bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular Cloning and Characterization of a Novel CXC Chemokine Macrophage Inflammatory Protein-2γ Chemoattractant for Human Neutrophils and Dendritic Cells
Authors: Cao Xuetao , Zhang Weiping , Wan Tao , He Long , Chen Taoyong , Yuan Zhenglong , Ma Shihua , Yu Yizhi , Chen Guoyou 
Published: April 2014

AbstractChemokines play important roles in leukocyte trafficking as well as function regulation. In this study, we described the identification and characterization of a novel CXC chemokine from a human dendritic cell (DC) cDNA library, the full-length cDNA of which contains an open reading frame encoding 111 aa with a putative signal peptide of 34 aa. This CXC chemokine shares greatest homology with macrophage inflammatory protein (MIP)-2αβ, hence is designated as MIP-2γ. Mouse MIP-2γ was identified by electrocloning and is highly homologous to human MIP-2γ. Northern blotting revealed that MIP-2γ was constitutively and widely expressed in most normal tissues with the greatest expression in kidney, but undetectable in most tumor cell lines except THP-1 cells. In situ hybridization analysis demonstrated that MIP-2γ was mainly expressed by the epithelium of tubules in the kidney and hepatocytes in the liver. Although no detectable expression was observed in freshly isolated or PMA-treated monocytes, RT-PCR analysis revealed MIP-2γ expression by monocyte-derived DC. Recombinant MIP-2γ from 293 cells is about 9.5 kDa in size and specifically detectable by its polyclonal Ab developed by the immunization with its 6His-tagged fusion protein. The eukaryotically expressed MIP-2γ is a potent chemoattractant for neutrophils, and weaker for DC, but inactive to monocytes, NK cells, and T and B lymphocytes. Receptor binding assays showed that MIP-2γ does not bind to CXCR2. This implies that DC might contribute to the innate immunity through the production of neutrophil-attracting chemokines and extends the knowledge about the regulation of DC migration.
Enhanced Pulmonary Allergic Responses toAspergillusin CCR2−/− Mice
Authors: Blease Kate , Mehrad Borna , Standiford Theodore J. , Lukacs Nicholas W. , Gosling Jennifa , Boring Landin , Charo Israel F. , Kunkel Steven L. , Hogaboam Cory M. 
Published: April 2014

AbstractAllergic responses to Aspergillus species exacerbate asthma and cystic fibrosis. The natural defense against live Aspergillus fumigatus spores or conidia depends on the recruitment and activation of mononuclear and polymorphonuclear leukocytes, events that are dependent on chemotactic cytokines. In this study, we explored the relative contribution of the monocyte chemoattractant protein-1 receptor, CCR2, in the pulmonary response to A. fumigatus conidia. Following sensitization to soluble A. fumigatus Ags, mice lacking CCR2 due to targeted deletion were markedly more susceptible to the injurious effects of an intrapulmonary challenge with live conidia compared with mice that expressed CCR2 or CCR2+/+. CCR2−/− mice exhibited a major defect in the recruitment of polymorphonuclear cells, but these mice also had significantly more eosinophils and lymphocytes in bronchoalveolar lavage samples. CCR2−/− mice also had significant increases in serum levels of total IgE and whole lung levels of IL-5, IL-13, eotaxin, and RANTES compared with CCR2+/+ mice. Airway inflammation, hyper-responsiveness to spasmogens, and subepithelial fibrosis were significantly enhanced in CCR2−/− mice compared with CCR2+/+ mice after the conidia challenge. Thus, these findings demonstrate that CCR2 plays an important role in the immune response against A. fumigatus, thereby limiting the allergic airway inflammatory and remodeling responses to this fungus.
Identification of STAT4-Dependent and Independent Mechanisms of Resistance toToxoplasma gondii
Authors: Cai Guifang , Radzanowski Thad , Villegas Eric N. , Kastelein Robert , Hunter Christopher A. 
Published: April 2014

AbstractThe capacity of IL-12 to stimulate T and NK cell production of IFN-γ is required for resistance to Toxoplasma gondii. To identify the transcription factors involved in this mechanism of resistance, mice deficient in STAT4, a protein involved in IL-12 signaling, were infected with T. gondii and their immune responses were analyzed. STAT4−/− mice were unable to control parasite replication and died during the acute phase of infection, whereas wild-type mice controlled parasite replication and survived this challenge. The susceptibility of STAT4−/− mice to toxoplasmosis correlated with a defect in their ability to produce IFN-γ in response to infection, whereas administration of IFN-γ to these mice inhibited parasite replication and delayed time to death. Interestingly, analysis of infected STAT4−/− mice revealed that these mice did produce low levels of IFN-γ during infection, and the ability of splenocytes from infected or uninfected STAT4−/− mice to produce IFN-γ was enhanced by the addition of IL-2 plus IL-18. Moreover, administration of IL-2 plus IL-18 to STAT4−/− mice resulted in elevated serum levels of IFN-γ associated with a decreased parasite burden and delayed time to death. In vivo depletion studies demonstrated that the ability of IL-2 plus IL-18 to mediate STAT4-independent resistance to T. gondii is dependent on NK cell production of IFN-γ. Together, these studies identify STAT4 as an important transcription factor required for development of the innate NK and adaptive T cell responses necessary for resistance to T. gondii. However, other signaling pathways can be used to bypass STAT4-dependent production of IFN-γ and enhance innate resistance to T. gondii.
An Immunomodulatory Function for Neutrophils During the Induction of a CD4+ Th2 Response in BALB/c Mice Infected withLeishmania major
Authors: Tacchini-Cottier Fabienne , Zweifel C. , Belkaid Y. , Mukankundiye C. , Vasei M. , Launois P. , Milon G. , Louis J. A. 
Published: April 2014

AbstractThe possible immunomodulatory role of polymorphonuclear leukocytes (PMN) in CD4+ T lymphocyte differentiation in mice was examined by studying the effect of transient depletion of PMN during the early phase after Leishmania major delivery. A single injection of the PMN-depleting NIMP-R14 mAb 6 h before infection with L. major prevented the early burst of IL-4 mRNA transcription otherwise occurring in the draining lymph node of susceptible BALB/c mice. Since this early burst of IL-4 mRNA transcripts had previously been shown to instruct Th2 differentiation in mice from this strain, we examined the effect of PMN depletion on Th subset differentiation at later time points after infection. The transient depletion of PMN in BALB/c mice was sufficient to inhibit Th2 cell development otherwise occurring after L. major infection. Decreased Th2 responses were paralleled with partial resolution of the footpad lesions induced by L. major. Furthermore, draining lymph node-derived CD4+ T cells from PMN-depleted mice remained responsive to IL-12 after L. major infection, unlike those of infected BALB/c mice receiving control Ab. PMN depletion had no effect when the NIMP-R14 mAb was injected 24 h postinfection. The protective effect of PMN depletion was shown to be IL-12 dependent, as concomitant neutralization of IL-12 reversed the protective effect of PMN depletion. These results suggest a role for an early wave of PMN in the development of the Th2 response characteristic of mice susceptible to infection with L. major.
The Anti-Tumor Activity of IL-12: Mechanisms of Innate Immunity That Are Model and Dose Dependent
Authors: Smyth Mark J. , Taniguchi Masaru , Street Shayna E. A. 
Published: April 2014

AbstractIL-12 has been demonstrated to have potent anti-tumor activities in a variety of mouse tumor models, but the relative roles of NK, NKT, and T cells and their effector mechanisms in these responses have not been fully addressed. Using a spectrum of gene-targeted or Ab-treated mice we have shown that for any particular tumor model the effector mechanisms downstream of IL-12 often mimic the natural immune response to that tumor. For example, metastasis of the MHC class I-deficient lymphoma, EL4-S3, was strictly controlled by NK cells using perforin either naturally or following therapy with high-dose IL-12. Intriguingly, in B16F10 and RM-1 tumor models both NK and NKT cells contribute to natural protection from tumor metastasis. In these models, a lower dose of IL-12 or delayed administration of IL-12 dictated a greater relative role of NKT cells in immune protection from tumor metastasis. Overall, both NK and NKT cells can contribute to natural and IL-12-induced immunity against tumors, and the relative role of each population is tumor and therapy dependent.
The Role of a Mitochondrial Pathway in the Induction of Apoptosis by Chemicals Extracted from Diesel Exhaust Particles
Authors: Hiura Timothy S. , Li Ning , Kaplan Roman , Horwitz Marcus , Seagrave Jean-Clare , Nel Andre E. 
Published: April 2014

Abstract
We are interested in the cytotoxic and proinflammatory effects of particulate pollutants in the respiratory tract. We demonstrate that methanol extracts made from diesel exhaust particles (DEP) induce apoptosis and reactive oxygen species (ROS) in pulmonary alveolar macrophages and RAW 264.7 cells. The toxicity of these organic extracts mimics the cytotoxicity of the intact particles and could be suppressed by the synthetic sulfhydryl compounds, N-acetylcysteine and bucillamine. Because DEP-induced apoptosis follows cytochrome c release, we studied the effect of DEP chemicals on mitochondrially regulated death mechanisms. Crude DEP extracts induced ROS production and perturbed mitochondrial function before and at the onset of apoptosis. This mitochondrial perturbation follows an orderly sequence of events, which commence with a change in mitochondrial membrane potential, followed by cytochrome c release, development of membrane asymmetry (annexin V staining), and propidium iodide uptake. Structural damage to the mitochondrial inner membrane, evidenced by a decrease in cardiolipin mass, leads to O⨪2 generation and uncoupling of oxidative phosphorylation (decreased intracellular ATP levels). N-Acetylcysteine reversed these mitochondrial effects and ROS production. Overexpression of the mitochondrial apoptosis regulator, Bcl-2, delayed but did not suppress apoptosis. Taken together, these results suggest that DEP chemicals induce apoptosis in macrophages via a toxic effect on mitochondria.
Activation of Human Leukocytes Reduces Surface P-Selectin Glycoprotein Ligand-1 (PSGL-1, CD162) and Adhesion to P-Selectin In Vitro
Authors: Davenpeck Kelly L. , Brummet Mary E. , Hudson Sherry A. , Mayer Ruth J. , Bochner Bruce S. 
Published: April 2014

AbstractP-selectin glycoprotein ligand-1 (PSGL-1), the primary ligand for P-selectin, is constitutively expressed on the surface of circulating leukocytes. The objective of this study was to examine the effect of leukocyte activation on PSGL-1 expression and PSGL-1-mediated leukocyte adhesion to P-selectin. PSGL-1 expression was examined via indirect immunofluorescence and flow cytometry before and after leukocyte stimulation with platelet activating factor (PAF) and PMA. Human neutrophils, monocytes, and eosinophils were all demonstrated to have significant surface expression of PSGL-1 at baseline, which decreased within minutes of exposure to PAF or PMA. PSGL-1 was detected in the supernatants of PAF-activated neutrophils by immunoprecipitation. Along with the expression data, this suggests removal of PSGL-1 from the cell surface. Soluble PSGL-1 was also detected in human bronchoalveolar lavage fluids. Down-regulation of PSGL-1 was inhibited by EDTA. However, inhibitors of L-selectin shedding and other sheddase inhibitors did not affect PSGL-1 release, suggesting that PSGL-1 may be shed by an as yet unidentified sheddase or removed by some other mechanism. Functionally, PSGL-1 down-regulation was associated with decreased neutrophil adhesion to immobilized P-selectin under both static and flow conditions, with the most profound effects seen under flow conditions. Together, these data indicate that PSGL-1 can be removed from the surface of activated leukocytes, and that this decrease in PSGL-1 expression has profound effects on leukocyte binding to P-selectin, especially under conditions of flow.
Secretory Phospholipase A2 Receptor-Mediated Activation of Cytosolic Phospholipase A2 in Murine Bone Marrow-Derived Mast Cells
Authors: Fonteh Alfred N. , Atsumi Gen-ichi , LaPorte Tiffany , Chilton Floyd H. 
Published: April 2014

AbstractThe current study examined the signal transduction steps involved in the selective release of arachidonic acid (AA) induced by the addition of secretory phospholipase A2 (sPLA2) isotypes to bone marrow-derived mast cells (BMMC). Overexpression of sPLA2 receptors caused a marked increase in AA and PGD2 release after stimulation of BMMC, implicating sPLA2 receptors in this process. The hypothesis that the release of AA by sPLA2 involved activation of cytosolic PLA2 (cPLA2) was next tested. Addition of group IB PLA2 to BMMC caused a transient increase in cPLA2 activity and translocation of this activity to membrane fractions. Western analyses revealed that these changes in cPLA2 were accompanied by a time-dependent gel shift of cPLA2 induced by phosphorylation of cPLA2 at various sites. A noncatalytic ligand of the sPLA2 receptor, p-amino-phenyl-α-d-mannopyranoside BSA, also induced an increase in cPLA2 activity in BMMC. sPLA2 receptor ligands induced the phosphorylation of p44/p42 mitogen-activated protein kinase. Additionally, an inhibitor of p44/p42 mitogen-activated protein kinase (PD98059) significantly inhibited sPLA2-induced cPLA2 activation and AA release. sPLA2 receptor ligands also increased Ras activation while an inhibitor of tyrosine phosphorylation (herbimycin) inhibited the increase in cPLA2 activation and AA release. Addition of partially purified sPLA2 from BMMC enhanced cPLA2 activity and AA release. Similarly, overexpression of mouse groups IIA or V PLA2 in BMMC induced an increase in AA release. These data suggest that sPLA2 mediate the selective release of AA by binding to cell surface receptors and then inducing signal transduction events that lead to cPLA2 activation.
Proinflammatory Effects of IL-10 During Human Endotoxemia
Authors: Lauw Fanny N. , Pajkrt Dasja , Hack C. Erik , Kurimoto Masashi , van Deventer Sander J. H. , van der Poll Tom 
Published: April 2014

AbstractIL-10 is considered a potent antiinflammatory cytokine that strongly inhibits the production of proinflammatory cytokines. Recent studies have suggested that IL-10 also has immunostimulatory properties on CD4+, CD8+ T cells, and/or NK cells, resulting in increased IFN-γ production. To determine the effect of IL-10 on IFN-γ production and related inflammatory responses in humans, 16 healthy subjects received a bolus i.v. injection of LPS (4 ng/kg) in combination with either placebo or recombinant human IL-10 (25 μg/kg), administered just before or 1 h after LPS. IL-10 treatment, particularly when administered after LPS, enhanced LPS-induced IFN-γ release, as well as the release of the IFN-γ-dependent chemokines IFN-γ-inducible protein-10 and monokine induced by IFN-γ, while inhibiting or not influencing the production of IFN-γ-inducing cytokines. In addition, IL-10 treatment enhanced activation of CTLs and NK cells after LPS injection, as reflected by increased levels of soluble granzymes. These data indicate that high-dose IL-10 treatment in patients with inflammatory disorders can be associated with undesired proinflammatory effects.
Differential Requirement for Classic and Novel PKC Isoforms in Respiratory Burst and Phagocytosis in RAW 264.7 Cells
Authors: Larsen Elaine C. , DiGennaro Jeannine A. , Saito Naoaki , Mehta Sapna , Loegering Daniel J. , Mazurkiewicz Joseph E. , Lennartz Michelle R. 
Published: April 2014

AbstractThe binding of Ab (IgG)-opsonized particles by FcγRs on macrophages results in phagocytosis of the particles and generation of a respiratory burst. Both IgG-stimulated phagocytosis and respiratory burst involve activation of protein kinase C (PKC). However, the specific PKC isoforms required for these responses have yet to be identified. We have studied the involvement of PKC isoforms in IgG-mediated phagocytosis and respiratory burst in the mouse macrophage-like cell line, RAW 264.7. Like primary monocyte/macrophages, their IgG-mediated phagocytosis was calcium independent and diacylglycerol sensitive, consistent with novel PKC activation. Respiratory burst in these cells was Ca2+ dependent and inhibited by staurosporine and calphostin C as well as by the classic PKC-selective inhibitors Gö 6976 and CGP 41251, suggesting that classic PKC is required. In contrast, phagocytosis was blocked by general PKC inhibitors but not by the classic PKC-specific drugs. RAW 264.7 cells expressed PKCs α, βI, δ, ε, and ζ. Subcellular fractionation demonstrated that PKCs α, δ, and ε translocate to membranes during phagocytosis. In Ca2+-depleted cells, only novel PKCs δ and ε increased in membranes, and the time course of their translocation was consistent with phagosome formation. Confocal microscopy of cells transfected with green fluorescent protein-conjugated PKC α or ε confirmed that these isoforms translocated to the forming phagosome in Ca-replete cells, but only PKC ε colocalized with phagosomes in Ca2+-depleted cells. Taken together, these results suggest that the classic PKC α mediates IgG-stimulated respiratory burst in macrophages, whereas the novel PKCs δ and/or ε are necessary for phagocytosis.
Cellular and Molecular Mechanism for Kilham Rat Virus-Induced Autoimmune Diabetes in DR-BB Rats
Authors: Chung Young-Hwa , Jun Hee Sook , Son Mike , Bao Min , Bae Hak Yeon , Kang Yup , Yoon Ji-Won 
Published: April 2014

AbstractKilham rat virus (KRV) causes autoimmune diabetes in diabetes-resistant BioBreeding (DR-BB) rats; however, the mechanism by which KRV induces autoimmune diabetes without the direct infection of β cells is not well understood. We first asked whether molecular mimicry, such as a common epitope between a KRV-specific peptide and a β cell autoantigen, is involved in the initiation of KRV-induced autoimmune diabetes in DR-BB rats. We found that KRV peptide-specific T cells generated in DR-BB rats infected with recombinant vaccinia virus expressing KRV-specific structural and nonstructural proteins could not induce diabetes, indicating that molecular mimicry is not the mechanism by which KRV induces autoimmune diabetes. Alternatively, we asked whether KRV infection of DR-BB rats could disrupt the finely tuned immune balance and activate autoreactive T cells that are cytotoxic to β cells, resulting in T cell-mediated autoimmune diabetes. We found that both Th1-like CD45RC+CD4+ and cytotoxic CD8+ T cells were up-regulated, whereas Th2-like CD45RC−CD4+ T cells were down-regulated, and that isolated and activated CD45RC+CD4+ and CD8+ T cells from KRV-infected DR-BB rats induced autoimmune diabetes in young diabetes-prone BioBreeding (DP-BB) rats. We conclude that KRV-induced autoimmune diabetes in DR-BB rats is not due to molecular mimicry, but is due to a breakdown of the finely tuned immune balance of Th1-like CD45RC+CD4+ and Th2-like CD45RC−CD4+ T cells, resulting in the selective activation of β cell-cytotoxic effector T cells.
IL-1-Independent Role of IL-17 in Synovial Inflammation and Joint Destruction During Collagen-Induced Arthritis
Authors: Lubberts Erik , Joosten Leo A. B. , Oppers Birgitte , van den Bersselaar Liduine , Coenen-de Roo Christina J. J. , Kolls Jay K. , Schwarzenberger Paul , van de Loo Fons A. J. , van den Berg Wim B. 
Published: April 2014

AbstractT cell IL-17 displays proinflammatory properties and is expressed in the synovium of patients with rheumatoid arthritis. Its contribution to the arthritic process has not been identified. Here, we show that blocking of endogenous IL-17 in the autoimmune collagen-induced arthritis model results in suppression of arthritis. Also, joint damage was significantly reduced. In contrast, overexpression of IL-17 enhanced collagen arthritis. Moreover, adenoviral IL-17 injected in the knee joint of type II collagen-immunized mice accelerated the onset and aggravated the synovial inflammation at the site. Radiographic and histologic analysis showed markedly increased joint destruction. Elevated levels of IL-1β protein were found in synovial tissue. Intriguingly, blocking of IL-1αβ with neutralizing Abs had no effect on the IL-17-induced inflammation and joint damage in the knee joint, implying an IL-1 independent pathway. This direct potency of IL-17 was underscored in the unabated IL-17-induced exaggeration of bacterial cell wall-induced arthritis in IL-1β−/− mice. In conclusion, this data shows that IL-17 contributes to joint destruction and identifies an IL-1-independent role of IL-17. These findings suggest IL-17 to be a novel target for the treatment of destructive arthritis and may have implications for tissue destruction in other autoimmune diseases.
Functional Expression of IL-12 Receptor by Human Eosinophils: IL-12 Promotes Eosinophil Apoptosis
Authors: Nutku Esra , Zhuang Qianli , Soussi-Gounni Abdelillah , Aris Fadi , Mazer Bruce D. , Hamid Qutayba 
Published: April 2014

AbstractIn murine models of allergic inflammation, IL-12 has been shown to decrease tissue eosinophilia, but the underlying mechanisms are not known. We evaluated the expression of IL-12R and the effect of IL-12 on eosinophil survival. In situ hybridization demonstrated the presence of mRNA and immunoreactivity for IL-12Rβ1 and -β2 subunits in human peripheral blood eosinophils. Surface expression of IL-12Rβ1 and -β2 subunits on freshly isolated human eosinophils was optimally expressed after incubation with PMA. To determine the functional significance of IL-12R studies, we studied cell viability and apoptosis. Morphological analysis and propidium iodide staining for cell cycle demonstrated that recombinant human IL-12 increased in vitro human eosinophil apoptosis in a dose-dependent manner. Addition of IL-5 together with IL-12 abrogated eosinophil apoptosis, suggesting that IL-12 and IL-5 have antagonistic effects. Our findings provide evidence for a novel role for IL-12 in regulating eosinophil function by increasing eosinophil apoptosis.
Tissue-Type Plasminogen Activator Deficiency Exacerbates Arthritis
Authors: Yang Yuan H. , Carmeliet Peter , Hamilton John A. 
Published: April 2014

Abstract
Fibrin deposition, cell migration, and tissue remodeling are key components in the lesions of inflammatory joint diseases, such as rheumatoid arthritis. The plasminogen activators (PAs), namely, tissue-type PA (t-PA) and urokinase PA, are implicated in these aspects of an inflammatory response, although their precise roles are yet to be defined. We therefore used gene-deficient mice to explore their role in a two-stage arthritis model involving intraarticular methylated BSA injection, followed by systemic IL-1 treatment. We report in this study that both t-PA and urokinase PA are protective for the mild arthritis induced by intraarticular methylated BSA injection alone, since absence of either of them exacerbates the response; following s.c. IL-1 injection, t-PA−/− mice had particularly severe disease. Fibrin deposition appeared to parallel disease severity under the various conditions, suggesting that PA-mediated fibrinolysis may be normally playing a protective role in inflammatory joint disease.