bluuebunny/crossref_metadata_2025_split huggingface dataset:
The p38 Mitogen-Activated Protein Kinase Is Required for IL-12-Induced IFN-γ Expression
Authors: Zhang Shangming , Kaplan Mark H. 
Published: April 2014

AbstractIL-12 is a central immunoregulatory cytokine that promotes cell-mediated immune responses and the differentiation of naive CD4+ cells into Th1 cells. We and others have demonstrated that the Stat4 is critical for IFN-γ production by activated T cells and Th1 cells. However, several studies have suggested that other pathways may be involved in IL-12-stimulated IFN-γ expression. In this report we demonstrate that IL-12 activates mitogen-activated protein kinase kinase 3/6 (MKK) and p38 mitogen-activated protein kinase (MAPK), but not p44/42 (ERK) or stress-activated protein kinase/c-Jun N-terminal kinase MAPK. The activation of p38 MAPK is required for normal induction of IFN-γ mRNA and IFN-γ secretion by IL-12 in activated T cells and Th1 cells. Importantly, IL-12-stimulated p38 MAPK effector functions occur through a Stat4-independent mechanism and correlate with increased serine phosphorylation of activating transcription factor-2. The requirement for p38 MAPK in IL-12 function suggests that this pathway may be an important in vivo target for the anti-inflammatory actions of p38 MAPK inhibitors.
The Role of Cell Surface Receptors in the Activation of Human B Cells by Phosphorothioate Oligonucleotides
Authors: Liang Hua , Reich Charles F. , Pisetsky David S. , Lipsky Peter E. 
Published: April 2014

AbstractPhosphorothioate oligodeoxynucleotides (sODN) containing the CpG motif or TCG repeats induce T cell-independent polyclonal activation of human B cells. To elucidate the mechanism of this response, the role of cell surface receptors was investigated. Sepharose beads coated with stimulatory but not nonstimulatory sODNs induced B cell proliferation comparably with soluble sODNs. The B cell stimulatory activity of Sepharose-bound sODN did not result from free sODN released from the beads since media incubated with coated beads were inactive. Using FITC-labeled sODNs as probes, binding to human B cells could be detected by flow cytometry. Binding was rapid, saturable, initially temperature independent, but with a rapid off-rate. Competition studies indicated that both stimulatory sODNs and minimally stimulatory sODNs bound to the same receptor. By contrast, phosphodiester oligonucleotides with the same nucleotide sequence as sODNs and bacterial DNA inhibited the binding of sODNs to B cells minimally. Charge appeared to contribute to the binding of sODNs to B cells since binding of sODNs was competitively inhibited by negatively charged molecules, including fucoidan, poly I, and polyvinyl sulfate. These data indicate that human B cells bind sODNs by a receptor-mediated mechanism that is necessary but not sufficient for polyclonal activation.
The Complexity of Protective Immunity Against Liver-Stage Malaria
Authors: Doolan Denise L. , Hoffman Stephen L. 
Published: April 2014

Abstract
Sterile protective immunity against challenge with Plasmodium spp. sporozoites can be induced in multiple model systems and humans by immunization with radiation-attenuated Plasmodium spp. sporozoites. The infected hepatocyte has been established as the primary target of this protection, but the underlying mechanisms have not been completely defined. Abs, CD8+ T cells, CD4+ T cells, cytokines (including IFN-γ and IL-12), and NO have all been implicated as critical effectors. Here, we have investigated the mechanisms of protective immunity induced by immunization with different vaccine delivery systems (irradiated sporozoites, plasmid DNA, synthetic peptide/adjuvant, and multiple Ag peptide) in genetically distinct inbred strains, genetically modified mice, and outbred mice. We establish that there is a marked diversity of T cell-dependent immune responses that mediate sterile protective immunity against liver-stage malaria. Furthermore, we demonstrate that distinct mechanisms of protection are induced in different strains of inbred mice by a single method of immunization, and in the same strain by different methods of immunization. These data underscore the complexity of the murine host response to a parasitic infection and suggest that an outbred human population may behave similarly. Data nevertheless suggest that a pre-erythrocytic-stage vaccine should be designed to induce CD8+ T cell- and IFN-γ-mediated immune responses and that IFN-γ responses may represent an in vitro correlate of pre-erythrocytic-stage protective immunity.
Increased Susceptibility of Stat4-Deficient and Enhanced Resistance in Stat6-Deficient Mice to Infection withTrypanosoma cruzi
Authors: Tarleton Rick L. , Grusby Michael J. , Zhang Lei 
Published: April 2014

AbstractAlthough Th1-type responses tend to be associated with resistance to Trypanosoma cruzi infection, mixed Th1 and Th2 cytokine responses are generally observed in both resistant and susceptible mice. To help clarify the role of type 1 and type 2 cytokine responses in immunity to T. cruzi, mice with induced deficiencies in the Stat4 or Stat6 genes were infected with T. cruzi. As expected, Stat4−/− mice deficient in type 1 cytokine responses were highly susceptible to infection, exhibiting increased parasitemia levels relative to wild-type mice and 100% mortality. In contrast, parasitemia levels and survival in Stat6-deficient mice were not different from wild type. The type 1 and type 2 cytokine bias of Stat6- and Stat4-deficient mice, respectively, was confirmed by in situ immunocytochemical analysis of cytokine-producing cells in the tissues of infected mice and by subclass analysis of anti-T. cruzi serum Abs. Notably, both Stat4- and Stat6-deficient mice produced substantial amounts of anti-T. cruzi Abs. Tissues from chronically infected Stat6-deficient mice had little to no evidence of inflammation in the heart and skeletal muscle in contrast to wild-type mice, which exhibited substantial inflammation. In situ PCR analysis of these tissues provided evidence of the persistence of T. cruzi in wild-type mice, but no evidence of parasite persistence in Stat6-deficient mice. These data suggest that type 1 T cells are required for the development of immune control to T. cruzi, but that type 2 T cells contribute to parasite persistence and increased severity of disease.
Inducible Nitric Oxide Synthase Inhibitors Suppress Airway Inflammation in Mice Through Down-Regulation of Chemokine Expression
Authors: Trifilieff Alexandre , Fujitani Yasushi , Mentz Franck , Dugas Bernard , Fuentes Maria , Bertrand Claude 
Published: April 2014

AbstractGrowing evidence demonstrates that inducible NO synthase (iNOS) is induced in the airways of asthmatic patients. However, the precise role of NO in the lung inflammation is unknown. This study investigated the effect of both selective and nonselective iNOS inhibitors in an allergen-driven murine lung inflammation model. OVA challenge resulted in an accumulation of eosinophils and neutrophils in the airways. Expression of iNOS immunostaining in lung sections together with an increase in calcium-independent NOS activity in lung homogenates was also observed after OVA challenge. Treatment with iNOS inhibitors from the day of challenge to the day of sacrifice resulted in an inhibition of the inflammatory cell influx together with a down-regulation of macrophage inflammatory protein-2 and monocyte chemoattractant protein-1 production. In contrast, eosinophilic and neutrophilic inhibition was not observed with treatment during the sensitization. Both treatments induced an increased production of Th2-type cytokines (IL-4 and IL-5) with a concomitant decrease in production of Th1-type cytokine (IFN-γ). In vitro exposure of primary cultures of murine lung fibroblasts to a NO donor, hydroxylamine, induced a dose-dependent release of macrophage inflammatory protein-2 and monocyte chemoattractant protein-1. Our results suggest that lung inflammation after allergen challenge in mice is partially dependent on NO produced mainly by iNOS. NO appears to increase lung chemokine expression and, thereby, to facilitate influx of inflammatory cells into the airways.
Quantification of Self-Recognition in Multiple Sclerosis by Single-Cell Analysis of Cytokine Production
Authors: Pelfrey Clara M. , Rudick Richard A. , Cotleur Anne C. , Lee Jar-Chi , Tary-Lehmann Magdalena , Lehmann Paul V. 
Published: April 2014

AbstractIdentifying and quantifying autoaggressive responses in multiple sclerosis (MS) has been difficult in the past due to the low frequency of autoantigen-specific T cells, the high number of putative determinants on the autoantigens, and the different cytokine signatures of the autoreactive T cells. We used single-cell resolution enzyme-linked immunospot (ELISPOT) assays to study, directly ex vivo, proteolipid protein (PLP)-specific memory cell reactivity from MS patients and controls. Overlapping 9-aa-long peptides, spanning the entire PLP molecule in single amino acid steps, were used to determine the frequency and fine specificity of PLP-specific lymphocytes as measured by their IFN-γ and IL-5 production. MS patients (n = 22) responded to 4 times as many PLP peptides as did healthy controls (n = 22). The epitopes recognized in individual patients, up to 22 peptides, were scattered throughout the PLP molecule, showing considerable heterogeneity among MS patients. Frequency measurements showed that the number of PLP peptide-specific IFN-γ-producing cells averaged 11 times higher in MS patients than in controls. PLP peptide-induced IL-5-producing T cells occurred in very low frequencies in both MS patients and controls. This first comprehensive assessment of the anti-PLP-Th1/Th2 response in MS shows a greatly increased Th1 effector cell mass in MS patients. Moreover, the highly IFN-γ-polarized, IL-5-negative cytokine profile of the PLP-reactive T cells suggests that these cells are committed Th1 cells. The essential absence of uncommitted Th0 cells producing both cytokines may explain why therapeutic strategies that aim at the induction of immune deviation show little efficacy in the established disease.
Linkage Analysis of Systemic Lupus Erythematosus Induced in Diabetes-Prone Nonobese Diabetic Mice byMycobacterium bovis
Authors: Jordan Margaret A. , Silveira Pablo A. , Shepherd Darren P. , Chu Clara , Kinder Simon J. , Chen Jianhe , Palmisano Linda J. , Poulton Lynn D. , Baxter Alan G. 
Published: April 2014

AbstractSystemic lupus erythematosus induced by Mycobacterium bovis in diabetes-prone nonobese diabetic mice was mapped in a backcross to the BALB/c strain. The subphenotypes—hemolytic anemia, antinuclear autoantibodies, and glomerular immune complex deposition—did not cosegregate, and linkage analysis for each trait was performed independently. Hemolytic anemia mapped to two loci: Bah1 at the MHC on chromosome 17 and Bah2 on distal chromosome 16. Antinuclear autoantibodies mapped to three loci: Bana1 at the MHC on chromosome 17, Bana2 on chromosome 10, and Bana3 on distal chromosome 1. Glomerular immune complex deposition did not show significant linkage to any genomic region. Mapping of autoantibodies (Coombs’ or antinuclear autoantibodies) identified two loci: Babs1 at the MHC and Babs2 on distal chromosome 1. It has previously been reported that genes conferring susceptibility to different autoimmune diseases map nonrandomly to defined regions of the genome. One possible explanation for this clustering is that some alleles at loci within these regions confer susceptibility to multiple autoimmune diseases—the “common gene” hypothesis. With the exception of the H2, this study failed to provide direct support for the common gene hypothesis, because the loci identified as conferring susceptibility to systemic lupus erythematosus did not colocalize with those previously implicated in diabetes. However, three of the four regions identified had been previously implicated in other autoimmune diseases.
Early Growth Response (Egr)-1 Gene Induction in the Thymus in Response to TCR Ligation During Early Steps in Positive Selection Is Not Required for CD8 Lineage Commitment
Authors: Basson M. Albert , Wilson Timothy J. , Legname Giuseppe A. , Sarner Nitza , Tomlinson Peter D. , Tybulewicz Victor L. J. , Zamoyska Rose 
Published: April 2014

AbstractThe early growth response gene 1 (Egr-1) is induced during positive selection in the thymus and has been implicated in the differentiation of CD4+ thymocytes. Here, we show that signals that specifically direct CD8 lineage commitment also induce Egr-1 DNA-binding activity in the nucleus. However, we find that pharmacological inhibition of mitogen-activated protein kinase/extracellular signal-related kinase kinase activity potently inhibits Egr-1 DNA-binding function at concentrations that promote differentiation of CD8+ thymocytes, suggesting Egr-1 activity is not essential for CD8 commitment. To further determine the role of Egr-1 in thymocyte development, we compare steady-state Egr-1 DNA-binding activity in thymocytes from mice with defined defects in positive selection. The data indicate that the appearance of functional Egr-1 is downstream of signals induced by TCR/MHC engagement, whereas it is less sensitive to alterations in Lck-mediated signals, and does not correlate directly with proficient positive selection. Egr-1 is one of the earliest transcription factors induced upon TCR ligation on immature thymocytes, and plays a potential role in the transcription of genes involved in thymocyte selection.
B Lymphocyte-Derived IL-16 Attracts Dendritic Cells and Th Cells
Authors: Kaser Arthur , Dunzendorfer Stefan , Offner Felix A. , Ludwiczek Othmar , Enrich Barbara , Koch Robert O. , Cruikshank William W. , Wiedermann Christian J. , Tilg Herbert 
Published: April 2014

AbstractInteraction of B lymphocytes with Th cells is a fundamental step in the establishment of humoral immunity, and recent evidence suggests that direct interaction between B lymphocytes and dendritic cells (DCs) is also an important prerequisite. Factors involved in the selective recruitment of Th cells and DCs by B lymphocytes are insufficiently defined. We set out to delineate the role of IL-16, the soluble ligand of CD4, which is expressed on Th cells and DCs. B lymphocytes express IL-16 mRNA and synthesize bioactive IL-16 protein, and IL-16 is expressed in lymph node follicles in situ. B lymphocyte supernatant efficiently induces migration of CD4+ Th cells, monocyte-derived DCs, and circulating blood DCs in nitrocellulose filter-based assays. Neutralization of IL-16 bioactivity strongly inhibits this migratory response, suggesting that IL-16 might be a major chemotactic factor derived from B cells. The present data further support the idea that IL-16 might have a role in the initiation of cellular as well as humoral immunity by mediating the cellular cross-talk among T lymphocytes, B cells, and DCs, leading to recruitment of these cell types at common anatomical sites.
Evidence for Two Subgroups of CD4−CD8− NKT Cells with Distinct TCRαβ Repertoires and Differential Distribution in Lymphoid Tissues
Authors: Apostolou Irina , Cumano Ana , Gachelin Gabriel , Kourilsky Philippe 
Published: April 2014

AbstractNKT cells are a subset of T lymphocytes that is mainly restricted by the nonclassical MHC class I molecule, CD1d, and that includes several subpopulations, in particular CD4+ and CD4−CD8− (DN) cells. In the mouse, differential distribution of these subpopulations as well as heterogeneity in the expression of various markers as a function of tissue localization have been reported. We have thus undertaken a detailed study of the DN NKT cell subpopulation. With a highly sensitive semiquantitative RT-PCR technique, its TCR repertoire was characterized in various tissues. We found that mouse DN NKT cells are a variable mixture of two subgroups, one bearing the invariant Vα14 chain paired to rearranged Vβ2, Vβ7, Vβ8.1, Vβ8.2, or Vβ8.3 β-chains and the other exhibiting unskewed α- and β-chains. The proportion of these subgroups varies from about 100:0 in thymus, 80:20 in liver, and 50:50 in spleen to 20:80% in bone marrow, respectively. Finally, further heterogeneity in the tissue-derived DN NKT cells was discovered by sequencing extensively Vβ8.2-Jβ2.5 rearrangements in individual mice. Despite a few recurrences in TCR sequences, we found that each population exhibits its own and broad TCRβ diversity.
Signal Transduction of IL-6, Leukemia-Inhibitory Factor, and Oncostatin M: Structural Receptor Requirements for Signal Attenuation
Authors: Anhuf Dirk , Weissenbach Manuela , Schmitz Jochen , Sobota Radoslaw , Hermanns Heike M. , Radtke Simone , Linnemann Sonja , Behrmann Iris , Heinrich Peter C. , Schaper Fred 
Published: April 2014

Abstract
Stimulation of the IL-6R complex leads to Src homology domain containing tyrosine phosphatase 2 (SHP2) recruitment to the receptor subunit gp130 and its subsequent tyrosine phosphorylation. SHP2 is a two-SH2 domain-containing protein tyrosine phosphatase that is activated by many cytokines and growth factors. SHP2 counteracts the activation of transcription factors of the STAT family and the induction of IL-6-responsive genes. Tyrosine 759 of gp130, the signal transducing subunit of the IL-6R complex, is essential for the phosphorylation of SHP2. Mutation of tyrosine 759 to phenylalanine leads to an enhanced inducibility of IL-6-dependent genes. Here we demonstrate that no further tyrosines in the cytoplasmic part of gp130 are required for the phosphorylation of SHP2. We also tested whether the tyrosine 759 motifs in both subunits of the gp130 dimer are required for SHP2 association and tyrosine phosphorylation. Interestingly, one SHP2-recruiting phosphotyrosine motif in a single chain of the gp130 dimer is sufficient to mediate SHP2 association to the gp130 receptor subunit and its tyrosine phosphorylation as well as to attenuate IL-6-dependent gene induction. Furthermore, we show that repression of gene induction via Y759 does not require the presence of the SHP2 and STAT recruitment sites within the same receptor subunit, but within the same receptor complex. The Y759 motif in gp130 also attenuates gene induction mediated by the oncostatin M and leukemia inhibitory factor receptor complexes, which both contain gp130 as the shared subunit.
Saturation, Competition, and Specificity in Interaction of Heat Shock Proteins (hsp) gp96, hsp90, and hsp70 with CD11b+ Cells
Authors: Binder Robert J. , Harris Michelle L. , Ménoret Antoine , Srivastava Pramod K. 
Published: April 2014

AbstractHeat shock proteins (hsp(s)) have been postulated to interact with APCs through specific receptors, although the receptors are yet to be identified. Specificity, saturation, and competition are the three defining attributes of a receptor-ligand interaction. We demonstrate here that the interaction of the heat shock proteins gp96 and hsp90 with CD11b+ cells is specific and saturable and that gp96 can compete with itself in gp96-macrophage interaction. Interestingly, the phylogenetically related hsp90 also competes quite effectively with gp96 for binding to macrophages, whereas the unrelated hsp70 does so relatively poorly, although it binds CD11b+ cells just as effectively. These data provide evidence that the heat shock proteins interact with APCs with specificity and for the existence of at least two distinct receptors, one for gp96 and hsp90 and the other for hsp70.
Relevance of the Tumor Antigen in the Validation of Three Vaccination Strategies for Melanoma
Authors: Bellone Matteo , Cantarella Daniela , Castiglioni Paola , Crosti Maria Cristina , Ronchetti Anna , Moro Monica , Garancini Maria Paola , Casorati Giulia , Dellabona Paolo 
Published: April 2014

Abstract
Many preclinical studies of cancer immunotherapy are based on the testing of a single vaccination strategy in several tumor models. Moreover, most of those studies used xenogeneic Ags, which, owing to their high immunogenicity, may not represent realistic models for the validation of cancer immunotherapies. To address these issues, we compared the vaccination efficacy of three well established strategies (i.e., naked DNA; peptide-pulsed dendritic cells (DC), or a mixture of peptide and the Escherichia coli toxin LTR72) using the xenogeneic OVA or the naturally expressed tyrosinase-related protein 2 (TRP-2) tumor Ag in the B16 melanoma model. C57BL/6 mice received one to three s.c. injections of peptide-pulsed DC or DNA, or one to four mucosal administrations of peptide-toxin mixture. One to 2 wk later, the animals were challenged s.c. with B16 or B16 cells expressing OVA (B16-OVA). Vaccination of mice with OVA induced in all cases melanoma-specific CTL and protection against B16-OVA. When TRP-2 was used, all three vaccines elicited B16-specific CTL, but only DC pulsed with the immunodominant T cell epitope TRP-2181–188 allowed protection against B16. Even more importantly, a vaccination regimen with TRP-2-pulsed DC, started 24 h after the injection of a lethal number of B16 cells, caused a therapeutic effect in 60% of the challenged animals. Our results strongly emphasize the relevance of the tumor Ag in the definition of immunotherapeutic strategies for cancer, and support the use of peptide-pulsed DC as cancer vaccine in humans.
Regulation of Infection withHistoplasma capsulatumby TNFR1 and -2
Authors: Allendoerfer Ruth , Deepe George S. 
Published: April 2014

AbstractThe concerted action of several cytokines is necessary for resolution of both primary and secondary infection with Histoplasma capsulatum. Among the soluble factors that contribute to tissue sterilization, TNF-α stands as a central mediator of protective immunity to this fungus. In this study, we explored the regulation of protective immunity by TNFR1 and -2. In primary pulmonary infection, both TNFR1−/− and -2−/− mice manifested a high mortality after infection with H. capsulatum, although TNFR1−/− mice were more susceptible than TNFR2 −/− mice. Overwhelming infection in the former was associated with a pronounced decrement in the number of inflammatory cells in the lungs and elevated IFN-γ and TNF-α levels in the lungs. In contrast, IFN-γ levels were markedly decreased in TNFR2−/− mice, and treatment with this cytokine restored protective immunity. Lung macrophages from both groups of knockout mice released substantial amounts of NO. Upon secondary infection, TNFR2−/− mice survived rechallenge and cleared infection as efficiently as C57BL/6 animals. In contrast, mice given mAb to TNFR1 succumbed to reexposure, and the high mortality was accompanied by a significant increase in fungal burden in the lungs. Both IL-4 and IL-10 were elevated in the lungs of these mice. The results demonstrate the pivotal influence of TNFR1 and -2 in controlling primary infection and highlight the differences between these receptors for regulation reexposure histoplasmosis.