bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vaccination with Heat-KilledListeriaas Adjuvant Reverses Established Allergen-Induced Airway Hyperreactivity and Inflammation: Role of CD8+ T Cells and IL-18
Authors: Hansen Gesine , Yeung V. Peter , Berry Gerald , Umetsu Dale T. , DeKruyff Rosemarie H. 
Published: April 2014

AbstractAsthma is a respiratory disorder characterized by airway hyperreactivity (AHR) and inflammation and is associated with high serum IgE and overproduction of IL-4, IL-5, and IL-13 by allergen-specific Th2 cells. Our previous studies demonstrated that heat-killed Listeria monocytogenes (HKL) as an adjuvant in immunotherapy successfully reversed ongoing Ag-specific Th2-dominated responses toward Th1-dominated responses, but it was unclear if such immune modulation could reverse ongoing, established disease in target organs such as the lung. In this paper we show that a single dose of Ag plus HKL as adjuvant significantly reduced AHR in a murine model for asthma and reversed established AHR when given late after allergen sensitization. HKL as adjuvant also dramatically inhibited airway inflammation, eosinophilia, and mucus production, significantly reduced Ag-specific IgE and IL-4 production, and dramatically increased Ag-specific IFN-γ synthesis. The inhibitory effect of HKL on AHR depended on the presence of IL-12 and CD8+ T cells and was associated with an increase of IL-18 mRNA expression. Thus, our results demonstrate that HKL as an adjuvant for immunotherapy mediates immune deviation from a pathological Th2-dominated response toward a protective immune response in peripheral lymphoid tissues and in the lungs and may be clinically effective in the treatment of patients with established asthma and allergic disease.
IFN-β Differentially Regulates CD40-Induced Cytokine Secretion by Human Dendritic Cells
Authors: McRae Bradford L. , Beilfuss Beth A. , Seventer Gijs A. van 
Published: April 2014

AbstractWe have previously shown that IFN-β, a key cytokine associated with the early phase of the innate host defense, can prevent the generation of human Th1 cells. Specifically, we demonstrated that IFN-β prevents the in vitro monocyte-derived mature dendritic cell (DC)-dependent differentiation of naive Th cells into IFN-γ-secreting Th cells, as a result of its ability to inhibit DC IL-12 secretion. The goal of the present study was to identify how IFN-β negatively regulates IL-12 secretion by DC. We report that in our Th cell differentiation model, DC IL-12 secretion is dependent on the CD40L/CD40 accessory pathway, and, utilizing a Th cell-free system, we find that IFN-β inhibits anti-CD40 mAb-induced DC secretion of the p40 chain of the IL-12 heterodimer. In addition, we show that IFN-β-mediated inhibition of CD40 signaling does not interfere with all signaling pathways emanating from CD40, since anti-CD40 mAb-induced DC IL-6 secretion is augmented by IFN-β. Thus, our results demonstrate that signaling from CD40 is differentially regulated by IFN-β. A second critical element of innate immunity involves the response against components of bacterial membranes such as LPS. DC respond to LPS by secreting IL-6 and IL-12. In contrast to CD40-dependent IL-6 and IL-12 secretion, we find that LPS-induced DC secretion of p40 IL-12 and IL-6 is not affected by IFN-β. Our findings show that IFN-β influences the generation of acquired immune responses through its regulation of CD40-dependent DC functions.
A Role for Pref-1 and HES-1 in Thymocyte Development
Authors: Kaneta Midori , Osawa Masatake , Osawa Mitsujiro , Sudo Kazuhiro , Nakauchi Hiromitsu , Farr Andrew G. , Takahama Yousuke 
Published: April 2014

AbstractT lymphocyte development requires a series of interactions between developing thymocytes and thymic epithelial (TE) cells. In this paper we show that TE cells in the developing thymus express Pref-1, a Delta-like cell-surface molecule. In fetal thymus organ cultures (FTOC), thymocyte cellularity was increased by the exogenous dimeric Pref-1 fusion protein, but was reduced by the soluble Pref-1 monomer or anti-Pref-1 Ab. Dimeric Pref-1 in FTOC also increased thymocyte expression of the HES-1 transcription factor. Thymocyte cellularity was increased in FTOC repopulated with immature thymocytes overexpressing HES-1, whereas FTOC from HES-1-deficient mice were hypocellular and unresponsive to the Pref-1 dimer. We detected no effects of either Pref-1 or HES-1 on developmental choice among thymocyte lineages. These results indicate that Pref-1 expressed by TE cells and HES-1 expressed by thymocytes are critically involved in supporting thymocyte cellularity.
Importance of the Membrane-Proximal Extracellular Domains for Activation of the Signal Transducer Glycoprotein 130
Authors: Kurth Ingo , Horsten Ursula , Pflanz Stefan , Timmermann Andreas , Küster Andrea , Dahmen Heike , Tacken Ingrid , Heinrich Peter C. , Müller-Newen Gerhard 
Published: April 2014

AbstractThe transmembrane glycoprotein gp130 is the common signal transducing receptor subunit of the IL-6-type cytokines. The gp130 extracellular part is predicted to consist of six individual domains. Whereas the role of the three membrane-distal domains (D1–D3) in binding of IL-6 and IL-11 is well established, the function of the membrane-proximal domains (D4–D6) is unclear. Mapping of a neutralizing mAb to the membrane-proximal part of gp130 suggests a functional role of D4–D6 in receptor activation. Individual deletion of these three domains differentially interferes with ligand binding of the soluble and membrane-bound receptors. All deletion mutants do not signal in response to IL-6 and IL-11. The deletion mutants Δ4 and, to a lesser extent, Δ6 are still activated by agonistic monoclonal gp130 Abs, whereas the deletion mutant Δ5 does not respond. Because membrane-bound Δ5 binds IL-6/soluble IL-6R as does wild-type gp130, but does not transduce a signal in response to various stimuli, this domain plays a prominent role in coupling of ligand binding and signal transduction. Replacement of the fifth domain of gp130 by the corresponding domain of the homologous G-CSF receptor leads to constitutive activation of the chimera upon overexpression in COS-7 cells. In HepG2 cells this mutant responds to IL-6 comparable to wild-type gp130. Our findings suggest a functional role of the membrane-proximal domains of gp130 in receptor activation. Thus, within the hematopoietic receptor family the mechanism of receptor activation critically depends on the architecture of the receptor ectodomain.
Limited Diversity of Peptides Related to an Alloreactive T Cell Epitope in the HLA-B27-Bound Peptide Repertoire Results from Restrictions at Multiple Steps Along the Processing-Loading Pathway
Authors: Paradela Alberto , Alvarez Iñaki , García-Peydró Marina , Sesma Laura , Ramos Manuel , Vázquez Jesús , López de Castro José A. 
Published: April 2014

AbstractThe influence of various factors along the processing-loading pathway in limiting the diversity of HLA-B27-bound peptides around a core protein sequence was analyzed. The C5 proteasome subunit-derived RRFFPYYV and RRFFPYYVY peptides are natural B*2705 ligands. The octamer is an allospecific CTL epitope. Digestion of a 27-mer fragment of C5 revealed that both ligands are generated from this precursor substrate with the 20S proteasome in vitro in a ratio comparable to that in the B*2705-bound peptide pool. The C5 sequence allowed to derive a nested set of six additional peptides with 8–11 residues containing the core octamer sequence and the Arg2 motif of HLA-B27, none of which was found in the B27-bound pool. Together, low proteasomal yield, disfavored TAP-binding motifs, and low affinity for B*2705 accounted for the absence of four of the six peptides. The two remaining differed from the natural octamer or nonamer ligands only by an additional N-terminal Ser residue. Their stability in complex with B*2705 was lower than the respective natural ligands, raising the possibility that N-terminal trimming might have favored a shift toward the more stable peptides. The results suggest that the B*2705-bound peptide repertoire has a highly restricted diversity around a core alloantigenic sequence. This is not explained by a single bottleneck feature, but by multiple factors, including proteasomal generation, TAP-binding motifs, MHC-binding efficiency, and perhaps optimized stability through N-terminal trimming. Tapasin-dependent restrictions, although not excluded, were not required to explain the absence in vivo of the particular peptide set in this study.
Point Mutation of a Tyrosine in the Linker Region of Syk Results in a Gain of Function
Authors: Sada Kiyonao , Zhang Juan , Siraganian Reuben P. 
Published: April 2014

AbstractThe protein tyrosine kinase Syk plays an essential role in FcεRI-mediated histamine release in mast cells by regulating the phosphorylation of other proteins. We investigated the functional role of a putative Syk phosphorylation site, Tyr317. This tyrosine in the linker region of Syk is a possible site for binding by the negative regulator Cbl. Syk with Tyr317 mutated to Phe (Y317F) was expressed in a Syk-negative variant of the RBL-2H3 mast cells. Compared with cells expressing wild-type Syk, expression of the Y317F mutant resulted in an increase in the FcεRI-mediated tyrosine phosphorylation of phospholipase C-γ and a dramatic enhancement of histamine release. The in vivo FcεRI-induced tyrosine phosphorylation of wild-type Syk and that of the Y317F mutant were similar. Although the FcεRI-induced tyrosine phosphorylation of total cellular proteins was enhanced in the cells expressing the Y317F Syk, the phosphorylation of some other molecules, including the receptor subunits, Vav and mitogen-activated protein kinase, was not increased. The FcεRI-induced phosphorylation of Cbl was downstream of Syk kinase activity and was unchanged by expression of the Y317F mutation. These data indicate that Tyr317 in the linker region of Syk functions to negatively regulate the signals leading to degranulation.
Specific Inhibition of Cyclooxygenase 2 Restores Antitumor Reactivity by Altering the Balance of IL-10 and IL-12 Synthesis
Authors: Stolina Marina , Sharma Sherven , Lin Ying , Dohadwala Mariam , Gardner Brian , Luo Jie , Zhu Li , Kronenberg Mitchell , Miller Patrice W. , Portanova Joseph , Lee Jason C. , Dubinett Steven M. 
Published: April 2014

AbstractCyclooxygenase-2 (COX-2), the enzyme at the rate-limiting step of prostanoid production, has been found to be overexpressed in human lung cancer. To evaluate lung tumor COX-2 modulation of antitumor immunity, we studied the antitumor effect of specific genetic or pharmacological inhibition of COX-2 in a murine Lewis lung carcinoma (3LL) model. Inhibition of COX-2 led to marked lymphocytic infiltration of the tumor and reduced tumor growth. Treatment of mice with anti-PGE2 mAb replicated the growth reduction seen in tumor-bearing mice treated with COX-2 inhibitors. COX-2 inhibition was accompanied by a significant decrement in IL-10 and a concomitant restoration of IL-12 production by APCs. Because the COX-2 metabolite PGE2 is a potent inducer of IL-10, it was hypothesized that COX-2 inhibition led to antitumor responses by down-regulating production of this potent immunosuppressive cytokine. In support of this concept, transfer of IL-10 transgenic T lymphocytes that overexpress IL-10 under control of the IL-2 promoter reversed the COX-2 inhibitor-induced antitumor response. We conclude that abrogation of COX-2 expression promotes antitumor reactivity by restoring the balance of IL-10 and IL-12 in vivo.
Development of Lupus in BXSB Mice Is Independent of IL-4
Authors: Kono Dwight H. , Balomenos Dimitrios , Park Miyo S. , Theofilopoulos Argyrios N. 
Published: April 2014

AbstractAlthough systemic lupus erythematosus appears to be a humorally mediated disease, both Th1 and Th2 type responses have been implicated in its pathogenesis. The Th1 response, as exemplified by IFN-γ production, has been uniformly shown in mouse lupus models to be critical for disease induction. The role of Th2 type responses, however, is more complicated, with some studies showing detrimental and others beneficial effects of IL-4 in these models. To further address this issue, we generated and analyzed IL-4 gene-deficient BXSB mice. Mice homozygous for this deletion had significantly lower serum levels of total IgG1 compared with wild-type BXSB, consistent with the lack of IL-4. However, no significant differences were observed in mortality, spleen weight, severity of glomerulonephritis, levels of anti-chromatin and anti-ssDNA Abs, or frequency of activated (CD44high) CD4+ T cells. The anti-chromatin Ab isotype response was virtually all Th1 type in both the knockout and wild-type BXSB. These findings directly demonstrate that IL-4 and, by inference, Th2 cells are not obligatory participants in the induction and maintenance of lupus in this strain.
Differential Contribution of Fas- and Perforin-Mediated Mechanisms to the Cell-Mediated Cytotoxic Activity of Naive and In Vivo-Primed Intestinal Intraepithelial Lymphocytes
Authors: Corazza Nadia , Müller Stefan , Brunner Thomas , Kägi David , Mueller Christoph 
Published: April 2014

AbstractIntestinal intraepithelial lymphocytes (IELs) are known to exert strong constitutive cytotoxic activity. In the present study we compared the Ag-specific cytotoxic activity and the effector mechanisms involved in non-Ag-primed, naive and in in vivo-primed IELs and splenic CD8 T cells. Ex vivo isolated naive CD8αα TCRαβ IELs, CD8αβ IELs, and splenocytes from lymphocytic choriomeningitis virus (LCMV)-specific TCR transgenic mice exert Ag-specific cytotoxic activity in a long-term, but not in a short-term, cytotoxicity assay. This cytotoxic activity is mainly Fas-Fas ligand mediated and is significantly reduced in the presence of 20 μg/ml Fas-Fcγ1 fusion protein. Both CD8αβ IELs and CD8αβ splenocytes isolated from LCMV-infected C57BL/6 mice exert potent perforin-dependent cell-mediated cytotoxicity. CD8αα TCRαβ IELs from LCMV-infected animals, however, show only minimal Ag-specific cytotoxicity. The potent cytotoxic activity of in vivo activated CD8αβ IELs is not affected by the addition of Fas-Fcγ1. Nevertheless CD8αβ IELs from LCMV-infected perforin-deficient mice exert Ag-specific cytotoxicity in a short-term cytotoxicity assay, and this cytotoxicity is almost completely blocked by the addition of Fas-Fcγ1. These results demonstrate that naive CD8αβ IELs exert Ag-specific, Fas-Fas ligand-mediated, constitutive cytotoxic activity in a long-term cytotoxicity assay, whereas primed CD8αβ IELs primarily use the perforin-dependent exocytosis pathway to exert their potent cytotoxic activity. Furthermore, these results clearly illustrate the requirement for Ag-specific determination of IEL-mediated cytotoxicity, because the elevated, but variable, frequencies of memory-type T cells in this compartment may lead to ambiguous results when polyclonal activation or redirected assays are used.
fMet-Leu-Phe Stimulates Proinflammatory Cytokine Gene Expression in Human Peripheral Blood Monocytes: The Role of Phosphatidylinositol 3-Kinase
Authors: Pan Zhixing K. , Chen Ling-Yu , Cochrane Charles G. , Zuraw Bruce L. 
Published: April 2014

AbstractThe fMLP-stimulated release of proinflammatory cytokines such as IL-1 by human peripheral blood monocytes is an important component of the inflammatory process. The signaling mechanisms used by fMLP to stimulate the release of cytokines are still incompletely understood. We previously demonstrated that fMLP-stimulated NF-κB activation in PBMC and now we present evidence that the lipid products of phosphatidylinositol 3-kinase (PI 3-kinase) are required for fMLP-stimulated activation of NF-κB. Pretreatment with the PI 3-kinase inhibitors, wortmannin and LY294002, effectively blocked fMLP-induced IL-1β gene expression as well as NF-κB activation. Transient transfection of THP1 cells with a dominant-negative mutant of the PI 3-kinase p85 subunit also abrogated fMLP-induced κB activity. These results suggest a potential role of fMLP in the transcription of proinflammatory cytokines and provide the first evidence that such regulation may occur through PI 3-kinase activity.
Role of B7-CD28/CTLA-4 Costimulation and NF-κB in Allergen-Induced T Cell Chemotaxis by IL-16 and RANTES
Authors: Hidi Rabia , Riches Vanessa , Al-Ali Musa , Cruikshank William W. , Center David M. , Holgate Stephen T. , Djukanović Ratko 
Published: April 2014

AbstractThe mechanisms that cause T cell recruitment into inflamed airways of asthmatic individuals are poorly understood. It has been shown previously that both natural exposure to allergen and challenge in the laboratory induce T cell accumulation in the bronchial mucosa of sensitized asthmatics. To study the mechanisms involved in this process, we have used an explant model in which bronchial biopsies taken from mild atopic asthmatic volunteers during fiberoptic bronchoscopy were stimulated in culture for 24 h by the common aeroallergen house dust mite (Dermatophagoides pteronyssinus (Der p)). Analysis of culture supernatants showed that stimulation with Der p significantly enhanced both the generation of T cell chemotactic activity by the mucosal tissue, as assayed in microchemotaxis chambers, and the production of IL-16 and RANTES. Neutralization experiments showed that IL-16 contributed more to the chemotactic activity than RANTES. The fusion protein CTLA-4-Ig, blocking B7:CD28 costimulation, and dexamethasone both significantly reduced the ex vivo production of chemotactic activity and release of IL-16 and RANTES. The proteasome inhibitor Cbz-Ile-Glu(OtBu)-Ala-leucinal also had a significant inhibitory effect on T cell chemotactic activity and IL-16 but not RANTES generation, indicating a role for nuclear factor NFκB activation. These results indicate that allergen stimulates cells within the bronchial mucosa to increase IL-16 and RANTES release, both of which contribute to T cell accumulation in asthmatic airways. The allergen-induced chemotactic activity is dependent on cell activation via CD28 and involves, at least partly, NF-κB.
Monocyte Migration Through the Alveolar Epithelial Barrier: Adhesion Molecule Mechanisms and Impact of Chemokines
Authors: Rosseau Simone , Selhorst Jochen , Wiechmann Kristina , Leissner Katja , Maus Ulrich , Mayer Konstantin , Grimminger Friedrich , Seeger Werner , Lohmeyer Jürgen 
Published: April 2014

AbstractAlveolar monocyte influx requires adherence and transmigration through the vascular endothelium, extracellular matrix, and alveolar epithelium. For investigating the monocyte migratory process across the epithelial barrier, we employed both the A549 cell line and isolated human alveolar epithelial cells. Under baseline conditions, spontaneous bidirectional transepithelial monocyte migration was noted, which was dose-dependently increased in the presence of the monocyte chemoattractant protein-1. TNF-α stimulation of the alveolar epithelium provoked the polarized apical secretion of monocyte chemoattractant protein-1 and RANTES and up-regulation of ICAM-1 and VCAM-1 expression, accompanied by markedly enhanced transepithelial monocyte traffic in the basal-to-apical direction. Multiple adhesive interactions were noted to contribute to the enhanced monocyte traffic across the TNF-α-stimulated alveolar epithelium: these included the β2 integrins CD11a, CD11b, CD11c/CD18, the β1 integrins very late Ag (VLA)-4, -5, and -6, and the integrin-associated protein CD47 on monocytes, as well as ICAM-1, VCAM-1, CD47, and matrix components on the epithelial side. In contrast, spontaneous monocyte migration through unstimulated epithelium depended predominantly on CD11b/CD18 and CD47, with some additional contribution of VLA-4, -5, and -6. In summary, unlike transendothelial monocyte traffic, for which β1 and β2 integrins are alternative mechanisms, monocyte migration across the alveolar epithelium largely depends on CD11b/CD18 and CD47 but required the additional engagement of the β1 integrins for optimal migration. In response to inflammatory challenge, the alveolar epithelium orchestrates enhanced monocyte traffic to the apical side by polarized chemokine secretion and up-regulation of ICAM-1 and VCAM-1.
The Arthus Reaction in Rodents: Species-Specific Requirement of Complement
Authors: Szalai Alexander J. , Digerness Stanley B. , Agrawal Alok , Kearney John F. , Bucy R. Pat , Niwas Shri , Kilpatrick John M. , Babu Y. Sudhakara , Volanakis John E. 
Published: April 2014

AbstractWe induced reverse passive Arthus (RPA) reactions in the skin of rodents and found that the contribution of complement to immune complex-mediated inflammation is species specific. Complement was found to be necessary in rats and guinea pigs but not in C57BL/6J mice. In rats, within 4 h after initiation of an RPA reaction, serum alternative pathway hemolytic titers decreased significantly below basal levels, whereas classical pathway titers were unchanged. Thus the dermal reaction proceeds coincident with systemic activation of complement. The serine protease inhibitor BCX 1470, which blocks the esterolytic and hemolytic activities of the complement enzymes Cls and factor D in vitro, also blocked development of RPA-induced edema in the rat. These data support the proposal that complement-mediated processes are of major importance in the Arthus reaction in rats and guinea pigs, and suggest that BCX 1470 will be useful as an anti-inflammatory agent in diseases where complement activation is known to be detrimental.
Cutting Edge: Tyrosine-Independent Transmission of Inhibitory Signals by CTLA-4
Authors: Cinek Tomas , Sadra Ali , Imboden John B. 
Published: April 2014

AbstractCTLA-4 is an important inhibitor of T cell activation. We used Jurkat cells expressing mutants of murine CTLA-4 to study the structural requirements for inhibitory signaling. We find that signals for the inhibition of IL-2 secretion are delivered efficiently by a CTLA-4 mutant in which both cytoplasmic tyrosines have been replaced by phenylalanines. A CTLA-4 mutant that lacks the carboxyl-terminal half of the intracellular domain also retains the ability to inhibit, but deletion of an additional 11 aa completely abrogates that capability. We conclude that delivery of an inhibitory signal requires the membrane-proximal region of the CTLA-4 cytoplasmic domain and does not depend upon the tyrosine phosphorylation of CTLA-4.
Synergistic Effects of IL-4 and IL-18 on IL-12-Dependent IFN-γ Production by Dendritic Cells
Authors: Fukao Taro , Matsuda Satoshi , Koyasu Shigeo 
Published: April 2014

AbstractMouse splenic dendritic cells (DCs) produce IFN-γ in response to IL-12. In the present study, we analyzed effects of Th1 and Th2 cytokines on IFN-γ production by DCs. IL-18 produced by DCs and macrophages acts in an autocrine manner and augments IL-12-induced IFN-γ production by DCs as also observed in T and NK cells. Surprisingly, IL-4, a Th2 cytokine, also acts synergistically with IL-12 on IFN-γ production by DCs. In addition, IL-4 markedly enhances IFN-γ production when DCs are stimulated through CD40 or MHC class II. These results indicate that both Th1 and Th2 cytokines act on DCs during T cell-DC interaction upon Ag presentation. p38 mitogen-activated protein kinase is constitutively activated in mature DCs and is required for IFN-γ production by DCs. IL-18 but not IL-4 or IL-12 further activates the p38 mitogen-activated protein kinase activity, suggesting that IL-4 and IL-18 enhance IFN-γ production through distinct intracellular signal transduction pathways in DCs.