bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel C5a Receptor-Tissue Factor Cross-Talk in Neutrophils Links Innate Immunity to Coagulation Pathways
Authors: Ritis Konstantinos , Doumas Michael , Mastellos Dimitrios , Micheli Anastasia , Giaglis Stavros , Magotti Paola , Rafail Stavros , Kartalis Georgios , Sideras Paschalis , Lambris John D. 
Published: April 2014

Abstract
Neutrophils and complement are key sentinels of innate immunity and mediators of acute inflammation. Recent studies have suggested that inflammatory processes modulate thrombogenic pathways. To date, the potential cross-talk between innate immunity and thrombosis and the precise molecular pathway by which complement and neutrophils trigger the coagulation process have remained elusive. In this study, we demonstrate that antiphospholipid Ab-induced complement activation and downstream signaling via C5a receptors in neutrophils leads to the induction of tissue factor (TF), a key initiating component of the blood coagulation cascade. TF expression by neutrophils was associated with an enhanced procoagulant activity, as verified by a modified prothrombin time assay inhibited by anti-TF mAb. Inhibition studies using the complement inhibitor compstatin revealed that complement activation is triggered by antiphospholipid syndrome (APS) IgG and leads to the induction of a TF-dependent coagulant activity. Blockade studies using a selective C5a receptor antagonist and stimulation of neutrophils with recombinant human C5a demonstrated that C5a, and its receptor C5aR, mediate the expression of TF in neutrophils and thereby significantly enhance the procoagulant activity of neutrophils exposed to APS serum. These results identify a novel cross-talk between the complement and coagulation cascades that can potentially be exploited therapeutically in the treatment of APS and other complement-associated thrombotic diseases.
Regulation of IL-1 and TNF Receptor Expression and Function by Endogenous Macrophage Migration Inhibitory Factor
Authors: Toh Myew-Ling , Aeberli Daniel , Lacey Derek , Yang Yuan , Santos Leilani L. , Clarkson Michael , Sharma Laveena , Clyne Colin , Morand Eric F. 
Published: April 2014

Abstract
Macrophage migration inhibitory factor (MIF) has a key role in regulation of innate and adaptive immunity and is implicated in sepsis, tumorigenesis, and autoimmune disease. MIF deficiency or immunoneutralization leads to protection against fatal endotoxic, exotoxic, and infective shock, and anti-inflammatory effects in other experimental models of inflammatory disease. We report a novel regulatory role of MIF in type 1 IL-1R and p55 TNFR expression and function. Compared with wild-type cells, MIF-deficient cells were hyporesponsive to IL-1- and TNF-induced MAPK activity, AP-1 activity, and cellular proliferation, while NF-κB function was preserved. Hyporesponsiveness of MIF-deficient cells was associated with down-regulation of cytokine receptor expression, which was restored by reconstitution of either an upstream kinase of MAPK, MAPK/ERK kinase, or MIF. These data suggest that endogenous MIF is required for cytokine activation of MAPK/AP-1 and cytokine receptor expression. This autocrine regulatory pathway defines an important amplifying role of endogenous MIF in cytokine-mediated immune and inflammatory diseases and provides further molecular evidence for the critical role of MIF in cellular activation.
A Microbial TLR2 Agonist Imparts Macrophage-Activating Ability to Apolipoprotein A-1
Authors: Hasebe Akira , Pennock Nathan D. , Mu Hong-Hua , Chan Fok V. , Taylor Michael L. , Cole Barry C. 
Published: April 2014

AbstractThere is increasing epidemiologic evidence implying a role for chronic infection in atherosclerosis and that microbial TLR agonists may contribute to this disease. Mycoplasma arthritidis is an agent of acute and chronic inflammatory disease in rodents, and has been used extensively as a model for defining the mechanisms involved in arthritis and other inflammatory diseases. We have purified a 28-kDa, apolipoprotein A-1 (apoA-1)-like TLR2-dependent macrophage-activating moiety from a culture of a virulent strain of M. arthritidis. ApoA-1 similarly isolated from uninoculated mycoplasma medium was without bioactivity. The activity of the mycoplasma-derived molecule was resistant to heat and to digestion with proteinase K, but was susceptible to alkaline hydrolysis and H2O2 oxidation. Infrared profiles of normal apoA-1 and that derived from mycoplasma were distinct. Unlike the activity of other mycoplasmal TLR2 agonists such as macrophage-activating lipopeptide-2, activity of the M. arthritidis-derived 28-kDa component was dependent upon CD14, a coreceptor for LPS. Finally, we showed that bioactive lipopeptides prepared from M. arthritidis grown in serum-free medium and also from a 41-kDa known bioactive lipoprotein of M. arthritidis, avidly bound to purified apoA-1 that separated out by SDS-PAGE, induced TNF-α and IL-12p40 both in vitro and in vivo. ApoA-1 is a key functional component of the high-density lipoprotein cholesterol complex by scavenging and removing unwanted lipids. Our finding that this molecule can acquire macrophage-activating properties from microbial TLR2-dependent agonists suggests a novel mechanism whereby some microbial agents might reverse the protective role of apoA-1, thus contributing to the genesis of atherosclerosis.
Exposure of the Promonocytic Cell Line THP-1 toEscherichia coliInduces IFN-γ-Inducible Lysosomal Thiol Reductase Expression by Inflammatory Cytokines
Authors: Lackman Rebecca L. , Cresswell Peter 
Published: April 2014

AbstractIFN-γ-inducible lysosomal thiol reductase (GILT), which plays a role in MHC class II-restricted processing and presentation of Ags containing disulfide bonds, can be induced in various cell types by the cytokine IFN-γ. APCs, including circulating macrophages, constitutively express high levels of GILT, although the pathways regulating its expression in these cells have not been characterized. In this study, we used the promonocytic cell line THP-1, an established model for monocyte to macrophage differentiation, to investigate the induction of GILT upon exposure to bacteria. We show that contact with LPS or intact Escherichia coli causes THP-1 cells to undergo programmed differentiation, characterized by adhesion, cytokine secretion, and up-regulation of Ag processing and presentation components, including GILT. Unlike GILT induction in response to IFN-γ treatment, induction by bacteria is dependent on new protein synthesis, NF-κB signaling, and secretion of the inflammatory cytokines TNF and IL-1β. Furthermore, we show that both cytokines are sufficient for GILT induction in the absence of a microbial stimulus. The majority of GILT synthesized by differentiated THP-1 cells is secreted as the precursor form rather than being transported to, and maturing in, lysosomes, suggesting a novel role for GILT in cells of the macrophage lineage.
Caveolin-1 Regulates NF-κB Activation and Lung Inflammatory Response to Sepsis Induced by Lipopolysaccharide
Authors: Garrean Sean , Gao Xiao-Pei , Brovkovych Victor , Shimizu Jun , Zhao You-Yang , Vogel Stephen M. , Malik Asrar B. 
Published: April 2014

AbstractCaveolin-1, the principal structural and signaling protein of caveolae, is implicated in NO-mediated cell signaling events, but its precise role in inflammation is not well understood. Using caveolin-1-knockout (Cav-1−/−) mice, we addressed the role of caveolin-1 in the lung inflammatory response to sepsis induced by i.p. injection of LPS. LPS-challenged wild-type (WT) lungs exhibited significant increases in neutrophil sequestration (∼16-fold), lung microvascular permeability Kf,c (∼5.7-fold), and edema formation (∼1.6-fold). Compared with WT, Cav-1−/− lungs showed marked attenuation of LPS-induced neutrophil sequestration (∼11-fold increase) and inhibition of microvascular barrier breakdown and edema formation. Prevention of lung injury in Cav-1−/− mice was associated with decreased mortality in response to LPS challenge. To address the basis of the reduced inflammation and injury in Cav-1−/− lungs, we examined the role of NO because its plasma concentration is known to be increased in Cav-1−/− mice. Cav-1−/− mouse lungs demonstrated a significant increase in endothelial NO synthase (eNOS)-derived NO production relative to WT, which is consistent with the role of caveolin-1 as a negative regulator of eNOS activity. Cav-1−/− lungs concurrently showed suppression of NF-κB activity and decreased transcription of inducible NO synthase and ICAM-1. Coadministration of LPS with the NO synthase inhibitor nitro-l-arginine in Cav-1−/− mice prevented the suppression of NF-κB activity and restored lung polymorphonuclear leukocyte sequestration in response to LPS challenge. Thus, caveolin-1, through its ability to regulate eNOS-derived NO production, is a crucial determinant of NF-κB activation and the lung inflammatory response to LPS.
Essential Role for IL-10 in Resistance to Lipopolysaccharide-Induced Preterm Labor in Mice
Authors: Robertson Sarah A. , Skinner Rebecca J. , Care Alison S. 
Published: April 2014

AbstractIL-10 is highly expressed in the uterus and placenta and is implicated in controlling inflammation-induced pathologies of pregnancy. To investigate the role of IL-10 in regulating preterm labor, the response of IL-10 null mutant mice to low-dose LPS in late gestation was evaluated. When IL-10 null mutant C57BL/6 (IL-10−/−) and control (IL-10+/+) mice were administered LPS on day 17 of pregnancy, the dose of LPS required to elicit 50% preterm fetal loss was 10-fold lower in IL-10−/− mice than in IL-10+/+ mice. Surviving fetuses in IL-10−/− mice exhibited fetal growth restriction at lower doses of LPS than IL-10+/+ mice. Marked elevation of LPS-induced immunoactive TNF-α and IL-6 was evident in the serum, uterus, and placenta of IL-10−/− mice, and TNF-α and IL-6 mRNA expression was elevated in the uterus and placenta, but not the fetus. Serum IL-1α, IFN-γ, and IL-12p40 were increased and soluble TNFRII was diminished in the absence of IL-10, with these changes also reflected in the gestational tissues. Administration of rIL-10 to IL-10−/− mice attenuated proinflammatory cytokine synthesis and alleviated their increased susceptibility to preterm loss. Exogenous IL-10 also protected IL-10+/+ mice from fetal loss. These data show that IL-10 modulates resistance to inflammatory stimuli by down-regulating proinflammatory cytokines in the uterus and placenta. Abundance of endogenous IL-10 in gestational tissues is therefore identified as a critical determinant of resistance to preterm labor, and IL-10 may provide a useful therapeutic agent in this common condition.
Functional Reversion of Antigen-Specific CD8+ T Cells from Patients with Hodgkin Lymphoma following In Vitro Stimulation with Recombinant Polyepitope
Authors: Smith Corey , Cooper Leanne , Burgess Melinda , Rist Michael , Webb Natasha , Lambley Eleanore , Tellam Judy , Marlton Paula , Seymour John F. , Gandhi Maher , Khanna Rajiv 
Published: April 2014

AbstractRecent studies on Hodgkin’s lymphoma (HL) have indicated that patients with active disease display functional impairment of Ag-specific CD8+ T cells due to expansion of regulatory T cells at sites of disease and in the peripheral blood. Adoptive cellular immunotherapy based on EBV-specific CD8+ T cells has been explored with limited success to date. It has been proposed that improved targeting of these CD8+ T cells toward viral Ags that are expressed in HL may enhance future therapeutic vaccine strategies. In this study, we have developed a novel replication-deficient adenoviral Ag presentation system that is designed to encode glycine alanine repeat-deleted EBV nuclear Ag 1 covalently linked to multiple CD8+ T cell epitopes from latent membrane proteins 1 and 2. A single stimulation of CD8+ T cells from healthy virus carriers, and patients with HL with this adenoviral construct in combination with IL-2, was sufficient to reverse the functional T cell impairment and restored both IFN-γ production and cytolytic function. More importantly, these activated CD8+ T cells responded to tumor cells expressing membrane proteins and recognized novel EBNA1 epitopes. Flow cytometric analysis revealed that a large proportion of T cells expanded from patients with HL were CD62Lhigh and CD27high, and CCR7low, consistent with early to mid effector T cells. These findings provide an important platform for translation of Ag-specific adoptive immunotherapy for the treatment of EBV-associated malignancies such as HL and nasopharyngeal carcinoma.
ICOS Deficiency Is Associated with a Severe Reduction of CXCR5+CD4 Germinal Center Th Cells
Authors: Bossaller Lukas , Burger Jan , Draeger Ruth , Grimbacher Bodo , Knoth Rolf , Plebani Alessandro , Durandy Anne , Baumann Ulrich , Schlesier Michael , Welcher Andrew A. , Peter Hans Hartmut , Warnatz Klaus 
Published: April 2014

Abstract
ICOS is expressed on activated T cells and particularly on CXCR5+ follicular Th cells in germinal centers (GC). Its deletion leads to a profound deficiency in memory B cell formation and switched Ab response in humans. Here, we show that in ICOS-deficient patients the generation of GCs is severely disturbed, and the numbers of circulating CXCR5+CD45RO+ memory CD4 T cells are significantly reduced, indicating an essential role of ICOS in the differentiation of CXCR5+CD4 T cells. The GC-specific CD57+CXCR5+ subpopulation is virtually absent. In ICOS−/− mice, the decrease of circulating CXCR5+CD4 T cells reflects the reduction of CXCR5+ follicular Th cells in lymph nodes and spleen. Therefore, in concurrence with the absence of CXCR5+ T cells in the blood of CD40L-deficient patients, these data support the hypothesis that circulating CD57+CXCR5+ T cells are GC derived and thus may serve as a surrogate marker for the presence of functional GCs in humans.
Autophagy: Eating for Good Health
Authors: Swanson Michele S. 
Published: April 2014

Abstract
A renaissance in the autophagy field has illuminated many areas of biology, and infectious disease is no exception. By identifying key components of this broadly conserved membrane traffic pathway, yeast geneticists generated tools for microbiologists and immunologists to explore whether autophagy contributes to host defenses. As a result, autophagy is now recognized to be another barrier confronted by microbes that invade eukaryotic cells. Mounting evidence also indicates that autophagy equips cells to deliver cytosolic Ags to the MHC class II pathway. By applying knowledge of the autophagy machinery and exploiting microbes as genetic probes, experimentalists can now examine in detail how this ancient membrane traffic pathway contributes to these and other mechanisms critical for infection and immunity.
Cutting Edge: Hypoxia-Inducible Factor 1α and Its Activation-Inducible Short Isoform I.1 Negatively Regulate Functions of CD4+ and CD8+ T Lymphocytes
Authors: Lukashev Dmitriy , Klebanov Boris , Kojima Hidefumi , Grinberg Alex , Ohta Akiko , Berenfeld Ludmilla , Wenger Roland H. , Ohta Akio , Sitkovsky Michail 
Published: April 2014

Abstract
To evaluate the role of hypoxia-inducible factor 1α (HIF-1α) and its TCR activation-inducible short isoform I.1 in T cell functions, we genetically engineered unique mice with: 1) knockout of I.1 isoform of HIF-1α; 2) T cell-targeted HIF-1α knockdown; and 3) chimeric mice with HIF-1α gene deletion in T and B lymphocytes. In all three types of mice, the HIF-1α-deficient T lymphocytes, which were TCR-activated in vitro, produced more proinflammatory cytokines compared with HIF-1α-expressing control T cells. Surprisingly, deletion of the I.1 isoform, which represents &lt;30% of total HIF-1α mRNA in activated T cells, was sufficient to markedly enhance TCR-triggered cytokine secretion. These data suggest that HIF-1α not only plays a critical role in oxygen homeostasis but also may serve as a negative regulator of T cells.
Role of Galectin-3 in Mast Cell Functions: Galectin-3-Deficient Mast Cells Exhibit Impaired Mediator Release and Defective JNK Expression
Authors: Chen Huan-Yuan , Sharma Bhavya B. , Yu Lan , Zuberi Riaz , Weng I-Chun , Kawakami Yuko , Kawakami Toshiaki , Hsu Daniel K. , Liu Fu-Tong 
Published: April 2014

Abstract
Galectin-3 is a member of the β-galactoside-binding animal lectin family expressed in various cell types, including mast cells. To determine the role of galectin-3 in the function of mast cells, we studied bone marrow-derived mast cells (BMMC) from wild-type (gal3+/+) and galectin-3-deficient (gal3−/−) mice. Cells from the two genotypes showed comparable expression of IgE receptor and c-Kit. However, upon activation by FcεRI cross-linkage, gal3−/− BMMC secreted a significantly lower amount of histamine as well as the cytokine IL-4, compared with gal3+/+ BMMC. In addition, we found significantly reduced passive cutaneous anaphylaxis reactions in gal3−/− mice compared with gal3+/+ mice. These results indicate that there is a defect in the response of mast cells in gal3−/− mice. Unexpectedly, we found that gal3−/− BMMC contained a dramatically lower basal level of JNK1 protein compared with gal3+/+ BMMC, which is probably responsible for the lower IL-4 production. The decreased JNK1 level in gal3−/− BMMC is accompanied by a lower JNK1 mRNA level, suggesting that galectin-3 regulates the transcription of the JNK gene or processing of its RNA. All together, these results point to an important role of galectin-3 in mast cell biology.
Peripheral T Cell Lymphopenia and Concomitant Enrichment in Naturally Arising Regulatory T Cells: The Case of the Pre-Tα Gene-Deleted Mouse
Authors: Bosco Nabil , Agenes Fabien , Rolink Antonius G. , Ceredig Rhodri 
Published: April 2014

Abstract
In pre-Tα (pTα) gene-deleted mice, the positively selectable CD4+CD8+ double-positive thymocyte pool is only 1% that in wild-type mice. Consequently, their peripheral T cell compartment is severely lymphopenic with a concomitant increase in proportion of CD25+FoxP3+ regulatory T cells. Using mixed bone marrow chimeras, where thymic output was 1% normal, the pTα−/− peripheral T cell phenotype could be reproduced with normal cells. In the pTα−/− thymus and peripheral lymphoid organs, FoxP3+CD4+ cells were enriched. Parabiosis experiments showed that many pTα−/−CD4+ single-positive thymocytes represented recirculating peripheral T cells. Therefore, the enrichment of FoxP3+CD4+ single-positive thymocytes was not solely due to increased thymic production. Thus, the pTα−/− mouse serves as a model system with which to study the consequences of chronic decreased thymic T cell production on the physiology of the peripheral T cell compartment.
Evidence for a Role for Notch Signaling in the Cytokine-Dependent Survival of Activated T Cells
Authors: Bheeshmachar Geetha , Purushotaman Divya , Sade Hadassah , Gunasekharan Vigneshkumar , Rangarajan Annapoorni , Sarin Apurva 
Published: April 2014

Abstract
Peripheral T cell homeostasis results from a balance between factors promoting survival and those that trigger deletion of Ag-reactive cells. The cytokine IL-2 promotes T cell survival whereas reactive oxygen species (ROS) sensitize T cells to apoptosis. Two pathways of activated T cell apoptosis–one triggered by Fas ligand and the other by cytokine deprivation–depend on ROS, with the latter also regulated by members of the Bcl-2 family. Notch family proteins regulate several cell-fate decisions in metazoans. Ectopic expression of the Notch1 intracellular domain (NICD) in T cells inhibits Fas-induced apoptosis. The underlying mechanism is not known and the role, if any, of Notch in regulating apoptosis triggered by cytokine deprivation or neglect has not been examined. In this study, we use a Notch1/Fc chimera; a blocking Ab to Notch1 and chemical inhibitors of γ-secretase to investigate the role of Notch signaling in activated T cells of murine origin. We show that perturbing Notch signaling in activated CD4+/CD8+ T cells maintained in IL-2 results in the accumulation of ROS, reduced Akt/protein kinase B activity, and expression of the antiapoptotic protein Bcl-xL, culminating in apoptosis. A broad-spectrum redox scavenger inhibits apoptosis but T cells expressing mutant Fas ligand are sensitive to apoptosis. Activated T cells isolated on the basis of Notch expression (Notch+) are enriched for Bcl-xL expression and demonstrate reduced susceptibility to apoptosis triggered by neglect or oxidative stress. Furthermore, enforced expression of NICD protects activated T cells from apoptosis triggered by cytokine deprivation. Taken together, these data implicate Notch1 signaling in the cytokine-dependent survival of activated T cells.
Identification of a Novel Human Granzyme B Inhibitor Secreted by Cultured Sertoli Cells
Authors: Sipione Simonetta , Simmen Katia C. , Lord Sarah J. , Motyka Bruce , Ewen Catherine , Shostak Irene , Rayat Gina R. , Dufour Jannette M. , Korbutt Greg S. , Rajotte Ray V. , Bleackley R. Chris 
Published: April 2014

Abstract
Sertoli cells have long since been recognized for their ability to suppress the immune system and protect themselves as well as other cell types from harmful immune reaction. However, the exact mechanism or product produced by Sertoli cells that affords this immunoprotection has never been fully elucidated. We examined the effect of mouse Sertoli cell-conditioned medium on human granzyme B-mediated killing and found that there was an inhibitory effect. We subsequently found that a factor secreted by Sertoli cells inhibited killing through the inhibition of granzyme B enzymatic activity. SDS-PAGE analysis revealed that this factor formed an SDS-insoluble complex with granzyme B. Immunoprecipitation and mass spectroscopic analysis of the complex identified a proteinase inhibitor, serpina3n, as a novel inhibitor of human granzyme B. We cloned serpina3n cDNA, expressed it in Jurkat cells, and confirmed its inhibitory action on granzyme B activity. Our studies have led to the discovery of a new inhibitor of granzyme B and have uncovered a new mechanism used by Sertoli cells for immunoprotection.
RANTES Modulates TLR4-Induced Cytokine Secretion in Human Peripheral Blood Monocytes
Authors: Shahrara Shiva , Park Christy C. , Temkin Vladislav , Jarvis Jared W. , Volin Michael V. , Pope Richard M. 
Published: April 2014

AbstractMonocytes are the key regulators of joint inflammation and destruction in rheumatoid arthritis; hence, suppression of their recruitment into the joint may be therapeutically beneficial. Chemokines, including RANTES, are highly expressed in the joints of patient with rheumatoid arthritis, and they promote leukocyte trafficking into the synovial tissue. Because endogenous TLR4 ligands are expressed in the rheumatoid joint, the TLR4 ligand LPS was used to characterize the effects of RANTES on the TLR4-mediated induction of TNF-α and IL-6. Using peripheral blood (PB) monocytes, RANTES decreased LPS-induced IL-6 transcriptionally, whereas TNF-α was suppressed at the posttranscriptional level. RANTES signaled through p38 MAPK, and this signaling was further enhanced by LPS stimulation in PB monocytes, resulting in the earlier and increased secretion of IL-10. Inhibition of p38 by short-interfering RNA or a chemical inhibitor, as well as neutralization of IL-10, reversed the RANTES-mediated suppression of LPS-induced IL-6 and TNF-α. Further, when rheumatoid arthritis synovial fluid was added to PB monocytes, the neutralization of RANTES in fluid reduced the LPS-induced IL-10 and increased TNF-α. In conclusion, the results of this study suggest that RANTES down-regulates TLR4 ligation-induced IL-6 and TNF-α secretion by enhancing IL-10 production in PB monocytes. These observations suggest that the therapeutic neutralization of RANTES, in addition to decreasing the trafficking of leukocytes, may have a proinflammatory effect at the site of established chronic inflammation.