bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Mechanisms of High-Dose Antigen Therapy in Experimental Autoimmune Encephalomyelitis: Rapid Induction of Th1-Type Cytokines and Inducible Nitric Oxide Synthase
Authors: Weishaupt Andreas , Jander Sebastian , Brück Wolfgang , Kuhlmann Tanja , Stienekemeier Martina , Hartung Thomas , Toyka Klaus V. , Stoll Guido , Gold Ralf 
Published: April 2014

AbstractHigh-dose Ag administration induces apoptotic death of autoreactive T cells and is an effective therapy of experimental autoimmune diseases of the nervous system. To explore the role of cytokines in Ag-specific immunotherapy, we analyzed mRNA induction and protein expression for the proinflammatory cytokines TNF-α and IFN-γ, the anti-inflammatory cytokine IL-10, and the cytokine-inducible NO synthase (iNOS) during high-dose Ag therapy of adoptive transfer experimental autoimmune encephalomyelitis (AT-EAE) in the Lewis rat. Using semiquantitative and competitive RT-PCR, we found 5- to 6-fold induction of TNF-α mRNA and 3-fold induction of IFN-γ mRNA in the spinal cord that occurred within 1 h after i.v. injection of Ag and was accompanied by a 2-fold increase of iNOS mRNA. Both IFN-γ and iNOS mRNA remained elevated for at least 6 h, whereas TNF-α mRNA was already down-regulated 6 h after Ag injection. A comparable time course was found for circulating serum levels of TNF-α and IFN-γ. IL-10 mRNA levels did not change significantly following Ag injection. Neutralization of TNF-α by anti-TNF-α antiserum in vivo led to a significant decrease in the rate of T cell and oligodendrocyte apoptosis induced by high-dose Ag administration, but did not change the beneficial clinical effect of Ag therapy. Our data suggest profound activation of proinflammatory but not of anti-inflammatory cytokine gene expression by high-dose Ag injection. Functionally, TNF-α contributes to increased apoptosis of both autoaggressive T cells and oligodendrocytes in the target organ and may thereby play a dual role in this model of Ag-specific therapy of CNS autoimmune diseases.
L-Selectin Facilitates Emigration and Extravascular Locomotion of Leukocytes During Acute Inflammatory Responses In Vivo
Authors: Hickey Michael J. , Forster Melanie , Mitchell Debra , Kaur Jaswinder , De Caigny Catherine , Kubes Paul 
Published: April 2014

AbstractL-selectin has been shown to be important in mediating leukocyte recruitment during inflammatory responses. Although there are numerous in vitro studies demonstrating that engagement of L-selectin leads to the activation of several signaling pathways potentially contributing to subsequent adhesion, emigration, or even migration through the interstitium, whether this actually induces cellular events in vivo is completely unknown. Therefore, we used intravital microscopy to visualize the role of L-selectin in downstream leukocyte adhesion, emigration, and interstitial migration events in wild-type and L-selectin-deficient (L-selectin−/−) mice. The cremaster muscle was superfused with the chemotactic inflammatory mediators platelet-activating factor or KC. Leukocyte rolling, adhesion, and emigration in postcapillary venules were examined, and the migration of emigrated leukocytes was recorded continuously using time-lapse videomicroscopy. Platelet-activating factor increased leukocyte adhesion to a similar level in both wild-type and L-selectin−/− mice. In contrast, both the number of emigrated leukocytes and the distance of extravascular migration were significantly reduced in L-selectin−/− mice. A similar pattern was observed in response to the superfusion of KC. Because superfusion of these mediators induced chemokinesis, we developed a new in vivo chemotaxis assay using slow release of KC from an agarose gel positioned 350 μm from a postcapillary venule. These experiments showed that L-selectin−/− leukocytes were also severely impaired in their ability to respond to a directional cue. These findings indicate that L-selectin is important in enabling leukocytes to respond effectively to chemotactic stimuli in inflamed tissues.
Tat Protein Is an HIV-1-Encoded β-Chemokine Homolog That Promotes Migration and Up-Regulates CCR3 Expression on Human FcεRI+ Cells
Authors: de Paulis Amato , De Palma Raffaele , Di Gioia Luisa , Carfora Maria , Prevete Nella , Tosi Giovanna , Accolla Roberto S. , Marone Gianni 
Published: April 2014

AbstractHuman basophils and mast cells express the chemokine receptor CCR3, which binds the chemokines eotaxin and RANTES. HIV-1 Tat protein is a potent chemoattractant for basophils and lung mast cells obtained from healthy individuals seronegative for Abs to HIV-1 and HIV-2. Tat protein induced a rapid and transient Ca2+ influx in basophils and mast cells, analogous to β-chemokines. Tat protein neither induced histamine release from human basophils and mast cells nor increased IL-3-stimulated histamine secretion from basophils. The chemotactic activity of Tat protein was blocked by preincubation of FcεRI+ cells with anti-CCR3 Ab. Preincubation of Tat with a mAb anti-Tat (aa 1–86) blocked the migration induced by Tat. In contrast, a mAb specific for the basic region (aa 46–60) did not inhibit the chemotactic effect of Tat protein. Tat protein or eotaxin desensitized basophils to a subsequent challenge with the autologous or the heterologous stimulus. Preincubation of basophils with Tat protein up-regulated the level of CCR3 mRNA and the surface expression of the CCR3 receptor. Tat protein is the first identified HIV-1-encoded β-chemokine homologue that influences the directional migration of human FcεRI+ cells and the expression of surface receptor CCR3 on these cells.
Vitamin C Inhibits NF-κB Activation by TNF Via the Activation of p38 Mitogen-Activated Protein Kinase
Authors: Bowie Andrew G. , O’Neill Luke A. J. 
Published: April 2014

AbstractThe transcription factor NF-κB is a central mediator of altered gene expression during inflammation, and is implicated in a number of pathologies, including cancer, atherosclerosis, and viral infection. We report in this study that vitamin C inhibits the activation of NF-κB by multiple stimuli, including IL-1 and TNF in the endothelial cell line ECV304 and in primary HUVECs. The induction of a NF-κB-dependent gene, IL-8, by TNF was also inhibited. The effect requires millimolar concentrations of vitamin C, which occur intracellularly in vivo, particularly during inflammation. Vitamin C was not toxic to cells, did not inhibit another inducible transcription factor, STAT1, and had no effect on the DNA binding of NF-κB. Inhibition by vitamin C was not simply an antioxidant effect, because redox-insensitive pathways to NF-κB were also blocked. Vitamin C was shown to block IL-1- and TNF-mediated degradation and phosphorylation of I-κBα (inhibitory protein that dissociates from NF-κB), due to inhibition of I-κB kinase (IKK) activation. Inhibition of TNF-driven IKK activation was mediated by p38 mitogen-activated protein kinase, because treatment of cells with vitamin C led to a rapid and sustained activation of p38, and the specific p38 inhibitor SB203580 reversed the inhibitory effect of vitamin C on IKK activity, I-κBα phosphorylation, and NF-κB activation. The results identify p38 as an intracellular target for high dose vitamin C.
Endotoxin Activation of Macrophages Does Not Induce ATP Release and Autocrine Stimulation of P2 Nucleotide Receptors
Authors: Beigi Reza D. , Dubyak George R. 
Published: April 2014

AbstractReceptors for extracellular nucleotides (P2, or purinergic receptors) have previously been implicated in the transduction of endotoxin signaling in macrophages. The most compelling evidence has been the observation that inhibitors of ionotropic nucleotide (P2X) receptors, including periodate-oxidized ATP (oATP), attenuate a subset of endotoxin-induced effects such as activation of NF-κB and up-regulation of inducible NO synthase. We investigated whether endotoxin induces ATP release from a murine macrophage cell line (BAC1.2F5) using sensitive on-line assays for extracellular ATP. These cells constitutively released ATP, producing steady-state extracellular concentrations of ∼1 nM when assayed as monolayers of 106 adherent cells bathed in 1 ml of medium. However, the macrophages did not release additional ATP during either acute or prolonged endotoxin stimulation. In addition, cellular ecto-ATPase activities were measured following prolonged endotoxin activation and were found not to be significantly altered. Although oATP treatment significantly attenuated the endotoxin-induced production of NO, this inhibitory effect was not reproduced when the cells were coincubated with apyrase, a highly effective ATP scavenger. These results indicate that activation of macrophages by endotoxin does not induce autocrine stimulation of P2 nucleotide receptors by endogenous ATP released to extracellular compartments. Moreover, the data suggest that the ability of oATP to interfere with endotoxin signaling is due to its interaction with molecular species other than ATP-binding P2 receptors.
Regulation of IL-6 and IL-8 Expression in Rheumatoid Arthritis Synovial Fibroblasts: the Dominant Role for NF-κB But Not C/EBPβ or c-Jun
Authors: Georganas Constantinos , Liu Hongtao , Perlman Harris , Hoffmann Alexander , Thimmapaya Bayar , Pope Richard M. 
Published: April 2014

AbstractRheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS) produce IL-6 and IL-8, which contribute to inflammation and joint damage. The promoters of both cytokines possess binding sites for NF-κB, C/EBPβ, and c-Jun, but the contribution of each to the regulation of IL-6 and IL-8 in RA FLS is unknown. We employed adenoviral-mediated gene delivery of a nondegradable IκBα, or dominant-negative versions of C/EBPβ or c-Jun, to determine the contribution of each transcription factor to IL-6 and IL-8 expression. Inhibition of NF-κB activation significantly reduced the spontaneous and IL-1β-induced secretion of IL-6 and IL-8 by RA FLS and the IL-1β-induced production of IL-6 and IL-8 by human dermal fibroblasts. Inhibition of C/EBPβ modestly reduced constitutive and IL-1β-induced IL-6 by RA FLS, but not by human dermal fibroblasts, and had no effect on IL-8. Inhibition of c-Jun/AP-1 had no effect on the production of either IL-6 or IL-8. Employing gel shift assays, NF-κB, C/EBPβ, and c-Jun were constitutively activated in RA FLS, but only NF-κB and c-Jun activity increased after IL-1β. The reduction of cytokines by IκBα was mediated through inhibition of NF-κB activation, which resulted in decreased IL-6 and IL-8 mRNA. NF-κB was essential for IL-6 expression, because fibroblasts in which both NF-κB p50/p65 genes were deleted failed to express IL-6 in response to IL-1. These findings document the importance of NF-κB for the regulation of the constitutive and IL-1β-stimulated expression of IL-6 and IL-8 by RA FLS and support the role of inhibition of NF-κB as a therapeutic goal in RA.
The Efficacy of Immunotherapy in an Experimental Murine Model of Allergic Asthma Is Related to the Strength and Site of T Cell Activation During Immunotherapy
Authors: Janssen Edith M. , van Oosterhout Antoon J. M. , Nijkamp Frans P. , van Eden Willem , Wauben Marca H. M. 
Published: April 2014

AbstractIn the present study, the relation between the efficacy of immunotherapy, and the strength and site of T cell activation during immunotherapy was evaluated. We used a model of allergic asthma in which OVA-sensitized and OVA-challenged mice display increased airway hyperresponsiveness, airway inflammation, and Th2 cytokine production by OVA-specific T cells. In this model, different immunotherapy strategies, including different routes of administration, or treatment with entire OVA or the immunodominant T cell epitope OVA323–339, or treatment with a peptide analogue of OVA323–339 with altered T cell activation capacity were studied. To gain more insight in how immunotherapy affects allergen-specific T cells, the site of Ag-specific T cell activation and the magnitude of the T cell response induced during different immunotherapy strategies were determined using an adoptive transfer model. Our data suggest that amelioration of airway hyperresponsiveness and inflammation is associated with the induction of a strong, synchronized, and systemic T cell response, resulting in a decreased OVA-specific Th2 response. In contrast, deterioration of the disease after immunotherapy is associated with the induction of a weak nonsynchronized T cell response, resulting in the enhancement of the OVA-specific Th2 response after challenge.
Chemokine Production by G Protein-Coupled Receptor Activation in a Human Mast Cell Line: Roles of Extracellular Signal-Regulated Kinase and NFAT
Authors: Ali Hydar , Ahamed Jasimuddin , Hernandez-Munain Cristina , Baron Jonathan L. , Krangel Michael S. , Patel Dhavalkumar D. 
Published: April 2014

AbstractChemoattractants are thought to be the first mediators generated at sites of bacterial infection. We hypothesized that signaling through G protein-coupled chemoattractant receptors may stimulate cytokine production. To test this hypothesis, a human mast cell line (HMC-1) that normally expresses receptors for complement components C3a and C5a at low levels was stably transfected to express physiologic levels of fMLP receptors. We found that fMLP, but not C3a or C5a, induced macrophage inflammatory protein (MIP)-1β (CCL4) and monocyte chemoattractant protein-1 (CCL2) mRNA and protein. Although fMLP stimulated both sustained Ca2+ mobilization and phosphorylation of extracellular signal-regulated kinase (ERK), these responses to C3a or C5a were transient. However, transient expression of C3a receptors in HMC-1 cells rendered the cells responsive to C3a for sustained Ca2+ mobilization and MIP-1β production. The fMLP-induced chemokine production was blocked by pertussis toxin, PD98059, and cyclosporin A, which respectively inhibit Giα activation, mitgen-activated protein kinase kinase-mediated ERK phosphorylation, and calcineurin-mediated activation of NFAT. Furthermore, fMLP, but not C5a, stimulated NFAT activation in HMC-1 cells. These data indicate that chemoattractant receptors induce chemokine production in HMC-1 cells with a selectivity that depends on the level of receptor expression, the length of their signaling time, and the synergistic interaction of multiple signaling pathways, including extracellular signal-regulated kinase phosphorylation, sustained Ca2+ mobilization and NFAT activation.
Basophil Responses to Chemokines Are Regulated by Both Sequential and Cooperative Receptor Signaling
Authors: Heinemann Akos , Hartnell Adele , Stubbs Victoria E. L. , Murakami Kazuki , Soler Dulce , LaRosa Gregory , Askenase Philip W. , Williams Timothy J. , Sabroe Ian 
Published: April 2014

AbstractTo investigate human basophil responses to chemokines, we have developed a sensitive assay that uses flow cytometry to measure leukocyte shape change as a marker of cell responsiveness. PBMC were isolated from the blood of volunteers. Basophils were identified as a single population of cells that stained positive for IL-3Rα (CDw123) and negative for HLA-DR, and their increase in forward scatter (as a result of cell shape change) in response to chemokines was measured. Shape change responses of basophils to chemokines were highly reproducible, with a rank order of potency: monocyte chemoattractant protein (MCP) 4 (peak at &lt;1 nM) ≥ eotaxin-2 = eotaxin-3 ≥ eotaxin &gt; MCP-1 = MCP-3 &gt; macrophage-inflammatory protein-1α &gt; RANTES = MCP-2 = IL-8. The CCR4-selective ligand macrophage-derived chemokine did not elicit a response at concentrations up to 10 nM. Blocking mAbs to CCR2 and CCR3 demonstrated that responses to higher concentrations (&gt;10 nM) of MCP-1 were mediated by CCR3 rather than CCR2, whereas MCP-4 exhibited a biphasic response consistent with sequential activation of CCR3 at lower concentrations and CCR2 at 10 nM MCP-4 and above. In contrast, responses to MCP-3 were blocked only in the presence of both mAbs, but not after pretreatment with either anti-CCR2 or anti-CCR3 mAb alone. These patterns of receptor usage were different from those seen for eosinophils and monocytes. We suggest that cooperation between CCRs might be a mechanism for preferential recruitment of basophils, as occurs in tissue hypersensitivity responses in vivo.
Up-Regulation of the IL-12 Receptor β2 Chain in Crohn’s Disease
Authors: Parrello Tiziana , Monteleone Giovanni , Cucchiara Salvatore , Monteleone Ivan , Sebkova Ladislava , Doldo Patrizia , Luzza Francesco , Pallone Francesco 
Published: April 2014

AbstractCrohn’ s disease (CD) is a chronic intestinal inflammatory disorder characterized by aberrant mucosal Th1 cell activation and production of IL-12, the major Th1-driving factor. The T cell response to IL-12 is dependent on the expression of a specific receptor composed of two subunits, termed IL-12Rβ1 and IL-12Rβ2. The content of IL-12Rβ2, as measured at the mRNA level, is crucial in regulating Th1 differentiation. In this study we therefore investigated IL-12Rβ2 RNA transcripts in CD. IL-12Rβ2 expression was increased in active CD as well as Helicobacter pylori (HP)-associated gastritis and Salmonella colitis compared with that in inactive CD, ulcerative colitis, noninflammatory controls, and celiac disease. In contrast, IL-12Rβ1 transcripts were expressed at comparable levels in all samples. In CD, IL-12Rβ2 expression strictly correlated with tyrosine phosphorylation of STAT4, a key component of the IL-12-dependent Th1 polarization. This was associated with a pronounced expression of IFN-γ. Transcripts for IL-12/p40 were detected in CD, HP-positive, and Salmonella colitis patients, but not in celiac disease, indicating that IL-12Rβ2 up-regulation occurs only in IL-12-associated Th1 gastrointestinal diseases. Finally, we showed that stimulation of lamina propria mononuclear cells with IL-12 enhanced IL-12Rβ2, suggesting that IL-12 regulates IL-12Rβ2 expression in human gastrointestinal mucosa. The data show that the signaling pathway used by IL-12 to induce Th1 differentiation is increased at the site of disease in CD, further supporting the view that IL-12/IL-12R signals contribute to the inflammatory response in this condition.
Evaluation of TNF-α and IL-1 Blockade in Collagen-Induced Arthritis and Comparison with Combined Anti-TNF-α/Anti-CD4 Therapy
Authors: Williams Richard O. , Marinova-Mutafchieva Lilia , Feldmann Marc , Maini Ravinder N. 
Published: April 2014

AbstractWe have evaluated the effects of anti-TNF-α, anti-IL-1, and combined anti-TNF-α/anti-CD4 therapy in collagen-induced arthritis. Blockade of TNF-α or IL-1 before disease onset delayed, but did not prevent, the induction of arthritis. When treatment was initiated after onset of arthritis, anti-TNF-α, anti-IL-1β, and anti-IL-1R (which blocks IL-1α and IL-1β) were all found to be effective in reducing the severity of arthritis, with anti-IL-1R and anti-IL-1β showing greater efficacy than anti-TNF-α. Anti-IL-1β was equally as effective as anti-IL-1R, indicating that IL-1β plays a more prominent role than IL-1α in collagen-induced arthritis. An additive effect was observed between anti-TNF-α and anti-IL-1R in the prevention of joint erosion and in normalization of the levels of serum amyloid P. Combined anti-TNF-α/anti-CD4 therapy also caused normalization of serum amyloid P levels. The therapeutic effect of anti-TNF-α plus anti-CD4 was comparable to that of anti-TNF-α plus anti-IL-1R, suggesting that combined anti-TNF-α/anti-CD4 therapy prevents both TNF-α- and IL-1-mediated pathology. Anti-TNF-α treatment reduced IL-1β expression in the joint and, conversely, anti-IL-1β treatment reduced TNF-α expression. Combined anti-TNF-α/anti-CD4 treatment almost completely blocked the expression of IL-1β, thereby confirming the ability of this form of combination therapy to prevent IL-1β-mediated pathology.
Adenoviral Transfer of Cyclin-Dependent Kinase Inhibitor Genes Suppresses Collagen-Induced Arthritis in Mice
Authors: Nasu Kimio , Kohsaka Hitoshi , Nonomura Yoshinori , Terada Yoshio , Ito Hiroshi , Hirokawa Katsuiku , Miyasaka Nobuyuki 
Published: April 2014

AbstractIn rheumatoid synovial tissues, synovial fibroblasts are activated by proinflammatory cytokines and proliferate to develop hyperplastic pannus tissues, which irreversibly damage the affected joints. We recently reported that the cyclin-dependent kinase inhibitors p16INK4a and p21Cip1 are not expressed in vivo in rheumatoid synovial fibroblasts, but are readily inducible in vitro. This observation was followed by the successful treatment of rat adjuvant arthritis by local p16INK4a gene transfer, showing that the inhibition of the cell cycle of the synovial cells ameliorates the arthritis. In this study, we show that another animal model of rheumatoid arthritis, murine collagen-induced arthritis, can be effectively treated by local gene transfer of p21Cip1 as well as that of p16INK4a. The anti-arthritic effects were observed even when the treatment was conducted after the arthritis had developed. Furthermore, the effects included suppression of the expression of proinflammatory cytokines such as IL-1β, IL-6, and TNF-α. Our results demonstrate that the ectopic expression of cyclin-dependent kinase inhibitors not only prevents synovial overgrowth but also ameliorates the proinflammatory milieu in the affected joints. The induction of p21Cip1 in rheumatoid synovial tissues by pharmacological agents may also be an effective strategy to treat rheumatoid arthritis.
Efficient Simultaneous Presentation of NY-ESO-1/LAGE-1 Primary and Nonprimary Open Reading Frame-Derived CTL Epitopes in Melanoma
Authors: Rimoldi Donata , Rubio-Godoy Verena , Dutoit Valerie , Lienard Danielle , Salvi Suzanne , Guillaume Philippe , Speiser Daniel , Stockert Elisabeth , Spagnoli Giulio , Servis Catherine , Cerottini Jean-Charles , Lejeune Ferdy , Romero Pedro , Valmori Danila 
Published: April 2014

AbstractRecent studies have shown that CTL epitopes derived from tumor-associated Ags can be encoded by both primary and nonprimary open reading frames (ORF). In this study we have analyzed the HLA-A2-restricted CD8+ T cell response to a recently identified CTL epitope derived from an alternative ORF product of gene LAGE-1 (named CAMEL), and the highly homologous gene NY-ESO-1 in melanoma patients. Using MHC/peptide tetramers we detected CAMEL1–11-specific CD8+ T cells in peptide-stimulated PBMC as well as among tumor-infiltrated lymph node cells from several patients. Sorting and expansion of tetramer+ CD8+ T cells allowed the isolation of tetramerbright and tetramerdull populations that specifically recognized the peptide Ag with high and low avidity, respectively. Remarkably, only high avidity CAMEL-specific CTL were able to recognize Ag-expressing tumor cells. A large series of HLA-A2-positive melanoma cell lines was characterized for the expression of LAGE-1 and NY-ESO-1 mRNA and protein and tested for recognition by CAMEL-specific CTL as well as CTL that recognize a peptide (NY-ESO-1157–165) encoded by the primary ORF products of the LAGE-1 and NY-ESO-1 genes. This analysis revealed that tumor-associated CD8+ T cell epitopes are simultaneously and efficiently generated from both primary and nonprimary ORF products of LAGE-1 and NY-ESO-1 genes and, importantly, that this occurs in the majority of melanoma tumors. These findings underscore the in vivo immunological relevance of CTL epitopes derived from nonprimary ORF products and support their use as candidate vaccines for inducing tumor specific cell-mediated immunity against cancer.