclerosis lesions development in wild type and APO E-/- mice. This method involves pinning out the aorta and quantifying lesion area as a percentage of total surface area. The use of this mice model offers a unique opportunity to characterize the therapeutic benefits of pharmacologicals agents designed in our laboratory of which antioxidants and thromboxane modulators. The pharmacological characterization of BM-573 as potential antiatherosclerotic agent will also be discussed [less ▲]

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