bluuebunny/crossref_metadata_2025_split huggingface dataset:
15-Deoxy-Δ12,1412,14-PGJ2 Induces IL-8 Production in Human T Cells by a Mitogen-Activated Protein Kinase Pathway
Authors: Harris Sarah G. , Smith Roger S. , Phipps Richard P. 
Published: April 2014

AbstractMast cells, platelets, and some macrophages are abundant sources of PGD2 and its active metabolite 15-deoxy-Δ12,14-PGJ2 (15-d-PGJ2). The lipid mediator 15-d-PGJ2 regulates numerous processes, including adipogenesis, apoptosis, and inflammation. The 15-d-PGJ2 has been shown to both inhibit as well as induce the production of inflammatory mediators such as TNF-α, IL-1β, and cyclooxygenase, mostly occurring via a nuclear receptor called peroxisome proliferator-activated receptor-γ (PPAR-γ). Data concerning the effects of 15-d-PGJ2 on human T cells and immune regulation are sparse. IL-8, a cytokine with both chemotactic and angiogenic effects, is produced by T lymphocytes following activation. Whether 15-d-PGJ2 can regulate the production of IL-8 in T cells in unknown. Interestingly, 15-d-PGJ2 treatment of unstimulated T cells induces cell death. In contrast, in activated human T lymphocytes, 15-d-PGJ2 does not kill them, but induces the synthesis of IL-8. In this study, we report that 15-d-PGJ2 induced a significant increase in both IL-8 mRNA and protein from activated human T lymphocytes. The induction of IL-8 by 15-d-PGJ2 did not occur through the nuclear receptor PPAR-γ, as synthetic PPAR-γ agonists did not mimic the IL-8-inducing effects of 15-d-PGJ2. The mechanism of IL-8 induction was through a mitogen-activated protein kinase and NF-κB pathway, as inhibitors of both systems abrogated IL-8 protein induction. Therefore, 15-d-PGJ2 can act as a potent proinflammatory mediator in activated T cells by inducing the production of IL-8. These findings show the complexity with which 15-d-PGJ2 regulates T cells by possessing both pro- and anti-inflammatory properties depending on the activation state of the cell. The implications of this research also include that caution is warranted in assigning a solely anti-inflammatory role for 15-d-PGJ2.
Hypertonic Preconditioning Inhibits Macrophage Responsiveness to Endotoxin
Authors: Cuschieri Joseph , Gourlay David , Garcia Iris , Jelacic Sandra , Maier Ronald V. 
Published: April 2014

AbstractHypertonic saline has been shown to modulate cell shape and the response of components of the innate immune response. However, the effect of hypertonic saline on the macrophage remains unknown. We hypothesized that hypertonic preconditioning would impair subsequent inflammatory mediator signaling through a reduction in stress fiber polymerization and mitogen-activated protein kinase activity after LPS stimulation. Rabbit alveolar macrophages were stimulated with 100 ng/ml of LPS. Selected cells were preconditioned with 40–100 mM of NaCl, mannitol, or urea for 4 h and returned to isotonic medium before LPS stimulation. Cellular protein was harvested and subjected to Western blot analysis for the dually phosphorylated active forms of p38 and extracellular signal-related kinase (ERK) 1/2. TNF production was determined by an L929 bioassay, and stress fiber polymerization was evaluated by confocal microscopy. Preconditioning of macrophages with NaCl or mannitol resulted in dose-dependent reduction in ERK 1/2 phosphorylation with no effect on p38 phosphorylation. Urea preconditioning had no effect on either mitogen-activated protein kinase. A dose-dependent attenuation of TNF production was seen with NaCl and mannitol preconditioning (p &lt; 0.05), but not with urea. NaCl and mannitol preconditioning resulted in failure of LPS-induced stress fiber polymerization, whereas urea did not. Extracellular hypertonic conditions (i.e., NaCl and mannitol) have an immunomodulatory effect on macrophages, demonstrated through failure of optimal stress fiber polymerization, ERK 1/2 activity, and TNF production. Intracellular hypertonic conditions (i.e., urea) had no significant effect. Hypertonic saline or mannitol resuscitation, therefore, may help protect against multiple-organ dysfunction syndrome as a result of this reduced proinflammatory responsiveness.
Regulation of Prostaglandin Endoperoxide Synthase-2 and IL-6 Expression in Mouse Bone Marrow-Derived Mast Cells by Exogenous But Not Endogenous Prostanoids
Authors: Diaz Bruno L. , Fujishima Hiroshi , Kanaoka Yoshihide , Urade Yoshihiro , Arm Jonathan P. 
Published: April 2014

AbstractMouse bone marrow-derived mast cells (BMMC), stimulated with stem cell factor, IL-1β, and IL-10, secrete IL-6 and demonstrate a delayed phase of PGD2 generation that is dependent upon the induced expression of PG endoperoxide synthase (PGHS)-2. We have examined the potential for exogenous prostanoids, acting in a paracrine fashion, and endogenous prostanoids, acting in an autocrine fashion, to regulate PGHS-2 induction and IL-6 secretion in mouse BMMC. Exogenous PGE2, which acts through G protein-coupled receptors, and 15-deoxy-Δ12,14-PGJ2, which is a ligand for peroxisome proliferator-activated receptor (PPAR)γ, elicited a 2- to 3-fold amplification of PGHS-2 induction, delayed-phase PGD2 generation, and IL-6 secretion in response to stem cell factor, IL-1β, and IL-10. The effect of PGE2 was reproduced by the E prostanoid (EP)1 receptor agonist 17-trinor-PGE2, and the EP1/EP3 agonist, sulprostone, but not the EP2 receptor agonist, butaprost. Although BMMC express PPARγ, the effects of 15-deoxy-Δ12,14-PGJ2 were not reproduced by the PPARγ agonists, troglitazone and ciglitazone. PGHS-2 induction, but not IL-6 secretion, was impaired in cPLA2-deficient BMMC. However, there was no impairment of PGHS-2 induction in BMMC deficient in hematopoietic PGD synthase or PGHS-1 in the presence or absence of the PGHS-2 inhibitor, NS-398. Thus, although exogenous prostanoids may contribute to amplification of the inflammatory response by augmenting PGD2 generation and IL-6 secretion from mast cells, endogenous prostanoids do not play a role.
Expression and Regulation of Aggrecanase in Arthritis: The Role of TGF-β
Authors: Yamanishi Yuji , Boyle David L. , Clark Melody , Maki Rich A. , Tortorella Micky D. , Arner Elizabeth C. , Firestein Gary S. 
Published: April 2014

Abstract
Aggrecanases are key matrix-degrading enzymes that act by cleaving aggrecan at the Glu373-Ala374 site. While these fragments have been detected in osteoarthritis (OA) and rheumatoid arthritis (RA) cartilage and synovial fluid, no information is available on the regulation or expression of the two key aggrecanases (aggrecanase-1 and aggrecanase-2) in synovial tissue (ST) or fibroblast-like synoviocytes (FLS). The aggrecanase-1 gene was constitutively expressed by both RA and OA FLS. Real-time PCR demonstrated that TGF-β significantly increased aggrecanase-1 gene expression in FLS. Aggrecanase-1 induction peaked after 24 h of TGF-β stimulation. The expression of aggrecanase-1 mRNA was significantly greater in RA ST than in OA or nonarthritis ST. Aggrecanase-2 mRNA and protein were constitutively produced by nonarthritis, OA, and RA FLS but were not increased by IL-1, TNF-α, or TGF-β. Furthermore, OA, RA, and nonarthritis ST contained similar amounts of immunoreactive aggrecanase-2. The major form of the aggrecanase-2 enzyme was 70 kDa in nonarthritis ST, whereas a processed 53-kDa form was abundant in RA ST. Therefore, aggrecanase-1 and -2 are differentially regulated in FLS. Both are constitutively expressed, but aggrecanase-1 is induced by cytokines, especially TGF-β. In contrast, aggrecanase-2 protein may be regulated by a post-translational mechanism in OA and RA ST. Synovial and FLS production of aggrecanase can contribute to cartilage degradation in RA and OA.
Mechanisms Involved in Spontaneous and Viscum album Agglutinin-I-Induced Human Neutrophil Apoptosis: Viscum album Agglutinin-I Accelerates the Loss of Antiapoptotic Mcl-1 Expression and the Degradation of Cytoskeletal Paxillin and Vimentin Proteins Via Caspases
Authors: Lavastre Valérie , Pelletier Martin , Saller Reinhard , Hostanska Katarina , Girard Denis 
Published: April 2014

Abstract
Viscum album agglutinin-I (VAA-I) is a plant lectin that possesses interesting potential therapeutic properties and immunomodulatory activities. We have recently found that VAA-I is a potent inducer of human neutrophil apoptosis, but the mechanism(s) involved require further elucidation. In this study, we found that VAA-I alters mitochondrial transmembrane potential and increases intracellular levels of reactive oxygen species (ROS). Despite these observations, treatment with the mitochondrial stabilizer, bongkrekic acid, or with catalase, known to degrade H2O2, fails to reverse VAA-I-induced apoptosis. Moreover, VAA-I was found to induce apoptosis in PLB-985 cells deficient in gp91phox, indicating that the lectin acts via an ROS-independent mechanism. Pretreatment of neutrophils with brefeldin A, an inhibitor of vesicular transport, was found to reverse VAA-I-induced apoptosis. Protein expression of Mcl-1 was decreased by VAA-I. The role of caspases in the degradation of cytoskeletal proteins during both spontaneous and VAA-I-induced neutrophil apoptosis was also investigated. Paxillin and vimentin were markedly degraded by VAA-I when compared with neutrophils that undergo spontaneous apoptosis, but not vinculin or α- and β-tubulin. Caspases were involved in cytoskeletal protein degradation because preincubation with the pan-caspase inhibitor N-benzyloxycarbonyl-V-A-D-O-methylfluoromethyl ketone was found to reverse protein cleavage. We conclude that VAA-I needs to be internalized to mediate apoptosis and that its activity is not dependent on a cell surface receptor-mediated pathway. Also, we conclude that VAA-I induces apoptosis by ROS-independent and Mcl-1-dependent mechanisms and that caspases are involved in cytoskeletal protein degradation in both spontaneous and VAA-I-induced neutrophil apoptosis.
Chlamydial Heat Shock Protein 60 Activates Macrophages and Endothelial Cells Through Toll-Like Receptor 4 and MD2 in a MyD88-Dependent Pathway
Authors: Bulut Yonca , Faure Emmanuelle , Thomas Lisa , Karahashi Hisae , Michelsen Kathrin S. , Equils Ozlem , Morrison Sandra G. , Morrison Richard P. , Arditi Moshe 
Published: April 2014

Abstract
Active inflammation and NF-κB activation contribute fundamentally to atherogenesis and plaque disruption. Accumulating evidence has implicated specific infectious agents including Chlamydia pneumoniae in the progression of atherogenesis. Chlamydial heat shock protein 60 (cHSP60) has been implicated in the induction of deleterious immune responses in human chlamydial infections and has been found to colocalize with infiltrating macrophages in atheroma lesions. cHSP60 might stimulate, enhance, and maintain innate immune and inflammatory responses and contribute to atherogenesis. In this study, we investigated the signaling mechanism of cHSP60. Recombinant cHSP60 rapidly activated NF-κB in human microvascular endothelial cells (EC) and in mouse macrophages, and induced human IL-8 promoter activity in EC. The inflammatory effect of cHSP60 was heat labile, thus excluding a role of contaminating LPS, and was blocked by specific anti-chlamydial HSP60 mAb. In human vascular EC which express Toll-like receptor 4 (TLR4) mRNA and protein, nonsignaling TLR4 constructs that act as dominant negative blocked cHSP60-mediated NF-κB activation. Furthermore, an anti-TLR4 Ab abolished cHSP60-induced cellular activation, whereas a control Ab had no effect. In 293 cells, cHSP60-mediated NF-κB activation required both TLR4 and MD2. A dominant-negative MyD88 construct also inhibited cHSP60-induced NF-κB activation. Collectively, our results indicate that cHSP60 is a potent inducer of vascular EC and macrophage inflammatory responses, which are very relevant to atherogenesis. The inflammatory effects are mediated through the innate immune receptor complex TLR4-MD2 and proceeds via the MyD88-dependent signaling pathway. These findings may help elucidate the mechanisms by which chronic asymptomatic chlamydial infection contribute to atherogenesis.
In Vivo Imaging of NF-κB Activity
Authors: Carlsen Harald , Moskaug Jan Ø. , Fromm Sigurd H. , Blomhoff Rune 
Published: April 2014

Abstract
A wide range of human disorders involves inappropriate regulation of NF-κB, including cancers and numerous inflammatory conditions. Toward our goal to define mechanisms through which NF-κB leads to the development of disease, we have developed transgenic mice that express luciferase under the control of NF-κB, enabling real-time in vivo imaging of NF-κB activity in intact animals. We show that in the absence of extrinsic stimulation, strong luminescence is evident in lymph nodes in the neck region, thymus, and Peyer’s patches. Treating mice with TNF-α, IL-1α, or LPS increased the luminescence in a tissue-specific manner, with the strongest activity observed in skin, lungs, spleen, Peyer’s patches, and the wall of the small intestine. Liver, kidney, heart, muscle, and adipose tissue displayed less intense activities. Also, exposure of skin to a low dose of UV radiation increased luminescence in the exposed areas. Furthermore, induction of chronic inflammation resembling rheumatoid arthritis produced strong NF-κB activity in the affected joints, as revealed by in vivo imaging. Thus, we have developed a versatile model for monitoring NF-κB activation in vivo.
Cutting Edge: Organogenesis of Nasal-Associated Lymphoid Tissue (NALT) Occurs Independently of Lymphotoxin-α (LTα) and Retinoic Acid Receptor-Related Orphan Receptor-γ, but the Organization of NALT Is LTα Dependent
Authors: Harmsen Allen , Kusser Kimberley , Hartson Louise , Tighe Michael , Sunshine Mary Jean , Sedgwick Jonathon D. , Choi Yongwon , Littman Dan R. , Randall Troy D. 
Published: April 2014

Abstract
Peyer’s patch and nasal-associated lymphoid tissue (NALT) are mucosal lymphoid tissues that appear similar in structure and function. Surprisingly, we found that NALT, unlike Peyer’s patch, was formed independently of lymphotoxin (LT)α. Furthermore, using mice deficient in the retinoic acid receptor-related orphan receptor-γ, we found that NALT was formed in the absence of CD4+CD3− cells, which are thought to be the embryonic source of LTα. However, we also found that NALT of LTα−/− animals was disorganized and lymphopenic, suggesting that the organization and recruitment of lymphocytes within NALT remained dependent on LTα. Finally, we demonstrated that both the structure and function of NALT were restored in LTα−/− animals upon reconstitution with normal bone marrow. These results demonstrate that the organogenesis of NALT occurs through unique mechanisms.
Cutting Edge: CD8 T Cell-Mediated Demyelination Is IFN-γ Dependent in Mice Infected with a Neurotropic Coronavirus
Authors: Pewe Lecia , Perlman Stanley 
Published: April 2014

AbstractMice infected with the murine coronavirus, mouse hepatitis virus, strain JHM (MHV) develop an immune-mediated demyelinating encephalomyelitis. We showed previously that adoptive transfer of MHV-immune splenocytes depleted of either CD4 or CD8 T cells to infected RAG1−/− recipients (mice deficient in recombination activation gene 1) resulted in demyelination. Herein we show that transfer of CD8 T cell-enriched splenocytes from MHV-immune IFN-γ−/− donors resulted in a substantial decrease in demyelination (4.8% of the white matter of the spinal cord compared with 26.3% in those receiving cells from C57BL/6 donors). Similar numbers of lymphocytes were present in the CNS of recipients of either C57BL/6 or IFN-γ−/− CD8 T cells, suggesting that IFN-γ was not crucial for lymphocyte entry into the CNS. Rather, IFN-γ was critical for optimal activation or migration of macrophages or microglia into the white matter in the context of CD8 T cell-mediated demyelination.
Identification and Characterization of Myeloid Translocation Gene 16b as a Novel A Kinase Anchoring Protein in T Lymphocytes
Authors: Schillace Robynn V. , Andrews Sarah F. , Liberty Greg A. , Davey Michael P. , Carr Daniel W. 
Published: April 2014

Abstract
Increased levels of intracellular cAMP inhibit T cell activation and proliferation. One mechanism is via activation of the cAMP-dependent protein kinase (PKA). PKA is a broad specificity serine/threonine kinase whose fidelity in signaling is maintained through interactions with A kinase anchoring proteins (AKAPs). AKAPs are adaptor/scaffolding molecules that convey spatial and temporal localization to PKA and other signaling molecules. To determine whether T lymphocytes contain AKAPs that could influence the inflammatory response, PBMCs and Jurkat cells were analyzed for the presence of AKAPs. RII overlay and cAMP pull down assays detected at least six AKAPs. Western blot analyses identified four known AKAPs: AKAP79, AKAP95, AKAP149, and WAVE. Screening of a PMA-stimulated Jurkat cell library identified two additional known AKAPs, AKAP220 and AKAP-KL, and one novel AKAP, myeloid translocation gene 16 (MTG16b). Mutational analysis identified the RII binding domain in MTG16b as residues 399–420, and coimmunoprecipitation assays provide strong evidence that MTG16b is an AKAP in vivo. Immunofluorescence and confocal microscopy illustrate distinct subcellular locations of AKAP79, AKAP95, and AKAP149 and suggest colocalization of MTG and RII in the Golgi. These experiments represent the first report of AKAPs in T cells and suggest that MTG16b is a novel AKAP that targets PKA to the Golgi of T lymphocytes.
Prolonged Blockade of CD40-CD40 Ligand Interactions by Gene Transfer of CD40Ig Results in Long-Term Heart Allograft Survival and Donor-Specific Hyporesponsiveness, But Does Not Prevent Chronic Rejection
Authors: Guillot Cécile , Guillonneau Carole , Mathieu Patrick , Gerdes Christian A. , Ménoret Séverine , Braudeau Cécile , Tesson Laurent , Renaudin Karine , Castro Maria G. , Löwenstein Pedro R. , Anegon Ignacio 
Published: April 2014

AbstractPrevious work on blockade of CD40-CD40 ligand interaction in mice and primates with anti-CD40 ligand mAbs has resulted in a moderate prolongation of allograft survival without the development of true allograft tolerance. In this study, we show in rats that adenovirus-mediated gene transfer of CD40Ig sequences into the graft resulted in prolonged (&gt;200 days) expression of CD40Ig and in long-term (&gt;300 days) survival. Recipients expressing CD40Ig displayed strongly (&gt;90%) inhibited mixed leukocyte reactions and alloantibody production at early (days 5 and 17) and late time points (&gt;100 day) after transplantation, but showed limited inhibition of leukocyte infiltration and cytokine production as evaluated by immunohistology at early time points (day 5). Recipients of long-surviving hearts showed donor-specific hyporesponsiveness since acceptance of second cardiac allografts was donor specific. Nevertheless, long-term allografts (&gt;100 days) displayed signs of chronic rejection vasculopathy. Occluded vessels showed leukocyte infiltration, mainly composed of CD4+ and CD8+ cells, macrophages, and mast cells. These recipients also showed antidonor CTL activity. Recipients expressing CD40Ig did not show nonspecific immunosuppression, as they were able to mount anticognate immune responses that were partially inhibited at early time points and were normal thereafter. We conclude that gene transfer-mediated expression of CD40Ig resulted in a highly efficient inhibition of acute heart allograft rejection in rats. This treatment induced donor-specific inhibition of certain alloreactive mechanisms in the short-, but not the long-term, which resulted in long-term survival of allografts concomitant with the development of chronic rejection.
CpG Oligodeoxynucleotides as Vaccine Adjuvants in Primates
Authors: Verthelyi Daniela , Kenney Richard T. , Seder Robert A. , Gam Albert A. , Friedag Brenda , Klinman Dennis M. 
Published: April 2014

AbstractSynthetic oligodeoxynucleotides (ODN) containing unmethylated CpG motifs act as immune adjuvants in mice, boosting the humoral and cellular response to coadministered Ags. CpG ODN that stimulate human PBMC are only weakly active in mice. Thus, alternative animal models are needed to monitor the activity and safety of “human” CpG ODN in vivo. This work demonstrates that rhesus macaques recognize and respond to the same CpG motifs that trigger human immune cells. Coadministering CpG ODN with heat-killed Leishmania vaccine provided significantly increased protection of macaques against cutaneous Leishmania infection. These findings indicate that rhesus macaques provide a useful model for studying the in vivo activity of human CpG motifs, and that ODN expressing these motifs act as strong immune adjuvants.
A Clonal Culture System Demonstrates That IL-4 Induces a Subpopulation of Noncytolytic T Cells with Low CD8, Perforin, and Granzyme Expression
Authors: Kienzle Norbert , Buttigieg Kathy , Groves Penny , Kawula Tom , Kelso Anne 
Published: April 2014

AbstractImmune deviation of cytolytic T cell function, induced by type 2 cytokines like IL-4, is an attractive concept to explain failure of the immune system in some diseases. However, this concept is challenged by previous conflicting results on whether type 2 cytokine-producing CD8+ T cells are cytolytic. Therefore, we have analyzed the relationship between cytolytic activity and cytokine production among large numbers of primary CD8+ T cell clones. Single murine CD8+ T cells of naive phenotype were activated at high efficiency with immobilized Abs to CD3, CD8, and CD11a in the presence of IL-2 (neutral conditions) or IL-2, IL-4, and anti-IFN-γ Ab (type 2-polarizing conditions) for 8–9 days. Under neutral conditions, most clones produced IFN-γ without IL-4 and were cytolytic. Under type 2-polarizing conditions, most clones produced IFN-γ and IL-4 but displayed variable cytolytic activity and CD8 expression. Separation on the basis of surface CD8 levels revealed that, compared with CD8high cells from the same cultures, CD8low cells were poorly cytolytic and expressed low levels of perforin mRNA and protein and granzyme A, B, and C mRNA. A similar, smaller population of noncytolytic CD8low cells was identified among CD8+ T cells activated in mixed lymphocyte reaction with IL-4. Variable efficiency of generation of the noncytolytic cells may account for the differing results of earlier studies. We conclude that IL-4 promotes the development of a noncytolytic CD8low T cell phenotype that might be important in tumor- or pathogen-induced immune deviation.
Continued Antigen Stimulation Is Not Required During CD4+ T Cell Clonal Expansion
Authors: Lee William T. , Pasos Gregory , Cecchini Luiza , Mittler James N. 
Published: April 2014

AbstractPeptide Ag initiates CD4+ T cell proliferation, but the subsequent effects of Ag on clonal expansion are not fully known. In this study, murine CD4+ T cells were labeled with the fluorescent dye CFSE and were stimulated with specific peptide Ag. Activation occurred, as CFSE-associated fluorescence was reduced 2-fold with each cell division. Separation of proliferating cells based upon CFSE fluorescence intensity showed that daughter cells from each cell division proliferate even after removal of Ag. A limited exposure (∼2 h) to peptide programmed the cells to proliferate independently of Ag. Although not required for cell division, Ag increased the survival of proliferating cells and increased the total number of cell divisions in the expansion process. These results indicate that Ag exposure begins a program of cell division that does not require but is modified by further TCR stimulation.