References of "Dubois, Sophie"
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See detailImmunomodulatory effects of Rapamycin in xenogeneic GVHD
Ehx, Grégory ULg; HANNON, Muriel ULg; DUBOIS, Sophie ULg et al

Poster (2014, January 27)

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See detailImpact of bone marrow-derived mesenchymal stromal cells on experimental xenogeneic graft-versus-host disease
Bruck, France; Belle, Ludovic ULg; LECHANTEUR, Chantal ULg et al

in Cytotherapy (2013), 15(3), 267-279

Background aims. Graft-versus-host disease (GVHD) is a life-threatening complication of allogeneic hematopoietic cell transplantation caused by donor T cells reacting against host tissues. Previous ... [more ▼]

Background aims. Graft-versus-host disease (GVHD) is a life-threatening complication of allogeneic hematopoietic cell transplantation caused by donor T cells reacting against host tissues. Previous studies have suggested that mesenchymal stromal cells (MSCs) could exert potent immunosuppressive effects. Methods. The ability of human bone marrow derived MSCs to prevent xenogeneic GVHD in non-obese diabetic/severe combined immunodeficient (NOD/SCID) mice and in NOD/SCID/interleukin-2Rg(null) (NSG) mice transplanted with human peripheral blood mononuclear cells (PBMCs) was assessed. Results. Injection of 200 106 human PBMCs intraperitoneally (IP) into sub-lethally (3.0 Gy) irradiated NOD/SCID mice also given anti-asialo GM1 antibodies IP 1 day prior and 8 days after transplantation induced lethal xenogeneic GVHD in all tested mice. Co-injection of 2 106 MSCs IP on day 0 did not prevent lethal xenogeneic GVHD induced by injection of human PBMCs. Similarly, injection of 30 106 human PBMCs IP into sub-lethally (2.5 Gy) irradiated NSG mice induced a lethal xenogeneic GVHD in all tested mice. Injection of 3 106 MSCs IP on days 0, 7, 14 and 21 did not prevent lethal xenogeneic GVHD induced by injection of human PBMCs. Conclusions. Injection of MSCs did not prevent xenogeneic GVHD in these two humanized mice models. [less ▲]

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See detailThe Immunomodulating Peptide Thymosin Alpha 1 Has no Effect on Multiple Myeloma Evolution and on Immune Reconstitution
Binsfeld, Marilène ULg; Otjacques, Eléonore ULg; Hannon, Muriel ULg et al

in Belgian Journal of Hematology (2013), Abstracts book(Supplement of 28th General Meeting of the Belgian Hematological Society), 41

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See detailNeutrophil Extracellular Traps (NET) Entrap and Kill Borrelia burgdorferi sensu stricto Spirochetes and Are not Affected by Ixodes ricinus Tick Saliva.
MENTEN-DEDOYART, Catherine ULg; Faccinetto, Céline; Golovchenko, Maryna et al

in Journal of Immunology (2012), 189(11), 5393-5401

Lyme disease is a pathology caused by members of the Borrelia burgdorferi sensu lato (s.l.) complex, most often by B. burgdorferi sensu stricto (s.s.). They are transmitted mainly by Ixodes ricinus ticks ... [more ▼]

Lyme disease is a pathology caused by members of the Borrelia burgdorferi sensu lato (s.l.) complex, most often by B. burgdorferi sensu stricto (s.s.). They are transmitted mainly by Ixodes ricinus ticks. After a few hours of infestation, neutrophils massively infiltrate the bite site. They can kill Borrelia via phagocytosis, oxidative burst and hydrolytic enzymes. However, factors in tick saliva promote propagation of the bacteria in the host even in the presence of a large number of neutrophils. Neutrophil extracellular trap (NET) consists in the extrusion of the neutrophil’s own DNA, forming traps that can retain and kill bacteria. The production of reactive oxygen species (ROS) is apparently associated with the onset of NEtosis. Here we describe NETs formation at the tick bite site in vivo in mice. We show that Borrelia burgdorferi s.s. spirochetes become trapped and killed by NETs in humans and that the bacteria do not seem to release significant nucleases to evade this process. Saliva from I. ricinus did not affect NET formation by human neutrophiles or it stability. However, it strongly decreased neutrophil ROS production, suggesting that a strong decrease of hydrogen peroxide does not affect NET formation. Finally, round bodies were observed trapped in NETs, some of them staining as live cells. This observation could help contribute to a better explanation of erythema migrans. [less ▲]

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See detailRapamycin Prevents Experimental Sclerodermatous Chronic Graft-versus-Host Disease in mice
Belle, Ludovic ULg; Binsfeld, Marilène ULg; DUBOIS, Sophie ULg et al

in Belgian Journal of Hematology (2012), Abstracts book(Supplement of 27th General Meeting of the Belgian Hematological Society), 14

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See detailRapamycin prevents experimental sclerodermatous chronic graft-versus-host disease in mice
Belle, Ludovic ULg; Binsfeld, Marilène ULg; DUBOIS, Sophie ULg et al

Conference (2012)

Background: The most widely used mice model of chronic graft-versus-host disease (cGvHD) is an MHC-matched bone marrow transplantation model of sclerodermatous cGvHD. A limitation of that model is that ... [more ▼]

Background: The most widely used mice model of chronic graft-versus-host disease (cGvHD) is an MHC-matched bone marrow transplantation model of sclerodermatous cGvHD. A limitation of that model is that mortality is relatively low, making difficult to study the impact of potentially therapeutic compounds. Aims: To develop a more severe model of cGVHD and to assess the impact of Rapamycin administration in that model. Results: Lethally irradiated Balb/C mice were injected with 10x106 bone marrow cells and 70x106 splenocytes from B10.D2 donor mice. Twenty-one days later, all mice developed cGvHD. For the severe model, donor B10.D2 mice were injected with 0.5x106 splenocytes from Balb/C twenty-one days before transplantation. All mice from the severe model (n=8) died a median of 32 days while 3 of 7 mice in the classical model survived beyond day 52. Mean survival was decreased in the severe model compared to the classical model (32 days versus 37 days; p=0.0185). Recipient mice in the severe group experienced higher weight loss, hair loss and skin fi brosis. Numbers of T lymphocytes (231.9 ± 151.4 versus 951 ± 532.8; p=0.0032) and CD4+ T cells (63.25 ± 41.93 versus 135.0 ± 14.39; p=0.0018) per microliter of blood at day 21 were lower in the severe group than in the classical model. Moreover, number of regulatory T cells (Tregs) was decreased in the severe model (1.250 ± 0.8864 versus 8.000 ± 6.753; p=0.0151). We then investigated whether rapamycin administration could prevent GVHD in the severe model. All (n=8) mice treated with PBS (placebo) died a median of 32 days after transplantation, while 6 of 8 mice given 1 mg/kg/day i.p. rapamycin survived beyond day 52 (p=0.0012). Number of Tregs/μl was higher at day 21 in rapamycin-treated mice than in mice given PBS (2.000±1.195 versus 1.250±0.8864; p=0.0796). Moreover, number of naïve CD4+T (10.00±4.192 versus 30.25±5.185; p= 0.0089) and effector memory T cells (EMT) (30.67±3.180 versus 67.33±7.881; p= 0.0125) were higher in rapamycin mice. Finally, proliferation of EMT (assessed by fl ow cytometry using Ki-67) was higher in PBS than in rapamycin mice (45.28%±4.084 versus 31.90%± 2.003; p=0.0474). Conclusion: We have developed a mice model of severe cGVHD. Interestingly, rapamycin prevented death from cGVHD in that model, perhaps through in vivo expansion of Treg. [less ▲]

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See detailAdaptation of a Murine Chronic GVH Model to Study Graft versus Myeloma Effect after Allogeneic Transplantation
Binsfeld, Marilène ULg; Belle, Ludovic ULg; Hannon, Muriel ULg et al

in Belgian Journal of Hematology (2012), Abstracts book(Supplement of 27th General Meeting of the Belgian Hematological Society), 16

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See detailProlonged ex vivo culture of human bone marrow mesenchymal stem cells influences their supportive activity toward NOD/SCID -repopulating cells and committed progenitor cells of B lymphoid and myeloid lineages
Briquet, Alexandra ULg; Dubois, Sophie ULg; Bekaert, Sandrine ULg et al

in Haematologica (2010), 95(1), 47-56

Background Bone marrow (BM) mesenchymal stem cells (MSC) support proliferation and differentiation of hematopoietic progenitor cells (HPC) in vitro. Since they represent a rare subset of BM cells, MSC ... [more ▼]

Background Bone marrow (BM) mesenchymal stem cells (MSC) support proliferation and differentiation of hematopoietic progenitor cells (HPC) in vitro. Since they represent a rare subset of BM cells, MSC preparations for clinical purposes involves a preparative step of ex vivo multiplication. The aim of our study was to analyze the influence of culture duration on MSC supportive activity. DESIGN AND METHODS: MSC were expanded for up to 10 passages. MSC and CD34(+) cells were seeded in cytokine-free co-cultures after which the phenotype, clonogenic capacity and in vivo repopulating activity of harvested hematopoietic cells were assessed. RESULTS: Early passage MSC supported HPC expansion and differentiation toward both B lymphoid and myeloid lineages. Late passage MSC did not support HPC and myeloid cell outgrowth but maintained B cell supportive ability. In vitro maintenance of NOD/SCID mouse repopulating cells cultured for one week in contact with MSC was effective until the fourth MSC passage and declined afterwards. CD34(+) cells achieved higher levels of engraftment in NOD/SCID mice when co-injected with early passage MSC; however MSC expanded beyond 9 passages were ineffective in promoting CD34(+) cell engraftment. Non-contact cultures indicated that MSC supportive activity involved diffusible factors. Among these, interleukin (IL)-6 and IL-8 contributed to the supportive activity of early passage MSC but not of late passage MSC. MSC phenotype as well as fat, bone and cartilage differentiation capacity did not change during MSC culture. Conclusions Extended MSC culture alters their supportive ability toward HPC without concomitant changes in phenotype and differentiation capacity. [less ▲]

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