References of "Journal of Immunology"
     in
Bookmark and Share    
Full Text
Peer Reviewed
See detailDual-Specificity Phosphatase Deletion Protects Female, but Not Male, Mice from Endotoxemia- and Polymicrobial-Induced Septic Shock
Vandereyken, Maud; Singh, Pratibha; Wathieu, Caroline ULiege et al

in Journal of Immunology (2017)

Dual-specificity phosphatase 3 (DUSP3) is a small phosphatase with poorly known physiological functions and for which only a few substrates are known. Using DUSP3-deficient mice, we recently reported that ... [more ▼]

Dual-specificity phosphatase 3 (DUSP3) is a small phosphatase with poorly known physiological functions and for which only a few substrates are known. Using DUSP3-deficient mice, we recently reported that DUSP3 deficiency confers resistance to endotoxin- and polymicrobial-induced septic shock. We showed that this protection was macrophage dependent. In this study, we further investigated the role of DUSP3 in sepsis tolerance and showed that the resistance is sex dependent. Using adoptive-transfer experiments and ovariectomized mice, we highlighted the role of female sex hormones in the phenotype. Indeed, in ovariectomized female and male mice, the dominance of M2-like macrophages observed in DUSP32/2 female mice was reduced, suggesting a role for this cell subset in sepsis tolerance. At the molecular level, DUSP3 deletion was associated with estrogen dependent decreased phosphorylation of ERK1/2 and Akt in peritoneal macrophages stimulated ex vivo by LPS. Our results demonstrate that estrogens may modulate M2-like responses during endotoxemia in a DUSP3-dependent manner. [less ▲]

Detailed reference viewed: 47 (7 ULiège)
Full Text
Peer Reviewed
See detailInositol-triphosphate-3-kinase C mediates inflammasome activation and treatment response in Kawasaki Disease
Alphonse, M. P.; Duong, T. T.; Shumitzu, C. et al

in Journal of Immunology (2016), 197

Kawasaki disease (KD) is a multisystem vasculitis that predominantly targets the coronary arteries in children. Phenotypic similarities between KD and recurrent fever syndromes point to the potential role ... [more ▼]

Kawasaki disease (KD) is a multisystem vasculitis that predominantly targets the coronary arteries in children. Phenotypic similarities between KD and recurrent fever syndromes point to the potential role of inflammasome activation in KD. Mutations in NLRP3 are associated with recurrent fever/auto-inflammatory syndromes. We show that the KD-associated genetic polymorphism in Inositol-triphosphate 3-kinase C (ITPKC) (rs28493229) has important functional consequences, governing ITPKC protein levels and thereby intracellular calcium, which in turn regulates NLRP3 expression and production of IL-1β and IL-18. Analysis of transcript abundance, protein levels, and cellular response profiles from matched, serial biospecimens from a cohort of genotyped KD subjects points to the critical role of ITPKC in mediating NLRP3 inflammasome activation. Treatment failure in those with the ‘high-risk’ ITPKC-genotype was associated with the highest basal and stimulated intracellular calcium levels and with increased cellular production of IL-1β and IL-18 and higher circulating levels of both cytokines. Mechanistic studies using Itpkc-deficient mice in a disease model support the genomic, cellular and clinical findings in affected children. Our findings provide the mechanism behind the observed efficacy of rescue therapy with IL-1 blockade in recalcitrant KD, and identify that regulation of calcium mobilization is fundamental to the underlying immunobiology in KD. [less ▲]

Detailed reference viewed: 38 (5 ULiège)
Full Text
Peer Reviewed
See detailDUSP3 genetic deletion confers M2-like−macrophage-dependent tolerance to septic shock
Singh, Pratibha; Dejager, Lien; Amand, Mathieu ULiege et al

in Journal of Immunology (2015), 194(10), 4951-62

DUSP3 is a small dual-specificity protein phosphatase with an unknown physiological function. We report that DUSP3 is strongly expressed in human and mouse monocytes and macrophages and that its ... [more ▼]

DUSP3 is a small dual-specificity protein phosphatase with an unknown physiological function. We report that DUSP3 is strongly expressed in human and mouse monocytes and macrophages and that its deficiency in mice promotes tolerance to lipopolysaccharide (LPS)-induced endotoxin shock and to polymicrobial septic shock following cecal ligation and puncture. By using adoptive transfer experiments, we demonstrate that resistance to endotoxin is macrophage-dependent and transferable and that this protection is associated with a striking increase of M2-like macrophages in DUSP3-/- mice in both the LPS and cecal ligation and puncture models. We show that the altered response of DUSP3-/- mice to sepsis is reflected in decreased TNF production and impaired ERK1/2 activation. Our results demonstrate that DUSP3 plays a key and non-redundant role as a regulator of innate immune responses by mechanisms involving the control of ERK1/2 activation, TNF secretion and macrophage polarization. [less ▲]

Detailed reference viewed: 57 (16 ULiège)
Full Text
Peer Reviewed
See detailA critical role for dendritic cells in the evolution of IL-1beta-mediated murine airway disease.
Hashimoto, Mitsuo; Yanagisawa, Haruhiko; Minagawa, Shunsuke et al

in Journal of Immunology (2015), 194(8), 3962-9

Chronic airway inflammation and fibrosis, known as airway remodeling, are defining features of chronic obstructive pulmonary disease and are refractory to current treatments. How and whether chronic ... [more ▼]

Chronic airway inflammation and fibrosis, known as airway remodeling, are defining features of chronic obstructive pulmonary disease and are refractory to current treatments. How and whether chronic inflammation contributes to airway fibrosis remain controversial. In this study, we use a model of chronic obstructive pulmonary disease airway disease utilizing adenoviral delivery of IL-1beta to determine that adaptive T cell immunity is required for airway remodeling because mice deficient in alpha/beta T cells (tcra(-/-)) are protected. Dendritic cells (DCs) accumulate around chronic obstructive pulmonary disease airways and are critical to prime adaptive immunity, but they have not been shown to directly influence airway remodeling. We show that DC depletion or deficiency in the crucial DC chemokine receptor ccr6 both protect from adenoviral IL-1beta-induced airway adaptive T cell immune responses and fibrosis in mice. These results provide evidence that chronic airway inflammation, mediated by accumulation of alpha/beta T cells and driven by DCs, is critical to airway fibrosis. [less ▲]

Detailed reference viewed: 24 (1 ULiège)
Full Text
Peer Reviewed
See detailCyprinid Herpesvirus 3 Il10 Inhibits Inflammatory Activities of Carp Macrophages and Promotes Proliferation of Igm+ B Cells and Memory T Cells in a Manner Similar to Carp Il10.
Piazzon, M. Carla; Wentzel, Annelieke S.; Tijhaar, Edwin J. et al

in Journal of Immunology (2015), 195(8), 3694-704

Cyprinid herpesvirus 3 (CyHV-3) is the causative agent of a lethal disease of carp and encodes for an Il10 homolog (ORF134). Our previous studies with a recombinant ORF134-deleted strain and the derived ... [more ▼]

Cyprinid herpesvirus 3 (CyHV-3) is the causative agent of a lethal disease of carp and encodes for an Il10 homolog (ORF134). Our previous studies with a recombinant ORF134-deleted strain and the derived revertant strain suggested that cyprinid herpesvirus 3 Il10 (CyHV-3 Il10 [cyhv3Il10]) is not essential for viral replication in vitro, or virulence in vivo. In apparent contrast, cyhv3Il10 is one of the most abundant proteins of the CyHV-3 secretome and is structurally very similar to carp Il10 and also human IL10. To date, studies addressing the biological activity of cyhv3Il10 on cells of its natural host have not been performed. To address the apparent contradiction between the presence of a structurally conserved Il10 homolog in the genome of CyHV-3 and the lack of a clear phenotype in vivo using recombinant cyhv3Il10-deleted viruses, we used an in vitro approach to investigate in detail whether cyhv3Il10 exerts any biological activity on carp cells. In this study, we provide direct evidence that cyhv3Il10 is biologically active and, similarly to carp Il10, signals via a conserved Stat3 pathway modulating immune cells of its natural host, carp. In vitro, cyhv3Il10 deactivates phagocytes with a prominent effect on macrophages, while also promoting proliferation of Igm(+) B cells and memory T cells. Collectively, this study demonstrates a clear biological activity of cyhv3Il10 on cells of its natural host and indicates that cyhv3Il10 is a true viral ortholog of carp Il10. Furthermore, to our knowledge, this is the first report on biological activities of a nonmammalian viral Il10 homolog. [less ▲]

Detailed reference viewed: 30 (2 ULiège)
Full Text
Peer Reviewed
See detailA role for APPL1 in tlr3/4-dependent TBK1 and IKKε activation in macrophages
Chau, Tieu-Lan ULiege; Göktuna, Serkan ULiege; Rammal, Ayman et al

in Journal of Immunology (2015)

Endosomes have important roles in intracellular signal transduction as a sorting platform. Signaling cascades from TLR engagement to IRF3-dependent gene transcription rely on endosomes, yet the proteins ... [more ▼]

Endosomes have important roles in intracellular signal transduction as a sorting platform. Signaling cascades from TLR engagement to IRF3-dependent gene transcription rely on endosomes, yet the proteins that specifically recruit IRF3-activating molécules to them are poorly defined. We show that adaptor protein containing a pleckstrin-homology domain, a phosphotyrosine-binding domain, and a leucine zipper motif (APPL)1, an early endosomal protein, is required for both TRIF- and retinoic acid–inducible gene 1–dependent signaling cascades to induce IRF3 activation. APPL1, but not early endosome Ag 1, deficiency impairs IRF3 target gene expression upon engagement of both TLR3 and TLR4 pathways, as well as in H1N1-infected macrophages. The IRF3-phosphorylating kinases TBK1 and IKK« are recruited to APPL1 endosomes in LPS-stimulated macrophages. Interestingly, APPL1 undergoes proteasome-mediated degradation through ERK1/2 to turn off signaling. APPL1 degradation is blocked when signaling through the endosome is inhibited by chloroquine or dynasore. Therefore, APPL1 endosomes are critical for IRF3-dependent gene expression in response to some viral and bacterial infections in macrophages. Those signaling pathways involve the signal-induced degradation of APPL1 to prevent aberrant IRF3-dependent gene expression linked to immune diseases. [less ▲]

Detailed reference viewed: 83 (15 ULiège)
Full Text
Peer Reviewed
See detailHuman L-ficolin recognizes phosphocholine moieties of pneumococcal teichoic acid.
Vassal-Stermann, Emilie; Lacroix, Monique; Gout, Evelyne et al

in Journal of Immunology (2014), 193(11), 5699-708

Human L-ficolin is a soluble protein of the innate immune system able to sense pathogens through its fibrinogen (FBG) recognition domains and to trigger activation of the lectin complement pathway through ... [more ▼]

Human L-ficolin is a soluble protein of the innate immune system able to sense pathogens through its fibrinogen (FBG) recognition domains and to trigger activation of the lectin complement pathway through associated serine proteases. L-Ficolin has been previously shown to recognize pneumococcal clinical isolates, but its ligands and especially its molecular specificity remain to be identified. Using solid-phase binding assays, serum and recombinant L-ficolins were shown to interact with serotype 2 pneumococcal strain D39 and its unencapsulated R6 derivative. Incubation of both strains with serum triggered complement activation, as measured by C4b and C3b deposition, which was decreased by using ficolin-depleted serum. Recombinant L-ficolin and its FBG-like recognition domain bound to isolated pneumococcal cell wall extracts, whereas binding to cell walls depleted of teichoic acid (TA) was decreased. Both proteins were also shown to interact with two synthetic TA compounds, each comprising part structures of the complete lipoteichoic acid molecule with two PCho residues. Competition studies and direct interaction measurements by surface plasmon resonance identified PCho as a novel L-ficolin ligand. Structural analysis of complexes of the FBG domain of L-ficolin and PCho revealed that the phosphate moiety interacts with amino acids previously shown to define an acetyl binding site. Consequently, binding of L-ficolin to immobilized acetylated BSA was inhibited by PCho and synthetic TA. Binding of serum L-ficolin to immobilized synthetic TA and PCho-conjugated BSA triggered activation of the lectin complement pathway, thus further supporting the hypothesis of L-ficolin involvement in host antipneumococcal defense. [less ▲]

Detailed reference viewed: 21 (1 ULiège)
Full Text
Peer Reviewed
See detailDual-specificity phosphatase 3 knockout female mice are resistant to LPS and to polymicrobial induced septic shock in TNF dependent manner.
Rahmouni, Souad ULiege; Singh; Dejager, Lien et al

in Journal of Immunology (2013, May)

We report the generation of dual-specificity phosphatase 3 (DUSP3) deficient mice. These mice develop normally and do not exhibit any spontaneous phenotype. However, VHR-/- females, but not males, are ... [more ▼]

We report the generation of dual-specificity phosphatase 3 (DUSP3) deficient mice. These mice develop normally and do not exhibit any spontaneous phenotype. However, VHR-/- females, but not males, are resistant to LPS- and to polymicrobial infection-induced septic shock. After LPS injection, while VHR-/- males and VHR+/+ mice of both genders, displayed an increased serum levels of TNF-α and IFN, the levels of these cytokines remained significantly low in the VHR-/- females. In vitro experiments using peritoneal macrophages showed the same results suggesting that the systemic cytokines profiles observed are macrophages-dependent. Adoptive transfer of VHR-/- females bone marrow to irradiated VHR+/+ female mice, but not to VHR-/- or VHR+/+ males, protected them from death after administration of LPS. Interestingly, VHR-/- females were sensitive to TNF-α- induced lethality. We also report that the decrease of TNF-α production observed in VHR-/- female’s macrophages after LPS activation was associated with a decreased ERK1/2, but not MEK1/2, activation. Interestingly, pervanadate (PTP pan inhibitor) treatment prior to LPS activation restored ERK1/2 activation in the VHR-deficient macrophages, suggesting that VHR is targeting one of the ERK1/2 PTPs or DUSPs. These results, together with our observation that DUSP3 is the most highly expressed phosphatase in macrophages, suggest a key non-redundant role of VHR as positive regulator of TNF-α in innate immune response in females. [less ▲]

Detailed reference viewed: 20 (4 ULiège)
Full Text
Peer Reviewed
See detailNeutrophil Extracellular Traps (NET) Entrap and Kill Borrelia burgdorferi sensu stricto Spirochetes and Are not Affected by Ixodes ricinus Tick Saliva.
Menten, Catherine ULiege; 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 ▲]

Detailed reference viewed: 126 (21 ULiège)
Full Text
Peer Reviewed
See detailOverexpression of CD39 in mouse airways promotes bacteria induced inflammation
Theatre, Emilie ULiege; Frederix, Kim; Guilmain, William et al

in Journal of Immunology (2012), 189(4), 1966-1974

In airways, the ecto-nucleoside triphosphate diphosphohydrolase CD39 plays a central role in the regulation of physiological mucosal nucleotide concentrations and likely contributes to the control of ... [more ▼]

In airways, the ecto-nucleoside triphosphate diphosphohydrolase CD39 plays a central role in the regulation of physiological mucosal nucleotide concentrations and likely contributes to the control of inflammation because accelerated ATP metabolism occurs in chronic inflammatory lung diseases.We sought to determine whether constant elevated CD39 activity in lung epithelia is sufficient to cause inflammation and whether this affects the response to acute LPS or Pseudomonas aeruginosa exposure. We generated transgenic mice overexpressing human CD39 under the control of the airway-specific Clara cell 10-kDa protein gene promoter. Transgenic mice did not develop any spontaneous lung inflammation. However, intratracheal instillation of LPS resulted in accelerated recruitment of neutrophils to the airways of transgenic mice. Macrophage clearance was delayed, and the amounts of CD8+ T and B cells were augmented. Increased levels of keratinocyte chemoattractant, IL-6, and RANTES were produced in transgenic lungs. Similarly, higher numbers of neutrophils and macrophages were found in the lungs of transgenic mice infected with P. aeruginosa, which correlated with improved bacteria clearance. The transgenic phenotype was partially and differentially restored by coinstillation of P2X1 or P2X7 receptor antagonists or of caffeine with LPS. Thus, a chronic increase of epithelial CD39 expression and activity promotes airway inflammation in response to bacterial challenge by enhancing P1 and P2 receptor activation. [less ▲]

Detailed reference viewed: 42 (12 ULiège)
Full Text
Peer Reviewed
See detailControl of Allergen-Induced Inflammation and Hyperresponsiveness by the Metalloproteinase ADAMTS-12
Paulissen, Geneviève ULiege; El Hour, Mehdi; Rocks, Natacha ULiege et al

in Journal of Immunology (2012), 189

A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) constitute a family of endopeptidases related to matrix metalloproteinases. These proteinases have been largely implicated in tissue ... [more ▼]

A disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS) constitute a family of endopeptidases related to matrix metalloproteinases. These proteinases have been largely implicated in tissue remodeling associated with pathological processes. Among them, ADAMTS12 was identified as an asthma-associated gene in a human genome screening program. However, its functional implication in asthma is not yet documented. The present study aims at investigating potential ADAMTS-12 functions in experimental models of allergic airways disease. Two different in vivo protocols of allergen-induced airways disease were applied to the recently generated Adamts12-deficient mice and corresponding wild-type mice. In this study, we provide evidence for a protective effect of ADAMTS-12 against bronchial inflammation and hyperresponsiveness. In the absence of Adamts12, challenge with different allergens (OVA and house dust mite) led to exacerbated eosinophilic inflammation in the bronchoalveolar lavage fluid and in lung tissue, along with airway dysfunction assessed by increased airway responsiveness following methacholine exposure. Furthermore, mast cell counts and ST2 receptor and IL-33 levels were higher in the lungs of allergen-challenged Adamts12-deficient mice. The present study provides, to our knowledge, the first experimental evidence for a contribution of ADAMTS-12 as a key mediator in airways disease, interfering with immunological processes leading to inflammation and airway hyperresponsiveness. [less ▲]

Detailed reference viewed: 108 (30 ULiège)
Full Text
Peer Reviewed
See detailHistone Deacetylase 7 Regulates Cell Survival and TCR Signaling in CD4/CD8 Double-Positive Thymocytes.
Kasler, Herbert G; Young, Bryan D; Mottet, Denis ULiege et al

in Journal of Immunology (2011), 186(8), 4782-93

CD4/CD8 double-positive thymocytes express the transcriptional repressor histone deacetylase (HDAC)7, a class IIa HDAC that is exported from the cell nucleus after TCR engagement. Through signal-dependent ... [more ▼]

CD4/CD8 double-positive thymocytes express the transcriptional repressor histone deacetylase (HDAC)7, a class IIa HDAC that is exported from the cell nucleus after TCR engagement. Through signal-dependent nuclear export, class IIa HDACs such as HDAC7 mediate signal-dependent changes in gene expression that are important to developmental fate decisions in multiple tissues. We report that HDAC7 is exported from the cell nucleus during positive selection in mouse thymocytes and that it regulates genes mediating the coupling between TCR engagement and downstream events that determine cell survival. Thymocytes lacking HDAC7 are inefficiently positively selected due to a severely shortened lifespan and exhibit a truncated repertoire of TCR Jalpha segments. The expression of multiple important mediators and modulators of the response to TCR engagement is altered in HDAC7-deficient thymocytes, resulting in increased tonic MAPK activity that contributes to the observed loss of viability. Remarkably, the activity of protein kinase D, the kinase that mediates nuclear export of HDAC7 in response to TCR signaling, is also increased in HDAC7-deficient thymocytes, suggesting that HDAC7 nuclear export governs a self-sustaining autoexcitatory loop. These experiments add to the understanding of the life/death decision in thymic T cell development, define a novel function for class IIa HDACs, and point to a novel feed-forward mechanism whereby these molecules regulate their own state and mediate stable developmental transitions. [less ▲]

Detailed reference viewed: 28 (9 ULiège)
Full Text
Peer Reviewed
See detailMice with Disrupted Type I Protein Kinase A Anchoring in T Cells Resist Retrovirus-Induced Immunodeficiency
Mosenden, Randi; Singh, Pratibha; Cornez, Isabelle et al

in Journal of Immunology (2011), 186(9), 5119-30

Type I protein kinase A (PKA) is targeted to the TCR-proximal signaling machinery by the A-kinase anchoring protein ezrin and negatively regulates T cell immune function through activation of the C ... [more ▼]

Type I protein kinase A (PKA) is targeted to the TCR-proximal signaling machinery by the A-kinase anchoring protein ezrin and negatively regulates T cell immune function through activation of the C-terminal Src kinase. RI anchoring disruptor (RIAD) is a high-affinity competitor peptide that specifically displaces type I PKA from A-kinase anchoring proteins. In this study, we disrupted type I PKA anchoring in peripheral T cells by expressing a soluble ezrin fragment with RIAD inserted in place of the endogenous A-kinase binding domain under the lck distal promoter in mice. Peripheral T cells from mice expressing the RIAD fusion protein (RIAD-transgenic mice) displayed augmented basal and TCR-activated signaling, enhanced T cell responsiveness assessed as IL-2 secretion, and reduced sensitivity to PGE2- and cAMP-mediated inhibition of T cell function. Hyperactivation of the cAMP–type I PKA pathway is involved in the T cell dysfunction of HIV infection, as well as murine AIDS, a disease model induced by infection of C57BL/6 mice with LP-BM5, a mixture of attenuated murine leukemia viruses. LP-BM5–infected RIADtransgenic mice resist progression of murine AIDS and have improved viral control. This underscores the cAMP–type I PKA pathway in T cells as a putative target for therapeutic intervention in immunodeficiency diseases. [less ▲]

Detailed reference viewed: 45 (6 ULiège)
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 ULiege; Fievez, Laurence ULiege 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: 60 (23 ULiège)
Full Text
Peer Reviewed
See detailP2X1 Ion Channels Promote Neutrophil Chemotaxis through Rho Kinase Activation
Lecut, Christelle ULiege; Frederix, Kim ULiege; Johnson, Daniel M et al

in Journal of Immunology (2009)

This study shows that activation of P2X1 ion channels by ATP promotes neutrophil chemotaxis, a process involving Rho kinase-dependent actomyosin-mediated contraction at the cell rear. These ion channels ... [more ▼]

This study shows that activation of P2X1 ion channels by ATP promotes neutrophil chemotaxis, a process involving Rho kinase-dependent actomyosin-mediated contraction at the cell rear. These ion channels may therefore play a significant role in host defense and inflammation. [less ▲]

Detailed reference viewed: 80 (21 ULiège)
Full Text
Peer Reviewed
See detailThe adaptor protein CIKS/Act1 is essential for IL-25-mediated allergic airway inflammation
Claudio, Estefania; Sonder, Soren Ulrik; Saret, Sun et al

in Journal of Immunology (2009), 182

IL-17 is the signature cytokine of recently discovered Th type 17 (Th17) cells, which are prominent in defense against extracellular bacteria and fungi as well as in autoimmune diseases, such as ... [more ▼]

IL-17 is the signature cytokine of recently discovered Th type 17 (Th17) cells, which are prominent in defense against extracellular bacteria and fungi as well as in autoimmune diseases, such as rheumatoid arthritis and experimental autoimmune encephalomyelitis in animal models. IL-25 is a member of the IL-17 family of cytokines, but has been associated with Th2 responses instead and may negatively cross-regulate Th17/IL-17 responses. IL-25 can initiate an allergic asthma-like inflammation in the airways, which includes recruitment of eosinophils, mucus hypersecretion, Th2 cytokine production, and airways hyperreactivity. We demonstrate that these effects of IL-25 are entirely dependent on the adaptor protein CIKS (also known as Act1). Surprisingly, this adaptor is necessary to transmit IL-17 signals as well, despite the very distinct biologic responses that these two cytokines elicit. We identify CD11c(+) macrophage-like lung cells as physiologic relevant targets of IL-25 in vivo. [less ▲]

Detailed reference viewed: 73 (9 ULiège)
Full Text
Peer Reviewed
See detailNicotinamide phosphoribosyl transferase/pre-B cell colony-enhancing factor/visfatin is required for lymphocyte development and cellular resistance to genotoxic stress.
Rongvaux, Anthony; Galli, Mara; Denanglaire, Sebastien et al

in Journal of Immunology (2008), 181(7), 4685-4695

Nicotinamide phosphoribosyl transferase (Nampt)/pre-B cell colony-enhancing factor (PBEF)/visfatin is a protein displaying multiple functional properties. Originally described as a cytokine-like protein ... [more ▼]

Nicotinamide phosphoribosyl transferase (Nampt)/pre-B cell colony-enhancing factor (PBEF)/visfatin is a protein displaying multiple functional properties. Originally described as a cytokine-like protein able to regulate B cell development, apoptosis, and glucose metabolism, this protein also plays an important role in NAD biosynthesis. To gain insight into its physiological role, we have generated a mouse strain expressing a conditional Nampt allele. Lack of Nampt expression strongly affects development of both T and B lymphocytes. Analysis of hemizygous cells and in vitro cell lines expressing distinct levels of Nampt illustrates the critical role of this protein in regulating intracellular NAD levels. Consequently, a clear relationship was found between intracellular Nampt levels and cell death in response to the genotoxic agent MNNG (N-methyl-N'-nitro-N-nitrosoguanidine), confirming that this enzyme represents a key regulator of cell sensitivity to NAD-consuming stress secondary to poly(ADP-ribose) polymerases overactivation. By using mutant forms of this protein and a well-characterized pharmacological inhibitor (FK866), we unequivocally demonstrate that the ability of the Nampt to regulate cell viability during genotoxic stress requires its enzymatic activity. Collectively, these data demonstrate that Nampt participates in cellular resistance to genotoxic/oxidative stress, and it may confer to cells of the immune system the ability to survive during stressful situations such as inflammation. [less ▲]

Detailed reference viewed: 72 (9 ULiège)
Full Text
Peer Reviewed
See detailDendritic cells genetically engineered to express IL-10 induce long-lasting antigen-specific tolerance in experimental asthma.
Henry, E.; Desmet, Christophe ULiege; Garze, V. et al

in Journal of Immunology (2008), 181(10), 7230-7242

Dendritic cells (DCs) are professional APCs that have a unique capacity to initiate primary immune responses, including tolerogenic responses. We have genetically engineered bone marrow-derived DCs to ... [more ▼]

Dendritic cells (DCs) are professional APCs that have a unique capacity to initiate primary immune responses, including tolerogenic responses. We have genetically engineered bone marrow-derived DCs to express the immunosuppressive cytokine IL-10 and tested the ability of these cells to control experimental asthma. A single intratracheal injection of OVA-pulsed IL-10-transduced DCs (OVA-IL-10-DCs) to naive mice before OVA sensitization and challenge prevented all of the cardinal features of airway allergy, namely, eosinophilic airway inflammation, airway hyperreactivity, and production of mucus, Ag-specific Igs, and IL-4. OVA-IL-10-DCs also reversed established experimental asthma and had long-lasting and Ag-specific effects. We furthermore showed, by using IL-10-deficient mice, that host IL-10 is required for mediating the immunomodulatory effects of OVA-IL-10-DCs and demonstrated a significant increase in the percentage of OVA-specific CD4(+)CD25(+)Foxp3(+)IL-10(+) regulatory T cells in the mediastinal lymph nodes of OVA-IL-10-DC-injected mice. Finally, adoptive transfer of CD4(+) mediastinal lymph node T cells from mice injected with OVA-IL-10-DCs protected OVA-sensitized recipients from airway eosinophilia upon OVA provocation. Our study describes a promising strategy to induce long-lasting Ag-specific tolerance in airway allergy. [less ▲]

Detailed reference viewed: 81 (15 ULiège)
Full Text
Peer Reviewed
See detailDendritic cell differentiation and immune tolerance to insulin-related peptides in Igf2-deficient mice
Hansenne, Isabelle ULiege; Renard-Charlet, C.; Greimers, Roland ULiege et al

in Journal of Immunology (2006), 176(8), 4651-4657

There is some evidence that insulin-like growth factor 2 (IGF-2) may intervene in the control of T cell differentiation. To further study the immunoregulatory function of this growth factor, we analyzed ... [more ▼]

There is some evidence that insulin-like growth factor 2 (IGF-2) may intervene in the control of T cell differentiation. To further study the immunoregulatory function of this growth factor, we analyzed the immune system of Igf2(-/-) mice. Phenotypically, some immunological parameters such as lymphoid organ morphology and cellularity were unaltered in Igf2(-/-) mice, but an increase of CD8(+) cells and a decrease of B220(+) cells were observed in spleen. In vitro, the development of bone marrow-derived dendritic cells was affected by the absence of Igf2 expression. After maturation, a higher percentage of immature dendritic cells was observed in Igf2(-/-) population, together with a secondary decrease in allogenic T cell proliferation. Activation of T cells was also affected by the lack of expression of this growth factor. The profile of B cell response in mutant mice immunized with IGF-2 evidenced a T-dependent profile of anti-IGF-2 Abs that was absent in Igf2(+/+) mice. The influence of IGF-2 upon tolerance to insulin was also assessed in this model, and this showed that IGF-2 also intervenes in tolerance to insulin. The presence of a T-dependent response in Igf2-deficient mice should allow cloning of specific "forbidden" T CD4(+) lymphocytes directed against IGF-2, as well as further investigation of their possible pathogenic properties against insulin family. [less ▲]

Detailed reference viewed: 42 (5 ULiège)
Full Text
Peer Reviewed
See detailLymphotoxin-beta receptor-dependent genes in lymph node and follicular dendritic cell transcriptomes
Huber, Christoph; Thielen, Caroline ULiege; Seeger, Harald et al

in Journal of Immunology (2005), 174(9), 5526-5536

Affinity-maturation and Ab class switches occur in lymphoid germinal centers (GCs), in which differentiation and maintenance depend on lymphotoxin (LT) signaling and include differentiation of follicular ... [more ▼]

Affinity-maturation and Ab class switches occur in lymphoid germinal centers (GCs), in which differentiation and maintenance depend on lymphotoxin (LT) signaling and include differentiation of follicular dendritic cells (FDCs). The events leading to FDC and GC maturation are poorly defined. Using several approaches of functional genomics, we enumerated transcripts affected in mice by suppressing LT beta receptor (LT beta R) signaling and/or overrepresented in FDC-enriched GC isolates. Protein expression analysis of 3 of 12 genes both enriched in FDCs and down-regulated by LT beta R signaling suppression validated them as FDC markers. Functional analysis of one of these three, clusterin, suggests a role as an FDC-derived trophic factor for GC B cells. Hence, the set of genes presented in this study includes markers emanating from LT beta R signaling and transcripts relevant to GC and FDC function. [less ▲]

Detailed reference viewed: 58 (7 ULiège)