bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression and Activity of NOX5 in the Circulating Malignant B Cells of Hairy Cell Leukemia
Authors: Kamiguti Aura S. , Serrander Lena , Lin Ke , Harris Robert J. , Cawley John C. , Allsup David J. , Slupsky Joseph R. , Krause Karl-Heinz , Zuzel Mirko 
Published: April 2014

Abstract
Hairy cells (HCs) are mature malignant B cells that contain a number of constitutively active signaling molecules including GTP-bound Rac1, protein kinase C, and Src family kinases. Because Rac1 is a component of the reactive oxidant species (ROS)-generating NADPH oxidase system, we investigated the role of this GTPase in ROS production in HCs. In this study, we show that ROS production in HCs involves a flavin-containing oxidase dependent on Ca2+, but not on GTP-Rac1 or protein kinase C. This suggests the involvement of the nonphagocytic NADPH oxidase NOX5, an enzyme found in lymphoid tissues, but not in circulating lymphocytes. By using RT-PCR and Southern and Western blotting and by measuring superoxide anion production in membrane fractions in the absence of cytosolic components, we demonstrate for the first time that HCs (but not circulating normal B cells or some other lymphoid cell types) express NOX5. We also demonstrate that inhibition of NADPH oxidase in HCs results in a selective increase in the activity of Src homology region 2 domain-containing phosphatase 1 (SHP-1). Furthermore, SHP-1 in HCs coimmunoprecipitates with tyrosine phosphorylated CD22 and localizes in the same cellular compartment as NOX5. This allows the inactivation of SHP-1 by NOX5-generated ROS and contributes to the maintenance of the constitutive activation of HCs.
Immunodominance of Poxviral-Specific CTL in a Human Trial of Recombinant-Modified Vaccinia Ankara
Authors: Smith Caroline L. , Mirza Fareed , Pasquetto Valerie , Tscharke David C. , Palmowski Michael J. , Dunbar P. Rod , Sette Alessandro , Harris Adrian L. , Cerundolo Vincenzo 
Published: April 2014

Abstract
Many recombinant poxviral vaccines are currently in clinical trials for cancer and infectious diseases. However, these agents have failed to generate T cell responses specific for recombinant gene products at levels comparable with T cell responses associated with natural viral infections. The recent identification of vaccinia-encoded CTL epitopes, including a new epitope described in this study, allows the simultaneous comparison of CTL responses specific for poxviral and recombinant epitopes. We performed detailed kinetic analyses of CTL responses in HLA-A*0201 patients receiving repeated injections of recombinant modified vaccinia Ankara encoding a string of melanoma tumor Ag epitopes. The vaccine-driven CTL hierarchy was dominated by modified vaccinia Ankara epitope-specific responses, even in patients who had not received previous smallpox vaccination. The only recombinant epitope that was able to impact on the CTL hierarchy was the melan-A26–35 analog epitope, whereas responses specific for the weaker affinity epitope NY-ESO-1157–165 failed to be expanded above the level detected in prevaccination samples. Our results demonstrate that immunodominant vaccinia-specific CTL responses limit the effectiveness of poxviruses in recombinant vaccination strategies and that more powerful priming strategies are required to overcome immunodominance of poxvirus-specific T cell responses.
Immunological Trigger of Mast Cells by Monomeric IgE: Effect on Microphthalmia Transcription Factor, STAT3 Network of Interactions
Authors: Sonnenblick Amir , Levy Carmit , Razin Ehud 
Published: April 2014

Abstract
Microphthalmia transcription factor (MITF) and STAT3 are two transcription factors that play a major role in the regulation of growth and function of mast cells and melanocytes. We have previously provided experimental evidence regarding the functional cross-talk between MITF, protein inhibitor of activated STAT3, and STAT3 in response to cytokine activation of mast cells. Recent studies have demonstrated that binding of different IgE molecules to their FcεRI induces a spectrum of intracellular events in the absence of specific Ag. In this work, we show for the first time that, in mouse bone marrow-derived mast cells and in rat basophilic leukemia cells, monomeric IgE alone can induce the MITF-protein inhibitor of activated STAT3-STAT3 network of interactions and leads to phosphorylation of MITF at S73 and of STAT3 at both tyrosine 705 and S727. This phosphorylation increases the transcriptional activity of MITF and STAT3 as indicated by mRNA accumulation of their target genes such as Bcl-2, granzyme B, and c-Myc. Interestingly, MITF and STAT3 were not found to be obligatory factors in the anti-apoptotic response induced by IgE. Thus, the phenomenon that IgE alone was able to induce transcription factors that are essential for mast cell function could contribute to our understanding of the pathogenesis of allergy and its associated diseases.
Multiple Members of the TNF Superfamily Contribute to IFN-γ-Mediated Inhibition of Erythropoiesis
Authors: Felli Nadia , Pedini Francesca , Zeuner Ann , Petrucci Eleonora , Testa Ugo , Conticello Concetta , Biffoni Mauro , Di Cataldo Andrea , Winkles Jeffrey A. , Peschle Cesare , De Maria Ruggero 
Published: April 2014

Abstract
IFN-γ inhibits the growth and differentiation of erythroid precursor cells and mediates hemopoietic suppression through mechanisms that are not completely understood. We found that treatment of human erythroid precursor cells with IFN-γ up-regulates the expression of multiple members of the TNF family, including TRAIL and the recently characterized protein TWEAK. TWEAK and its receptor fibroblast growth factor-inducible 14 (Fn14) were expressed by purified erythroblasts at all the stages of maturation. Exposure to recombinant TWEAK or agonist anti-Fn14 Abs was able to inhibit erythroid cell growth and differentiation through caspase activation. Because other members of the TNF family such as TRAIL and CD95 ligand (CD95L) are known to interfere with erythroblast growth and differentiation, we investigated the role of different TNF/TNFR family proteins as potential effectors of IFN-γ in the immature hemopoietic compartment. Treatment of erythroid precursor cells with agents that blocked either TRAIL, CD95L, or TWEAK activity was partially able to revert the effect of IFN-γ on erythroid proliferation and differentiation. However, the simultaneous inhibition of TRAIL, TWEAK, and CD95L resulted in a complete abrogation of IFN-γ inhibitory effects, indicating the requirement of different receptor-mediated signals in IFN-γ-mediated hemopoietic suppression. These results establish a new role for TWEAK and its receptor in normal and IFN-γ-mediated regulation of hematopoiesis and show that the effects of IFN-γ on immature erythroid cells depend on multiple interactions between TNF family members and their receptors.
Transient Loss of MHC Class I Tetramer Binding after CD8+ T Cell Activation Reflects Altered T Cell Effector Function
Authors: Drake Donald R. , Ream Rebecca M. , Lawrence Christopher W. , Braciale Thomas J. 
Published: April 2014

Abstract
Engagement of the Ag receptor on naive CD8+ T cells by specific peptide-MHC complex triggers their activation/expansion/differentiation into effector CTL. The frequency of Ag-specific CD8+ T cells can normally be determined by the binding of specific peptide-MHC tetramer complexes to TCR. In this study we demonstrate that, shortly after Ag activation, CD8+ T cells transiently lose the capacity to efficiently bind peptide-MHC tetramer complexes. This transient loss of tetramer binding, which occurs in response to naturally processed viral peptide during infection in vitro and in vivo, is associated with reduced signaling through the TCR and altered/diminished effector activity. This change in tetramer binding/effector response is likewise associated with a change in cell surface TCR organization. These and related results suggest that early during CD8+ T cell activation, there is a temporary alteration in both cell surface Ag receptor display and functional activity that is associated with a transient loss of cognate tetramer binding.
Direct Stimulation of Human T Cells via TLR5 and TLR7/8: Flagellin and R-848 Up-Regulate Proliferation and IFN-γ Production by Memory CD4+ T Cells
Authors: Caron Gersende , Duluc Dorothée , Frémaux Isabelle , Jeannin Pascale , David Catherine , Gascan Hugues , Delneste Yves 
Published: April 2014

Abstract
TLRs are involved in innate cell activation by conserved structures expressed by microorganisms. Human T cells express the mRNA encoding most of TLRs. Therefore, we tested whether some TLR ligands may modulate the function of highly purified human CD4+ T lymphocytes. We report that, in the absence of APCs, flagellin (a TLR5 ligand) and R-848 (a TLR7/8 ligand) synergized with suboptimal concentrations of TCR-dependent (anti-CD3 mAb) or -independent stimuli (anti-CD2 mAbs or IL-2) to up-regulate proliferation and IFN-γ, IL-8, and IL-10 but not IL-4 production by human CD4+ T cells. No effect of poly(I:C) and LPS, ligands for TLR3 and TLR4, respectively, was detected. We also observed that CD4+CD45RO+ memory T cell responses to TLR ligands were more potent than those observed with CD4+CD45RA+ naive T cells. Moreover, among the memory T cells, CCR7− effector cells were more sensitive to TLR ligands than CCR7+ central memory cells. These data demonstrate for the first time a direct effect of TLR5 and TLR7/8 ligands on human T cells, and highlight an innate arm in T cell functions. They also suggest that some components from invading microorganisms may directly stimulate effector memory T cells located in tissues by up-regulating cytokine and chemokine production.
A Theoretical Framework for Quantitative Analysis of the Molecular Basis of Costimulation
Authors: Jansson Andreas , Barnes Eleanor , Klenerman Paul , Harlén Mikael , Sørensen Poul , Davis Simon J. , Nilsson Patric 
Published: April 2014

Abstract
We present a theoretical framework for simulating the synaptic accumulation of the costimulatory molecules CD28, CTLA-4, B7-1, and B7-2, based on a system of mean-field, ordinary differential equations, and rigorous biophysical and expression data. The simulations show that binding affinity, stoichiometric properties, expression levels, and, in particular, competition effects all profoundly influence complex formation at cellular interfaces. B7-2 engages 33-fold more CD28 than CTLA-4 at the synapse in contrast to B7-1, which ligates ∼7-fold more CTLA-4 than CD28. Although B7-1 completely dominates interactions with CTLA-4, forming linear arrays of 7-18 receptor-ligand pairs, CTLA-4 is fully engaged by B7-2 when B7-1 is absent. Additional simulations reveal the sensitivity of CD28 interactions to modeled transport processes. The results support the concept that B7-2 and B7-1 are the dominant ligands of CD28 and CTLA-4, respectively, and indicate that the inability of B7-2 to recruit CTLA-4 to the synapse cannot be due to the differential binding properties of B7-1 and B7-2 only. We discuss the apparent redundancy of B7-1 in the context of a potentially dynamic synaptic microenvironment, and in light of functions other than the direct enhancement of T cell inhibition by CTLA-4.
Blockade of B7-H1 on Macrophages Suppresses CD4+ T Cell Proliferation by Augmenting IFN-γ-Induced Nitric Oxide Production
Authors: Yamazaki Tomohide , Akiba Hisaya , Koyanagi Akemi , Azuma Miyuki , Yagita Hideo , Okumura Ko 
Published: April 2014

Abstract
PD-1 is an immunoinhibitory receptor that belongs to the CD28/CTLA-4 family. B7-H1 (PD-L1) and B7-DC (PD-L2), which belong to the B7 family, have been identified as ligands for PD-1. Paradoxically, it has been reported that both B7-H1 and B7-DC costimulate or inhibit T cell proliferation and cytokine production. To determine the role of B7-H1 and B7-DC in T cell-APC interactions, we examined the contribution of B7-H1 and B7-DC to CD4+ T cell activation by B cells, dendritic cells, and macrophages using anti-B7-H1, anti-B7-DC, and anti-PD-1 blocking mAbs. Anti-B7-H1 mAb and its Fab markedly inhibited the proliferation of anti-CD3-stimulated naive CD4+ T cells, but enhanced IL-2 and IFN-γ production in the presence of macrophages. The inhibition of T cell proliferation by anti-B7-H1 mAb was abolished by neutralizing anti-IFN-γ mAb. Coculture of CD4+ T cells and macrophages from IFN-γ-deficient or wild-type mice showed that CD4+ T cell-derived IFN-γ was mainly responsible for the inhibition of CD4+ T cell proliferation. Anti-B7-H1 mAb induced IFN-γ-mediated production of NO by macrophages, and inducible NO synthase inhibitors abrogated the inhibition of CD4+ T cell proliferation by anti-B7-H1 mAb. These results indicated that the inhibition of T cell proliferation by anti-B7-H1 mAb was due to enhanced IFN-γ production, which augmented NO production by macrophages, suggesting a critical role for B7-H1 on macrophages in regulating IFN-γ production by naive CD4+ T cells and, hence, NO production by macrophages.
Anatomical Location Determines the Distribution and Function of Dendritic Cells and Other APCs in the Respiratory Tract
Authors: von Garnier Christophe , Filgueira Luis , Wikstrom Matthew , Smith Miranda , Thomas Jennifer A. , Strickland Deborah H. , Holt Patrick G. , Stumbles Philip A. 
Published: April 2014

Abstract
APCs, including dendritic cells (DC), are central to Ag surveillance in the respiratory tract (RT). Research in this area is dominated by mouse studies on purportedly representative RT-APC populations derived from whole-lung digests, comprising mainly parenchymal tissue. Our recent rat studies identified major functional differences between DC populations from airway mucosal vs parenchymal tissue, thus seriously questioning the validity of this approach. We addressed this issue for the first time in the mouse by separately characterizing RT-APC populations from these two different RT compartments. CD11chigh myeloid DC (mDC) and B cells were common to both locations, whereas a short-lived CD11cneg mDC was unique to airway mucosa and long-lived CD11chigh macrophage and rapid-turnover multipotential precursor populations were predominantly confined to the lung parenchyma. Airway mucosal mDC were more endocytic and presented peptide to naive CD4+ T cells more efficiently than their lung counterparts. However, mDC from neither site could present whole protein without further maturation in vitro, or following trafficking to lymph nodes in vivo, indicating a novel mechanism whereby RT-DC function is regulated at the level of protein processing but not peptide loading for naive T cell activation.
During Viral Infection of the Respiratory Tract, CD27, 4-1BB, and OX40 Collectively Determine Formation of CD8+ Memory T Cells and Their Capacity for Secondary Expansion
Authors: Hendriks Jenny , Xiao Yanling , Rossen John W. A. , van der Sluijs Koenraad F. , Sugamura Kazuo , Ishii Naoto , Borst Jannie 
Published: April 2014

Abstract
Independent studies have shown that CD27, 4-1BB, and OX40 can all promote survival of activated CD8+ T cells. We have therefore compared their impact on CD8+ memory T cell formation and responsiveness within one, physiologically relevant model system. Recombinant mice, selectively lacking input of one or two receptors, were challenged intranasally with influenza virus, and the immunodominant virus-specific CD8+ T cell response was quantified at priming and effector sites. Upon primary infection, CD27 and (to a lesser extent) 4-1BB made nonredundant contributions to accumulation of CD8+ virus-specific T cells in draining lymph nodes and lung, while OX40 had no effect. Interestingly though, in the memory response, accumulation of virus-specific CD8+ T cells in spleen and lung critically depended on all three receptor systems. This was explained by two observations: 1) CD27, 4-1BB, and OX40 were collectively responsible for generation of the same memory CD8+ T cell pool; 2) CD27, 4-1BB, and OX40 collectively determined the extent of secondary expansion, as shown by adoptive transfers with standardized numbers of memory cells. Surprisingly, wild-type CD8+ memory T cells expanded normally in primed OX40 ligand- or 4-1BB ligand-deficient mice. However, when wild-type memory cells were generated in OX40 ligand- or 4-1BB ligand-deficient mice, their secondary expansion was impaired. This provides the novel concept that stimulation of CD8+ T cells by OX40 and 4-1BB ligand during priming imprints into them the capacity for secondary expansion. Our data argue that ligand on dendritic cells and/or B cells may be critical for this.
Augmentation of Effector CD8+ T Cell Generation with Enhanced Granzyme B Expression by IL-27
Authors: Morishima Noriko , Owaki Toshiyuki , Asakawa Masayuki , Kamiya Sadahiro , Mizuguchi Junichiro , Yoshimoto Takayuki 
Published: April 2014

Abstract
IL-27 is a novel IL-12 family member that plays a role in the early regulation of Th1 initiation. We have recently demonstrated that IL-27 has a potent antitumor activity, which is mainly mediated through CD8+ T cells, and also has an adjuvant activity to induce epitope-specific CTL in vivo. In this study, we further investigated the in vitro effect of IL-27 on CD8+ T cells of mouse spleen cells. In a manner similar to CD4+ T cells, IL-27 activated STAT1, -2, -3, -4, and -5, and augmented the expression of T-bet, IL-12Rβ2, and granzyme B, and slightly that of perforin in naive CD8+ T cells stimulated with anti-CD3. IL-27 induced synergistic IFN-γ production with IL-12 and proliferation of naive CD8+ T cells. Moreover, IL-27 enhanced proliferation of CD4+ T cell-depleted spleen cells stimulated by allogeneic spleen cells and augmented the generation of CTL. In STAT1-deficient naive CD8+ T cells, IL-27-induced proliferation was not reduced, but synergistic IFN-γ production with IL-12 was diminished with decreased expression of T-bet, IL-12Rβ2, granzyme B, and perforin. In T-bet-deficient naive CD8+ T cells, IL-27-induced proliferation was hardly reduced, but synergistic IFN-γ production with IL-12 was diminished with decreased expression of IL-12Rβ2, granzyme B, and perforin. However, IL-27 still augmented the generation of CTL from T-bet-deficient CD4+ T cell-depleted spleen cells stimulated by allogeneic spleen cells with increased granzyme B expression. These results suggest that IL-27 directly acts on naive CD8+ T cells in T-bet-dependent and -independent manners and augments generation of CTL with enhanced granzyme B expression.
Runx3 Regulates Integrin αE/CD103 and CD4 Expression during Development of CD4−/CD8+ T Cells
Authors: Grueter Baerbel , Petter Michaela , Egawa Takeshi , Laule-Kilian Kirsten , Aldrian Christine J. , Wuerch Andreas , Ludwig Yvonne , Fukuyama Hidehiro , Wardemann Hedda , Waldschuetz Ralph , Möröy Tarik , Taniuchi Ichiro , Steimle Viktor , Littman Dan R. , Ehlers Marc 
Published: April 2014

Abstract
During thymic T cell development, immature CD4+CD8+ double-positive (DP) thymocytes develop either into CD4+CD8− Th cells or CD4−CD8+ CTLs. Differentially expressed primary factors inducing the fate of these cell types are still poorly described. The transcription factor Runx3/AML-2 Runx, rust dominant factor; AML, acute myeloid leukemia is expressed specifically during the development of CD8 single-positive (SP) thymocytes, where it silences CD4 expression. Deletion of murine Runx3 results in a reduction of CD8 SP T cells and concomitant accumulation of CD4+CD8+ T cells, which cannot down-regulate CD4 expression in the thymus and periphery. In this study we have investigated the role of Runx3 during thymocyte development and CD4 silencing and have identified integrin αE/CD103 on CD8 SP T cells as a new potential target gene of Runx3. We demonstrate that Runx3 is necessary not only to repress CD4, but also to induce CD103 expression during development of CD8 SP T cells. In addition, transgenic overexpression of Runx3 reduced CD4 expression during development of DP thymocytes, leading to a reduced number of CD4 SP thymocytes and an increased number of CD8 SP thymocytes. This reversal is not caused by redirection of specific MHC class II-restricted cells to the CD8 lineage. Overexpression of Runx3 also up-regulated CD103 expression on a subpopulation of CD4 SP T cells with characteristics of regulatory T cells. Thus, Runx3 is a main regulator of CD4 silencing and CD103 induction and thus contributes to the phenotype of CD8 SP T cells during thymocyte development.
The Human β-Defensins (-1, -2, -3, -4) and Cathelicidin LL-37 Induce IL-18 Secretion through p38 and ERK MAPK Activation in Primary Human Keratinocytes
Authors: Niyonsaba François , Ushio Hiroko , Nagaoka Isao , Okumura Ko , Ogawa Hideoki 
Published: April 2014

Abstract
In addition to its physical barrier against invading microorganisms, the skin produces antimicrobial peptides, human β-defensins (hBDs) and cathelicidin LL-37, that participate in the innate host defense. Because IL-18 is produced by keratinocytes and involved in skin diseases in which hBDs and LL-37 are highly expressed, we hypothesized that these peptides would activate keratinocytes to secrete IL-18. We found that hBD-2, -3, and -4 and LL-37, but not hBD-1, activated normal human keratinocytes to secrete IL-18; this secretion reached peak strength at 3 h. In addition, the combination of peptides resulted in a synergistic effect on IL-18 secretion. We also revealed that hBD-2, -3, and -4 and LL-37 increased IL-18 mRNA expression, and that IL-18 secretion was more enhanced in keratinocytes differentiated in vitro with high Ca2+-containing medium. Furthermore, because IL-18 secretion induced by hBDs and LL-37 could not be suppressed by caspase-1 or caspase family inhibitors, and because these peptides failed to increase caspase-1 activity, we suggest that hBD- and LL-37-induced IL-18 secretion is probably via a caspase-1-independent pathway. To determine the molecular mechanism involved, we demonstrated that IL-18 secretion was through p38 and ERK1/2 MAPK pathways, because the inhibitors of p38 and ERK1/2, but not JNK, almost completely nullified IL-18 secretion. Moreover, hBD-2, -3, and -4 and LL-37 could induce the phosphorylation of p38 and ERK1/2, but not JNK. Thus, the ability of hBDs and LL-37 to induce IL-18 secretion by keratinocytes provides a new mechanism for these peptides in innate immunity and an understanding of their role in the pathogenesis of skin disorders.