bluuebunny/crossref_metadata_2025_split huggingface dataset:
LIGHT, a TNF-Like Molecule, Costimulates T Cell Proliferation and Is Required for Dendritic Cell-Mediated Allogeneic T Cell Response
Authors: Tamada Koji , Shimozaki Koji , Chapoval Andrei I. , Zhai Yifan , Su Jeffery , Chen Su-Fang , Hsieh Shie-Liang , Nagata Shigekazu , Ni Jian , Chen Lieping 
Published: April 2014

AbstractLIGHT is a recently identified member of the TNF superfamily and its receptors, herpesvirus entry mediator and lymphotoxin β receptor, are found in T cells and stromal cells. In this study, we demonstrate that LIGHT is selectively expressed on immature dendritic cells (DCs) generated from human PBMCs. In contrast, LIGHT is not detectable in DCs either freshly isolated from PBMCs or rendered mature in vitro by LPS treatment. Blockade of LIGHT by its soluble receptors, lymphotoxin β receptor-Ig or HVEM-Ig, inhibits the induction of DC-mediated primary allogeneic T cell response. Furthermore, engagement of LIGHT costimulates human T cell proliferation, amplifies the NF-κB signaling pathway, and preferentially induces the production of IFN-γ, but not IL-4, in the presence of an antigenic signal. Our results suggest that LIGHT is a costimulatory molecule involved in DC-mediated cellular immune responses.
Perforin Lytic Activity Is Controlled by Calreticulin
Authors: Fraser Stephanie A. , Karimi Reza , Michalak Marek , Hudig Dorothy 
Published: April 2014

AbstractThe components within cytotoxic lymphocyte granules are responsible for a significant fraction of T and NK cell-mediated death. Perforin is stored in these granules together with calreticulin. Calreticulin has long been recognized as a chaperone protein of the endoplasmic reticulum (ER) and is the only resident ER protein to be found in the cytotoxic granules. Here we implicate a role for calreticulin in killing and report that it controls osmotic lysis mediated by purified perforin. Calreticulin, at a concentration of 2.2 × 10−7 M, completely blocked perforin-mediated lysis. Inhibition was stable and held over 5 h. Recombinant calreticulin, at a concentration of 8.8 × 10−7 M, also blocked lysis, indicating the inhibition was due to calreticulin and not a copurifying protein in the native calreticulin preparations. Using calreticulin domain fragments (expressed as GST fusion proteins), we found inhibitory activity in the high-capacity calcium-binding C-domain, which does not bind perforin. The N- or P-domains, which can bind perforin, were unable to block lysis. The inhibition of lysis was independent of granzyme inactivation or the ability of calreticulin to sequester calcium. Our data indicate that calreticulin regulation of perforin-mediated lysis probably occurs without direct interaction with perforin. We propose a novel model in which calreticulin stabilizes membranes to prevent polyperforin pore formation.
Human Anti-Thyroid Peroxidase Single-Chain Fragment Variable of Ig Isolated from a Combinatorial Library Assembled In-Cell: Insights into the In Vivo Situation
Authors: Chapal Nicolas , Peraldi-Roux Sylvie , Bresson Damien , Pugniere Martine , Mani Jean-Claude , Granier Claude , Baldet Line , Guerrier Bernard , Pau Bernard , Bouanani Majida 
Published: April 2014

AbstractIn an attempt to explore the natural variable heavy and light chain (VH/VL) pairing of autoantibodies involved in Graves’ disease, we constructed a phage-displayed Ab library obtained by in-cell PCR of thyroid-infiltrating cells. We report here the molecular cloning and characterization of human single-chain fragment variable regions (scFv) specific for thyroid peroxidase (TPO) generated from this library. On the basis of the nucleotide sequences, three different scFvs were obtained (ICA1, ICB7, and ICA5). All were encoded by genes derived from the VH1 and Vλ1 gene families. Using BIACORE for epitope mapping and kinetic analysis, we showed that these scFvs exhibited high affinity (Kd = 1 nM) for TPO and recognized three different epitopes. The biological relevance of these scFvs as compared with serum anti-TPO autoantibodies was assessed by competition studies. Sera from all the 29 Graves’ disease patients tested were able to strongly inhibit (60–100%) the binding of the 3 scFvs to TPO. These data demonstrate that the in-cell PCR library generated human anti-TPO scFvs that retained the VH/VL pairing found in vivo and that the different epitope specificities defined by these scFvs overlapped with those found in the sera of patients with autoimmune thyroid disease.
Mapping of the C1q Binding Site on Rituxan, a Chimeric Antibody with a Human IgG1 Fc
Authors: Idusogie Esohe E. , Presta Leonard G. , Gazzano-Santoro Helene , Totpal Klara , Wong Pin Yee , Ultsch Mark , Meng Y. Gloria , Mulkerrin Michael G. 
Published: April 2014

Abstract
Rituxan (Rituximab) is a chimeric mAb with human IgG1 constant domains used in the therapy of non-Hodgkin’s B cell lymphomas. This Ab targets B cells by binding to the cell-surface receptor, CD20. In our investigation of the mechanism of B cell depletion mediated by Rituximab, we first constructed mutants of Rituximab defective in complement activation but with all other effector functions intact. Our results demonstrate that the previously described C1q binding motif in murine IgG2b constituting residues E318, K320, and K322 is not applicable to a human IgG1 when challenged with either human, rabbit, or guinea pig complement. Alanine substitution at positions E318 and K320 in Rituximab had little or no effect on C1q binding and complement activation, whereas alanine substitution at positions D270, K322, P329, and P331 significantly reduced the ability of Rituximab to bind C1q and activate complement. We have also observed that concentrations of complement approaching physiological levels are able to rescue &gt;60% of the activity of these mutant Abs with low affinity for C1q. These data localize the C1q binding epicenter on human IgG1 and suggest that there are species-specific differences in the C1q binding site of Igs.
IL-9 Protects Mice from Gram-Negative Bacterial Shock: Suppression of TNF-α, IL-12, and IFN-γ, and Induction of IL-10
Authors: Grohmann Ursula , Van Snick Jacques , Campanile Franca , Silla Silvia , Giampietri Antonio , Vacca Carmine , Renauld Jean-Cristophe , Fioretti Maria C. , Puccetti Paolo 
Published: April 2014

Abstract
IL-9 is a T cell-derived cytokine that, similar to the Th2 cytokines IL-4 and IL-10, has been implicated in the response to parasitic infections, allergy, and inflammatory processes. Because both IL-4 and IL-10 can confer protection to mice from septic shock, we investigated whether IL-9 may also be capable of conferring resistance on recipients of an otherwise lethal challenge with Pseudomonas aeruginosa. Prophylactic injections of rIL-9 appeared to be most effective in preventing the onset of a lethal shock, according to a pattern that was both dose dependent and time dependent. The protective effect of IL-9 was correlated with marked decreases in the production of the inflammatory mediators TNF-α, IL-12, and IFN-γ, as well as the induction of the anti-inflammatory cytokine IL-10. Sustained levels of IL-9-specific transcripts could be detected in the spleens of mice recovering from sublethal P. aeruginosa infection. Therefore, IL-9 may be protective in septic shock via a rather unique mechanism involving a complex modulation of inflammatory and anti-inflammatory mediators.
Suppression of Endogenous IL-10 Gene Expression in Dendritic Cells Enhances Antigen Presentation for Specific Th1 Induction: Potential for Cellular Vaccine Development
Authors: Igietseme Joseph U. , Ananaba Godwin A. , Bolier Jacqueline , Bowers Samera , Moore Terri , Belay Tesfaye , Eko Francis O. , Lyn Deborah , Black Carolyn M. 
Published: April 2014

AbstractA new paradigm for designing vaccines against certain microbial pathogens, including Chlamydia trachomatis, is based on the induction of local mucosal Th1 response. IL-10 is an anti-inflammatory cytokine that exerts negative immunoregulatory influence on Th1 response. This study investigated whether biochemical modulation of endogenous IL-10 expression at the level of APCs is a practical strategy for enhancing the specific Th1 response against pathogens controlled by Th1 immunity. The results revealed that the high resistance of genetically engineered IL-10−/− (IL-10KO) mice to genital chlamydial infection is a function of the predilection of their APCs to rapidly and preferentially activate a high Th1 response. Thus, in microbiological analysis, IL-10KO mice suffered a shorter duration of infection, less microbial burden, and limited ascending infection than immunocompetent wild-type mice. Also, IL-10KO were resistant to reinfection after 8 wk of the primary infection. Cellular and molecular immunologic evaluation indicated that IL-10KO mice induced greater frequency of chlamydial-specific Th1 response following C. trachomatis infection. Moreover, IL-10KO APCs or antisense IL-10 oligonucleotide-treated wild-type APCs were potent activators of Th1 response from naive or immune T cells. Furthermore, both Ag-pulsed dendritic cells from IL-10KO mice and IL-10 antisense-treated dendritic cells from wild-type mice were efficient cellular vaccines in adoptive immunotherapeutic vaccination against genital chlamydial infection. These findings may furnish a novel immunotherapeutic strategy for boosting the Th1 response against T cell-controlled pathogens and tumors, using IL-10-deficient APCs as vaccine delivery agents.
Type I IFN Modulates Innate and Specific Antiviral Immunity
Authors: Durbin Joan E. , Fernandez-Sesma Ana , Lee Chien-Kuo , Rao T. Dharma , Frey Alan B. , Moran Thomas M. , Vukmanovic Stanislav , García-Sastre Adolfo , Levy David E. 
Published: April 2014

AbstractIFNs protect from virus infection by inducing an antiviral state and by modulating the immune response. Using mice deficient in multiple aspects of IFN signaling, we found that type I and type II IFN play distinct although complementing roles in the resolution of influenza viral disease. Both types of IFN influenced the profile of cytokines produced by T lymphocytes, with a significant bias toward Th2 differentiation occurring in the absence of responsiveness to either IFN. However, although a Th1 bias produced through inhibition of Th2 differentiation by IFN-γ was not required to resolve infection, loss of type I IFN responsiveness led to exacerbated disease pathology characterized by granulocytic pulmonary inflammatory infiltrates. Responsiveness to type I IFN did not influence the generation of virus-specific cytotoxic lymphocytes or the rate of viral clearance, but induction of IL-10 and IL-15 in infected lungs through a type I IFN-dependent pathway correlated with a protective response to virus. Combined loss of both IFN pathways led to a severely polarized proinflammatory immune response and exacerbated disease. These results reveal an unexpected role for type I IFN in coordinating the host response to viral infection and controlling inflammation in the absence of a direct effect on virus replication.
HLA-DQ Tetramers Identify Epitope-Specific T Cells in Peripheral Blood of Herpes Simplex Virus Type 2-Infected Individuals: Direct Detection of Immunodominant Antigen-Responsive Cells
Authors: Kwok William W. , Liu Andrew W. , Novak Erik J. , Gebe John A. , Ettinger Ruth A. , Nepom Gerald T. , Reymond Sigrid N. , Koelle David M. 
Published: April 2014

AbstractAg-specific CD4+ T cells are present in peripheral blood in low frequency, where they undergo recruitment and expansion during immune responses and in the pathogenesis of numerous autoimmune diseases. MHC tetramers, which constitute a labeled MHC-peptide ligand suitable for binding to the Ag-specific receptor on T cells, provide a novel approach for the detection and characterization of such rare cells. In this study, we utilized this technology to identify HLA DQ-restricted Ag-specific T cells in the peripheral blood of human subjects and to identify immunodominant epitopes associated with viral infection. Peptides representing potential epitope regions of the VP16 protein from HSV-2 were loaded onto recombinant DQ0602 molecules to generate a panel of Ag-specific DQ0602 tetramers. VP16 Ag-specific DQ-restricted T cells were identified and expanded from the peripheral blood of HSV-2-infected individuals, representing two predominant epitope specificities. Although the VP16 369–380 peptide has a lower binding affinity for DQ0602 molecules than the VP16 33–52 peptide, T cells that recognized the VP16 369–380 peptide occurred at a much higher frequency than those that were specific for the VP16 33–52 peptide.
Synthetic Peptides of CD66a Stimulate Neutrophil Adhesion to Endothelial Cells
Authors: Skubitz Keith M. , Campbell Kenneth D. , Skubitz Amy P. N. 
Published: April 2014

AbstractFour members of the carcinoembryonic Ag family, CD66a, CD66b, CD66c, and CD66d, are expressed on human neutrophils. CD66a, CD66b, CD66c, and CD66d Ab binding to the neutrophil surface triggers an activation signal that regulates the adhesive activity of CD11/CD18, resulting in an increase in neutrophil adhesion to HUVEC. To identify active sites on the CD66a Ag, molecular modeling was performed using IgG and CD4 as models, and 28 peptides of 14 aa in length were synthesized that were predicted to be present at loops and turns between β-sheets. The peptides were tested for their ability to alter neutrophil adhesion to HUVEC. Three peptides, each from the N-terminal domain, increased neutrophil adhesion to HUVEC monolayers. This increase in neutrophil adhesion caused by CD66a peptides was associated with up-regulation of CD11/CD18 and down-regulation of CD62L on the neutrophil surface. Scrambled versions of these three peptides had no effect on neutrophil adhesion to the endothelial cells. The data suggest that peptide motifs from at least three regions of the N-terminal domain of CD66a are involved in the interaction of CD66a with other ligands and can initiate signal transduction in neutrophils.
Stem Cell Factor Plays a Major Role in the Recruitment of Eosinophils in Allergic Pleurisy in Mice Via the Production of Leukotriene B4
Authors: Klein Andre , Talvani Andre , Cara Denise C. , Gomes Kenia L. , Lukacs Nicholas W. , Teixeira Mauro M. 
Published: April 2014

AbstractThe understanding of the mechanisms underlying eosinophil migration into tissue is an essential step in the development of novel therapies aimed at treating allergic diseases where eosinophil recruitment and activation are thought to play an essential role. In this study, we have examined the effects of the in vivo administration of stem cell factor (SCF) on eosinophil recruitment and tested whether endogenous SCF was involved in mediating eosinophil recruitment in response to Ag challenge in sensitized mice. The intrapleural injection of SCF induced a time- and concentration-dependent recruitment of eosinophils in mice. In allergic mice, SCF message was expressed early after Ag challenge and returned to baseline levels after 8 h. In agreement with the ability of SCF to induce eosinophil recruitment and its expression in the allergic reaction, an anti-SCF polyclonal Ab abrogated eosinophil recruitment when given before Ag challenge. SCF increased the levels of leukotriene B4 (LTB4) in the pleural cavity of mice and an LTB4 receptor antagonist, CP105,696, abrogated the effects of SCF on eosinophil recruitment. Similarly, recruitment of eosinophils in the allergic reaction was virtually abolished by CP105,696. Together, our data favor the hypothesis that the local release of SCF following Ag challenge may activate and/or prime mast cells for IgE-mediated release of inflammatory mediators, especially LTB4. The mediators released in turn drive the recruitment of eosinophils. Inhibition of the function of SCF in vivo may reduce the migration of eosinophils to sites of allergic inflammation and may, thus, be a relevant principle in the treatment of allergic diseases.
TNF-α Gene Expression in Macrophages: Regulation by NF-κB Is Independent of c-Jun or C/EBPβ
Authors: Liu Hongtao , Sidiropoulos Prodromos , Song Guobin , Pagliari Lisa J. , Birrer Michael J. , Stein Bernd , Anrather Josef , Pope Richard M. 
Published: April 2014

AbstractThe interaction of transcription factors is critical in the regulation of gene expression. This study characterized the mechanism by which NF-κB family members interact to regulate the human TNF-α gene. A 120-bp TNF-α promoter-reporter, possessing binding sites for NF-κB (κB3), C/EBPβ (CCAAT/enhancer binding protein β), and c-Jun, was activated by cotransfection of plasmids expressing the wild-type version of each of these transcription factors. Employing adenoviral vectors, dominant-negative versions of NF-κB p65, and c-Jun, but not C/EBPβ, suppressed (p &lt; 0.05–0.001) LPS-induced TNF-α secretion in primary human macrophages. Following LPS stimulation, NF-κB p50/p65 heterodimers bound to the κB3 site and c-Jun to the −103 AP-1 site of the TNF-α promoter. By transient transfection, NF-κB p65 and p50 synergistically activated the TNF-α promoter. In contrast, no synergy was observed between NF-κB p65, with or without NF-κB p50, and c-Jun or C/EBPβ, even in the presence of the coactivator p300. The contribution of the upstream κB binding sites was also examined. Following LPS stimulation, the κB1 site bound both NF-κB p50/p65 heterodimers and p50 homodimers. The binding by NF-κB p50 homodimers to the κB1, but not to the κB3, site contributed to the inability of macrophages to respond to a second LPS challenge. In summary, adjacent κB3 and AP-1 sites in the human TNF-α promoter contribute independently to LPS-induced activation. Although both the κB1 and κB3 sites bound transcriptionally active NF-κB p50/p65 heterodimers, only the κB1 site contributed to down-regulation by NF-κB p50 homodimers.
Granulocyte-Macrophage Colony-Stimulating Factor Delays Neutrophil Constitutive Apoptosis Through Phosphoinositide 3-Kinase and Extracellular Signal-Regulated Kinase Pathways
Authors: Klein Jon B. , Rane Madhavi J. , Scherzer Janice A. , Coxon Patricia Y. , Kettritz Ralph , Mathiesen Jeanine M. , Buridi Abdul , McLeish Kenneth R. 
Published: April 2014

Abstract
Activated neutrophils play an important role in the pathogenesis of sepsis, glomerulonephritis, acute renal failure, and other inflammatory processes. The resolution of neutrophil-induced inflammation relies, in large part, on removal of apoptotic neutrophils. Neutrophils are constitutively committed to apoptosis, but inflammatory mediators, such as GM-CSF, slow neutrophil apoptosis by incompletely understood mechanisms. We addressed the hypothesis that GM-CSF delays neutrophil apoptosis by activation of extracellular signal-regulated kinase (ERK) and phosphoinositide 3-kinase (PI 3-kinase) pathways. GM-CSF (20 ng/ml) significantly inhibited neutrophil apoptosis (GM-CSF, 32 vs 65% of cells p &lt; 0.0001). GM-CSF activated the PI 3-kinase/Akt pathway as determined by phosphorylation of Akt and BAD. GM-CSF-dependent Akt and BAD phosphorylation was blocked by the PI 3-kinase inhibitor LY294002. A role for the PI 3-kinase/Akt pathway in GM-CSF-stimulated delay of apoptosis was indicated by the ability of LY294002 to attenuate apoptosis delay. GM-CSF-dependent inhibition of apoptosis was significantly attenuated by PD98059, an ERK pathway inhibitor. LY294002 and PD98059 did not produce additive inhibition of apoptosis delay. To determine whether PI 3-kinase and ERK are used by other ligands that delay neutrophil apoptosis, we examined the role of these pathways in IL-8-induced apoptosis delay. LY294002 blocked IL-8-dependent Akt phosphorylation. PD98059 and LY294002 significantly attenuated IL-8 delay of apoptosis. These results indicate IL-8 and GM-CSF act, in part, to delay neutrophil apoptosis by stimulating PI 3-kinase and ERK-dependent pathways.
Kinase Pathways in Chemoattractant-Induced Degranulation of Neutrophils: The Role of p38 Mitogen-Activated Protein Kinase Activated by Src Family Kinases
Authors: Mócsai Attila , Jakus Zoltán , Vántus Tibor , Berton Giorgio , Lowell Clifford A. , Ligeti Erzsébet 
Published: April 2014

AbstractThe aim of the present study was to investigate the role of tyrosine phosphorylation pathways in fMLP-induced exocytosis of the different secretory compartments (primary and secondary granules, as well as secretory vesicles) of neutrophils. Genistein, a broad specificity tyrosine kinase inhibitor, blocked the exocytosis of primary and secondary granules, but had only a marginal effect on the release of secretory vesicles. Genistein also inhibited the phosphorylation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinases (MAPK), raising the possibility that inhibition of ERK and/or p38 MAPK might be responsible for the effect of the drug on the degranulation response. Indeed, SB203580, an inhibitor of p38 MAPK, decreased the release of primary and secondary granules, but not that of secretory vesicles. However, blocking the ERK pathway with PD98059 had no effect on any of the exocytic responses tested. PP1, an inhibitor of Src family kinases, also attenuated the release of primary and secondary granules, and neutrophils from mice deficient in the Src family kinases Hck, Fgr, and Lyn were also defective in secondary granule release. Furthermore, activation of p38 MAPK was blocked by both PP1 and the hck−/−fgr−/−lyn−/− mutation. Taken together, our data indicate that fMLP-induced degranulation of primary and secondary granules of neutrophils is mediated by p38 MAPK activated via Src family tyrosine kinases. Although piceatannol, a reportedly selective inhibitor of Syk, also prevented degranulation and activation of p38 MAPK, no fMLP-induced phosphorylation of Syk could be observed, raising doubts about the specificity of the inhibitor.
Neutrophil Tethering on E-Selectin Activates β2 Integrin Binding to ICAM-1 Through a Mitogen-Activated Protein Kinase Signal Transduction Pathway
Authors: Simon Scott I. , Hu Yu , Vestweber Dietmar , Smith C. Wayne 
Published: April 2014

AbstractOn inflamed endothelium selectins support neutrophil capture and rolling that leads to firm adhesion through the activation and binding of β2 integrin. The primary mechanism of cell activation involves ligation of chemotactic agonists presented on the endothelium. We have pursued a second mechanism involving signal transduction through binding of selectins while neutrophils tether in shear flow. We assessed whether neutrophil rolling on E-selectin led to cell activation and arrest via β2 integrins. Neutrophils were introduced into a parallel plate flow chamber having as a substrate an L cell monolayer coexpressing E-selectin and ICAM-1 (E/I). At shears ≥0.1 dyne/cm2, neutrophils rolled on the E/I. A step increase to 4.0 dynes/cm2 revealed that ∼60% of the interacting cells remained firmly adherent, as compared with ∼10% on L cells expressing E-selectin or ICAM-1 alone. Cell arrest was dependent on application of shear and activation of Mac-1 and LFA-1 to bind ICAM-1. Firm adhesion was inhibited by blocking E-selectin, L-selectin, or PSGL-1 with Abs and by inhibitors to the mitogen-activated protein kinases. A chimeric soluble E-selectin-IgG molecule specifically bound sialylated ligands on neutrophils and activated adhesion that was also inhibited by blocking the mitogen-activated protein kinases. We conclude that neutrophils rolling on E-selectin undergo signal transduction leading to activation of cell arrest through β2 integrins binding to ICAM-1.