bluuebunny/crossref_metadata_2025_split huggingface dataset:
Listeria monocytogenesModulates Macrophage Cytokine Responses Through STAT Serine Phosphorylation and the Induction of Suppressor of Cytokine Signaling 3
Authors: Stoiber Dagmar , Stockinger Silvia , Steinlein Peter , Kovarik Jan , Decker Thomas 
Published: April 2014

AbstractMacrophage activation as part of natural resistance to infection is caused by stimulation with IFN-γ and by the invading microorganisms or microbial products. Infection of macrophages with the Gram-positive bacterium Listeria monocytogenes for short periods before activation with IFN-γ increased the phosphorylation of transcription factor STAT1 at S727 and thereby the expression of IFN-γ-induced genes. By contrast, persistent infection with viable bacteria or treatment with heat-killed Listeria diminished IFN-γ-stimulated transcription and the phosphorylation of STAT1 at Y701. Decreased IFN-γ signaling correlated with the induction of suppressor of cytokine signaling 3 (SOCS3) mRNA and protein. Contrasting our previous findings with LPS, maximal synthesis of SOCS3 required both the immediate signals from Listeria receptors on the cell surface and the activity of a polypeptide secreted in response to bacterial infection. SOCS3 induction by the secreted protein could not be blocked by neutralizing Abs to IL-10 and it did not require the presence of STAT1. Consistent with the induction of SOCS3 activity, Listeria also inhibited activation of STAT5 by GM-CSF. The p38 mitogen-activated protein kinase was rapidly activated upon infection of macrophages with L. monocytogenes. Inhibition of p38 mitogen-activated protein kinase with the pyridinyl imidazol SB203580 abrogated both STAT1 S727 phosphorylation and the expression of SOCS3. The data suggest that STAT1 serine kinase and SOCS3 activity are hallmarks of immediate and delayed phases of influence by bacterial signals on signal transduction in response to IFN-γ.
Borrelia burgdorferiand Other Bacterial Products Induce Expression and Release of the Urokinase Receptor (CD87)
Authors: Coleman James L. , Gebbia Joseph A. , Benach Jorge L. 
Published: April 2014

AbstractThe urokinase-type plasminogen activator receptor (uPAR, CD87) is a highly glycosylated 55- to 60-kDa protein anchored to the cell membrane through a glycosylphosphatidylinositol moiety that promotes the acquisition of plasmin on the surface of cells and subsequent cell movement and migration by binding urokinase-type plasminogen activator. uPAR also occurs in a soluble form in body fluids and tumor extracts, and both membrane and soluble uPAR are overexpressed in patients with tumors. uPAR may be a factor in inflammatory disorders as well. We investigated whether Borrelia burgdorferi could stimulate up-regulation of cell membrane uPAR in vitro. B. burgdorferi, purified native outer surface protein A, and a synthetic outer surface protein A hexalipopeptide stimulated human monocytes to up-regulate membrane uPAR as measured by immunofluorescence/FACS and Western blot. The presence of soluble uPAR in culture supernatants, measured by Ag capture ELISA, was also observed. LPS from Salmonella typhimurium and lipotechoic acid from Streptococcus pyogenes also induced the up-regulation of both membrane and soluble uPAR protein by monocytes. Up-regulation of uPAR was induced by conditioned medium from B. burgdorferi/monocyte cocultures. The up-regulation of uPAR by B. burgdorferi was concomitant with an increase in uPAR mRNA, indicating that synthesis was de novo. The expression and release of uPAR in response to B. burgdorferi and other bacterial components suggests a role in the pathogenesis of Lyme disease as well as in other bacterial infections.
Protein-Tyrosine Kinase Syk Expressed in Human Nasal Fibroblasts and Its Effect on RANTES Production
Authors: Yamada Takechiyo , Fujieda Shigeharu , Yanagi Shigeru , Yamamura Hirohei , Inatome Ryoko , Sunaga Hiroshi , Saito Hitoshi 
Published: April 2014

AbstractFibroblasts, a rich source of chemokines, interact with eosinophils and play a key role in the pathogenesis of airway disease. RANTES is produced by fibroblasts to attract and activate eosinophils. LPS is known to induce RANTES and cause protein tyrosine phosphorylation. Nonreceptor protein tyrosine kinase Syk is widely expressed and an important role in intracellular signal transduction in hemopoietic cells. In the present study, we examined whether Syk was expressed in a number of primary human nasal polyp tissue-derived fibroblast lines and whether it played some role in cellular function. Syk proteins were expressed in human nasal fibroblasts, but the expression level varied. There were positive correlations between the level of Syk expression and RANTES production induced by LPS. Overexpression of wild-type Syk by gene transfer enhanced RANTES production from nasal fibroblasts stimulated with LPS. The decrease of Syk expression by the administration of Syk antisense inhibited RANTES production. These results suggest that Syk expression affects RANTES production in fibroblasts of nasal polyps.
Production of IL-12 by Human Monocyte-Derived Dendritic Cells Is Optimal When the Stimulus Is Given at the Onset of Maturation, and Is Further Enhanced by IL-4
Authors: Ebner Susanne , Ratzinger Gudrun , Krösbacher Beate , Schmuth Matthias , Weiss Angelika , Reider Daniela , Kroczek Richard A. , Herold Manfred , Heufler Christine , Fritsch Peter , Romani Nikolaus 
Published: April 2014

AbstractDendritic cells produce IL-12 both in response to microbial stimuli and to T cells, and can thus skew T cell reactivity toward a Th1 pattern. We investigated the capacity of dendritic cells to elaborate IL-12 with special regard to their state of maturation, different maturation stimuli, and its regulation by Th1/Th2-influencing cytokines. Monocyte-derived dendritic cells were generated with GM-CSF and IL-4 for 7 days, followed by another 3 days ± monocyte-conditioned media, yielding mature (CD83+/dendritic cell-lysosome-associated membrane glycoprotein+) and immature (CD83−/dendritic cell-lysosome-associated membrane glycoprotein−) dendritic cells. These dendritic cells were stimulated for another 48 h, and IL-12 p70 was measured by ELISA. We found the following: 1) Immature dendritic cells stimulated with CD154/CD40 ligand or bacteria (both of which concurrently also induced maturation) secreted always more IL-12 than already mature dendritic cells. Mature CD154-stimulated dendritic cells still made significant levels (up to 4 ng/ml). 2) Terminally mature skin-derived dendritic cells did not make any IL-12 in response to these stimuli. 3) Appropriate maturation stimuli are required for IL-12 production: CD40 ligation and bacteria are sufficient; monocyte-conditioned media are not. 4) Unexpectedly, IL-4 markedly increased the amount of IL-12 produced by both immature and mature dendritic cells, when present during stimulation. 5) IL-10 inhibited the production of IL-12. Our results, employing a cell culture system that is now being widely used in immunotherapy, extend prior data that IL-12 is produced most abundantly by dendritic cells that are beginning to respond to maturation stimuli. Surprisingly, IL-12 is only elicited by select maturation stimuli, but can be markedly enhanced by the addition of the Th2 cytokine, IL-4.
IL-12 and IL-18 Are Increased and Stimulate IFN-γ Production in Sarcoid Lungs
Authors: Shigehara Katsunori , Shijubo Noriharu , Ohmichi Mitsuhide , Takahashi Ryuji , Kon Shin-ichiro , Okamura Haruki , Kurimoto Masashi , Hiraga Yohmei , Tatsuno Tachio , Abe Shosaku , Sato Noriyuki 
Published: April 2014

AbstractSarcoidosis is a systemic chronic granulomatous disease of unknown cause. Recent investigations revealed that the cytokine profile in inflamed lesions of sarcoidosis is Th1 dominant. To obtain better immunopathologic understanding of sarcoidosis, we examined the expression of IL-12 and IL-18 and their roles in IFN-γ production in pulmonary sarcoidosis. Sarcoid cases had significantly elevated levels of IL-12 (p40 and p70) and IL-18 in bronchoalveolar lavage (BAL) fluids compared with healthy subjects. IL-12 p70 and IL-18 were immunohistochemically expressed in the epithelioid cells and giant cells of sarcoid granulomas. Significant induction of IFN-γ, IL-12 p70, and IL-18 was observed from sarcoid BAL fluid cells with LPS stimulation, whereas LPS tended to induce only IL-12 p70 in BAL fluid cells from healthy subjects. Sarcoid cases had significantly greater IFN-γ induction with LPS stimulation than healthy subjects did. IL-18 mRNA expression was observed in freshly isolated sarcoid BAL fluid cells as well as in LPS-stimulated sarcoid BAL fluid cells, but IFN-γ and IL-12 mRNA expression was observed only in LPS-stimulated BAL fluid cells. Treatment with anti-IL-12- and anti-IL-18-neutralizing Abs significantly inhibited IFN-γ production from LPS-stimulated BAL fluid cells of sarcoid cases. Coadministration of rIL-12 or rIL-18 induced greater IFN-γ production in sarcoid BAL fluid cells than in normal BAL fluid cells. We concluded that bioactive IL-12 and IL-18 were produced in sarcoid BAL fluid cells and synergistically induced IFN-γ production, indicating important cytokines in the Th1 response of sarcoidosis.
egc, A Highly Prevalent Operon of Enterotoxin Gene, Forms a Putative Nursery of Superantigens in Staphylococcus aureus
Authors: Jarraud Sophie , Peyrat Marie Alix , Lim Annick , Tristan Anne , Bes Michèle , Mougel Christophe , Etienne Jerome , Vandenesch François , Bonneville Marc , Lina Gerard 
Published: April 2014

Abstract
The recently described staphylococcal enterotoxins (SE) G and I were originally identified in two separate strains of Staphylococcus aureus. We have previously shown that the corresponding genes seg and sei are present in S. aureus in tandem orientation, on a 3.2-kb DNA fragment (Jarraud, J. et al. 1999. J. Clin. Microbiol. 37:2446–2449). Sequence analysis of seg-sei intergenic DNA and flanking regions revealed three enterotoxin-like open reading frames related to seg and sei, designated sek, sel, and sem, and two pseudogenes, ψ ent1 and ψ ent2. RT-PCR analysis showed that all these genes, including seg and sei, belong to an operon, designated the enterotoxin gene cluster (egc). Recombinant SEG, SEI, SEK, SEL, and SEM showed superantigen activity, each with a specific Vβ pattern. Distribution studies of genes encoding superantigens in clinical S. aureus isolates showed that most strains harbored such genes and in particular the enterotoxin gene cluster, whatever the disease they caused. Phylogenetic analysis of enterotoxin genes indicated that they all potentially derived from this cluster, identifying egc as a putative nursery of enterotoxin genes.
Requirement for Leptin in the Induction and Progression of Autoimmune Encephalomyelitis
Authors: Matarese Giuseppe , Di Giacomo Antonio , Sanna Veronica , Lord Graham M. , Howard Jane K. , Di Tuoro Antonino , Bloom Stephen R. , Lechler Robert I. , Zappacosta Serafino , Fontana Silvia 
Published: April 2014

Abstract
Recent evidence indicates that leptin modifies T cell immunity, and may provide a key link between nutritional deficiency and immune dysfunction. To study the influence of leptin on autoimmunity, susceptibility to experimental autoimmune encephalomyelitis induced by immunization with a myelin-derived peptide was examined in leptin-deficient, C57BL/6J-ob/ob mice, with or without leptin replacement, and in wild-type controls. Leptin replacement converted disease resistance to susceptibility in the C57BL/6J-ob/ob mice; this was accompanied by a switch from a Th2 to Th1 pattern of cytokine release and consequent reversal of Ig subclass production. Our findings suggest that leptin is required for the induction and maintenance of an effective proinflammatory immune response in the CNS.
B Cell Immunodeficiency Fails to Develop in CD4-Deficient Mice Infected with BM5: Murine AIDS as a Multistep Disease
Authors: Harris David P. , Koch Susanne , Mullen Lina M. , Swain Susan L. 
Published: April 2014

AbstractThe immunodeficiency syndrome murine AIDS (MAIDS), caused by the BM5 retrovirus preparation, involves the activation, division, and subsequent anergy of the entire CD4+ T cell population as well as extensive B cell hyperproliferation and hypergammaglobulinemia, resulting in splenomegaly and lymphadenopathy, followed many weeks later by death. The development of MAIDS requires CD4+ T cells and MHC class II expression by the infected host, supporting a role for T-B interaction in disease development or progression. To explore this possibility, we examined development of MAIDS in mice deficient in CD4 (CD4 knockout), in which T-B interactions are compromised. We find that in CD4 knockout hosts, BM5 causes T cell immunodeficiency in the remaining T cells but has only a limited ability to induce B cell phenotypic changes, hyperproliferation, hypergammaglobulinemia, or splenomegaly. There is also delayed death of infected mice. This implies that CD4 dependent T-B interaction is needed to induce the B cell aspects of disease and supports a multistep mechanism of disease in which B cell changes follow and are caused by CD4+ T cell effects.
CD8+ Tumor-Infiltrating Lymphocytes Are Primed for Fas-Mediated Activation-Induced Cell Death But Are Not Apoptotic In Situ
Authors: Radoja Sasa , Saio Masanao , Frey Alan B. 
Published: April 2014

AbstractInduction of Fas-mediated activation-induced cell death in antitumor T cells has been hypothesized to permit tumor escape from immune destruction. Several laboratories have proposed that expression of Fas ligand (L) by tumor is the basis for this form of T cell tolerance. In this study, we characterized murine tumor-infiltrating lymphocytes (TIL) for activation status, cell cycle status, level of apoptosis, cytokine secretion, and proliferative capacity. TILs express multiple activation markers (circa CD69, CD95L, CD122, and LFA-1) and contain IL-2 and IFN-γ mRNAs, but are neither cycling nor apoptotic in situ. In addition, TIL are dramatically suppressed in proliferative response and do not secrete IL-2 and IFN-γ. However, upon purification and activation in vitro, TIL secrete high levels of IL-2 and IFN-γ, enter S phase, and then die by Fas-mediated apoptosis. Activation by injection of anti-TCR Ab or IL-2 into tumor-bearing mice induced TIL entrance into S phase preceding apoptosis, showing that TIL have functional TCR-mediated signal transduction in situ. Our data demonstrate that TIL, not tumor, express both Fas and FasL, are arrested in G1, do not secrete cytokine in situ, and, upon activation in vitro and in vivo, rapidly die by activation-induced cell death.
p27kif Protein Levels and E2F Activity Are Targets of Cot Kinase During G1 Phase Progression in T Cells
Authors: Velasco-Sampayo Ana , Alemany Susana 
Published: April 2014

AbstractCot/Tpl-2 kinase, homologous to members of mitogen-activated protein kinase kinase kinase, was initially discovered by its capacity to promote cell transformation. Cot/Tpl-2 mRNA levels are increased during G0 to G1 phase progression in T lymphocytes, suggesting a role for this kinase later on in the cell cycle. The IL-2-dependent CTLL-2 cells were used to investigate the role of Cot kinase in G1 to S phase transition. Transient expression of Cot kinase in CTLL-2 cells increases DNA synthesis triggered by IL-2 and the transient expression of a dominant negative form of Cot kinase in CTLL-2 markedly reduces the DNA synthesis triggered by this cytokine. Cell cycle analysis of synchronized CTLL-2 stabling overexpressing Cot kinase indicates that this kinase contributes to the passage to S and G2-M phases of the cell cycle. Cot kinase reduces the levels of the cyclin kinase inhibitor p27kip, whereas bcl-xL expression is unaffected. Cot kinase also increases E2F transcriptional activity in a phosphatidylinositol 3 kinase-independent way and acts in synergy with this kinase. These data give evidence, for the first time, of the regulation of different G1 progression events by Cot kinase.
Transcriptional Regulation of CD28 Expression by CD28GR, a Novel Promoter Element Located in Exon 1 of the CD28 Gene
Authors: Lin Catherine J. , Tam Robert C. 
Published: April 2014

AbstractCD28 provides an essential costimulatory signal required for Ag-mediated T cell activation via the TCR. Although accumulating evidence exists for the signaling properties of CD28, less is known regarding the regulation of CD28 expression. In this study, we have identified a novel promoter element of CD28, CD28GR (GGGGAGGAGGGG), which is located between +181 and +192 in exon 1 of the CD28 gene. Mutations within the 12-bp CD28GR sequence abolished its transcriptional activity. CD28GR contains a Sp1/EGR-1 binding site, which was found to act as the predominant functional element for regulating CD28 gene expression in Jurkat cells. Exon 1/CD28GR-driven transcription in Jurkat cells was augmented by cotransfection with Sp1 or EGR-1 expression plasmid. Similar augmentation was also shown with pharmacologic activation. This study is the first to identify a regulatory element that is critical for conferring constitutive and activation-induced transcriptional activation of the CD28 gene. Furthermore, our results proposed potential involvement of Sp1 in regulating CD28 expression. The linkage between Sp1 and the expression of CD28 has important implications in how viral infections, such as HIV, can induce immunosuppression.
Extrafollicular Plasmablast B Cells Play a Key Role in Carrying Retroviral Infection to Peripheral Organs
Authors: Finke Daniela , Baribaud Frédéric , Diggelmann Heidi , Acha-Orbea Hans 
Published: April 2014

AbstractB cells can either differentiate in germinal centers or in extrafollicular compartments of secondary lymphoid organs. Here we show the migration properties of B cells after differentiation in murine peripheral lymph node infected with mouse mammary tumor virus. Naive B cells become activated, infected, and carry integrated retroviral DNA sequences. After production of a retroviral superantigen, the infected B cells receive cognate T cell help and differentiate along the two main differentiation pathways analogous to classical Ag responses. The extrafollicular differentiation peaks on day 6 of mouse mammary tumor virus infection, and the follicular one becomes detectable after day 10. B cells participating in this immune response carry a retroviral DNA marker that can be detected by using semiquantitative PCR. We determined the migration patterns of B cells having taken part in the T cell-B cell interaction from the draining lymph node to different tissues. Waves of immigration and retention of infected cells in secondary lymphoid organs, mammary gland, salivary gland, skin, lung, and liver were observed correlating with the two peaks of B cell differentiation in the draining lymph node. Other organs revealed immigration of infected cells at later time points. The migration properties were correlated with a strong up-regulation of α4β1 integrin expression. These results show the migration properties of B cells during an immune response and demonstrate that a large proportion of extrafolliculary differentiating plasmablasts can escape local cell death and carry the retroviral infection to peripheral organs.
IL-10-Deficient Mice Demonstrate Multiple Organ Failure and Increased Mortality DuringEscherichia coliPeritonitis Despite an Accelerated Bacterial Clearance
Authors: Sewnath Miguel E. , Olszyna Dariusz P. , Birjmohun Rakesh , ten Kate Fiebo J. W. , Gouma Dirk J. , van der Poll Tom 
Published: April 2014

AbstractTo determine the role of endogenous IL-10 in local antibacterial host defense and in the development of a systemic inflammatory response syndrome during abdominal sepsis, IL-10 gene-deficient (IL-10−/−) and wild-type (IL-10+/+) mice received an i.p. injection with Escherichia coli. Peritonitis was associated with a bacterial dose-dependent increase in IL-10 concentrations in peritoneal fluid and plasma. The recovery of E. coli from the peritoneal fluid, blood, and lungs was diminished in IL-10−/− mice, indicating that endogenous IL-10 impaired bacterial clearance. Despite a lower bacterial load, IL-10−/− mice had higher concentrations of TNF, macrophage inflammatory protein-2 and keratinocyte in peritoneal fluid and plasma, and demonstrated more severe multiple organ damage as indicated by clinical chemistry and histopathology. Furthermore, IL-10−/− mice showed an increased neutrophil recruitment to the peritoneal cavity. To examine the role of elevated TNF levels in the altered host response in IL-10−/− mice, the effect of a neutralizing anti-TNF mAb was determined. Anti-TNF did not influence the clearance of E. coli in either IL-10+/+ or IL-10−/− mice. Furthermore, anti-TNF did not affect leukocyte influx in the peritoneal fluid, multiple organ damage, or survival in IL-10+/+ mice. In IL-10−/− mice, anti-TNF partially attenuated neutrophil recruitment and multiple organ damage, and prevented the increased lethality. These data suggest that although endogenous IL-10 facilitates the outgrowth and dissemination of bacteria during E. coli peritonitis, it protects mice from lethality by attenuating the development of a systemic inflammatory response syndrome by a mechanism that involves inhibition of TNF release.
Identification of a Selective Nonpeptide Antagonist of the Anaphylatoxin C3a Receptor That Demonstrates Antiinflammatory Activity in Animal Models
Authors: Ames Robert S. , Lee Dennis , Foley James J. , Jurewicz Anthony J. , Tornetta Mark A. , Bautsch Wilfried , Settmacher Britta , Klos Andreas , Erhard Karl F. , Cousins Russell D. , Sulpizio Anthony C. , Hieble J. Paul , McCafferty Gerald , Ward Keith W. , Adams Jerry L. , Bondinell William E. , Underwood David C. , Osborn Ruth R. , Badger Alison M. , Sarau Henry M. 
Published: April 2014

AbstractThe anaphylatoxin C3a is a potent chemotactic peptide and inflammatory mediator released during complement activation which binds to and activates a G-protein-coupled receptor. Molecular cloning of the C3aR has facilitated studies to identify nonpeptide antagonists of the C3aR. A chemical lead that selectively inhibited the C3aR in a high throughput screen was identified and chemically optimized. The resulting antagonist, N2-[(2,2-diphenylethoxy)acetyl]-l-arginine (SB 290157), functioned as a competitive antagonist of 125I-C3a radioligand binding to rat basophilic leukemia (RBL)-2H3 cells expressing the human C3aR (RBL-C3aR), with an IC50 of 200 nM. SB 290157 was a functional antagonist, blocking C3a-induced C3aR internalization in a concentration-dependent manner and C3a-induced Ca2+ mobilization in RBL-C3aR cells and human neutrophils with IC50s of 27.7 and 28 nM, respectively. SB 290157 was selective for the C3aR in that it did not antagonize the C5aR or six other chemotactic G protein-coupled receptors. Functional antagonism was not solely limited to the human C3aR; SB 290157 also inhibited C3a-induced Ca2+ mobilization of RBL-2H3 cells expressing the mouse and guinea pig C3aRs. It potently inhibited C3a-mediated ATP release from guinea pig platelets and inhibited C3a-induced potentiation of the contractile response to field stimulation of perfused rat caudal artery. Furthermore, in animal models, SB 290157, inhibited neutrophil recruitment in a guinea pig LPS-induced airway neutrophilia model and decreased paw edema in a rat adjuvant-induced arthritis model. This selective antagonist may be useful to define the physiological and pathophysiological roles of the C3aR.