References of "Fievez, Laurence"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailThe Roles of Spinochromes in Four Shallow Water Tropical Sea Urchins and Their Potential as Bioactive Pharmacological Agents.
Brasseur, Lola; Hennebert, Elise; Fievez, Laurence ULg et al

in Marine Drugs (2017), 15(6),

Spinochromes are principally known to be involved in sea urchin pigmentation as well as for their potentially interesting pharmacological properties. To assess their biological role in sea urchin ... [more ▼]

Spinochromes are principally known to be involved in sea urchin pigmentation as well as for their potentially interesting pharmacological properties. To assess their biological role in sea urchin physiology, experiments are undertaken on crude extracts from four species and on four isolated spinochromes in order to test their antibacterial, antioxidant, inflammatory and cytotoxic activities. First, the antibacterial assays show that the use of crude extracts as representatives of antibacterial effects of spinochromes are inaccurate. The assays on purified spinochromes showed a decrease in the growth of four strains with an intensity depending on the spinochromes/bacteria system, revealing the participation of spinochromes in the defense system against microorganisms. Secondly, in the 2,2-diphenyl-1-picrylhydrazyl antioxidant assays, spinochromes show an enhanced activity compared to the positive control. This latter observation suggests their involvement in ultraviolet radiation protection. Third, spinochromes present a pro-inflammatory effect on lipopolysaccharide-stimulated macrophages, highlighting their possible implication in the sea urchin immune system. Finally, cytotoxicity assays based on Trypan blue exclusion, performed in view of their possible future applications as drugs, show a weak cytotoxicity of these compounds against human cells. In conclusion, all results confirm the implication of spinochromes in sea urchin defense mechanisms against their external environment and reveal their potential for pharmacological and agronomical industries. [less ▲]

Detailed reference viewed: 22 (2 ULg)
Full Text
Peer Reviewed
See detailExposure to Bacterial CpG DNA Protects from Airway Allergic Inflammation by Expanding Regulatory Lung Interstitial Macrophages.
Sabatel, Catherine ULg; Radermecker, Coraline ULg; Fievez, Laurence ULg et al

in Immunity (2017), 46(3), 457-473

Living in a microbe-rich environment reduces the risk of developing asthma. Exposure of humans or mice to unmethylated CpG DNA (CpG) from bacteria reproduces these protective effects, suggesting a major ... [more ▼]

Living in a microbe-rich environment reduces the risk of developing asthma. Exposure of humans or mice to unmethylated CpG DNA (CpG) from bacteria reproduces these protective effects, suggesting a major contribution of CpG to microbe-induced asthma resistance. However, how CpG confers protection remains elusive. We found that exposure to CpG expanded regulatory lung interstitial macrophages (IMs) from monocytes infiltrating the lung or mobilized from the spleen. Trafficking of IM precursors to the lung was independent of CCR2, a chemokine receptor required for monocyte mobilization from the bone marrow. Using a mouse model of allergic airway inflammation, we found that adoptive transfer of IMs isolated from CpG-treated mice recapitulated the protective effects of CpG when administered before allergen sensitization or challenge. IM-mediated protection was dependent on IL-10, given that Il10-/- CpG-induced IMs lacked regulatory effects. Thus, the expansion of regulatory lung IMs upon exposure to CpG might underlie the reduced risk of asthma development associated with a microbe-rich environment. [less ▲]

Detailed reference viewed: 66 (11 ULg)
Full Text
Peer Reviewed
See detailAre Th17 Cells Playing a Role in Immunity to Dermatophytosis?
Heinen, Marie-Pierre ULg; Cambier, Ludivine ULg; Fievez, Laurence ULg et al

in Mycopathologia (2017), 182(1), 251-261

Detailed reference viewed: 20 (1 ULg)
Full Text
Peer Reviewed
See detailCpG-DNA expand immunosuppressive interstitial macrophages from Ly6c+ local precursors
Sabatel, Catherine ULg; Radermecker, Coraline ULg; Fievez, Laurence ULg et al

in Proceeding of Cell Symposia: 100 years of phagocytes (2016, September)

Detailed reference viewed: 27 (6 ULg)
Full Text
See detailEffect of a CpG-ODN on the innate immune system of the horse: an in-vivo trial
Tosi, Irène ULg; Pirottin, Dimitri ULg; Fievez, Laurence ULg et al

Poster (2015, October 16)

Oligodeoxynucleotides containing cytosine-phosphate-guanosine motifs (CpG-ODN) represent a class of agonists of Toll-like Receptor 9 (TLR9). TLR9 activation induces the secretion of cytokines and the ... [more ▼]

Oligodeoxynucleotides containing cytosine-phosphate-guanosine motifs (CpG-ODN) represent a class of agonists of Toll-like Receptor 9 (TLR9). TLR9 activation induces the secretion of cytokines and the maturation of immune cells, thus initiating both innate and adaptive immune responses. Therefore, CpG-ODN has been investigated in different species as a potential immune-modulator targeting infectious, allergic and neoplastic diseases. It has been administered by nebulisation to RAO-affected horses with promising results. Nonetheless, there is no in-vivo study on the effect of CpG administered systemically to the horse. Therefore, we tested the effect of CpG, given by intramuscular injection, on the equine immune response. Eight horses were used for this study. Five mg/horse were injected to 4 horses at D0 and D7; the other horses received a placebo (PBS). Blood was collected 2 days prior to each injection, then regularly up to D21. A clinical exam was realised daily. Laboratory analyses included haematology, ELISA tests for IFN-alpha, IFN-gamma, TNF-alpha and IL-10 and cytometry analyses for MCHII and CD86 expressions on B-lymphocytes. A cross-over of the 2 groups was realised after 2 months of washout. CpG was well tolerated. Significant transient eosinopenia, monocytosis and leukopenia were observed after CpG injection, while ELISA and cytometry analyses did not reveal any significant modification. This trial represents the first in-vivo study where CpG is administered systemically to healthy horses. Further studies are needed to adjust the dose, the formulation and the sampling schedule and to fully investigate this molecule as potentiel modulator of the equine immune system. [less ▲]

Detailed reference viewed: 35 (7 ULg)
Full Text
Peer Reviewed
See detailGeneration of a soluble recombinant trimeric form of bovine CD40L and its potential use as a vaccine adjuvant in cows
Pujol, Julien ULg; Bouillenne, Fabrice ULg; Farnir, Frédéric ULg et al

in Veterinary immunology and immunopathology (2015), 168(1), 1-13

Detailed reference viewed: 21 (7 ULg)
Full Text
Peer Reviewed
See detailAntigen presenting cell-derived IL-6 restricts Th2-cell differentiation.
Mayer, Alice; Debuisson, Delphine; Denanglaire, Sebastien et al

in European Journal of Immunology (2014), 44(11), 3252-62

The identification of DC-derived signals orchestrating activation of Th1 and Th17 immune responses has advanced our understanding on how these inflammatory responses develop. However, whether specific ... [more ▼]

The identification of DC-derived signals orchestrating activation of Th1 and Th17 immune responses has advanced our understanding on how these inflammatory responses develop. However, whether specific signals delivered by DCs also participate in the regulation of Th2 immune responses remains largely unknown. In this study, we show that administration of antigen-loaded, IL-6-deficient DCs to naive mice induced an exacerbated Th2 response, characterized by the differentiation of GATA-3-expressing T lymphocytes secreting high levels of IL-4, IL-5, and IL-13. Coinjection of wild type and IL-6-deficient bone marrow-derived dendritic cells (BMDCs) confirmed that IL-6 exerted a dominant, negative influence on Th2-cell development. This finding was confirmed in vitro, where exogenously added IL-6 was found to limit IL-4-induced Th2-cell differentiation. iNKT cells were required for optimal Th2-cell differentiation in vivo although their activation occurred independently of IL-6 secretion by the BMDCs. Collectively, these observations identify IL-6 secretion as a major, unsuspected, mechanism whereby DCs control the magnitude of Th2 immunity. [less ▲]

Detailed reference viewed: 11 (1 ULg)
Full Text
Peer Reviewed
See detailCytokine and transcription factor expression by Aspergillus fumigatus-stimulated peripheral blood mononuclear cells in dogs with sino-nasal aspergillosis
Vanherberghen, Morgane; Bureau, Fabrice ULg; Peters, I.R. et al

in Veterinary Immunology and Immunopathology (2013), 154(3-4), 111-20

Detailed reference viewed: 30 (9 ULg)
Peer Reviewed
See detailMyeloid Hif1alpha counteracts allergic airway sensitization in mice through macrophage-mediated immunoregulation
Toussaint, Marie ULg; Fievez, Laurence ULg; Drion, Pierre ULg et al

in Abstract book of Keystone Symposium "Myeloid Cells: Regulation and Inflammation" (2013)

Hypoxia Inducible Factor (HIF) has important roles in promoting pro-inflammatory and bactericidal functions in myeloid cells. Conditional genetic ablation of its major subunit Hif1alpha in the myeloid ... [more ▼]

Hypoxia Inducible Factor (HIF) has important roles in promoting pro-inflammatory and bactericidal functions in myeloid cells. Conditional genetic ablation of its major subunit Hif1alpha in the myeloid lineage consequently results in decreased inflammatory responses in classical models of acute inflammation in mice. In contrast, we observed that mice conditionally deficient for Hif1alpha in myeloid cells display enhanced sensitivity to the development of airway allergy to the experimental allergen ovalbumin as well as to house dust mite antigens. Following allergen exposure, these mice indeed developed enhanced allergen-specific T cell responses due to augmented activation of lung dendritic cells. Further analyses supported the idea that upon allergen exposure, MyD88-dependent upregulation of Hif1alpha boosts the expression of the immunosuppressive cytokine Interleukin (IL)-10 by lung interstitial macrophages. Interstitial macrophage-derived IL-10 in turn counteracts allergen-induced lung dendritic cell activation, consequently preventing the development of allergen-specific T cell responses. Thus, this study supports that, in addition to its known pro-inflammatory activities, myeloid Hif1alpha possesses immunoregulatory functions implicated in the prevention of airway allergy. [less ▲]

Detailed reference viewed: 42 (10 ULg)
Full Text
Peer Reviewed
See detailMyeloid hypoxia-inducible factor 1alpha prevents airway allergy in mice through macrophage-mediated immunoregulation
Toussaint, Marie ULg; Fievez, Laurence ULg; Drion, Pierre ULg et al

in Mucosal Immunology (2013), 6(3), 485-97

Hypoxia-inducible factor (HIF) has important roles in promoting pro-inflammatory and bactericidal functions in myeloid cells. Conditional genetic ablation of its major subunit Hif1alpha in the myeloid ... [more ▼]

Hypoxia-inducible factor (HIF) has important roles in promoting pro-inflammatory and bactericidal functions in myeloid cells. Conditional genetic ablation of its major subunit Hif1alpha in the myeloid lineage consequently results in decreased inflammatory responses in classical models of acute inflammation in mice. By contrast, we report here that mice conditionally deficient for Hif1alpha in myeloid cells display enhanced sensitivity to the development of airway allergy to experimental allergens and house-dust mite antigens. We support that upon allergen exposure, MyD88-dependent upregulation of Hif1alpha boosts the expression of the immunosuppressive cytokine interleukin (IL)-10 by lung interstitial macrophages (IMs). Hif1alpha-dependent IL-10 secretion is required for IMs to block allergen-induced dendritic cell activation and consequently for preventing the development of allergen-specific T-helper cell responses upon allergen exposure. Thus, this study supports that, in addition to its known pro-inflammatory activities, myeloid Hif1alpha possesses immunoregulatory functions implicated in the prevention of airway allergy. [less ▲]

Detailed reference viewed: 45 (20 ULg)
Full Text
Peer Reviewed
See detailSirtuin inhibition attenuates the production of inflammatory cytokines in lipopolysaccharide-stimulated macrophages.
Fernandes, Claudia A.; Fievez, Laurence ULg; Neyrinck, Audrey M. et al

in Biochemical and Biophysical Research Communications (2012), 420(4), 857-861

In several inflammatory conditions such as rheumatoid arthritis or sepsis, the regulatory mechanisms of inflammation are inefficient and the excessive inflammatory response leads to damage to the host ... [more ▼]

In several inflammatory conditions such as rheumatoid arthritis or sepsis, the regulatory mechanisms of inflammation are inefficient and the excessive inflammatory response leads to damage to the host. Sirtuins are class III histone deacetylases that modulate the activity of several transcription factors that are implicated in immune responses. In this study, we evaluated the impact of sirtuin inhibition on the activation of lipopolysaccharide (LPS)-stimulated J774 macrophages by assessing the production of inflammatory cytokines. The pharmacologic inhibition of sirtuins decreased the production of tumour necrosis factor-alpha (TNF-alpha) interleukin 6 (IL-6) and Rantes. The reduction of cytokine production was associated with decreased nuclear factor kappa B (NF-kappaB) activity and inhibitor kappa B alpha (IkappaBalpha) phosphorylation while no impact was observed on the phosphorylation status of p38 mitogen-activated kinase (p38 MAPK). This work shows that sirtuin pharmacologic inhibitors are a promising tool for the treatment of inflammatory conditions. [less ▲]

Detailed reference viewed: 117 (1 ULg)
Full Text
Peer Reviewed
See detailIncreased hypoxia-inducible factor 1alpha expression in lung cells of horses with recurrent airway obstruction.
Toussaint, Marie ULg; Fievez, Laurence ULg; Desmet, Christophe ULg et al

in BMC Veterinary Research (2012), 8(1), 64

ABSTRACT: BACKGROUND: Recurrent airway obstruction (RAO, also known as equine heaves) is an inflammatory condition caused by exposure of susceptible horses to organic dusts in hay. The immunological ... [more ▼]

ABSTRACT: BACKGROUND: Recurrent airway obstruction (RAO, also known as equine heaves) is an inflammatory condition caused by exposure of susceptible horses to organic dusts in hay. The immunological processes responsible for the development and the persistence of airway inflammation are still largely unknown. Hypoxia-inducible factor (Hif) is mainly known as a major regulator of energy homeostasis and cellular adaptation to hypoxia. More recently however, Hif also emerged as an essential regulator of innate immune responses. Here, we aimed at investigating the potential involvement of Hif1-alpha in myeloid cells in horse with recurrent airway obstruction. RESULTS: In vitro, we observed that Hif is expressed in equine myeloid cells after hay dust stimulation and regulates genes such as tumor necrosis factor alpha (TNF-alpha), interleukin-8 (IL-8) and vascular endothelial growth factor A (VEGF-A). We further showed in vivo that airway challenge with hay dust upregulated Hif1-alpha mRNA expression in myeloid cells from the bronchoalveolar lavage fluid (BALF) of healthy and RAO-affected horses, with a more pronounced effect in cells from RAO-affected horses. Finally, Hif1-alpha mRNA expression in BALF cells from challenged horses correlated positively with lung dysfunction. CONCLUSION: Taken together, our results suggest an important role for Hif1-alpha in myeloid cells during hay dust-induced inflammation in horses with RAO. We therefore propose that future research aiming at functional inactivation of Hif1 in lung myeloid cells could open new therapeutic perspectives for RAO. [less ▲]

Detailed reference viewed: 37 (1 ULg)
Full Text
Peer Reviewed
See detailMyeloid HIF-1alpha prevents airway allergy in mice by promoting macrophage-mediated immunosuppression
Toussaint, Marie ULg; Fievez, Laurence ULg; Lekeux, Pierre ULg et al

in Proceedings of the 1st Scientific Meeting of the Faculty of Veterinary Medicine (2011, December 09)

Detailed reference viewed: 25 (9 ULg)
Full Text
Peer Reviewed
See detailSirtuin 1 Promotes Th2 Responses and Airway Allergy by Repressing Peroxisome Proliferator-Activated Receptor-γ Activity in Dendritic Cells
Legutko, Agnieszka; Marichal, Thomas ULg; Fievez, Laurence ULg et al

in Journal of Immunology (2011), 187(9), 4517-4529

Sirtuins are a unique class of NAD+-dependent deacetylases that regulate diverse biological functions such as aging, metabolism, and stress resistance. Recently, it has been shown that sirtuins may have ... [more ▼]

Sirtuins are a unique class of NAD+-dependent deacetylases that regulate diverse biological functions such as aging, metabolism, and stress resistance. Recently, it has been shown that sirtuins may have anti-inflammatory activities by inhibiting proinflammatory transcription factors such as NF-κB. In contrast, we report in this study that pharmacological inhibition of sirtuins dampens adaptive Th2 responses and subsequent allergic inflammation by interfering with lung dendritic cell (DC) function in a mouse model of airway allergy. Using genetic engineering, we demonstrate that sirtuin 1 represses the activity of the nuclear receptor peroxisome proliferator-activated receptor-γ in DCs, thereby favoring their maturation toward a pro-Th2 phenotype. This study reveals a previously unappreciated function of sirtuin 1 in the regulation of DC function and Th2 responses, thus shedding new light on our current knowledge on the regulation of inflammatory processes by sirtuins. [less ▲]

Detailed reference viewed: 54 (21 ULg)
Full Text
Peer Reviewed
See detailNicotinamide enhances apoptosis of G(M)-CSF-treated neutrophils and attenuates endotoxin-induced airway inflammation in mice.
Fernandes, Claudia A.; Fievez, Laurence ULg; Ucakar, Bernard et al

in American journal of physiology. Lung cellular and molecular physiology (2011), 300(3), 354-61

Neutrophils constitute the first line of host defense against invading microorganisms. Yet their removal from the inflammatory environment is fundamental for injury restraint and resolution of ... [more ▼]

Neutrophils constitute the first line of host defense against invading microorganisms. Yet their removal from the inflammatory environment is fundamental for injury restraint and resolution of inflammation. Nicotinamide, a component of vitamin B(3), is known to modulate cell survival. In this study, we assessed the influence of nicotinamide on neutrophil apoptosis, both in vitro and in vivo in a mouse model of endotoxin-induced lung inflammation. In vitro, nicotinamide promoted apoptosis of human blood neutrophils in a dose-dependent manner in the presence of the apoptosis inhibitors granulocyte colony-stimulating factor and granulocyte/macrophage colony-stimulating factor. The highest concentration of nicotinamide completely neutralized the pro-survival effect of granulocyte (macrophage) colony-stimulating factor. Nicotinamide proapoptotic effect was associated with enhanced caspase-3 activity. In addition, nicotinamide slightly reduced neutrophil chemotaxis in vitro. In vivo, pulmonary nicotinamide delivery decreased the levels of cellular and biochemical inflammation markers and increased the percentage of apoptotic neutrophils in bronchoalveolar lavages. Our findings suggest that nicotinamide is an apoptotic stimulus for neutrophils, thereby contributing to the resolution of neutrophilic inflammation in the lungs. [less ▲]

Detailed reference viewed: 42 (2 ULg)
Full Text
Peer Reviewed
See detailEffects of formoterol and ipratropium bromide on repeated cadmium inhalation -induced pulmonary inflammation and emphysema in rats
Zhang, Whenhui; Fievez, Laurence ULg; Zhang, F. et al

in European Journal of Pharmacology (2010), 25(647), 178-187

Detailed reference viewed: 64 (10 ULg)