bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polyclonal CTL Responses Observed in Melanoma Patients Vaccinated with Dendritic Cells Pulsed with a MAGE-3.A1 Peptide
Authors: Godelaine Danièle , Carrasco Javier , Lucas Sophie , Karanikas Vaios , Schuler-Thurner Beatrice , Coulie Pierre G. , Schuler Gerold , Boon Thierry , Van Pel Aline 
Published: April 2014

Abstract
Vaccination with mature, monocyte-derived dendritic cells (DC) pulsed with the MAGE-3168–176 peptide, which is presented by HLA-A1, has been reported to induce tumor regressions and CTL in some advanced stage IV melanoma patients. We present here a precise evaluation of the level of some of these anti-MAGE-3.A1 CTL responses and an analysis of their clonal diversity. Blood lymphocytes were stimulated with the MAGE-3.A1 peptide under limiting dilution conditions and assayed with an A1/MAGE-3 tetramer. This was followed by the cloning of the tetramer-positive cells and by TCR sequence analysis of the CTL clones that lysed targets expressing MAGE-3.A1. We also used direct ex vivo tetramer staining of CD8 cells, sorting, and cloning of the positive cells. In three patients who showed regression of some of their metastases after vaccination, CTL responses were observed with frequencies ranging from 7 × 10−6 to 9 × 10−4 of CD8+ blood T lymphocytes, representing an increase of 20- to 400-fold of the frequencies found before immunization. A fourth patient showed neither tumor regression nor an anti-MAGE-3.A1 CTL response. In each of the responses, several CTL clones were amplified. This polyclonality contrasts with the monoclonality of the CTL responses observed in patients vaccinated with MAGE-3.A1 peptide or with an ALVAC recombinant virus coding for this antigenic peptide.
Activation of Resting Human Primary T Cells with Chimeric Receptors: Costimulation from CD28, Inducible Costimulator, CD134, and CD137 in Series with Signals from the TCRζ Chain
Authors: Finney Helene M. , Akbar Arne N. , Lawson Alastair D. G. 
Published: April 2014

Abstract
Chimeric receptors that include CD28 signaling in series with TCRζ in the same receptor have been demonstrated to activate prestimulated human primary T cells more efficiently than a receptor providing TCRζ signaling alone. We examined whether this type of receptor can also activate resting human primary T cells, and whether molecules other than CD28 could be included in a single chimeric receptor in series with TCRζ to mediate the activation of resting human primary T cells. Human CD33-specific chimeric receptors were generated with CD28, inducible costimulator, CD134, or CD137 signaling regions in series with TCRζ signaling region and transfected by electroporation into resting human primary T cells. Their ability to mediate Ag-specific activation was analyzed in comparison with a receptor providing TCRζ signaling alone. Inclusion of any of the costimulatory signaling regions in series with TCRζ enhanced the level of specific Ag-induced IL-2, IFN-γ, TNF-α, and GM-CSF cytokine production and enabled resting primary T cells to survive and proliferate in response to Ag in the absence of any exogenous factors. Inclusion of CD28, inducible costimulator, or CD134 enhanced TCRζ-mediated, Ag-specific target cell lysis. Chimeric receptors providing B7 and TNFR family costimulatory signals in series with TCRζ in the same receptor can confer self-sufficient clonal expansion and enhanced effector function to resting human T cells. This type of chimeric receptor may now be used to discover the most potent combination of costimulatory signals that will improve current immunotherapeutic strategies.
NK Cell TRAIL Eliminates Immature Dendritic Cells In Vivo and Limits Dendritic Cell Vaccination Efficacy
Authors: Hayakawa Yoshihiro , Screpanti Valentina , Yagita Hideo , Grandien Alf , Ljunggren Hans-Gustaf , Smyth Mark J. , Chambers Benedict J. 
Published: April 2014

Abstract
Recent studies have implicated a possible role for NK cells in regulating dendritic cells (DC) in vitro. In the present study, we demonstrate that immature DC are rapidly eliminated by NK cells in vivo via a pathway dependent on the TNF-related apoptosis-inducing ligand (TRAIL). Elimination of NK cells and/or neutralization of TRAIL function during immunization with immature DC loaded with nonself or tumor Ags significantly enhanced T cell responses to these Ags and Ag-specific tumor immunity. These data suggested that NK cell TRAIL might regulate responses to vaccination by controlling the survival of Ag-loaded DC.
Cutting Edge: IL-7-Dependent Homeostatic Proliferation of CD8+ T Cells in Neonatal Mice Allows the Generation of Long-Lived Natural Memory T Cells
Authors: Schüler Thomas , Hämmerling Günter J. , Arnold Bernd 
Published: April 2014

Abstract
Healthy, nonimmunized C57BL/6 (B6) mice contain memory phenotype CD8+ T cells, which are assumed to be generated in response to environmental Ags. Since neonatal mice are functionally lymphopenic within the first days after birth, we investigated the alternative possibility that the memory CD8+ T cells of untreated B6 mice are the result of lymphopenia-induced proliferation during neonatal life. We show here that adoptively transferred CD8+ T cells proliferate in neonatal B6 mice, rapidly produce IFN-γ, and develop into memory cells which are maintained until adulthood. In contrast to CD4+ T cells, neonatal lymphopenia-induced proliferation of CD8+ T cells was IL-7 dependent. Thus, neonatal lymphopenia seems to allow CD8+ thymic emigrants to undergo lymphopenia-induced proliferation during early neonatal life to equip the immune system with a set of preactivated CD8+ T cells before any infection, which might contribute to the rapid initiation of immune responses in the adult.
A Repressor of GATA-Mediated Negative Feedback Mechanism of T Cell Activation
Authors: Miaw Shi-Chuen , Kang Bok Yun , White Ian Alexander , Ho I-Cheng 
Published: April 2014

Abstract
The NF-AT family is a group of potent transcription factors that are essential for T cell activation in vitro. However, NF-ATc2-deficient Th cells display hyperproliferation in response to stimulation, suggesting that NF-ATc2 functions as a negative regulator of Th cell activation/proliferation. In this study we show that the transcriptional repressor of GATA (ROG) is a direct target gene of NF-ATc2 and that NF-ATc2-deficient Th cells are unable to fully up-regulate ROG upon stimulation. Restoration of ROG expression in vivo partly corrects the hyperproliferation of NF-ATc2-deficient Th cells by attenuating TCR signals. Our data, therefore, depict a ROG-mediated negative feedback mechanism of T cell activation.
Role of TNF Receptor-Associated Factor 3 in the CD40 Signaling by Production of Reactive Oxygen Species through Association with p40phox, a Cytosolic Subunit of Nicotinamide Adenine Dinucleotide Phosphate Oxidase
Authors: Ha Yun Jung , Lee Jong Ran 
Published: April 2014

Abstract
To extend our previous report, which showed the production of the reactive oxygen species (ROS) after the CD40 ligation in the B cells, we further examined the possible mechanisms for ROS production and the involvement of CD40-induced ROS in p38 activation. Our research shows that the stimulation of WEHI 231 B lymphomas with anti-CD40 induced ROS production and p38 activation. An antioxidant N-acetyl-l-cysteine or an inhibitor for NADPH oxidase blocked both of these, but the inhibitors for 5-lipoxygenase did not. We also show that the treatment of cells with inhibitors for the phosphatidylinositol 3-kinase (PI3-K) interfered with the CD40-induced ROS production and p38 activation. In addition, when overexpressed with a dominant negative form of either Rac1 (N17Rac1) or the TNFR-associated factor (TRAF) 3, the WEHI 231 B cells did not show a full response to the CD40 stimulation to produce ROS. Molecular association studies further revealed that the TRAF3 association with p40phox, a cytosolic subunit of NADPH oxidase and p85 (a subunit of PI3-K), may possibly be responsible for the production of ROS by CD40 stimulation in WEHI 231 B cells. Collectively, these data suggest that the CD40-induced ROS production by NADPH oxidase in WEHI 231 requires the role of TRAF3, as well as activities of PI3-K and Rac1.
T Cell Clonal Conditioning: A Phase Occurring Early after Antigen Presentation but before Clonal Expansion Is Impacted by Toll-Like Receptor Stimulation
Authors: Maxwell Joseph R. , Rossi Robert J. , McSorley Stephen J. , Vella Anthony T. 
Published: April 2014

AbstractAfter in vivo immunization, Ag-specific T cells disappear from circulation and become sequestered in lymphoid tissue where they encounter Ag presented by dendritic cells. In the same site and just after Ag presentation, they “disappear” a second time and we investigated this process. Using a mouse model of T cell deletion (without Toll-like receptor (TLR) stimulation) vs survival (with TLR stimulation), Ag-specific T cells indeed became undetectable by flow cytometry, however were readily detected by immunohistochemistry. Thus, whether or not the activated T cells were destined to delete or survive, they were difficult to extract from lymphoid tissue and did not disappear but in fact were abundantly present. Nevertheless, profound differences were observed during this time period when tolerizing conditions were compared with immunizing conditions. TLR stimulation induced an increase in CD25 expression, acquisition of surface MHC class II, and abnormally high increases in forward and side scatter of the peptide-specific T cells. Using a modified adoptive transfer approach, we demonstrated by flow cytometry that in the presence of TLR stimulation the Ag-specific T cells were tightly coupled to dendritic cells, explaining the unusual increases in size and granularity. Ultimately, these events induced the specific T cells to differentiate into memory cells. We postulate that this is a stage where T cells are either conditioned to survive or to delete depending upon the activation status of the innate immune system.
Expression of Preproinsulin-2 Gene Shapes the Immune Response to Preproinsulin in Normal Mice
Authors: Faideau Béatrice , Briand Jean-Paul , Lotton Chantal , Tardivel Isabelle , Halbout Philippe , Jami Jacques , Elliott John F. , Krief Patricia , Muller Sylviane , Boitard Christian , Carel Jean-Claude 
Published: April 2014

Abstract
Deciphering mechanisms involved in failure of self tolerance to preproinsulin-2 is a key issue in type 1 diabetes. We used nonautoimmune 129SV/Pas mice lacking preproinsulin-2 to study the immune response to preproinsulin-2. In these mice, a T cell response was detected after immunization with several preproinsulin-2 peptides and confirmed by generating hybridomas. Activation of some of these hybridomas by wild-type (wt) islet cells or recombinant murine proinsulin-2 demonstrated that two epitopes can be generated from the naturally expressed protein. Although T cells from wt mice responded to preproinsulin-2 peptides, we could not detect a response to the naturally processed epitopes in these mice. Moreover, after immunization with recombinant whole proinsulin-2, a T cell response was detected in preproinsulin-2-deficient but not in wt mice. This suggests that islet preproinsulin-2-autoreactive T cells are functionally eliminated in wt mice. We used a transplantation model to evaluate the relevance of reactivity to preproinsulin-2 in vivo. Wild-type preproinsulin-2-expressing islets transplanted in preproinsulin-2-deficient mice elicited a mononuclear cell infiltration and insulin Abs. Graft infiltration was further increased by immunization with preproinsulin-2 peptides. Preproinsulin-2 expression thus shapes the immune response and prevents self reactivity to the islet. Moreover, islet preproinsulin-2 primes an immune response to preproinsulin-2 in deficient mice.
Human Intestinal Fibroblasts Prevent Apoptosis in Human Intestinal Mast Cells by a Mechanism Independent of Stem Cell Factor, IL-3, IL-4, and Nerve Growth Factor
Authors: Sellge Gernot , Lorentz Axel , Gebhardt Thomas , Levi-Schaffer Francesca , Bektas Hueseyin , Manns Michael P. , Schuppan Detlef , Bischoff Stephan C. 
Published: April 2014

Abstract
In rodents, fibroblasts (FBs) mediate stem cell factor (SCF)-dependent growth of mast cells (MCs). In humans, SCF is mandatory for MC differentiation and survival. Other factors such as IL-3, IL-4, and nerve growth factor (NGF) act in synergism with SCF, thus enhancing proliferation and/or preventing apoptosis in MCs. In this study, we studied in vitro interactions between human MCs and human FBs, both isolated from the intestine and purified to homogeneity. In coculture with FBs, MCs survived for up to 3 wk, whereas purified MCs cultured alone died within a few days. TNF-α and IL-1β, which both did not affect MC survival directly, enhanced FB-dependent MC growth. We provide evidence that FB-derived MC growth factors are soluble, heat-sensitive molecules which down-regulate MC apoptosis without enhancing MC proliferation. However, only low amounts of SCF were measured in FB-conditioned medium (&lt;0.2 ng/ml). Moreover, blocking of SCF/c-kit interaction by anti-SCF or anti-c-kit Abs and neutralization of IL-3, IL-4, and NGF did not affect MC survival in the coculture system. In conclusion, our data indicate that human FBs promote survival of human MCs by mechanisms independent of SCF, IL-3, IL-4, and NGF. Such interactions between MCs and FBs may explain why MCs accumulate at sites of inflammatory bowel disease and intestinal fibrosis.
CXCR1+CD4+ T Cells in Human Allergic Disease
Authors: Francis James N. , Jacobson Mikila R. , Lloyd Clare M. , Sabroe Ian , Durham Stephen R. , Till Stephen J. 
Published: April 2014

Abstract
Chemokine receptors play an important role in the migration of leukocytes to sites of allergic inflammation in humans. In this study, we have identified increased expression of the chemokine receptor CXCR1 on CD4+ T lymphocytes derived from patients with atopic disease compared with normal donors. Enhanced expression of CXCR1 by atopic donors was identified on freshly isolated peripheral blood cells and on expanded cell populations derived from nasal mucosal biopsies and from the periphery. Identification of CXCR1 expression on CD4 cells in the nasal mucosa was confirmed by double immunofluorescence. In addition, expression of CXCR1 was dramatically decreased in patients undergoing successful treatment of allergic rhinitis by specific immunotherapy. CXCR1 provided a functional receptor capable of regulating T cells in the context of allergic disease, since expression of CXC chemokine ligand 8 was up-regulated at the site of allergic inflammation and freshly isolated CXCR1+CD4+ cells from atopic donors showed an enhanced functional response to this ligand. CXCR1 expression on CD4+ T cells was increased in vitro in response to the pro-Th2 cytokine IL-4. Phenotypic analysis reveals that IFN-γ expression was lower in the CXCR1+CD4+ cells. The identification of CXCR1 as a marker of allergic rhinitis reveals a possible target for therapeutic intervention in atopic disease.
Dendritic Cell Maturation Controls Adhesion, Synapse Formation, and the Duration of the Interactions with Naive T Lymphocytes
Authors: Benvenuti Federica , Lagaudrière-Gesbert Cecile , Grandjean Isabelle , Jancic Carolina , Hivroz Claire , Trautmann Alain , Lantz Olivier , Amigorena Sebastian 
Published: April 2014

Abstract
The initiation of adaptive immune responses requires the direct interaction of dendritic cells (DCs) with naive T lymphocytes. It is well established that the maturation state of DCs has a critical impact on the outcome of the response. We show here that mature DCs form stable conjugates with naive T cells and induce the formation of organized immune synapses. Immature DCs, in contrast, form few stable conjugates with no organized immune synapses. A dynamic analysis revealed that mature DCs can form long-lasting interactions with naive T cells, even in the absence of Ag. Immature DCs, in contrast, established only short intermittent contacts, suggesting that the premature termination of the interaction prevents the formation of organized immune synapses and full T cell activation.
Dexamethasone Inhibits IL-12p40 Production in Lipopolysaccharide-Stimulated Human Monocytic Cells by Down-Regulating the Activity of c-Jun N-Terminal Kinase, the Activation Protein-1, and NF-κB Transcription Factors
Authors: Ma Wei , Gee Katrina , Lim Wilfred , Chambers Kelly , Angel Jonathan B. , Kozlowski Maya , Kumar Ashok 
Published: April 2014

Abstract
IL-12 plays a critical role in the development of cell-mediated immune responses and in the pathogenesis of inflammatory and autoimmune disorders. Dexamethasone (DXM), an anti-inflammatory glucocorticoid, has been shown to inhibit IL-12p40 production in LPS-stimulated monocytic cells. In this study, we investigated the molecular mechanism by which DXM inhibits IL-12p40 production by studying the role of the mitogen-activated protein kinases (MAPKs), and the key transcription factors involved in human IL-12p40 production in LPS-stimulated monocytic cells. A role for c-Jun N-terminal kinase (JNK) MAPK in LPS-induced IL-12p40 regulation in a promonocytic THP-1/CD14 cell line was demonstrated by using specific inhibitors of JNK activation, SP600125 and a dominant-negative stress-activated protein/extracellular signal-regulated kinase kinase-1 mutant. To identify transcription factors regulating IL-12p40 gene transcription, extensive deletion analyses of the IL-12p40 promoter was performed. The results revealed the involvement of a sequence encompassing the AP-1-binding site, in addition to that of NF-κB. The role of AP-1 in IL-12p40 transcription was confirmed by using antisense c-fos and c-jun oligonucleotides. Studies conducted to understand the regulation of AP-1 and NF-κB activation by JNK MAPK revealed that both DXM and SP600125 inhibited IL-12p40 gene transcription by inhibiting the activation of AP-1 and NF-κB transcription factors as revealed by luciferase reporter and gel mobility shift assays. Taken together, our results suggest that DXM may inhibit IL-12p40 production in LPS-stimulated human monocytic cells by down-regulating the activation of JNK MAPK, the AP-1, and NF-κB transcription factors.
Domain Shuffling Has Been the Main Mechanism Forming New Hominoid Killer Cell Ig-Like Receptors
Authors: Rajalingam Raja , Parham Peter , Abi-Rached Laurent 
Published: April 2014

Abstract
The killer cell Ig-like receptor (KIR) gene family encodes MHC class I-specific receptors, which regulate NK cell responses and are also expressed on subpopulations of T cells. KIR haplotypes vary in gene content, which, in combination with allelic polymorphism, extensively diversifies the KIR genotype both within and between human populations. Species comparison indicates that formation of new KIR genes and loss of old ones are frequent events, so that few genes are conserved even between closely related species. In this regard, the hominoids define a time frame that is particularly informative for understanding the processes of KIR evolution and its potential impact on killer cell biology. KIR cDNA were characterized from PBMC of three gorillas, and genomic DNA were characterized for six additional individuals. Eleven gorilla KIR genes were defined. With attainment of these data, a set of 75 KIR sequences representing five hominoid species was assembled, which also included rhesus monkey, cattle, and rodent KIR. Searching this data set for recombination events, and phylogenetic analysis using Bayesian methods, demonstrated that new KIR were usually the result of recombination between loci in which complete protein domains were shuffled. Further phylogenetic analysis of the KIR sequences after removal of confounding recombined segments showed that only two KIR genes, KIR2DL4 and KIR2DL5, have been preserved throughout hominoid evolution, and one of them, KIR2DL4, is also common to rhesus monkey and hominoids. Other KIR genes represent recombinant forms present in a minority of species, often only one, as exemplified by 8 of the 11 gorilla KIR genes.
Molecular Characterization of a Putative Antiretroviral Transcriptional Factor, OTK18
Authors: Carlson Kimberly A. , Leisman Gary , Limoges Jenae , Pohlman Garrett D. , Horiba Masahide , Buescher James , Gendelman Howard E. , Ikezu Tsuneya 
Published: April 2014

AbstractElucidation of the factors involved in host defense against human immunodeficiency viral infection remains pivotal if viral control may be achieved. Toward these ends, we investigated the function of a putative antiretroviral factor, OTK18, isolated by differential display of mRNA from HIV type 1-infected primary human monocyte-derived macrophages. Molecular and immunohistochemical analyses showed that the OTK18 nucleotide sequence contains 13 adjacent C2H2-type zinc finger motifs, a Krüppel-associated box, and is localized to both cytosol and nucleus. Mutational analyses revealed that both the Krüppel-associated box and zinc finger regions of OTK18 are responsible for the transcriptional suppressive activities of this gene. OTK18 was copiously expressed in macrophages following HIV type I infection and diminished progeny virion production. A mechanism for this antiretroviral activity was by suppression of HIV type 1 Tat-induced viral long terminal repeat promoter activity. Our findings suggest that one possible function of OTK18 is as a HIV type 1-inducible transcriptional suppresser.
Actinobacillus actinomycetemcomitans Cytolethal Distending Toxin (Cdt): Evidence That the Holotoxin Is Composed of Three Subunits: CdtA, CdtB, and CdtC
Authors: Shenker Bruce J. , Besack Dave , McKay Terry , Pankoski Lisa , Zekavat Ali , Demuth Donald R. 
Published: April 2014

Abstract
We have shown the Actinobacillus actinomycetemcomitans produces an immunosuppressive factor encoded by the cytolethal distending toxin (cdt)B gene, which is homologous to a family of Cdts expressed by several Gram-negative bacteria. We now report that the capacity for CdtB to induce G2 arrest in Jurkat cells is greater in the presence of the other Cdt peptides: CdtA and CdtC. Plasmids containing the cdt operon were constructed and expressed in Escherichia coli; each plasmid contained a modified cdt gene that expressed a Cdt peptide containing a C-terminal His tag. All three Cdt peptides copurified with the His-tagged Cdt peptide. Each of the peptides associated with the complex was truncated; N-terminal amino acid analysis of CdtB and CdtC indicated that the truncation corresponds to cleavage of a previously described signal sequence. CdtA was present in two forms in crude extracts, 25 and 18 kDa; only the 18-kDa fragment copurified with the Cdt complexes. Cdt complexes were also immunoprecipitated from A. actinomycetemcomitans extracts using anti-CdtC mAb. Exposure of Jurkat cells to 40 pg resulted in &gt;50% accumulation of G2 cells. CdtB and CdtC were detected by immunofluorescence on the cell surface after 2-h exposure to the holotoxin. CdtA was not detected by immunofluorescence, but all three peptides were associated with Jurkat cells when analyzed by Western blot. These studies suggest that the active Cdt holotoxin is a heterotrimer composed of truncated CdtA, CdtB, and CdtC, and all three peptides appear to associate with lymphocytes.