bluuebunny/crossref_metadata_2025_split huggingface dataset:
Down-Regulation of Intestinal Lymphocyte Activation and Th1 Cytokine Production by Antibiotic Therapy in a Murine Model of Crohn’s Disease
Authors: Bamias Giorgos , Marini Marco , Moskaluk Christopher A. , Odashima Masaru , Ross William G. , Rivera-Nieves Jesús , Cominelli Fabio 
Published: April 2014

Abstract
Resident intestinal bacteria likely play an important role in the pathogenesis of Crohn’s disease through their interaction with the gut immune system. SAMP1/YitFc mice spontaneously develop chronic, discontinuous, transmural ileitis with many features similar to Crohn’s disease. The aim of this study was to determine the effects and elucidate the mechanisms of action of antibiotic treatment in the SAMP1/YitFc mouse model of ileitis. Mice were treated orally with ciprofloxacin and metronidazole before the development of ileitis (prevention protocol) or after ileitis was fully established (treatment protocol). Terminal ilea were harvested for histological scoring, and lamina propria and mesenteric lymph node cells were isolated for analysis of activation markers and cytokine production. Antibiotic therapy significantly decreased the severity of ileitis both in the prevention (40% reduction, p &lt; 0.05) and the treatment (25% reduction, p &lt; 0.01) protocols, compared with untreated, control mice. These effects were associated with a decreased percentage of CD4+/CD45RBhigh lymphocytes in mesenteric lymph nodes of antibiotic-treated mice, as well as decreased production of IFN-γ (prevention: 0.53 ± 0.21 vs 1.84 ± 0.04 ng/ml, p &lt; 0.05; treatment: 8.4 ± 0.4 vs 12.4 ± 0.7 ng/ml, p &lt; 0.005) and TNF (prevention: 61.5 ± 13 vs 134 ± 19 pg/ml, p &lt; 0.01; treatment: 333.5 ± 11 vs 496 ± 20 pg/ml, p &lt; 0.001). The number of activated lamina propria lymphocytes was also reduced after antibiotic treatment. In conclusion, antibiotic therapy significantly ameliorates the severity of ileitis in SAMP1/YitFc mice by a mechanism involving down-regulation of activated gut lymphocytes and inhibition of intestinal Th1 cytokine production.
Delineation of Five Thyroglobulin T Cell Epitopes with Pathogenic Potential in Experimental Autoimmune Thyroiditis
Authors: Verginis Panayotis , Stanford Marianne M. , Carayanniotis George 
Published: April 2014

Abstract
Experimental autoimmune thyroiditis (EAT) is a T cell-mediated disease that can be induced in mice after challenge with thyroglobulin (Tg) or Tg peptides. To date, five pathogenic Tg peptides have been identified, four of which are clustered toward the C-terminal end. Because susceptibility to EAT is under control of H-2Ak genes, we have used an algorithm-based approach to identify Ak-binding peptides with pathogenic potential within mouse Tg. Eight candidate synthetic peptides, varying in size from 9 to 15 aa, were tested and five of those (p306, p1579, p1826, p2102, and p2596) were found to induce EAT in CBA/J (H-2k) mice either after direct challenge with peptide in adjuvant or by adoptive transfer of peptide-sensitized lymph node cells (LNCs) into naive hosts. These pathogenic peptides were immunogenic at the T cell level, eliciting specific LNC proliferative responses and IL-2 and/or IFN-γ secretion in recall assays in vitro, but contained nondominant epitopes. All immunogenic peptides were confirmed as Ak binders because peptide-specific LNC proliferation was blocked by an Ak-specific mAb, but not by a control mAb. Peptide-specific serum IgG was induced only by p2102 and p2596, but these Abs did not bind to intact mouse Tg. This study reaffirms the predictive value of Ak-binding motifs in epitope mapping and doubles the number of known pathogenic T cell determinants in Tg that are now found scattered throughout the length of this large autoantigen. This knowledge may contribute toward our understanding of the pathogenesis of autoimmune thyroiditis.
Cutting Edge: Major CD8 T Cell Response to Live Bacillus Calmette-Guérin Is Mediated by CD1 Molecules
Authors: Kawashima Tetsuo , Norose Yoshihiko , Watanabe Yoshiyuki , Enomoto Yutaka , Narazaki Hidehiko , Watari Eiji , Tanaka Shigeo , Takahashi Hidemi , Yano Ikuya , Brenner Michael B. , Sugita Masahiko 
Published: April 2014

Abstract
MHC class I-restricted CD8+ T cells are a crucial component of the host defense against mycobacterial infection in mice, but it has often proved very difficult to identify the CD8 T cell response in humans. Human group 1 CD1 molecules (CD1a, -b, -c) mediate MHC-independent presentation of mycobacteria-derived lipid and glycolipid Ags to CD8+ T cells, and their intracellular localization to the endocytic system may favor efficient monitoring of phagosome-resident mycobacteria. Here, we show that bacillus Calmette-Guérin (BCG)-immunized subjects contain a significant circulating pool of CD8+ T cells that recognize BCG-infected DCs in a CD1-dependent, but MHC-independent, manner. These CD1-restricted T cells efficiently detected live, rather than dead, BCG and produced IFN-γ, an important cytokine for protection against mycobacterial infection. These results emphasize that lipid-reactive CD8+ T cells may contribute to host defense against mycobacterial infection.
Cutting Edge: Bradykinin Induces IL-12 Production by Dendritic Cells: A Danger Signal That Drives Th1 Polarization
Authors: Aliberti Julio , Viola João P. B. , Vieira-de-Abreu Adriana , Bozza Patricia T. , Sher Alan , Scharfstein Julio 
Published: April 2014

Abstract
Dendritic cells play a major role in the induction of both innate and acquired immune responses against pathogenic invaders. These cells are also able to sense endogenous activation signals liberated by injured tissues even in the absence of infection. In the present work, we demonstrate that kinins mobilize dendritic cells to produce IL-12 through activation of the B2 bradykinin receptor subtype and that bradykinin-induced IL-12 responses are tightly regulated both by angiotensin-converting enzyme, a kinin-degrading peptidase, and by endogenous IL-10. Using a mouse model of allergic inflammation, we further show that addition of bradykinin to OVA during immunization results in decreased eosinophil infiltration on Ag challenge. The latter effect was demonstrated to be due to IL-12-driven skewing of Ag-specific T cell responses to a type 1 cytokine profile. Our data thus indicate that kinin peptides can serve as danger signals that trigger dendritic cells to produce IL-12 through activation of B2 bradykinin receptors.
Differential Regulation of Human Eosinophil IL-3, IL-5, and GM-CSF Receptor α-Chain Expression by Cytokines: IL-3, IL-5, and GM-CSF Down-Regulate IL-5 Receptor α Expression with Loss of IL-5 Responsiveness, but Up-Regulate IL-3 Receptor α Expression
Authors: Gregory Bernard , Kirchem Antje , Phipps Simon , Gevaert Phillipe , Pridgeon Carol , Rankin Sara M. , Robinson Douglas S. 
Published: April 2014

Abstract
Our recent data suggested that tissue eosinophils may be relatively insensitive to anti-IL-5 treatment. We examined cross-regulation and functional consequences of modulation of eosinophil cytokine receptor expression by IL-3, IL-5 GM-CSF, and eotaxin. Incubation of eosinophils with IL-3, IL-5, or GM-CSF led to reduced expression of IL-5Rα, which was sustained for up to 5 days. Eosinophils incubated with IL-5 or IL-3 showed diminished respiratory burst and mitogen-activated protein kinase kinase phosphorylation in response to further IL-5 stimulation. In contrast to these findings, eosinophil expression of IL-3Rα was increased by IL-3, IL-5, and GM-CSF, whereas GM-CSF receptor α was down-regulated by GM-CSF, but was not affected by IL-3 or IL-5. CCR3 expression was down-regulated by IL-3 and was transiently reduced by IL-5 and GM-CSF, but rapidly returned toward baseline. Eotaxin had no effect on receptor expression for IL-3, IL-5, or GM-CSF. Up-regulation of IL-3Rα by cytokines was prevented by a phosphoinositol 3-kinase inhibitor, whereas this and other signaling inhibitors had no effect on IL-5Rα down-regulation. These data suggest dynamic and differential regulation of eosinophil receptors for IL-3, IL-5, and GM-CSF by the cytokine ligands. Since these cytokines are thought to be involved in eosinophil development and mobilization from the bone marrow and are present at sites of allergic inflammation, tissue eosinophils may have reduced IL-5R expression and responsiveness, and this may explain the disappointing effect of anti-IL-5 therapy in reducing airway eosinophilia in asthma.
Stimulation of Primary Human Endothelial Cell Proliferation by IFN
Authors: Gomez Dolores , Reich Nancy C. 
Published: April 2014

Abstract
The IFN family of cytokines has pleiotropic roles in immunity and development. In this study, we provide evidence that IFN can stimulate the proliferation of primary human endothelial cells. This is in contrast to the growth-suppressive effects of IFN observed on transformed human cells, thereby underscoring the distinctive responses of primary human cells. The growth-stimulatory effect of IFN was determined by an increase in DNA synthesis assessed with [3H]thymidine incorporation, an increase in G2 and M cell cycle phases assessed with flow cytometric analysis, and an increase in cell number. Distinct cell types, including primary human fibroblast and smooth muscle cells, were also growth stimulated by IFN. Neutralizing Abs to IFN were used to demonstrate the growth response was mediated specifically by the IFN cytokine. The signaling pathway of type I IFNs activates STAT1 and STAT2. In primary endothelial cells, we demonstrate that STAT3 and STAT5 are also activated, and these STATs may contribute to cellular proliferation. To evaluate possible effectors of positive growth, DNA microarray analyses were performed to assess gene induction in response to IFN. These results reveal changes in the RNA levels of genes in endothelial cells that encode proteins involved in cellular proliferation.
NK Cell Tolerance in Mixed Allogeneic Chimeras
Authors: Zhao Yong , Ohdan Hideki , Manilay Jennifer O. , Sykes Megan 
Published: April 2014

AbstractAlterations in inhibitory receptor expression on NK cells have been detected in mixed allogeneic chimeras and in mosaic MHC class I-expressing transgenic mice. However, it is not known whether or not NK cells are tolerant to host and donor Ags in mixed chimeras. In vitro studies have shown a lack of mutual tolerance of separated donor and host NK cells obtained from mixed chimeras. Using BALB/c→B6 fully MHC-mismatched mixed chimeras, we have now investigated this question in vivo. Neither donor nor host NK cells in mixed chimeras showed evidence for activation, as indicated by expression of B220 and Thy-1.2 on NK cells in chimeric mice at levels similar to those in nonchimeric control mice. Lethally irradiated, established mixed BALB/c→ B6 chimeras rejected a low dose of β2-microglobulin-deficient bone marrow cells (BMC) efficiently but did not reject BALB/c or B6 BMCs. In contrast, similarly conditioned B6 mice rejected both BALB/c and β2-microglobulin-deficient BMCs. Thus, NK cells were specifically tolerant to the donor and the host in mixed allogeneic chimeras. The similar growth of RMA lymphoma cells in both chimeric and control B6 mice further supports the conclusion that donor BALB/c NK cells are tolerant to B6 Ags in chimeras. Administration of a high dose of exogenous IL-2 could not break NK cell tolerance in chimeric mice, suggesting that NK cell tolerance in chimeras is not due to a lack of activating cytokine. No reduction in the level of expression of the activating receptor Ly-49D, recognizing a donor MHC molecule, was detected among recipient NK cells in mixed chimeras. Thus, the present studies demonstrate that NK cells in mixed chimeras are stably tolerant to both donor and host Ags, by mechanisms that are as yet unexplained.
IL-21 in Synergy with IL-15 or IL-18 Enhances IFN-γ Production in Human NK and T Cells
Authors: Strengell Mari , Matikainen Sampsa , Sirén Jukka , Lehtonen Anne , Foster Don , Julkunen Ilkka , Sareneva Timo 
Published: April 2014

Abstract
NK and T cell-derived IFN-γ is a key cytokine that stimulates innate immune responses and directs adaptive T cell response toward Th1 type. IL-15, IL-18, and IL-21 have significant roles as activators of NK and T cell functions. We have previously shown that IL-15 and IL-21 induce the expression of IFN-γ, T-bet, IL-12Rβ2, and IL-18R genes both in NK and T cells. Now we have studied the effect of IL-15, IL-18, and IL-21 on IFN-γ gene expression in more detail in human NK and T cells. IL-15 clearly activated IFN-γ mRNA expression and protein production in both cell types. IL-18 and IL-21 enhanced IL-15-induced IFN-γ gene expression. IL-18 or IL-21 alone induced a modest expression of the IFN-γ gene but a combination of IL-21 and IL-18 efficiently up-regulated IFN-γ production. We also show that IL-15 activated the binding of STAT1, STAT3, STAT4, and STAT5 to the regulatory sites of the IFN-γ gene. Similarly, IL-21 induced the binding of STAT1, STAT3, and STAT4 to these elements. IL-15- and IL-21-induced STAT1 and STAT4 activation was verified by immunoprecipitation with anti-phosphotyrosine Abs followed by Western blotting with anti-STAT1 and anti-STAT4 Abs. IL-18 was not able to induce the binding of STATs to IFN-γ gene regulatory sites. IL-18, however, activated the binding of NF-κB to the IFN-γ promoter NF-κB site. Our results suggest that both IL-15 and IL-21 have an important role in activating the NK cell-associated innate immune response.
Drug-Inducible, Dendritic Cell-Based Genetic Immunization
Authors: Timares Laura , Safer Karim Mahmoud , Qu Baoxi , Takashima Akira , Johnston Stephen Albert 
Published: April 2014

Abstract
Determining the mechanism of Ag loading of Langerhans cells (LC) for genetic immunization (GI) is complicated by the inability to distinguish between the response generated by direct transfection of LC from that due to exogenous uptake. To unravel this mechanism, we examined the impact of gene gun treatment on LC with respect to their activation and migration from skin, transgene expression, and ability to initiate humoral and cellular immune responses upon transfer to naive mice. To assess responses generated by direct LC transfection, an RU486-inducible expression system was used as a GI vector. In vitro skin organ cultures were developed from gene gun immunized mouse ear specimens to obtain LC. Gene gun treatment markedly augmented (3-fold) LC migration from ear skin, and these LC expressed the transgene at RNA and protein levels. Transfer of 2 × 105 migratory cells resulted in identical cellular responses to, but 10-fold lower humoral responses than, standard GI. Using an RU486-inducible system, we were able to measure responses generated by directly transfected LC. Our results indicate that direct transfection is a predominant pathway for LC Ag loading. The ability to regulate transgene expression with inducible DC-based vaccines demonstrates a new level of immunological control.
Thyroid-Specific Expression of IFN-γ Limits Experimental Autoimmune Thyroiditis by Suppressing Lymphocyte Activation in Cervical Lymph Nodes
Authors: Barin Jobert G. , Afanasyeva Marina , Talor Monica V. , Rose Noel R. , Burek C. Lynne , Caturegli Patrizio 
Published: April 2014

Abstract
The role of IFN-γ in the pathogenesis of autoimmune disease is controversial, being described as immunostimulatory in some studies and immunosuppressive in others. To determine the contribution of local expression of IFN-γ, we derived NOD.H-2h4 transgenic mice overexpressing IFN-γ in a thyroid-restricted manner. Transgenic mice, which had serum IFN-γ levels similar to wild-type littermates, showed up-regulation of MHC class II on thyrocytes, but did not develop spontaneous thyroiditis. Upon immunization with murine thyroglobulin, transgenic mice developed milder disease and reduced IgG1 responses compared with wild type. The milder disease was associated with decreased frequency of activated CD44+ lymphocytes in the cervical lymph nodes. This suppressive effect was confirmed by showing that blockade of systemic IFN-γ with mAb enhanced disease and increased IgG1 responses. The study supports a disease-limiting role of IFN-γ in autoimmune thyroiditis. Furthermore, it provides the first evidence that local IFN-γ activity in the thyroid is sufficient for disease suppression.
Novel Variants of the IL-10 Receptor 1 Affect Inhibition of Monocyte TNF-α Production
Authors: Gasche Christoph , Grundtner Paul , Zwirn Petra , Reinisch Walter , Shaw Sarah H. , Zdanov Alexander , Sarma Usha , Williams Lynn M. , Foxwell Brian M. , Gangl Alfred 
Published: April 2014

Abstract
IL-10-deficient mice exhibit spontaneous enterocolitis and other symptoms akin to Crohn’s disease, indicating that IL-10 might regulate normal physiology in the gut. However, clinical trials with IL-10 in Crohn’s disease were disappointing, although some patients showed healing of intestinal mucosa. This study searched for genetic polymorphisms within the IL-10 pathway. We decided to screen for mutations of the IL-10R1 cDNA in healthy volunteers and Crohn’s disease patients and identified two novel variants: a serine 138-to-glycine (S138G) and a glycine 330-to-arginine (G330R) substitution. The allelic frequency in a European cohort was relatively high (16% for the S138G and 33% for the G330R), and S138G was in strong linkage disequilibrium with G330R. A similar allele frequency was found in a group of Crohn’s patients. In IL-10R1 G330R-expressing monocytes, the inhibitory effect of IL-10 on TNF-α production was diminished, indicating that this variant may be a loss-of-function allele. No such difference was observed between haplotypes 4 (G330R only) and 7 (S138G and G330R). In addition, these IL-10R1 variants had no influence on the IL-10R1 expression density. Structural analysis of the S138G variant revealed that the substitution of S138G may interfere with binding of IL-10 to IL-10R1.
Wound Healing and Expression of Antimicrobial Peptides/Polypeptides in Human Keratinocytes, a Consequence of Common Growth Factors
Authors: Sørensen Ole E. , Cowland Jack B. , Theilgaard-Mönch Kim , Liu Lide , Ganz Tomas , Borregaard Niels 
Published: April 2014

Abstract
In addition to acting as a physical barrier against microorganisms, the skin produces antimicrobial peptides and proteins. After wounding, growth factors are produced to stimulate the regeneration of tissue. The growth factor response ceases after regeneration of the tissue, when the physical barrier protecting against microbial infections is re-established. We found that the growth factors important in wound healing, insulin-like growth factor I and TGF-α, induce the expression of the antimicrobial peptides/polypeptides human cationic antimicrobial protein hCAP-18/LL-37, human β-defensin 3, neutrophil gelatinase-associated lipocalin, and secretory leukocyte protease inhibitor in human keratinocytes. Both an individual and a synergistic effect of these growth factors were observed. These findings offer an explanation for the expression of these peptides/polypeptides in the skin disease psoriasis and in wound healing and define a host defense role for growth factors in wound healing.
IKKβ Plays an Essential Role in the Phosphorylation of RelA/p65 on Serine 536 Induced by Lipopolysaccharide
Authors: Yang Fan , Tang Eric , Guan Kunliang , Wang Cun-Yu 
Published: April 2014

Abstract
Activation of the IκB kinase (IKK) complex by LPS induces phosphorylation and degradation of IκBα, leading to the nuclear translocation of NF-κB. Although it is essential for NF-κB activation, emerging evidence has indicated that the nuclear translocation of NF-κB is not sufficient to activate NF-κB-dependent transcription. Here, we reported that LPS induced the phosphorylation of the p65 trans-activation domain on serine 536 in monocytes/macrophages. Using mouse embryonic fibroblasts lacking either IKKα or IKKβ, we found that IKKβ played an essential role in LPS-induced p65 phosphorylation on serine 536, while IKKα was partially required for the p65 phosphorylation. The LPS-induced p65 phosphorylation on serine 536 was independent of the phosphatidylinositol 3′-kinase/Akt signaling pathway. Furthermore, we found that the phosphorylation on serine 536 increased the p65 transcription activity. In summary, our results demonstrate that IKKβ plays an essential role in the LPS-induced p65 phosphorylation on serine 536, which may represent a mechanism to regulate the NF-κB transcription activity by LPS.
Effective Mucosal Immunity to Anthrax: Neutralizing Antibodies and Th Cell Responses Following Nasal Immunization with Protective Antigen
Authors: Boyaka Prosper N. , Tafaro Angela , Fischer Romy , Leppla Stephen H. , Fujihashi Kohtaro , McGhee Jerry R. 
Published: April 2014

Abstract
Mucosal, but not parenteral, immunization induces immune responses in both systemic and secretory immune compartments. Thus, despite the reports that Abs to the protective Ag of anthrax (PA) have both anti-toxin and anti-spore activities, a vaccine administered parenterally, such as the aluminum-adsorbed anthrax vaccine, will most likely not induce the needed mucosal immunity to efficiently protect the initial site of infection with inhaled anthrax spores. We therefore took a nasal anthrax vaccine approach to attempt to induce protective immunity both at mucosal surfaces and in the peripheral immune compartment. Mice nasally immunized with recombinant PA (rPA) and cholera toxin (CT) as mucosal adjuvant developed high plasma PA-specific IgG Ab responses. Plasma IgA Abs as well as secretory IgA anti-PA Abs in saliva, nasal washes, and fecal extracts were also induced when a higher dose of rPA was used. The anti-PA IgG subclass responses to nasal rPA plus CT consisted of IgG1 and IgG2b Abs. A more balanced profile of IgG subclasses with IgG1, IgG2a, and IgG2b Abs was seen when rPA was given with a CpG oligodeoxynucleotide as adjuvant, suggesting a role for the adjuvants in the nasal rPA-induced immunity. The PA-specific CD4+ T cells from mice nasally immunized with rPA and CT as adjuvant secreted low levels of CD4+ Th1-type cytokines in vitro, but exhibited elevated IL-4, IL-5, IL-6, and IL-10 responses. The functional significance of the anti-PA Ab responses was established in an in vitro macrophage toxicity assay in which both plasma and mucosal secretions neutralized the lethal effects of Bacillus anthracis toxin.
Urokinase-Type Plasminogen Activator Potentiates Lipopolysaccharide-Induced Neutrophil Activation
Authors: Abraham Edward , Gyetko Margaret R. , Kuhn Katherine , Arcaroli John , Strassheim Derek , Park Jong Sung , Shetty Sreerama , Idell Steven 
Published: April 2014

Abstract
Urokinase plasminogen activator (uPA) is a serine protease that catalyzes the conversion of plasminogen to plasmin. Although increased circulating levels of uPA are present in endotoxemia and sepsis, conditions in which activated neutrophils contribute to the development of acute organ dysfunction, the ability of uPA to participate directly in LPS-induced neutrophil activation has not been examined. In the present experiments, we show that uPA can enhance activation of neutrophils exposed to submaximal stimulatory doses of LPS. In particular, uPA increased LPS-induced activation of intracellular signaling pathways, including Akt and c-Jun N-terminal kinase, nuclear translocation of the transcriptional regulatory factor NF-κB, and expression of proinflammatory cytokines, including IL-1β, macrophage-inflammatory protein-2, and TNF-α. There was no effect of uPA on LPS-induced activation of p38 mitogen-activated protein kinase in neutrophils. Transgenic mice unable to produce uPA (uPA−/−) were protected from endotoxemia-induced lung injury, as determined by development of lung edema, pulmonary neutrophil accumulation, lung IL-1β, macrophage-inflammatory protein-2, and TNF-α cytokine levels. These results demonstrate that uPA can potentiate LPS-induced neutrophil responses and also suggest that such effects are sufficiently important in vivo to play a major contributory role in neutrophil-mediated inflammatory responses, such as the development of acute lung injury.