bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential Regulation of Neutrophil-Activating Chemokines by IL-6 and Its Soluble Receptor Isoforms
Authors: McLoughlin Rachel M. , Hurst Suzanne M. , Nowell Mari A. , Harris Dean A. , Horiuchi Sankichi , Morgan Llinos W. , Wilkinson Thomas S. , Yamamoto Naoki , Topley Nicholas , Jones Simon A. 
Published: April 2014

Abstract
Interleukin-6 signaling via its soluble receptor (sIL-6R) differentially regulates inflammatory chemokine expression and leukocyte apoptosis to coordinate transition from neutrophil to mononuclear cell infiltration. sIL-6R activities may, however, be influenced in vivo by the occurrence of two sIL-6R isoforms that are released as a consequence of differential mRNA splicing (DS) or proteolytic cleavage (PC) of the cognate IL-6R (termed DS- and PC-sIL-6R). Using human peritoneal mesothelial cells and a murine model of peritoneal inflammation, studies described in this work have compared the ability of both isoforms to regulate neutrophil recruitment. In this respect, DS- and PC-sIL-6R were comparable in their activities; however, these studies emphasized that IL-6 trans signaling differentially controls neutrophil-activating CXC chemokine expression. In vitro, stimulation of mesothelial cells with IL-6 in combination with either DS-sIL-6R or PC-sIL-6R showed no induction of CXC chemokine ligand (CXCL)1 (GROα) and CXCL8 (IL-8), whereas both isoforms enhanced CXCL5 (ENA-78) and CXCL6 (granulocyte chemotactic protein-2) expression. Moreover, when complexed with IL-6, both isoforms specifically inhibited the IL-1β-induced secretion of CXCL8. These findings were paralleled in vivo, in which induction of peritoneal inflammation in IL-6-deficient (IL-6−/−) mice resulted in enhanced keratinocyte-derived chemokine and macrophage-inflammatory protein-2 (the murine equivalent of CXCL1 and CXCL8) levels, but reduced LPS-induced CXC chemokine (the murine equivalent of CXCL5) expression. Reconstitution of IL-6 signaling in IL-6−/− mice with IL-6 and its soluble receptor isoforms corrected this chemokine imbalance and suppressed overall neutrophil infiltration. These data confirm that sIL-6R-mediated signaling primarily limits neutrophil influx; however, induction of CXCL5 and CXCL6 may regulate other neutrophil responses.
Generation of an Allergy Vaccine by Disruption of the Three-Dimensional Structure of the Cross-Reactive Calcium-Binding Allergen, Phl p 7
Authors: Westritschnig Kerstin , Focke Margarete , Verdino Petra , Goessler Walter , Keller Walter , Twardosz Anna , Mari Adriano , Horak Friedrich , Wiedermann Ursula , Hartl Arnulf , Thalhamer Josef , Sperr Wolfgang R. , Valent Peter , Valenta Rudolf 
Published: April 2014

Abstract
The grass pollen allergen, Phl p 7, belongs to a family of highly cross-reactive calcium-binding pollen allergens. Because Phl p 7 contains most of the disease-eliciting epitopes of pollen-derived calcium-binding allergens, hypoallergenic variants were engineered according to the x-ray crystal structure of Phl p 7 for allergy vaccination. In three recombinant variants, amino acids essential for calcium binding were mutated, and two peptides comprising the N- and C-terminal half were obtained by synthetic peptide chemistry. As determined by circular dichroism analysis and size exclusion chromatography coupled to mass spectrometry, recombinant mutants showed altered structural fold and lacked calcium-binding capacity, whereas the two synthetic peptides had completely lost their structural fold. Allergic patients’ IgE Ab binding was strongest reduced to the variant containing two mutations in each of the two calcium-binding sites and to the peptides. Basophil histamine release and skin test experiments in allergic patients identified the peptides as the vaccine candidates with lowest allergenic activity. Immunization of rabbits with the peptides induced IgG Abs that blocked allergic patients’ IgE binding to Phl p 7 and inhibited allergen-induced basophil degranulation. Our results indicate that disruption of an allergen’s three-dimensional structure represents a general strategy for the generation of hypoallergenic allergy vaccines, and demonstrate the importance of allergen-specific IgG Abs for the inhibition of immediate allergic symptoms.
NK Cells Stimulate Proliferation of T and NK Cells through 2B4/CD48 Interactions
Authors: Assarsson Erika , Kambayashi Taku , Schatzle John D. , Cramer Sven O. , von Bonin Arne , Jensen Peter E. , Ljunggren Hans-Gustaf , Chambers Benedict J. 
Published: April 2014

Abstract
Few studies have addressed the consequences of physical interactions between NK and T cells, as well as physical interactions among NK cells themselves. We show in this study that NK cells can enhance T cell activation and proliferation in response to CD3 cross-linking and specific Ag through interactions between 2B4 (CD244) on NK cells and CD48 on T cells. Furthermore, 2B4/CD48 interactions between NK cells also enhanced proliferation of NK cells in response to IL-2. Overall, these results suggest that NK cells augment the proliferation of neighboring T and NK cells through direct cell-cell contact. These results provide new insights into NK cell-mediated control of innate and adaptive immunity and demonstrate that receptor/ligand-specific cross talk between lymphocytes may occur in settings other than T-B cell or T-T cell interactions.
Liver Sinusoidal Endothelial Cells Are Insufficient to Activate T Cells
Authors: Katz Steven C. , Pillarisetty Venu G. , Bleier Joshua I. , Shah Alaap B. , DeMatteo Ronald P. 
Published: April 2014

Abstract
Liver sinusoidal endothelial cells (LSEC) have been reported to express MHC class II, CD80, CD86, and CD11c and effectively stimulate naive T cells. Because dendritic cells (DC) are known to possess these characteristics, we sought to directly compare the phenotype and function of murine LSEC and DC. Nonparenchymal cells from C57BL/6 mice were obtained by collagenase digestion of the liver followed by density gradient centrifugation. From the enriched nonparenchymal cell fraction, LSEC (CD45−) were then isolated to 99% purity using immunomagnetic beads. Flow cytometric analysis of LSEC demonstrated high expression of CD31, von Willebrand factor, and FcγRs. However, unlike DC, LSEC had low or absent expression of MHC class II, CD86, and CD11c. LSEC demonstrated a high capacity for Ag uptake in vitro and in vivo. Although acetylated low-density lipoprotein uptake has been purported to be a specific function of LSEC, we found DC captured acetylated low-density lipoprotein to a similar extent in vivo. Consistent with their phenotype, LSEC were poor stimulators of allogeneic T cells. Furthermore, in the absence of exogenous costimulation, LSEC induced negligible proliferation of CD4+ or CD8+ TCR-transgenic T cells. Thus, contrary to previous reports, our data indicate that LSEC alone are insufficient to activate naive T cells.
CD4+ CD25+ Regulatory T Cell Repertoire Formation in Response to Varying Expression of a neo-Self-Antigen
Authors: Lerman Melissa A. , Larkin Joseph , Cozzo Cristina , Jordan Martha S. , Caton Andrew J. 
Published: April 2014

Abstract
We have examined the development of self-peptide-specific CD4+CD25+ regulatory T cells in lineages of transgenic mice that express the influenza virus PR8 hemagglutinin (HA) under the control of several different promoters (HA transgenic mice). By mating these lineages with TS1-transgenic mice expressing a TCR that recognizes the major I-Ed-restricted determinant from HA (site 1 (S1)), we show that S1-specific T cells undergo selection to become CD4+CD25+ regulatory T cells in each of the lineages, although in varying numbers. In some lineages, S1-specific CD4+CD25+ regulatory T cells are highly abundant; indeed, TS1xHA-transgenic mice can contain as many S1-specific CD4+ T cells as are present in TS1 mice, which do not express the neo-self HA. In another lineage, however, S1-specific thymocytes are subjected to more extensive deletion and far fewer S1-specific CD4+CD25+ regulatory T cells accumulate in the periphery. We show that radioresistant stromal cells can direct both deletion and CD4+CD25+ regulatory T cell selection of S1-specific thymocytes. Interestingly, even though their numbers can vary, the S1-specific CD4+CD25+ regulatory T cells in all cases coexist with clonally related CD4+CD25− T cells that lack regulatory function. These findings show that the formation of the CD4+CD25+ regulatory T cell repertoire is sensitive to variations in the expression of self-peptides.
LIGHT Expression by Mucosal T Cells May Regulate IFN-γ Expression in the Intestine
Authors: Cohavy Offer , Zhou Jaclyn , Granger Steve W. , Ware Carl F. , Targan Stephan R. 
Published: April 2014

Abstract
The TNF superfamily of cytokines play an important role in T cell activation and inflammation. Sustained expression of lymphotoxin-like inducible protein that competes with glycoprotein D for binding herpesvirus entry mediator on T cells (LIGHT) (TNFSF14) causes a pathological intestinal inflammation when constitutively expressed by mouse T cells. In this study, we characterized LIGHT expression on activated human T cell subsets in vitro and demonstrated a direct proinflammatory effect on regulation of IFN-γ. LIGHT was induced in memory CD45RO CD4+ T cells and by IFN-γ-producing CD4+ T cells. Kinetic analysis indicated rapid induction of LIGHT by human lamina propria T cells, reaching maximal levels by 2–6 h, whereas peripheral blood or lymph node-derived T cells required 24 h. Further analysis of intestinal specimens from a 41 patient cohort by flow cytometry indicated membrane LIGHT induction to higher peak levels in lamina propria T cells from the small bowel or rectum but not colon, when compared with lymph node or peripheral blood. Independent stimulation of the LIGHT receptor, herpesvirus entry mediator, induced IFN-γ production in lamina propria T cells, while blocking LIGHT inhibited CD2-dependent induction of IFN-γ synthesis, indicating a role for LIGHT in the regulation of IFN-γ and as a putative mediator of proinflammatory T-T interactions in the intestinal mucosa. Taken together, these findings suggest LIGHT-herpesvirus entry mediator mediated signaling as an important immune regulatory mechanism in mucosal inflammatory responses.
High Mobility Group Box Protein 1: An Endogenous Signal for Dendritic Cell Maturation and Th1 Polarization
Authors: Messmer Davorka , Yang Huan , Telusma Gloria , Knoll Faye , Li Jianhua , Messmer Bradley , Tracey Kevin J. , Chiorazzi Nicholas 
Published: April 2014

Abstract
High mobility group box protein 1 (HMGB1), a DNA binding nuclear and cytosolic protein, is a proinflammatory cytokine released by monocytes and macrophages. This study addressed the hypothesis that HMGB1 is an immunostimulatory signal that induces dendritic cell (DC) maturation. We show that HMGB1, via its B box domain, induced phenotypic maturation of DCs, as evidenced by increased CD83, CD54, CD80, CD40, CD58, and MHC class II expression and decreased CD206 expression. The B box caused increased secretion of the proinflammatory cytokines IL-12, IL-6, IL-1α, IL-8, TNF-α, and RANTES. B box up-regulated CD83 expression as well as IL-6 secretion via a p38 MAPK-dependent pathway. In the MLR, B box-activated DCs acted as potent stimulators of allogeneic T cells, and the magnitude of the response was equivalent to DCs activated by exposure to LPS, nonmethylated CpG oligonucleotides, or CD40L. Furthermore, B box induced secretion of IL-12 from DCs as well as IL-2 and IFN-γ secretion from allogeneic T cells, suggesting a Th1 bias. HMGB1 released by necrotic cells may be a signal of tissue or cellular injury that, when sensed by DCs, induces and/or enhances an immune reaction.
Monomeric IgG in Intravenous Ig Preparations Is a Functional Antagonist of FcγRII and FcγRIIIb
Authors: van Mirre Edwin , Teeling Jessica L. , van der Meer Jos W. M. , Bleeker Wim K. , Hack C. Erik 
Published: April 2014

Abstract
Intravenous Ig preparations (IVIg), originally developed as a substitution therapy for patients with low plasma IgG, are nowadays frequently used in the treatment of various immune diseases. However, the mechanism of action of IVIg in these diseases remains elusive and is often referred to as “immunomodulatory.” We hypothesized that monomeric IgG may act as a low-affinity FcγR antagonist and sought experimental evidence for this hypothesis. Human neutrophils as well FcγRIIa-transfected IIA1.6 cells were used as FcγR-positive cells and aggregated IgG (aIgG) or stable dimeric IgG as FcγR-specific agonists for these cells. We found that monomeric IgG purified from IVIg at concentrations similar to that of IgG in plasma, diminished the binding of stable dimeric IgG to FcγRIIa transfectants, reduced aIgG-induced influx of Ca2+ ions into the cytosol of neutrophils, and attenuated the aIgG-induced release of elastase. Notably, monomeric IgG by itself did not elicit these responses, nor did it affect these processes in response to fMLP. Absorption of IgG from normal plasma revealed that plasma IgG exerted similar effects as monomeric IgG in IVIg. In addition, adding monomeric IgG to blood of healthy volunteers showed a dose-dependent decrease of aIgG-induced elastase release. Finally, we observed decreased aIgG-induced polymorphonuclear neutrophil responses in two hypogammaglobulinemic patients upon treatment with IVIg. We conclude that monomeric IgG at physiological levels acts as a low-affinity FcγR antagonist. Moreover, FcγR antagonism constitutes an immunomodulatory effect of IVIg.
Constitutive and Ligand-Induced TCR Degradation
Authors: von Essen Marina , Bonefeld Charlotte Menné , Siersma Volkert , Rasmussen Anette Bødker , Lauritsen Jens Peter H. , Nielsen Bodil L. , Geisler Carsten 
Published: April 2014

AbstractModulation of TCR expression levels is a central event during T cell development and activation, and it probably plays an important role in adjusting T cell responsiveness. Conflicting data have been published on down-regulation and degradation rates of the individual TCR subunits, and several divergent models for TCR down-regulation and degradation have been suggested. The aims of this study were to determine the rate constants for constitutive and ligand-induced TCR degradation and to determine whether the TCR subunits segregate or are processed as an intact unit during TCR down-regulation and degradation. We found that the TCR subunits in nonstimulated Jurkat cells were degraded with rate constants of ∼0.0011 min−1, resulting in a half-life of ∼10.5 h. Triggering of the TCR by anti-TCR Abs resulted in a 3-fold increase in the degradation rate constants to ∼0.0033 min−1, resulting in a half-life of ∼3.5 h. The subunits of the TCR complex were down-regulated from the cell surface and degraded with identical kinetics, and most likely remained associated during the passage throughout the endocytic pathway from the cell surface to the lysosomes. Similar results were obtained in studies of primary human Vβ8+ T cells stimulated with superantigen. Based on these results, the simplest model for TCR internalization, sorting, and degradation is proposed.
Intercellular Adhesion Molecule 1 Deficiency Leads to Impaired Recruitment of T Lymphocytes and Enhanced Host Susceptibility to Infection withTrypanosoma cruzi
Authors: Michailowsky Vladimir , Celes Mara R. N. , Marino Ana P. , Silva Andréa A. , Vieira Leda Q. , Rossi Marcos A. , Gazzinelli Ricardo T. , Lannes-Vieira Joseli , Silva João S. 
Published: April 2014

AbstractIn this study, we investigated the involvement of Th1 cytokines in the expression of cell adhesion molecules (CAM) and recruitment of inflammatory cells to the heart of mice infected with Trypanosoma cruzi. Our results show that endogenously produced IFN-γ is essential to induce optimal expression of VCAM-1 and ICAM-1 on the cardiac vascular endothelium of infected mice. Furthermore, the influx of inflammatory cells into the cardiac tissue was impaired in Th1 cytokine-deficient infected mice, paralleling the intensity of VCAM-1 and ICAM-1 expression on the vascular endothelium. Consistent with the importance of ICAM-1 in host resistance, ICAM-1 knockout (KO) mice were highly susceptible to T. cruzi infection, as assessed by mortality rate, parasitemia, and heart tissue parasitism. The enhanced parasitism was associated with a decrease in the numbers of CD4+ and CD8+ T lymphocytes in the heart tissue of ICAM-1 KO mice. Additionally, ICAM-1 KO mice mounted an unimpaired IFN-γ response and IFN-γ-dependent production of reactive nitrogen intermediates and parasite- specific IgG2a. Supporting the participation of ICAM-1 in cell migration during T. cruzi infection, the entrance of adoptively transferred PBL from T. cruzi-infected wild-type C57BL/6 mice into the cardiac tissue of ICAM-1 KO mice was significantly abrogated. Therefore, we favor the hypothesis that ICAM-1 plays a crucial role in T lymphocyte recruitment to the cardiac tissue and host susceptibility during T. cruzi infection.
Dual Roles of PspC, a Surface Protein of Streptococcus pneumoniae, in Binding Human Secretory IgA and Factor H
Authors: Dave Sandhya , Carmicle Stephanie , Hammerschmidt Sven , Pangburn Michael K. , McDaniel Larry S. 
Published: April 2014

Abstract
Streptococcus pneumoniae, also known as the pneumococcus, contains several surface proteins that along with the polysaccharide capsule function in antiphagocytic activities and evasion of the host immune system. These pneumococcal proteins interact with the host immune system in various ways and possess a wide range of biological activities that suggests that they may be involved at different stages of pneumococcal infection. PspC, also known as CbpA and SpsA, is one of several pneumococcal surface proteins that binds host proteins, including factor H (FH) and secretory IgA (sIgA) via the secretory component. Previous work by our laboratory has demonstrated that PspC on the surface of live pneumococcal cells binds FH. This paper provides evidence that FH activity is maintained in the presence of PspC and that the PspC binding site is located in the short consensus repeat 6–10 region of FH. We also report for the first time that although both FH and sIgA binding has been localized to the α-helical domain of PspC, the binding of FH to PspC is not inhibited by sIgA. ELISA, surface plasmon resonance, and flow cytometry indicate that the two host proteins do not compete for binding with PspC and likely do not share the same binding sites. We confirmed by Western analysis that the binding sites are separate using recombinant PspC proteins. These PspC variants bind FH yet fail to bind sIgA. Thus, we conclude that FH and sIgA can bind concurrently to the α-helical region of PspC.
The Hybrid Cytomegalovirus Enhancer/Chicken β-Actin Promoter along with Woodchuck Hepatitis Virus Posttranscriptional Regulatory Element Enhances the Protective Efficacy of DNA Vaccines
Authors: Garg Sanjay , Oran Alp E. , Hon Huiming , Jacob Joshy 
Published: April 2014

Abstract
DNA vaccines represent a novel and powerful alternative to conventional vaccine approaches. They are extremely stable and can be produced en masse at low cost; more importantly, DNA vaccines against emerging pathogens or bioterrorism threats can be quickly constructed based solely upon the pathogen’s genetic code. The main drawback of DNA vaccines is that they often induce lower immune responses than traditional vaccines, particularly in nonrodent species. Thus, improving the efficacy of DNA vaccines is a critical issue in vaccine development. In this study we have enhanced the efficacy of DNA vaccines by adopting strategies that increase gene expression. We generated influenza-hemagglutinin (HA)-encoding DNA vaccines that contain the hybrid CMV enhancer/chicken β-actin (CAG) promoter and/or the mRNA-stabilizing post-transcriptional regulatory element from the woodchuck hepatitis virus (WPRE). Mice were immunized with these DNA vaccines, and the influenza-HA-specific cellular and humoral immune responses were compared with a conventional, HA-encoding DNA vaccine whose gene expression was driven by the CMV immediate-early promoter (pCMV-HA). CAG promoter-driven DNA vaccines elicited significantly higher humoral and cellular immune responses compared with the pCMV-HA vaccine. DNA vaccines consisting of both CAG and WPRE elements (pCAG-HA-WPRE) induced the highest level of protective immunity, such that immunization with 10-fold lower DNA doses prevented death in 100% of the mice upon lethal viral challenge, whereas all mice immunized with the conventional pCMV-HA vaccine succumbed to influenza infection.
A Caspase-6 and Anti-Human Epidermal Growth Factor Receptor-2 (HER2) Antibody Chimeric Molecule Suppresses the Growth of HER2-Overexpressing Tumors
Authors: Xu Yan-Ming , Wang Li-Feng , Jia Lin-Tao , Qiu Xiu-Chun , Zhao Jing , Yu Cui-Juan , Zhang Rui , Zhu Feng , Wang Cheng-Ji , Jin Bo-Quan , Chen Si-Yi , Yang An-Gang 
Published: April 2014

Abstract
Clinical studies have suggested that human epidermal growth factor receptor-2 (HER2) provide a useful target for antitumor therapy. We previously described the generation of a chimeric HER2-targeted immunocasp-3 protein. In this study, we extend the repertoire of chimeric proapoptotic proteins with immunocasp-6, a construct that comprises a HER2-specific single-chain Ab, a single-chain Pseudomonas exotoxin A, and an active caspase-6, which can directly cleave lamin A leading to nucleus damage and inducing programmed cell death. We demonstrate that the secreted immunocasp-6 molecule selectively recognizes and induces apoptosis in HER2-overexpressing tumor cells in vitro, but not in cells with undetectable HER2. The immunocasp-6 gene was next transferred into BALB/c athymic mice bearing human breast SK-BR-3 tumors by i.m. injection of liposome-encapsulated vectors, by intratumor injection of adenoviral vectors, or by i.v. injection of PBMC modified by retroviral infection. Regardless of the method used, expression of immunocasp-6 suppressed tumor growth and prolonged animal survival significantly. Our data show that the chimeric immunocasp-6 molecule can recognize HER2–positive tumor cells, promptly attack their nucleus, and induce their apoptotic death, suggesting the potential of this strategy for the treatment of human cancers that overexpress HER2.
Abundant Expression of Granzyme A, but Not Perforin, in Granules of CD8+ T Cells in GALT: Implications for Immune Control of HIV-1 Infection
Authors: Shacklett Barbara L. , Cox Catherine A. , Quigley Máire F. , Kreis Christophe , Stollman Neil H. , Jacobson Mark A. , Andersson Jan , Sandberg Johan K. , Nixon Douglas F. 
Published: April 2014

AbstractBecause GALT is a major portal of entry for HIV-1 and reservoir for viral replication, we hypothesized that an ineffective cellular immune response in intestinal mucosa might partially explain the failure of immune control in AIDS. In this study, we demonstrate that the vast majority of CD8+ T cells in rectal tissue, including HIV-1-specific cells, fail to express the cytolytic protein, perforin. However, rectal CD8+ T cells do express granzyme A, and are also capable of releasing IFN-γ upon stimulation with cognate peptide. Confocal microscopy showed that granzyme A was located in intracellular granules in the absence of perforin. The majority of rectal CD8+ T cells exhibit an effector memory phenotype, expressing CD45RO but not CCR7. Quantitative real-time PCR analysis demonstrated that perforin RNA is expressed in rectal CD8+ T cells from healthy and HIV-1-positive individuals. In HIV-1-positive individuals, similar amounts of perforin RNA were detected in CD8+ T cells from rectal tissue and PBMC, despite a relative absence of perforin protein in rectal tissue. These findings demonstrate an important difference in perforin expression between CD8+ T cells in blood and mucosa. Furthermore, the relative absence of armed effector cells may serve to protect the integrity of rectal mucosa under normal conditions, but might also provide an early advantage to HIV-1 and other sexually transmitted viruses.