bluuebunny/crossref_metadata_2025_split huggingface dataset:
Viral Macrophage-Inflammatory Protein-II: A Viral Chemokine That Differentially Affects Adaptive Mucosal Immunity Compared with Its Mammalian Counterparts
Authors: Singh Udai P. , Singh Shailesh , Ravichandran Palaniappan , Taub Dennis D. , Lillard James W. 
Published: April 2014

AbstractChemokines play a profound role in leukocyte trafficking and the development of adaptive immune responses. Perhaps due to their importance in host defense, viruses have adopted many of the hallmarks displayed by chemokines. In particular, viral MIP-II (vMIP-II) is a human chemokine homologue that is encoded by human herpes virus 8. vMIP-II is angiogenic, selectively chemotactic for Th2 lymphocytes, and a homologue of human I-309 and mouse TCA-3, which also differentially attracts Th2 cells. To better understand the effect of viral chemokines on mucosal immunity, we compared the affects of vMIP-II, I-309, and TCA-3 on cellular and humoral immune responses after nasal immunization with OVA. These CCR8 ligands significantly enhanced Ag-specific serum and mucosal Abs through increasing Th2 cytokine secretion by CD4+ T cells. These alterations in adaptive humoral and cellular responses were preceded (12 h after immunization) by an increase in CD4+ T and B cells in nasal tracts with decreases of these leukocyte populations in the lung. Interestingly, vMIP-II increased neutrophil infiltration in the lung and Ag-specific IL-10-secreting CD4+ T cells after immunization. Although I-309 increased the number of CD28-, CD40L-, and CD30-positive, Ag-stimulated naive CD4+ T cells, vMIP-II and TCA-3 decreased the number of CD28-, CD40L-, and CD30-positive, resting naive CD4+ T cells. Taken together, these studies suggest that CCR8 ligands direct host Th2 responses, and vMIP-II up-regulates IL-10 responses and limits costimulatory molecule expression to mitigate host immunity.
Germline Transcription and Switch Recombination of a Transgene Containing the Entire H Chain Constant Region Locus: Effect of a Mutation in a STAT6 Binding Site in the γ1 Promoter
Authors: Dunnick Wesley A. , Shi Jian , Graves Kevin A. , Collins John T. 
Published: April 2014

AbstractThe switch (S) in H chain class is preceded by germline transcription and then mediated by a DNA recombination event. One of the impediments toward understanding the mechanism is the lack of a system in which a recombinant DNA molecule undergoes cytokine-regulated class S recombination. To study class S recombination, we used transgenic mice with a 230-kb bacterial artificial chromosome that included a rearranged VDJ gene and the entire murine H chain constant region locus. We found that both germline transcription and S recombination to the transgenic γ1 H chain gene were regulated by IL-4 like that of the endogenous genes. In mice with two or more copies of the H chain locus transgene, both germline transcripts and S recombination took place at levels comparable to those from the endogenous loci. We also prepared a version of the transgene with a 4-bp mutation in a STAT6 binding site in the γ1 promoter region. On the average, this mutation reduced germline transcription by 80%, but did not change the amount of S recombination in vitro. Among both the wild-type and mutant transgenes, we found no significant correlation between the amount of germline transcripts and the amount of S recombination. We infer that the physiologic level of germline transcription of the γ1 gene is in excess over the amount required for efficient S recombination.
Complement Inactivation by Recombinant Human C3 Derivatives
Authors: Kölln Johanna , Spillner Edzard , Andrä Jörg , Klensang Katrin , Bredehorst Reinhard 
Published: April 2014

Abstract
From the implications of the complement system in a large number of diseases, an urgent need for therapeutics effecting reduced complement activity in vivo has emerged. In this study we report the design of a novel class of enzymes of human origin that obliterate functional complement by a noninhibitory, catalytic mechanism. Combining the framework of human C3 and the enzymatic mechanism of cobra venom factor, a nontoxic snake venom protein, we established molecules capable of forming stable C3 convertase complexes. Although the half-life of naturally occurring C3 convertase complexes ranges between 1 and 2 min, these complexes exhibit a half-life of up to several hours. Because the overall identity to human C3 could be extended to &gt;90%, the novel C3 derivatives can be assumed to exhibit low immunogenicity and, therefore, represent promising candidates for therapeutic reduction of complement activity in vivo.
NF-κB Regulates Expression of the MHC Class I-Related Chain A Gene in Activated T Lymphocytes
Authors: Molinero Luciana L. , Fuertes Mercedes B. , Girart María Victoria , Fainboim Leonardo , Rabinovich Gabriel A. , Costas Mónica A. , Zwirner Norberto W. 
Published: April 2014

Abstract
MHC class I-related chain A gene (MICA) is a stress-regulated, HLA-related molecule which exhibits a restricted pattern of expression. MICA protein is up-regulated on different tumor cells, and is recognized by the lectin-like NKG2D molecule expressed by cytotoxic γδ T lymphocytes, CD8+ αβ T lymphocytes, and NK cells. Although MICA is not expressed on resting lymphocytes, we demonstrated that it is induced on activated T cells. Because NF-κB is actively involved in T cell activation, and is constitutively activated in many tumors, here we investigated whether NF-κB may modulate MICA expression. Treatment with the NF-κB inhibitor sulfasalazine (Sz) resulted in a dose-dependent inhibition of MICA expression in anti-CD3- and anti-CD28/PMA-activated T lymphocytes, as assessed by Western blot and RT-PCR analysis. Moreover, Sz also down-regulated MICA expression on epithelial tumor HeLa cells. MICA expression was accompanied by a Sz-sensitive IκBα degradation. EMSA with nuclear extracts from anti-CD3- and anti-CD28/PMA-stimulated T lymphocytes demonstrated the binding of a potential NF-κB family transcription factor to a MICA gene intron 1-derived oligonucleotide that contains a putative κB binding site. Supershift assays demonstrated the presence of p65(RelA)/p50 heterodimers and p50/p50 homodimers in the NF-κB complexes bound to the κB-MICA oligonucleotide. Transient transfection of HeLa cells with p65(RelA) up-regulated MICA expression, as assessed by Western blot and flow cytometry analysis. Hence, we conclude that NF-κB regulates MICA expression on activated T lymphocytes and HeLa tumor cells, by binding to a specific sequence in the long intron 1 of the MICA gene. This constitutes the first description of a transcription factor that regulates MICA gene expression.
The Actin Cytoskeleton Controls the Efficiency of Killer Ig-Like Receptor Accumulation at Inhibitory NK Cell Immune Synapses
Authors: Standeven Leah J. , Carlin Leo M. , Borszcz Peter , Davis Daniel M. , Burshtyn Deborah N. 
Published: April 2014

Abstract
Killer cell Ig-like receptors (KIRs) are MHC class I-specific receptors expressed in NK and T lymphocytes. KIR antagonism of activation signals occurs at the immune synapse between the effector and target cells. The processes that regulate clustering of KIR are not well defined. We have expressed KIR-GFP receptor chimeras in two human NK-like lines, YTS and NK92. In this study, we show that the frequency of KIR enrichment at the synapse was decreased for a KIR that lacks a portion of the cytoplasmic tail. Strikingly, blocking actin polymerization with a high dose of cytochalasin D also substantially decreased clustering of KIR as well as KIR-induced clustering of HLA-C-GFP in target cells. However, the effect of inhibiting actin polymerization was only clearly evident at the earlier time points after cell mixing, and eventually clustering of KIR and HLA-C occurred independently of actin remodeling. Although treatment with anti-LFA-1 also decreased conjugate formation, the frequency of KIR clustering remained normal within the population of conjugates that did form, suggesting that the effect of cytochalasin D is not solely through LFA-1. Collectively, these data suggest that the actin cytoskeleton and the cytoplasmic tail of KIR regulate the efficiency by which KIR accumulates at inhibitory NK cell synapses.
Dendritic Cell-Specific Intercellular Adhesion Molecule 3-Grabbing Nonintegrin Mediates Binding and Internalization of Aspergillus fumigatus Conidia by Dendritic Cells and Macrophages
Authors: Serrano-Gómez Diego , Domínguez-Soto Angeles , Ancochea Julio , Jimenez-Heffernan José A. , Leal Juan Antonio , Corbí Angel L. 
Published: April 2014

Abstract
Aspergillus fumigatus is responsible for a large percentage of nosocomial opportunistic fungal infections in immunocompromised hosts, especially during cytotoxic chemotherapy and after bone marrow transplantation, and is currently a major direct cause of death in leukemia patients. Dendritic cell-specific ICAM-3-grabbing nonintegrin (DC-SIGN) is a type II C-type lectin that functions as an adhesion receptor and is used by viral and bacterial pathogens to gain access to human DC. We report that DC-SIGN specifically interacts with clinical isolates of A. fumigatus. DC-SIGN-dependent binding of A. fumigatus conidia can be demonstrated with stable transfectants and monocyte-derived DC and is inhibited by anti-DC-SIGN Abs. Binding and internalization of A. fumigatus conidia correlates with DC-SIGN cell surface expression levels and is abolished in the presence of A. funigatus-derived cell wall galactomannans. The clinical relevance of this interaction is emphasized by the presence of DC-SIGN in lung DC and alveolar macrophages, and further illustrated by the DC-SIGN-dependent attachment of A. fumigatus conidia to the cell membrane of IL-4-treated monocyte-derived macrophages. Our results suggest the involvement of DC-SIGN in the initial stages of pulmonary infection as well as in fungal spreading during invasive aspergillosis.
Duration of Infection and Antigen Display Have Minimal Influence on the Kinetics of the CD4+ T Cell Response to Listeria monocytogenes Infection
Authors: Corbin Gail A. , Harty John T. 
Published: April 2014

Abstract
The T cell response to infection consists of clonal expansion of effector cells, followed by contraction to memory levels. It was previously thought that the duration of infection determines the magnitude and kinetics of the T cell response. However, recent analysis revealed that transition between the expansion and contraction phases of the Ag-specific CD8+ T cell response is not affected by experimental manipulation in the duration of infection or Ag display. We studied whether the duration of infection and Ag display influenced the kinetics of the Ag-specific CD4+ T cell response to Listeria monocytogenes (LM) infection. We found that truncating infection and Ag display with antibiotic treatment as early as 24 h postinfection had minimal impact on the expansion or contraction of CD4+ T cells; however, the magnitudes of the Ag-specific CD4+ and CD8+ T cell responses were differentially affected by the timing of antibiotic treatment. Treatment of LM-infected mice with antibiotics at 24 h postinfection did not prevent generation of detectable CD4+ and CD8+ memory T cells at 28 days after infection, vigorous secondary expansion of these memory T cells, or protection against a subsequent LM challenge. These results demonstrate that events within the first few days of infection stimulate CD4+ and CD8+ T cell responses that are capable of carrying out the full program of expansion and contraction to functional memory, independently of prolonged infection or Ag display.
Expression of Functional TLR4 Confers Proinflammatory Responsiveness toTrypanosoma cruziGlycoinositolphospholipids and Higher Resistance to Infection withT. cruzi
Authors: Oliveira Ana-Carolina , Peixoto Jaqueline R. , de Arruda Luciana B. , Campos Marco A. , Gazzinelli Ricardo T. , Golenbock Douglas T. , Akira Shizuo , Previato José O. , Mendonça-Previato Lúcia , Nobrega Alberto , Bellio Maria 
Published: April 2014

AbstractTLRs function as pattern recognition receptors in mammals and play an essential role in the recognition of microbial components. We found that the injection of glycoinositolphospholipids (GIPLs) from Trypanosoma cruzi into the peritoneal cavity of mice induced neutrophil recruitment in a TLR4-dependent manner: the injection of GIPL in the TLR4-deficient strain of mice (C57BL/10ScCr) caused no inflammatory response. In contrast, in TLR2 knockout mice, neutrophil chemoattraction did not differ significantly from that seen in wild-type controls. GIPL-induced neutrophil attraction and MIP-2 production were also severely affected in TLR4-mutant C3H/HeJ mice. The role of TLR4 was confirmed in vitro by testing genetically engineered mutants derived from TLR2-deficient Chinese hamster ovary (CHO)-K1 fibroblasts that were transfected with CD14 (CHO/CD14). Wild-type CHO/CD14 cells express the hamster TLR4 molecule and the mutant line, in addition, expresses a nonfunctional form of MD-2. In comparison to wild-type cells, mutant CHO/CD14 cells failed to respond to GIPLs, indicating a necessity for a functional TLR4/MD-2 complex in GIPL-induced NF-κB activation. Finally, we found that TLR4-mutant mice were hypersusceptible to T. cruzi infection, as evidenced by a higher parasitemia and earlier mortality. These results demonstrate that natural resistance to T. cruzi is TLR4 dependent, most likely due to TLR4 recognition of their GIPLs.
Rac1 Contributes to Maximal Activation of STAT1 and STAT3 in IFN-γ-Stimulated Rat Astrocytes
Authors: Park Eun Jung , Ji Kyung-Ae , Jeon Sae-Bom , Choi Woo-Hyuck , Han Inn-oc , You Hye-Jin , Kim Jae-Hong , Jou Ilo , Joe Eun-Hye 
Published: April 2014

AbstractRac1 GTPase is implicated as a signaling mediator in various cellular events. In this study, we show that Rac1 contributes to IFN-γ-induced inflammatory responses in rat astrocytes. We revealed that IFN-γ rapidly stimulated activation of Rac1 in C6 astroglioma cells by investigating GST-PAK-PBD-binding ability. We also found that Rac1 deficiency led to attenuation of IFN-γ-responsive transcriptional responses. Compared with levels in control cells, IFN-γ-induced IFN-γ-activated sequence promoter activity was markedly reduced in both C6 astroglioma cells and primary astrocytes expressing RacN17, a well-characterized Rac1-negative mutant. The expression of several IFN-γ-responsive genes, such as MCP-1 and ICAM-1, was also reduced in cells expressing RacN17. Consistent with these observations, IFN-γ-induced phosphorylation of STAT1 and STAT3 was lower in C6 cells expressing RacN17 (referred to as C6-RacN17) than in control cells. However, there was no difference in expression level of IFN-γRα subunit and IFN-γ-induced phosphorylation of JAK1 between C6 control and C6-RacN17 cells. Interestingly, Rac1 appeared to associate with IFN-γRα and augment the interaction of IFN-γR with either STAT1 or STAT3 in response to IFN-γ. Taken together, we suggest that Rac1 may serve as an auxiliary mediator of IFN-γ-signaling, at least at the level of STAT activation, thus contributing to maximal activation of IFN-γ-responsive inflammatory signaling in rat astrocytes.
A New Pharmacological Effect of Salicylates: Inhibition of NFAT-Dependent Transcription
Authors: Aceves Mónica , Dueñas Ana , Gómez Cristina , San Vicente Edurne , Crespo Mariano Sánchez , García-Rodríguez Carmen 
Published: April 2014

AbstractThe anti-inflammatory effects of salicylates, originally attributed to inhibition of cyclooxygenase activity, are currently known to involve additional mechanisms. In this study we investigated the possible modulation by salicylates of NFAT-mediated transcription in lymphocytic and monocytic cell lines. RNase protection assays showed that 2-acetoxy-4-trifluoromethylbenzoic acid (triflusal) inhibited, in a dose-dependent manner, mRNA expression of several cytokine genes, most of which are NFAT-regulated and cyclosporin A (CsA)-sensitive. In Jurkat cells, the expression of IL-3, GM-CSF, TNF-α, TGF-β1, IL-2, lymphotactin, MIP-1α, and MIP-1β was inhibited to different extents. In THP-1 cells, inhibition of the expression of M-CSF, G-CSF, stem cell factor, IFN-γ, TNF-α, TGF-β1, lymphotoxin-β1, MIP-1α, MIP-1β, and IL-8 was observed. Sodium salicylate and aspirin only showed significant effects at 5 mM. The transcriptional activity of two genes that contain NFAT sites, a GM-CSF full promoter and a T cell-specific enhancer from the IL-3 locus, was also inhibited by salicylates. Transactivation experiments performed with several NFAT-dependent and AP-1-dependent reporter genes showed that triflusal strongly inhibited NFAT-dependent transcription at concentrations as low as 0.25 mM. Sodium salicylate and aspirin were less potent. The triflusal inhibitory effect was reversible and synergized with suboptimal doses of CsA. Experiments to address the mechanism of action of salicylates in the NFAT activation cascade disclosed a mechanism different from that of CsA, because salicylates inhibited DNA-binding and NFAT-mediated transactivation without affecting phosphorylation or subcellular localization of NFAT. In summary, these data describe a new pharmacological effect of salicylates as inhibitors of NFAT-dependent transcription.
Toll Receptor-Mediated Regulation of NADPH Oxidase in Human Dendritic Cells
Authors: Vulcano Marisa , Dusi Stefano , Lissandrini Daniele , Badolato Raffaele , Mazzi Paola , Riboldi Elena , Borroni Elena , Calleri Angelica , Donini Marta , Plebani Alessandro , Notarangelo Luigi , Musso Tiziana , Sozzani Silvano 
Published: April 2014

AbstractActivation of NADPH oxidase represents an essential mechanism of defense against pathogens. Dendritic cells (DC) are phagocytic cells specialized in Ag presentation rather than in bacteria killing. Human monocyte-derived DC were found to express the NADPH oxidase components and to release superoxide anions in response to phorbol esters and phagocytic agonists. The NADPH oxidase components p47phox and gp91phox were down-regulated during monocyte differentiation to DC, and maturation of DC with pathogen-derived molecules, known to activate TLRs, increased p47phox and gp91phox expression and enhanced superoxide anions release. Similar results were obtained with plasmacytoid DC following maturation with influenza virus. In contrast, activation of DC by immune stimuli (CD40 ligand) did not regulate NADPH oxidase components or respiratory burst. NADPH oxidase-derived oxygen radicals did not play any role in DC differentiation, maturation, cytokine production, and induction of T cell proliferation, as based on the normal function of DC generated from chronic granulomatous disease patients and the use of an oxygen radical scavenger. However, NADPH oxidase activation was required for DC killing of intracellular Escherichia coli. It is likely that the selective regulation of oxygen radicals production by pathogen-activated DC may function to limit pathogen dissemination during DC trafficking to secondary lymphoid tissues.
Selective Blockade of NF-κB Activity in Airway Immune Cells Inhibits the Effector Phase of Experimental Asthma
Authors: Desmet Christophe , Gosset Philippe , Pajak Bernard , Cataldo Didier , Bentires-Alj Mohamed , Lekeux Pierre , Bureau Fabrice 
Published: April 2014

AbstractKnockout mice studies have revealed that NF-κB plays a critical role in Th2 cell differentiation and is therefore required for induction of allergic airway inflammation. However, the questions of whether NF-κB also plays a role in the effector phase of airway allergy and whether inhibiting NF-κB could have therapeutic value in the treatment of established asthma remain unanswered. To address these issues, we have assessed in OVA-sensitized wild-type mice the effects of selectively antagonizing NF-κB activity in the lungs during OVA challenge. Intratracheal administration of NF-κB decoy oligodeoxynucleotides to OVA-sensitized mice led to efficient nuclear transfection of airway immune cells, but not constitutive lung cells and draining lymph node cells, associated with abrogation of NF-κB activity in the airways upon OVA provocation. NF-κB inhibition was associated with strong attenuation of allergic lung inflammation, airway hyperresponsiveness, and local production of mucus, IL-5, IL-13, and eotaxin. IL-4 and OVA-specific IgE and IgG1 production was not reduced. This study demonstrates for the first time that activation of NF-κB in local immune cells is critically involved in the effector phase of allergic airway disease and that specific NF-κB inhibition in the lungs has therapeutic potential in the control of pulmonary allergy.
Green Tea Epigallocatechin-3-Gallate Mediates T Cellular NF-κB Inhibition and Exerts Neuroprotection in Autoimmune Encephalomyelitis
Authors: Aktas Orhan , Prozorovski Timour , Smorodchenko Alina , Savaskan Nicolai E. , Lauster Roland , Kloetzel Peter-Michael , Infante-Duarte Carmen , Brocke Stefan , Zipp Frauke 
Published: April 2014

AbstractRecent studies in multiple sclerosis and its animal model, experimental autoimmune encephalomyelitis (EAE), point to the fact that even in the early phase of inflammation, neuronal pathology plays a pivotal role in the sustained disability of affected individuals. We show that the major green tea constituent, (−)-epigallocatechin-3-gallate (EGCG), dramatically suppresses EAE induced by proteolipid protein 139–151. EGCG reduced clinical severity when given at initiation or after the onset of EAE by both limiting brain inflammation and reducing neuronal damage. In orally treated mice, we found abrogated proliferation and TNF-α production of encephalitogenic T cells. In human myelin-specific CD4+ T cells, cell cycle arrest was induced, down-regulating the cyclin-dependent kinase 4. Interference with both T cell growth and effector function was mediated by blockade of the catalytic activities of the 20S/26S proteasome complex, resulting in intracellular accumulation of IκB-α and subsequent inhibition of NF-κB activation. Because its structure implicates additional antioxidative properties, EGCG was capable of protecting against neuronal injury in living brain tissue induced by N-methyl-d-aspartate or TRAIL and of directly blocking the formation of neurotoxic reactive oxygen species in neurons. Thus, a natural green tea constituent may open up a new therapeutic avenue for young disabled adults with inflammatory brain disease by combining, on one hand, anti-inflammatory and, on the other hand, neuroprotective capacities.
Modulation of Ca2+ Signaling by Na+/Ca2+ Exchangers in Mast Cells
Authors: Aneiros Eduardo , Philipp Stephan , Lis Annette , Freichel Marc , Cavalié Adolfo 
Published: April 2014

Abstract
Mast cells rely on Ca2+ signaling to initiate activation programs leading to release of proinflammatory mediators. The interplay between Ca2+ release from internal stores and Ca2+ entry through store-operated Ca2+ channels has been extensively studied. Using rat basophilic leukemia (RBL) mast cells and murine bone marrow-derived mast cells, we examine the role of Na+/Ca2+ exchangers. Calcium imaging experiments and patch clamp current recordings revealed both K+-independent and K+-dependent components of Na+/Ca2+ exchange. Northern blot analysis indicated the predominant expression of the K+-dependent sodium-calcium exchanger NCKX3. Transcripts of the exchangers NCX3 and NCKX1 were additionally detected in RBL cells with RT-PCR. The Ca2+ clearance via Na+/Ca2+ exchange represented ∼50% of the total clearance when Ca2+ signals reached levels ≥200 nM. Ca2+ signaling and store-operated Ca2+ entry were strongly reduced by inverting the direction of Na+/Ca2+ exchange, indicating that Na+/Ca2+ exchangers normally extrude Ca2+ ions from cytosol and prevent the Ca2+-dependent inactivation of store-operated Ca2+ channels. Working in the Ca2+ efflux mode, Na+/Ca2+ exchangers such as NCKX3 and NCX3 might, therefore, play a role in the Ag-induced mast cell activation by controlling the sustained phase of Ca2+ mobilization.