bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intercellular Adhesion Molecule-1/LFA-1 Ligation Favors Human Th1 Development
Authors: Smits Hermelijn H. , de Jong Esther C. , Schuitemaker Joost H. N. , Geijtenbeek Theo B. H. , van Kooyk Yvette , Kapsenberg Martien L. , Wierenga Eddy A. 
Published: April 2014

AbstractTh cell polarization toward Th1 or Th2 cells is strongly driven by exogenous cytokines, in particular IL-12 or IL-4, if present during activation by Ag-presenting dendritic cells (DC). However, additional Th cell polarizing mechanisms are induced by the ligation of cell surface molecules on DC and naive Th cells. In the present study, the role of LFA-1/ICAM-1 ligation in human Th cell polarization was investigated. Triggering of LFA-1 on anti-CD3/CD28 stimulated naive Th cells with immobilized Fc-ICAM-1, in the absence of DC and exogenous cytokines, induced a marked shift toward Th1 cell development, accompanied by a dose-dependent decrease in GATA-3 expression and a dose-dependent increase in T-bet expression. Th1 polarization by LFA-1 ligation could be demonstrated only under low cytokine conditions, as it was largely overruled by IL-12 or IL-4. This IL-12-independent Th1-driving mechanism appears to be operated by certain subsets of effector DC. Maturation of DC by poly(I:C), a synthetic dsRNA, used as an in vitro model for viral infections, leads to the generation of Th1-driving effector DC (DC1), which express elevated levels of ICAM-1 but produce only low levels of IL-12p70. Blocking the ICAM-1/LFA-1 interaction in cocultures of these DC with naive Th cells attenuated their Th1-driving capacity. The molecular mechanism by which LFA-1 signaling supports Th1 differentiation is blocked by specific inhibitors of extracellular signal-regulated kinase phosphorylation. The present data indicate the existence of an IL-12-independent, extracellular signal-regulated kinase-mediated mechanism, through which high ICAM-1-expressing DC1 can drive Th1 polarization. This mechanism may be operational during viral infections.
Proteasome-Assisted Identification of a SSX-2-Derived Epitope Recognized by Tumor-Reactive CTL Infiltrating Metastatic Melanoma
Authors: Ayyoub Maha , Stevanovic Stefan , Sahin Ugur , Guillaume Philippe , Servis Catherine , Rimoldi Donata , Valmori Danila , Romero Pedro , Cerottini Jean-Charles , Rammensee Hans-Georg , Pfreundschuh Michael , Speiser Daniel , Lévy Frédéric 
Published: April 2014

Abstract
The tumor Ag SSX-2 (HOM-MEL-40) was found by serological identification of Ags by recombinant expression cloning and was shown to be a cancer/testis Ag expressed in a wide variety of tumors. It may therefore represent a source of CD8+ T cell epitopes useful for specific immunotherapy of cancer. To identify potential SSX-2-derived epitopes that can be recognized by CD8+ T cells, we used an approach that combined: 1) the in vitro proteasomal digestion of precursor peptides overlapping the complete SSX-2 sequence; 2) the prediction of SSX-2-derived peptides with an appropriate HLA-A2 binding score; and 3) the analysis of a tumor-infiltrated lymph node cell population from an HLA-A2+ melanoma patient with detectable anti-SSX-2 serum Abs. This strategy allowed us to identify peptide SSX-241–49 as an HLA-A2-restricted epitope. SSX241–49-specific CD8+ T cells were readily detectable in the tumor-infiltrated lymph node population by multimer staining, and CTL clones isolated by multimer-guided cell sorting were able to lyse HLA-A2+ tumor cells expressing SSX-2.
Impaired NK Cell Development in an IFN-γ Transgenic Mouse: Aberrantly Expressed IFN-γ Enhances Hematopoietic Stem Cell Apoptosis and Affects NK Cell Differentiation
Authors: Shimozato Osamu , Ortaldo John R. , Komschlies Kristin L. , Young Howard A. 
Published: April 2014

AbstractAberrant expression of IFN-γ has been demonstrated to cause a wide variety of alterations in cell function and development. Previously we reported that constitutive expression of IFN-γ in bone marrow (BM) and thymus results in a total absence of B cells and a substantial decrease in the number of hematopoietic progenitor cells. In this study, we demonstrate a severe deficiency of NK1.1+CD3− cells in this transgenic mouse model. Compared with normal control littermates, we found a pronounced reduction of NK cells in IFN-γ transgenic mouse spleen and liver despite maintenance of normal function. In addition, we observed a reduced number of BM cells in the IFN-γ transgenic mouse despite normal expression of hematopoietic growth factors in the BM. Interestingly, these cells were less responsive to stem cell factor (SCF) despite c-kit expression on hematopoietic stem cells (HSCs). We observed that addition of exogenous IFN-γ inhibited proliferation of HSCs and differentiation of NK precursors from HSCs in normal mice in response to SCF, IL-7, fms-like tyrosine kinase 3 ligand, and IL-15. Furthermore, we found that HSCs express the IFN-γRα subunit and undergo apoptosis in response to exogenous IFN-γ. Thus, we have demonstrated the occurrence of a severe deficiency of NK cells and lower numbers of BM cells in an IFN-γ transgenic mouse model. Furthermore, because exogenous IFN-γ affects the responsiveness to hematopoietic growth factors such as SCF in vitro, our results indicate that chronic expression of IFN-γ in vivo leads to widespread immune system defects, including alterations in NK cell differentiation.
Innate Direct Anticancer Effector Function of Human Immature Dendritic Cells. II. Role of TNF, Lymphotoxin-α1β2, Fas Ligand, and TNF-Related Apoptosis-Inducing Ligand
Authors: Lu Ganwei , Janjic Bratislav M. , Janjic Jelena , Whiteside Theresa L. , Storkus Walter J. , Vujanovic Nikola L. 
Published: April 2014

AbstractOur recent studies have demonstrated that human immature dendritic cells (DCs) are able to directly and effectively mediate apoptotic killing against a wide array of cultured and freshly-isolated cancer cells without harming normal cells. In the present study, we demonstrate that this tumoricidal activity is mediated by multiple cytotoxic TNF family ligands. We determine that human immature DCs express on their cell surface four different cytotoxic TNF family ligands: TNF, lymphotoxin-α1β2, Fas ligand, and TNF-related apoptosis inducing ligand; while cancer cells express the corresponding death receptors. Disruptions of interactions between the four ligands expressed on DCs and corresponding death-signaling receptors expressed on cancer cells using specific Abs or R:Fc fusion proteins block the cytotoxic activity of DCs directed against cancer cells. The novel findings suggest that DC killing of cancer cells is mediated by the concerted engagement of four TNF family ligands of DCs with corresponding death receptors of cancer cells. Overall, our data demonstrate that DCs are fully equipped for an efficient direct apoptotic killing of cancer cells and suggest that this mechanism may play a critical role in both afferent and efferent anti-tumor immunity.
Induction of Neutrophil Apoptosis by thePseudomonas aeruginosaExotoxin Pyocyanin: A Potential Mechanism of Persistent Infection
Authors: Usher Lynne R. , Lawson Roderick A. , Geary Ian , Taylor Christopher J. , Bingle Colin D. , Taylor Graham W. , Whyte Moira K. B. 
Published: April 2014

AbstractPseudomonas aeruginosa colonizes and infects human tissues, although the mechanisms by which the organism evades the normal, predominantly neutrophilic, host defenses are unclear. Phenazine products of P. aeruginosa can induce death in Caenorhabditis elegans. We hypothesized that phenazines induce death of human neutrophils, and thus impair neutrophil-mediated bacterial killing. We investigated the effects of two phenazines, pyocyanin and 1-hydroxyphenazine, upon apoptosis of neutrophils in vitro. Pyocyanin induced a concentration- and time-dependent acceleration of neutrophil apoptosis, with 50 μM pyocyanin causing a 10-fold induction of apoptosis at 5 h (p &lt; 0.001), a concentration that has been documented in sputum from patients colonized with P. aeruginosa. 1-hydroxyphenazine was without effect. In contrast to its rapid induction of neutrophil apoptosis, pyocyanin did not induce significant apoptosis of monocyte-derived macrophages or airway epithelial cells at time points up to 24 h. Comparison of wild-type and phenazine-deleted strains of P. aeruginosa showed a highly significant reduction in neutrophil killing by the phenazine-deleted strain. In clinical isolates of P. aeruginosa pyocyanin production was associated with a proapoptotic effect upon neutrophils in culture. Pyocyanin-induced neutrophil apoptosis was not delayed either by treatment with LPS, a powerfully antiapoptotic bacterial product, or in neutrophils from cystic fibrosis patients. Pyocyanin-induced apoptosis was associated with rapid and sustained generation of reactive oxygen intermediates and subsequent reduction of intracellular cAMP. Treatment of neutrophils with either antioxidants or synthetic cAMP analogues significantly abrogated pyocyanin-induced apoptosis. We conclude that pyocyanin-induced neutrophil apoptosis may be a clinically important mechanism of persistence of P. aeruginosa in human tissue.
Inflammatory Response and Glutathione Peroxidase in a Model of Stroke
Authors: Ishibashi Nobuya , Prokopenko Olga , Reuhl Kenneth R. , Mirochnitchenko Oleg 
Published: April 2014

AbstractStroke is one of the leading causes of death in major industrial countries. Many factors contribute to the cellular damage resulting from ischemia/reperfusion (I/R). Experimental data indicate an important role for oxidative stress and the inflammatory cascade during I/R. We are testing the hypothesis that the mechanism of protection against I/R damage observed in transgenic mice overexpressing human antioxidant enzymes (particularly intracellular glutathione peroxidase) involves the modulation of inflammatory response as well as reduced sensitivity of neurons to cytotoxic cytokines. Transgenic animals show significant reduction of expression of chemokines, IL-6, and cell death-inducing ligands as well as corresponding receptors in a focal cerebral I/R model. Reduction of DNA binding activity of consensus and potential AP-1 binding sites in mouse Fas ligand promoter sequence was observed in nuclear extracts from transgenic mice overexpressing intracellular glutathione peroxidase compared with normal animals following I/R. This effect was accompanied by modulation of the c-Jun N-terminal kinase/stress-activated protein kinase pathway. Cultured primary neurons from the transgenic mice demonstrated protection against hypoxia/reoxygenation injury as well as cytotoxicity after TNF-α and Fas ligand treatment. These results indicate that glutathione peroxidase-sensitive reactive oxygen species play an important role in regulation of cell death during cerebral I/R by modulating intrinsic neuronal sensitivity as well as brain inflammatory reactions.
The Role of E-Selectin, P-Selectin, and Very Late Activation Antigen-4 in T Lymphocyte Migration to Dermal Inflammation
Authors: Issekutz Andrew C. , Issekutz Thomas B. 
Published: April 2014

AbstractT lymphocyte infiltration into inflamed tissues is thought to involve lymphocyte rolling on vascular endothelial cells. Because both selectin and α4 integrin adhesion molecules can mediate leukocyte rolling, the contribution of these receptors to lymphocyte migration to inflammation was examined. The recruitment of 111In-labeled spleen T cells to intradermal sites injected with IFN-γ, TNF-α, LPS, poly inosine-cytosine, and Con A was measured in the rat, and the effect of blocking mAbs to E-selectin, P-selectin, very late activation Ag-4 (VLA-4), and LFA-1 was determined on this T cell migration in vivo. Anti-E-selectin and anti-P-selectin mAbs each inhibited 10–40 and 20–48%, respectively, of the T lymphocyte migration to the inflammatory sites, depending on the stimulus. Blocking VLA-4 inhibited 50% of the migration to all of the lesions except Con A. Treatment with both anti-VLA-4 and anti-E-selectin mAbs inhibited up to 85% of the lymphocyte accumulation, while P-selectin and VLA-4 blockade in combination was not more effective than VLA-4 blockade alone in TNF-α, IFN-γ, LPS, and poly inosine-cytosine lesions. Inhibiting E-selectin, P-selectin, and VLA-4 together nearly abolished lymphocyte migration to all inflammatory sites. Anti-LFA-1 mAb strongly inhibited lymphocyte accumulation by itself, and this inhibition was not significantly further reduced by E- or P-selectin blockade. Thus, T cell migration to dermal inflammation is dependent on E-selectin, P-selectin, and VLA-4, likely because these three receptors are required for rolling of memory T lymphocytes, but VLA-4 and E-selectin are especially important for lymphocyte infiltration in these tissues.
Lyn Tyrosine Kinase Is Important for IL-5-Stimulated Eosinophil Differentiation
Authors: Stafford Susan , Lowell Clifford , Sur Sanjiv , Alam Rafeul 
Published: April 2014

Abstract
IL-5 plays a pivotal role in growth and differentiation of eosinophils. The signal transduction mechanism of IL-5Rα is largely unknown. We have demonstrated that IL-5 induces tyrosine phosphorylation of IL-5Rα in eosinophils. To identify IL-5Rα-associated tyrosine kinases, we have examined the expression of Src family tyrosine kinases in eosinophils. Among the Src family members, Lyn, Hck, Fgr, and Lck are present in eosinophils, and, among these four kinases, only Lyn is associated with the IL-5Rα under basal conditions. We also confirm the association of Janus kinase (Jak)2 with IL-5Rα. Lyn kinase phosphorylates both IL-5Rα and βcR in vitro. The importance of Lyn kinase for eosinophil differentiation was studied using antisense oligodeoxynucleotides. Lyn antisense oligodeoxynucleotide blocks eosinophil differentiation from stem cells in a dose-dependent manner. The Jak2 inhibitor tyrphostin AG490 also inhibits eosinophil differentiation. The importance of Lyn for eosinophil differentiation was further studied using Lyn knockout mice. The IL-5-stimulated eosinophil differentiation from bone marrow cells is significantly inhibited in Lyn−/− mice as compared with that in control mice. We conclude that both Lyn and Jak2 play an essential role in IL-5Rα signaling, leading to eosinophil differentiation. The effect of Lyn appears to be relatively specific for the eosinophilic lineage.
Autocrine Induction of the Human Pro-IL-1β Gene Promoter by IL-1β in Monocytes
Authors: Toda Yoko , Tsukada Junichi , Misago Masahiro , Kominato Yoshihiko , Auron Philip E. , Tanaka Yoshiya 
Published: April 2014

AbstractIL-1β is produced primarily by activated monocytes/macrophages. We report in this study that IL-1β induces the human pro-IL-1β (IL1B) gene promoter in human THP-1 monocytic cells. The −131 to +12 minimal IL1B promoter was induced by IL-1β in a dose-dependent manner. The promoter possesses two important transcription factor binding motifs, one for an ETS family transcription factor Spi-1 (PU.1), and the other a binding site for NF-IL6 (CCAAT/enhancer binding protein β). Autocrine promoter activity was completely inhibited by mutation of the Spi-1 site. Mutation of the NF-IL6 binding motif caused partial loss of activity. EMSAs using THP-1 cell nuclear extracts indicated that IL-1β significantly induced Spi-1 binding to its target site within the IL1B promoter that was maximal at 1 h after stimulation, correlating with the kinetics of IL-1β induction. The importance of Spi-1 was supported by our observation that Spi-1-deficient EL4 thymocytes exhibited IL-1β-induced activity only after transfection with a Spi-1 expression vector. Moreover, TNFR-associated factor 6 also required Spi-1 to activate the promoter. Transfection studies using Spi-1 mutant constructs showed that the TATA-binding protein binding and glutamine-rich domains of Spi-1 were important for IL-1β induction, whereas LPS induction required the proline, glutamic acid, serine, and threonine-rich domain containing serine 148 as well as the TATA-binding protein and glutamine-rich domains. We conclude that the IL1B promoter is an IL-1β-responsive sequence as a result of its ability to bind Spi-1 in response to IL-1β.
Functional Genomic Analysis of Type II IL-1β Decoy Receptor: Potential for Gene Therapy in Human Arthritis and Inflammation
Authors: Attur Mukundan G. , Dave Mandar N. , Leung Mary Y. , Cipolletta Christine , Meseck Marcia , Woo Savio L. C. , Amin Ashok R. 
Published: April 2014

AbstractGene expression arrays show that human epithelial cells and human arthritis-affected cartilage lack detectable amounts of mRNA for IL-1 antagonizing molecules: IL-1Ra and IL-1RII, but constitutively express IL-1. Functional genomic analysis was performed by reconstituting human IL-1RII expression in various IL-1RII-deficient cell types to examine its antagonist role using gene therapy approaches. Adenovirus-expressing IL-1RII when transduced into human and bovine chondrocytes, human and rabbit synovial cells, human epithelial cells, and rodent fibroblasts expressed membrane IL-1RII and spontaneously released functional soluble IL-1RII. The IL-1RII+ (but not IL-1RII−) cells were resistant to IL-1β-induced, NO, PGE2, IL-6, and IL-8 production or decreased proteoglycan synthesis. IL-1RII inhibited the function of IL-1 in chondrocytes and IL-1- and TNF-α-induced inflammatory mediators in human synovial and epithelial cells. IL-1RII+ chondrocytes were more resistant to induction of NO and PGE2 by IL-1β compared with IL-1RII− cells incubated with a 10-fold (weight) excess of soluble type II IL-1R (sIL-1RII) protein. In cocultures, IL-1RII+ synovial cells released sIL-1RII, which in a paracrine fashion protected chondrocytes from the effects of IL-1β. Furthermore, IL-1RII+ (but not IL-1RII−) chondrocytes when transplanted onto human osteoarthritis-affected cartilage in vitro, which showed spontaneous release of sIL-1RII for 20 days, inhibited the spontaneous production of NO and PGE2 in cartilage in ex vivo. In summary, reconstitution of IL-1RII in IL-1RII− cells using gene therapy approaches significantly protects cells against the autocrine and paracrine effects of IL-1 at the signaling and transcriptional levels.
G-CSF Therapy of Ongoing Experimental Allergic Encephalomyelitis Via Chemokine- and Cytokine-Based Immune Deviation
Authors: Zavala Flora , Abad Sébastien , Ezine Sophie , Taupin Véronique , Masson Annie , Bach Jean-François 
Published: April 2014

AbstractConverging evidence that G-CSF, the hemopoietic growth factor of the myeloid lineage, also exerts anti-inflammatory and pro-Th2 effects, prompted us to evaluate its direct therapeutic potential in autoimmune diseases. Here we report a novel activity of G-CSF in experimental allergic encephalomyelitis, a murine model for multiple sclerosis, driven by Th1-oriented autoaggressive cells. A short 7-day treatment with G-CSF, initiated at the onset of clinical signs, provided durable protection from experimental autoimmune encephalomyelitis. G-CSF-treated mice displayed limited demyelination, reduced recruitment of T cells to the CNS, and very discrete autoimmune inflammation, as well as barely detectable CNS mRNA levels of cytokines and chemokines. In the periphery, G-CSF treatment triggered an imbalance in the production by macrophages as well as autoreactive splenocytes of macrophage inflammatory protein-1α and monocyte chemoattractant protein-1, the prototypical pro-Th1 and pro-Th2 CC chemokines, respectively. This chemokine imbalance was associated with an immune deviation of the autoreactive response, with reduced IFN-γ and increased IL-4 and TGF-β1 levels. Moreover, G-CSF limited the production of TNF-α, a cytokine also associated with early CNS infiltration and neurological deficit. These findings support the potential application of G-CSF in the treatment of human autoimmune diseases such as multiple sclerosis, taking advantage of the wide clinical favorable experience with this molecule.
Mechanism of Action of Combined Short-Term CTLA4Ig and Anti-CD40 Ligand in Murine Systemic Lupus Erythematosus
Authors: Wang Xiaobo , Huang Weiqing , Mihara Masahiko , Sinha Jayashree , Davidson Anne 
Published: April 2014

AbstractShort-term combination therapy with the costimulatory antagonists CTLA4Ig and anti-CD40 ligand induces prolonged suppression of disease onset in New Zealand Black/New Zealand White F1 systemic lupus erythematosus-prone mice. To determine the mechanism for this effect, 20- to 22-wk-old New Zealand Black/New Zealand White F1 mice were treated with six doses each of CTLA4Ig and anti-CD40 ligand Ab over 2 wk. Combination-treated mice, but not mice treated with either agent alone, had prolonged survival and the production of pathogenic IgG anti-dsDNA Ab was suppressed. Twenty weeks after completion of treatment the frequency of activated B cells producing anti-dsDNA Ab was decreased, and the abnormal transition of T cells from the naive to the memory compartment was blocked. Combination treatment partially suppressed class switching and decreased the frequency of somatic mutations in the VHBW-16 gene, which is expressed by pathogenic anti-DNA Abs. Treated mice were still able to respond to the hapten oxazolone when it was given 8 wk after treatment initiation, and they mounted a somatically mutated IgG anti-oxazolone response that was noncross-reactive with dsDNA. Fifty to 60% of previously treated mice, but only 14% of previously untreated mice, responded within 2–3 wk to a second course of therapy given at the onset of fixed proteinuria and remained well for a further 3–4 mo. Although this treatment had no immediate effect on serum anti-dsDNA Abs or on the abnormal T cell activation observed in sick mice, 25% of treated mice lived for &gt;18 mo compared with 5% of untreated controls. These results suggest that the effect of costimulatory blockade in remission induction must be mediated by a different mechanism than is demonstrated in the disease prevention studies.
Cutting Edge: Identification of c-Rel-Dependent and -Independent Pathways of IL-12 Production During Infectious and Inflammatory Stimuli
Authors: Mason Nicola , Aliberti Julio , Caamano Jorge C. , Liou Hsiou-Chi , Hunter Christopher A. 
Published: April 2014

AbstractThe production of IL-12 is required for immunity to many intracellular pathogens. Recent studies have shown that c-Rel, a member of the NF-κB family of transcription factors, is essential for LPS-induced IL-12p40 production by macrophages. In this study, we demonstrate that c-Rel is also required for IL-12p40 production by macrophages in response to Corynebacterium parvum, CpG oligodeoxynucleotides, anti-CD40 and low molecular weight hyaluronic acid. However, c-Rel−/− mice infected with Toxoplasma gondii produce comparable amounts of IL-12p40 to infected wild-type mice and have an IL-12-dependent mechanism of resistance to this infection. Furthermore, c-Rel was not required for IL-12p40 production by macrophages or dendritic cells in response to soluble Toxoplasma Ag, and neutrophils from c-Rel−/− mice contain normal amounts of preformed IL-12p40. Together these studies reveal the presence of c-Rel-dependent pathways critical for IL-12p40 production in response to inflammatory stimuli and demonstrate a novel c-Rel-independent pathway of IL-12p40 production during toxoplasmosis.