bluuebunny/crossref_metadata_2025_split huggingface dataset:
Differential IFN-γ Stimulation of HLA-A Gene Expression through CRM-1-Dependent Nuclear RNA Export
Authors: Browne Sarah K. , Roesser James R. , Zhu Sheng Zu , Ginder Gordon D. 
Published: April 2014

Abstract
IFNs regulate most MHC class I genes by stimulating transcription initiation. As shown previously, IFN-γ controls HLA-A expression primarily at the posttranscriptional level. We have defined two 8-base sequences in a 39-nucleotide region in the 3′-transcribed region of the HLA-A gene that are required for the posttranscriptional response to IFN-γ. Stimulation of HLA-A expression by IFN-γ requires nuclear export of HLA-A mRNA by chromosome maintenance region 1 (CRM-1). Treatment of cells with leptomycin B, a specific inhibitor of CRM-1, completely inhibited IFN-γ induction of HLA-A. Expression of a truncated, dominant-negative form of the nucleoporin NUP214/CAN, ΔCAN, that specifically interacts with CRM-1, also prevented IFN-γ stimulation of HLA-A, providing confirmation of the role of CRM-1. Increased expression of HLA-A induced by IFN-γ also requires protein methylation, as shown by the fact that treatment of SK-N-MC cells or HeLa cells with the PRMT1 inhibitor 5′-methyl-5′-thioadenosine abolished the cellular response to IFN-γ. In contrast with HLA-A, IFN-γ-induced expression of the HLA class Ib gene, HLA-E, was not affected by either 5′-methyl-5′-thioadenosine or leptomycin B. These results provide proof of principle that it is possible to differentially modulate the IFN-γ-induced expression of the HLA-E and HLA-A genes, whose products often mediate opposing effects on cellular immunity to tumor cells, pathogens, and autoantigens.
Vav Proteins Regulate the Plasma Cell Program and Secretory Ig Production
Authors: Stephenson Linda M. , Miletic Ana V. , Kloeppel Tracie , Kusin Shana , Swat Wojciech 
Published: April 2014

Abstract
Plasma cell (PC) development is initiated following B cell activation and controlled by a B lymphocyte-induced maturation protein (Blimp)-1-dependent program involving the concerted action of several proplasma transcriptional regulators. However, the factors that control Blimp-1 expression remain largely unknown. In this context, mice deficient for all three of the Vav family of proteins (Vavnull) develop substantial B cell populations, including marginal zone B cells, yet have a virtual absence of serum Igs, indicating that Vav may be specifically required in PC development and Ig production. We show in this study that mature marginal zone B cells from Vavnull mice proliferate following stimulation with TLR ligands but exhibit severe defects in PC differentiation and Ig secretion. Under conditions inducing PC differentiation, Vavnull B cells fail to efficiently induce Blimp-1, X box-binding protein-1, J chain, or secretory Ig μ transcripts but express IFN-regulatory factor-4 at levels similar to wild-type cells. These data indicate a previously unknown role for Vav as an upstream regulator of Blimp-1.
Pseudomonas Lipopolysaccharide Accelerates Wound Repair via Activation of a Novel Epithelial Cell Signaling Cascade
Authors: Koff Jonathan L. , Shao Matt X. G. , Kim Suil , Ueki Iris F. , Nadel Jay A. 
Published: April 2014

Abstract
The surface of the airway epithelium represents a battleground in which the host intercepts signals from pathogens and activates epithelial defenses to combat infection. Wound repair is an essential function of the airway epithelium in response to injury in chronic airway diseases, and inhaled pathogens such as Pseudomonas bacteria are implicated in the pathobiology of several of these diseases. Because epidermal growth factor receptor (EGFR) activation stimulates wound repair and because LPS activates EGFR, we hypothesized that LPS accelerates wound repair via a surface signaling cascade that causes EGFR phosphorylation. In scrape wounds of NCI-H292 human airway epithelial cells, high concentrations of LPS were toxic and decreased wound repair. However, lower concentrations of LPS accelerated wound repair. This effect was inhibited by treatment with a selective inhibitor of EGFR phosphorylation (AG 1478) and by an EGFR neutralizing Ab. Metalloprotease inhibitors and TNF-α-converting enzyme (TACE) small interfering RNA inhibited wound repair, implicating TACE. Additional studies implicated TGF-α as the active EGFR ligand cleaved by TACE during wound repair. Reactive oxygen species scavengers, NADPH oxidase inhibitors, and importantly small interfering RNA of dual oxidase 1 inhibited LPS-induced wound repair. Inhibitors of protein kinase C isoforms αβ and a TLR-4 neutralizing Ab also inhibited LPS-induced wound repair. Normal human bronchial epithelial cells responded similarly. Thus, LPS accelerates wound repair in airway epithelial cells via a novel TLR-4→protein kinase C αβ→dual oxidase 1→reactive oxygen species→TACE→TGF-α→EGFR phosphorylation pathway.
Inhibition of Macrophage Migration Inhibitory Factor or Its Receptor (CD74) Attenuates Growth and Invasion of DU-145 Prostate Cancer Cells
Authors: Meyer-Siegler Katherine L. , Iczkowski Kenneth A. , Leng Lin , Bucala Richard , Vera Pedro L. 
Published: April 2014

Abstract
Macrophage migration inhibitory factor (MIF), a proinflammatory cytokine, is overexpressed in prostate cancer, but the mechanism by which MIF exerts effects on tumor cells remains undetermined. MIF interacts with its identified membrane receptor, CD74, in association with CD44, resulting in ERK 1/2 activation. Therefore, we hypothesized that increased expression or surface localization of CD74 and MIF overexpression by prostate cancer cells regulated tumor cell viability. Prostate cancer cell lines (LNCaP and DU-145) had increased MIF gene expression and protein levels compared with normal human prostate or benign prostate epithelial cells (p &lt; 0.01). Although MIF, CD74, and CD44 variant 9 expression were increased in both androgen-dependent (LNCaP) and androgen-independent (DU-145) prostate cancer cells, cell surface of CD74 was only detected in androgen-independent (DU-145) prostate cancer cells. Therefore, treatments aimed at blocking CD74 and/or MIF (e.g., inhibition of MIF or CD74 expression by RNA interference or treatment with anti-MIF- or anti-CD74- neutralizing Abs or MIF-specific inhibitor, ISO-1) were only effective in androgen-independent prostate cancer cells (DU-145), resulting in decreased cell proliferation, MIF protein secretion, and invasion. In DU-145 xenografts, ISO-1 significantly decreased tumor volume and tumor angiogenesis. Our results showed greater cell surface CD74 in DU-145 prostate cancer cells that bind to MIF and, thus, mediate MIF-activated signal transduction. DU-145 prostate cancer cell growth and invasion required MIF activated signal transduction pathways that were not necessary for growth or viability of androgen-dependent prostate cells. Thus, blocking MIF either at the ligand (MIF) or receptor (CD74) may provide new, targeted specific therapies for androgen-independent prostate cancer.
The Expression and Possible Roles of Chemokine CXCL11 and Its Receptor CXCR3 in the Human Endometrium
Authors: Hirota Yasushi , Osuga Yutaka , Koga Kaori , Yoshino Osamu , Hirata Tetsuya , Morimoto Chieko , Harada Miyuki , Takemura Yuri , Nose Emi , Yano Tetsu , Tsutsumi Osamu , Taketani Yuji 
Published: April 2014

Abstract
IFN-γ secreted by a human embryo and trophoblast cells during implantation is suggested to play an important role in implantation and pregnancy. In the present study, we explored expression and possible functions of CXCL11, a CXC chemokine strongly induced by IFN-γ, and its receptor CXCR3 in the human endometrium. Secreted CXCL11 protein was not detected in cultured endometrial stromal cells (ESC) but was detected in cultured endometrial epithelial cells (EEC). IFN-γ stimulated the protein levels of CXCL11 in a dose-dependent manner in EEC and ESC. CXCL11 secreted from EEC with 100 ng/ml IFN-γ was 220-fold of the control, and 100-fold as compared with that secreted from ESC with the same dose of IFN-γ. CXCR3 was expressed in EEC, ESC, and trophoblast cells. Addition of IFN-γ to EEC increased the chemotactic activity of its culture medium to trophoblast cells and T cells, and the effect was suppressed by immunoneutralization with Abs of three CXCR3 ligands, including anti-CXCL11 Ab. CXCL11 significantly increased BrdU incorporation of ESC, which was inhibited by a p42/44 MAPK pathway inhibitor PD98059. In contrast, CXCL11 significantly decreased BrdU incorporation and increased the release of lactate dehydrogenase and the positive staining of annexin V in EEC. These findings suggest that IFN-γ promotes implantation by stimulating EEC to produce CXCL11, which induces migration of trophoblast cells and T cells, proliferation of ESC, and apoptosis of EEC.
Characterization of the B Cell Epitopes Associated with a Truncated Form of Pseudomonas Exotoxin (PE38) Used to Make Immunotoxins for the Treatment of Cancer Patients
Authors: Onda Masanori , Nagata Satoshi , FitzGerald David J. , Beers Richard , Fisher Robert J. , Vincent James J. , Lee Byungkook , Nakamura Michihiro , Hwang Jaulang , Kreitman Robert J. , Hassan Raffit , Pastan Ira 
Published: April 2014

Abstract
Recombinant immunotoxins composed of an Ab Fv fragment joined to a truncated portion of Pseudomonas exotoxin A (termed PE38) have been evaluated in clinical trials for the treatment of various human cancers. Immunotoxin therapy is very effective in hairy cell leukemia and also has activity in other hemological malignancies; however, a neutralizing Ab response to PE38 in patients with solid tumors prevents repeated treatments to maximize the benefit. In this study, we analyze the murine Ab response as a model to study the B cell epitopes associated with PE38. Sixty distinct mAbs to PE38 were characterized. Mutual competitive binding of the mAbs indicated the presence of 7 major epitope groups and 13 subgroups. The competition pattern indicated that the epitopes are discrete and could not be reproduced using a computer simulation program that created epitopes out of random surface residues on PE38. Using sera from immunotoxin-treated patients, the formation of human Abs to each of the topographical epitopes was demonstrated. One epitope subgroup, E1a, was identified as the principal neutralizing epitope. The location of each epitope on PE38 was determined by preparing 41 mutants of PE38 in which bulky surface residues were mutated to either alanine or glycine. All 7 major epitope groups and 9 of 13 epitope subgroups were identified by 14 different mutants and these retained high cytotoxic activity. Our results indicate that a relatively small number of discrete immunogenic sites are associated with PE38, most of which can be eliminated by point mutations.
Familial NK Cell Deficiency Associated with Impaired IL-2- and IL-15-Dependent Survival of Lymphocytes
Authors: Eidenschenk Céline , Jouanguy Emmanuelle , Alcaïs Alexandre , Mention Jean-Jacques , Pasquier Benoit , Fleckenstein Ingrid M. , Puel Anne , Gineau Laure , Carel Jean-Claude , Vivier Eric , Le Deist Françoise , Casanova Jean-Laurent 
Published: April 2014

Abstract
We previously reported the clinical phenotype of two siblings with a novel inherited developmental and immunodeficiency syndrome consisting of severe intrauterine growth retardation and the impaired development of specific lymphoid lineages, including transient CD8 αβ T lymphopenia and a persistent lack of blood NK cells. We describe here the elucidation of a plausible underlying pathogenic mechanism, with a cellular phenotype of impaired survival of both fresh and herpesvirus saimiri-transformed T cells, in the surviving child. Clearly, NK cells could not be studied. However, peripheral blood T lymphocytes displayed excessive apoptosis ex vivo. Moreover, the survival rates of CD4 and CD8 αβ T cell blasts generated in vitro, and herpesvirus saimiri-transformed T cells cultured in vitro, were low, but not nil, following treatment with IL-2 and IL-15. In contrast, Fas-mediated activation-induced cell death was not enhanced, indicating a selective excess of cytokine deprivation-mediated apoptosis. In keeping with the known roles of IL-2 and IL-15 in the development of NK and CD8 T cells in the mouse model, these data suggest that an impaired, but not abolished, survival response to IL-2 and IL-15 accounts for the persistent lack of NK cells and the transient CD8 αβ T lymphopenia documented in vivo. Impaired cytokine-mediated lymphocyte survival is likely to be the pathogenic mechanism underlying this novel form of inherited and selective NK deficiency in humans.
Modulation of the Effector Functions of a Human IgG1 through Engineering of Its Hinge Region
Authors: Dall’Acqua William F. , Cook Kimberly E. , Damschroder Melissa M. , Woods Robert M. , Wu Herren 
Published: April 2014

Abstract
We report here the engineering of a humanized anti-human EphA2 mAb (mAb 12G3H11) in an effort to explore the relationship between the hinge of a human IgG1 and its effector functions. mAb 12G3H11, used here as a model, is directed against the human receptor tyrosine kinase EphA2, which is an actively investigated target for cancer therapy due to its up-regulation in many cancer cells. Various rational modifications were introduced into the hinge region of mAb 12G3H11. These mutations were predicted to modulate the hinge’s length, flexibility, and/or biochemical properties. We show that the upper and middle hinge both play important, although functionally distinct roles. In particular, middle hinge modifications predicted to decrease its rigidity or length as well as eliminating either one of its two cysteine residues had a strong negative impact on C1q binding and complement-dependent cytotoxicity. Disruption of covalent bonds between both H chains may account in part for these effects. We also describe middle hinge mutants with a significantly decreased ability to bind FcγRIIIA and trigger Ab-dependent cell-mediated cytotoxicity. Conversely, we also generated upper hinge mutants exhibiting an increase in C1q binding and complement-dependent cytotoxicity activity. Therefore, this approach represents a novel strategy to fine-tune the biological activity of a given human IgG1. We also define, for the first time in such a systematic fashion, the relationship between various characteristics of the middle and upper hinge and the corresponding effector functions.
Roles of the Ig κ Light Chain Intronic and 3′ Enhancers inIgkSomatic Hypermutation
Authors: Inlay Matthew A. , Gao Heather H. , Odegard Valerie H. , Lin Tongxiang , Schatz David G. , Xu Yang 
Published: April 2014

AbstractSomatic hypermutation (SHM) of the rearranged Ig genes is required for the affinity maturation of Abs. SHM is almost exclusively targeted to the rearranged Ig loci, but the mechanism of this gene-specific targeting remains unclear. The Ig κ L chain locus contains multiple enhancers, including the MAR/intronic (iEκ) and 3′ enhancers (3′Eκ). Previous transgenic studies indicate that both κ enhancers are individually necessary for SHM of Igk. In contrast, later studies of Ag-selected Vκ genes in 3′Eκ−/− mice found no absolute requirement for 3′Eκ in κ SHM. To address the roles of the two κ enhancers in SHM in a physiological context, we analyzed SHM of the endogenous Igk in mice with a targeted deletion of either iEκ or 3′Eκ in Peyer’s patch germinal center B cells. Our findings indicate that, although 3′Eκ is quantitatively important for SHM of Igk, iEκ is not required for κ SHM. In addition, a reduction of κ mRNA levels is also detected in activated 3′Eκ−/− B cells. These findings suggest that iEκ and 3′Eκ play distinct roles in regulating Igk transcription and SHM.
Dynamic and Transient Remodeling of the Macrophage IL-10 Promoter during Transcription
Authors: Zhang Xia , Edwards Justin P. , Mosser David M. 
Published: April 2014

Abstract
To gain insight into the molecular mechanism(s) whereby macrophages produce large amounts of IL-10, we analyzed IL-10 gene expression and temporally correlated it with modifications to chromatin associated with the IL-10 promoter. In resting cells, which make essentially no cytokines, the IL-10 promoter is associated with histones containing little or no detectable modifications. Macrophages stimulated in the presence of immune complexes begin to produce high levels of IL-10 pre-mRNA transcripts within minutes of stimulation. Coincident with this transcription was a rapid and dynamic phosphorylation of histone H3 at specific sites in the IL-10 promoter. Histone phosphorylation was closely followed by the binding of transcription factors to the IL-10 promoter. Blocking the activation of ERK prevented histone phosphorylation and transcription factor binding to the IL-10 promoter. In contrast to histone phosphorylation, the peak of histone acetylation at this promoter did not occur until after transcription had peaked. Inhibition of histone deactylase did not alter IL-10 gene expression, suggesting that phosphorylation but not acetylation was the proximal event responsible for IL-10 transcription. Our findings reveal a rapid and well-orchestrated series of events in which ERK activation causes a rapid and transient phosphorylation of histone H3 at specific regions of the IL-10 promoter, resulting in a transient exposure of the IL-10 promoter to the transcription factors that bind there. This exposure is essential for the efficient induction of IL-10 gene expression in macrophages. To our knowledge, this represents a unique way in which the expression of a cytokine gene is regulated in macrophages.
Interleukin-13 Enhances Cyclooxygenase-2 Expression in Activated Rat Brain Microglia: Implications for Death of Activated Microglia
Authors: Yang Myung-Soon , Ji Kyung-Ae , Jeon Sae-Bom , Jin Byung-Kwan , Kim Seung U. , Jou Ilo , Joe Eunhye 
Published: April 2014

Abstract
Brain inflammation has recently attracted widespread interest because it is a risk factor for the onset and progression of brain diseases. In this study, we report that cyclooxygenase-2 (COX-2) plays a key role in the resolution of brain inflammation by inducing the death of microglia. We previously reported that IL-13, an anti-inflammatory cytokine, induced the death of activated microglia. These results revealed that IL-13 significantly enhanced COX-2 expression and production of PGE2 and 15-deoxy-Δ12,14-PGJ2 (15d-PGJ2) in LPS-treated microglia. Two other anti-inflammatory cytokines, IL-10 and TGF-β, neither induced microglial death nor enhanced COX-2 expression or PGE2 or 15d-PGJ2 production. Therefore, we hypothesized that the effect of IL-13 on COX-2 expression may be linked to death of activated microglia. We found that COX-2 inhibitors (celecoxib and NS398) suppressed the death of microglia induced by a combination of LPS and IL-13 and that exogenous addition of PGE2 and 15d-PGJ2 induced microglial death. Agonists of EP2 (butaprost) and peroxisome proliferator-activated receptor γ (ciglitazone) mimicked the effect of PGE2 and 15d-PGJ2, and an EP2 antagonist (AH6809) and a peroxisome proliferator-activated receptor γ antagonist (GW9662) suppressed microglial death induced by LPS in combination with IL-13. In addition, IL-13 potentiated LPS-induced activation of JNK, and the JNK inhibitor SP600125 suppressed the enhancement of COX-2 expression and attenuated microglial death. Taken together, these results suggest that IL-13 enhanced COX-2 expression in LPS-treated microglia through the enhancement of JNK activation. Furthermore, COX-2 products, PGE2 and 15d-PGJ2, caused microglial death, which terminates brain inflammation.
Activation of Ca2+-Dependent Signaling by TLR2
Authors: Chun Jarin , Prince Alice 
Published: April 2014

Abstract
Upon contact with airway epithelial cells, bacterial products activate Ca2+ fluxes that are required for induction of NF-κB-dependent gene expression. TLR2 is apically displayed on airway cells, making it a likely transducer linking bacterial stimuli and kinases that affect Ca2+ release. Using biochemical and genetic approaches, we demonstrate that TLR2 ligands stimulate release of Ca2+ from intracellular stores by activating TLR2 phosphorylation by c-Src, and recruiting PI3K and phospholipase Cγ to affect Ca2+ release through inositol (1,4,5) trisphosphate receptors. In the absence of TLR2, murine macrophages as well as airway cells do not generate Ca2+ fluxes or induce proinflammatory signaling. Thus, Ca2+ participates as a second messenger in TLR2-dependent signaling and provides another target to modulate proinflammatory responses to bacterial infection.
Clustering of Pre-B Cell Integrins Induces Galectin-1-Dependent Pre-B Cell Receptor Relocalization and Activation
Authors: Rossi Benjamin , Espeli Marion , Schiff Claudine , Gauthier Laurent 
Published: April 2014

AbstractInteractions between B cell progenitors and bone marrow stromal cells are essential for normal B cell differentiation. We have previously shown that an immune developmental synapse is formed between human pre-B and stromal cells in vitro, leading to the initiation of signal transduction from the pre-BCR. This process relies on the direct interaction between the pre-BCR and the stromal cell-derived galectin-1 (GAL1) and is dependent on GAL1 anchoring to cell surface glycosylated counterreceptors, present on stromal and pre-B cells. In this study, we identify α4β1 (VLA-4), α5β1 (VLA-5), and α4β7 integrins as major GAL1-glycosylated counterreceptors involved in synapse formation. Pre-B cell integrins and their stromal cell ligands (ADAM15/fibronectin), together with the pre-BCR and GAL1, form a homogeneous lattice at the contact area between pre-B and stromal cells. Moreover, integrin and pre-BCR relocalizations into the synapse are synchronized and require actin polymerization. Finally, cross-linking of pre-B cell integrins in the presence of GAL1 is sufficient for driving pre-BCR recruitment into the synapse, leading to the initiation of pre-BCR signaling. These results suggest that during pre-B/stromal cell synapse formation, relocalization of pre-B cell integrins mediated by their stromal cell ligands drives pre-BCR clustering and activation, in a GAL1-dependent manner.
Electron Transport Complex I Is Required for CD8+ T Cell Function
Authors: Yi John S. , Holbrook Beth C. , Michalek Ryan D. , Laniewski Nathan G. , Grayson Jason M. 
Published: April 2014

Abstract
After Ag encounter, CD8+ T cells become activated and begin to proliferate. Early during infection, when Ag-specific effector CD8+ T cells are proliferating, producing cytokines, and lysing infected cells in vivo, their mitochondrial potential is increased. The purpose of the experiments presented here was to determine whether mitochondrial function was required for CD8+ T cell function. To block mitochondrial function, transgenic CD8+ T cells were incubated with increasing doses of rotenone, an inhibitor of electron transport complex I. Within minutes of T cell activation, rotenone incubation decreased the production of H2O2, calcium flux, and ERK1/2 phosphorylation. Failure to undergo signal transduction resulted in a decrease in T cell division initiated by peptide-coated cells, CD3/CD28 Abs, and PMA/ionomycin stimulation. Decreased function following rotenone incubation was not restricted to naive cells, as effector and memory CD8+ T cells isolated directly ex vivo from lymphocytic choriomeningitis virus-infected mice displayed decreased production of IFN-γ and TNF-α production after peptide stimulation. Furthermore, incubation with rotenone decreased degranulation of effector and memory cells, a critical step in the cytolysis of infected cells. These data suggest that electron transport complex I is required for CD8+ T cell signal transduction, proliferation, cytokine production, and degranulation.