bluuebunny/crossref_metadata_2025_split huggingface dataset:
TLR3- and Th2 Cytokine-Dependent Production of Thymic Stromal Lymphopoietin in Human Airway Epithelial Cells
Authors: Kato Atsushi , Favoreto Silvio , Avila Pedro C. , Schleimer Robert P. 
Published: April 2014

Abstract
Thymic stromal lymphopoietin (TSLP) is elevated in asthma and triggers dendritic cell-mediated activation of Th2 inflammatory responses. Although TSLP has been shown to be produced mainly by airway epithelial cells, the regulation of epithelial TSLP expression has not been extensively studied. We investigated the expression of TSLP in cytokine- or TLR ligand-treated normal human bronchial epithelial cells (NHBE). The mRNA for TSLP was significantly up-regulated by stimulation with IL-4 (5.5-fold) and IL-13 (5.3-fold), weakly up-regulated by TNF-α, TGF-β, and IFN-β, and not affected by IFN-γ in NHBE. TSLP mRNA was only significantly up-regulated by the TLR3 ligand (dsRNA) among the TLR ligands tested (66.8-fold). TSLP was also induced by in vitro infection with rhinovirus. TSLP protein was detected after stimulation with dsRNA (120 ± 23 pg/ml). The combination of TNF-α and IL-4 produced detectable levels of TSLP protein (40 ± 13 pg/ml). In addition, TSLP was synergistically enhanced by a combination of IL-4 and dsRNA (mRNA; 207-fold, protein; 325 ± 75 pg/ml). The induction of TSLP by dsRNA was dependent upon NF-κB and IFN regulatory factor 3 (IRF-3) signaling via TLR3 as indicated by a study with small interfering RNA. The potent topical glucocorticoid fluticasone propionate significantly suppressed dsRNA-dependent TSLP production in NHBE. These results suggest that the expression of TSLP is induced in airway epithelial cells by stimulation with the TLR3 ligand and Th2 cytokines and that this response is suppressed by glucocorticoid treatment. This implies that respiratory viral infection and the recruitment of Th2 cytokine producing cells may amplify Th2 inflammation via the induction of TSLP in the asthmatic airway.
TCR/CD28-Stimulated Actin Dynamics Are Required for NFAT1-Mediated Transcription of c-rel Leading to CD28 Response Element Activation
Authors: Nolz Jeffrey C. , Fernandez-Zapico Martin E. , Billadeau Daniel D. 
Published: April 2014

Abstract
TCR/CD28 engagement triggers the initiation of a variety of signal transduction pathways that lead to changes in gene transcription. Although reorganization of the actin cytoskeleton is required for T cell activation, the molecular pathways controlled by the actin cytoskeleton are ill defined. To this end, we analyzed TCR/CD28-stimulated signaling pathways in cytochalasin D-treated T cells to determine the cytoskeletal requirements for T cell activation. Cytochalasin D treatment impaired T cell activation by causing a reduction in TCR/CD28-mediated calcium flux, and blocked activation of two regulatory elements within the IL-2 promoter, NFAT/AP-1 and CD28RE/AP. Treatment had no effect on signaling leading to the activation of either AP-1 or NF-κB. Significantly, we found that NFAT1 is required for optimal c-rel up-regulation in response to TCR/CD28 stimulation. In fact, NFAT1 could be detected bound at the c-rel promoter in response to TCR/CD28 stimulation, and targeting of NFAT1 using RNA interference in human CD4+ T cells abrogated c-rel transcription. Overall, these findings establish that disrupting actin cytoskeletal dynamics impairs TCR/CD28-mediated calcium flux required for NFAT1-mediated c-rel transcription and, thus, activation of the CD28RE/AP.
The Antiviral CD8+ T Cell Response Is Differentially Dependent on CD4+ T Cell Help Over the Course of Persistent Infection
Authors: Kemball Christopher C. , Pack Christopher D. , Guay Heath M. , Li Zhu-Nan , Steinhauer David A. , Szomolanyi-Tsuda Eva , Lukacher Aron E. 
Published: April 2014

Abstract
Although many studies have investigated the requirement for CD4+ T cell help for CD8+ T cell responses to acute viral infections that are fully resolved, less is known about the role of CD4+ T cells in maintaining ongoing CD8+ T cell responses to persistently infecting viruses. Using mouse polyoma virus (PyV), we asked whether CD4+ T cell help is required to maintain antiviral CD8+ T cell and humoral responses during acute and persistent phases of infection. Though fully intact during acute infection, the PyV-specific CD8+ T cell response declined numerically during persistent infection in MHC class II-deficient mice, leaving a small antiviral CD8+ T cell population that was maintained long term. These unhelped PyV-specific CD8+ T cells were functionally unimpaired; they retained the potential for robust expansion and cytokine production in response to Ag rechallenge. In addition, although a strong antiviral IgG response was initially elicited by MHC class II-deficient mice, these Ab titers fell, and long-lived PyV-specific Ab-secreting cells were not detected in the bone marrow. Finally, using a minimally myeloablative mixed bone marrow chimerism approach, we demonstrate that recruitment and/or maintenance of new virus-specific CD8+ T cells during persistent infection is impaired in the absence of MHC class II-restricted T cells. In summary, these studies show that CD4+ T cells differentially affect CD8+ T cell responses over the course of a persistent virus infection.
Blocking of the TLR5 Activation Domain Hampers Protective Potential of Flagellin DNA Vaccine
Authors: Saha Sukumar , Takeshita Fumihiko , Matsuda Tomoko , Jounai Nao , Kobiyama Kouji , Matsumoto Tetsuya , Sasaki Shin , Yoshida Atsushi , Xin Ke-Qin , Klinman Dennis M. , Uematsu Satoshi , Ishii Ken J. , Akira Shizuo , Okuda Kenji 
Published: April 2014

Abstract
Flagellin is a key component of the flagella of many pathogens, including Pseudomonas aeruginosa. Flagellin is an attractive vaccine candidate because it is readily produced and manipulated as a recombinant protein and has intrinsic adjuvant activity mediated through TLR5. Although DNA vaccines encoding native Pseudomonas B-type (FliC) or A-type (FlaA) flagellin are strongly immunogenic, the resultant Ab response interferes with the interaction of homologous flagellin with TLR5. This reduces the ability of the host to clear homologous, but not heterologous, flagellin-expressing P. aeruginosa. To circumvent this problem, a DNA vaccine encoding a mutant FliC R90A flagellin was developed. The mutant Ag encoded by this vaccine was highly immunogenic, but its ability to interact with TLR5 was reduced by &gt;100-fold. Vaccination with this flagellin mutant DNA vaccine induced cross-reactive Abs against both FliC and FlaA, but few Abs capable of interfering with TLR5 activation. The flagellin mutant DNA vaccine provided excellent protection against both FliC- and FlaA-expressing P. aeruginosa. These findings suggest that vaccines against flagellated pathogens should avoid inducing Abs against TLR5 and raise the possibility that flagellated bacteria evade host elimination by facilitating the production of Abs that reduce the host’s ability to mount an innate immune response.
IL-1 Receptor-Mediated Signal Is an Essential Component of MyD88-Dependent Innate Response to Mycobacterium tuberculosis Infection
Authors: Fremond Cecile M. , Togbe Dieudonnée , Doz Emilie , Rose Stephanie , Vasseur Virginie , Maillet Isabelle , Jacobs Muazzam , Ryffel Bernhard , Quesniaux Valerie F. J. 
Published: April 2014

Abstract
MyD88, the common adapter involved in TLR, IL-1, and IL-18 receptor signaling, is essential for the control of acute Mycobacterium tuberculosis (MTB) infection. Although TLR2, TLR4, and TLR9 have been implicated in the response to mycobacteria, gene disruption for these TLRs impairs only the long-term control of MTB infection. Here, we addressed the respective role of IL-1 and IL-18 receptor pathways in the MyD88-dependent control of acute MTB infection. Mice deficient for IL-1R1, IL-18R, or Toll-IL-1R domain-containing adaptor protein (TIRAP) were compared with MyD88-deficient mice in an acute model of aerogenic MTB infection. Although primary MyD88-deficient macrophages and dendritic cells were defective in cytokine production in response to mycobacterial stimulation, IL-1R1-deficient macrophages exhibited only a reduced IL-12p40 secretion with unaffected TNF, IL-6, and NO production and up-regulation of costimulatory molecules CD40 and CD86. Aerogenic MTB infection of IL-1R1-deficient mice was lethal within 4 wk with 2-log higher bacterial load in the lung and necrotic pneumonia but efficient pulmonary CD4 and CD8 T cell responses, as seen in MyD88-deficient mice. Mice deficient for IL-18R or TIRAP controlled acute MTB infection. These data demonstrate that absence of IL-1R signal leads to a dramatic defect of early control of MTB infection similar to that seen in the absence of MyD88, whereas IL-18R and TIRAP are dispensable, and that IL-1, together with IL-1-induced innate response, might account for most of MyD88-dependent host response to control acute MTB infection.
Microglia-Mediated Neurotoxicity Is Inhibited by Morphine through an Opioid Receptor-Independent Reduction of NADPH Oxidase Activity
Authors: Qian Li , Tan Kai Soo , Wei Sung-Jen , Wu Hung-Ming , Xu Zongli , Wilson Belinda , Lu Ru-Bin , Hong Jau-Shyong , Flood Patrick M. 
Published: April 2014

AbstractRecent studies have shown that morphine modulates the function of glia cells through both opioid receptor dependent and independent mechanisms. However, the mechanism by which morphine regulates neuronal disorders through the alteration of microglia activity remains unclear. In this study, using rat primary mesencephalic neuron-glia cultures, we report that both l-morphine and its synthetic stereoenantiomer, d-morphine, an ineffective opioid receptor agonist, significantly reduced LPS- or 1-methyl-4-phenylpyridinium-induced dopaminergic neurotoxicity with similar efficacy, indicating a nonopioid receptor-mediated effect. In addition, using reconstituted neuron and glia cultures, subpicomolar concentrations of morphine were found to be neuroprotective only in the presence of microglia, and significantly inhibited the production of inflammatory mediators from LPS-stimulated microglia cells. Mechanistic studies showed that both l- and d- morphine failed to protect dopaminergic neurons in cultures from NADPH oxidase (PHOX) knockout mice and significantly reduced LPS-induced PHOX cytosolic subunit p47phox translocation to the cell membrane by inhibiting ERK phosphorylation. Taken together, our results demonstrate that morphine, even at subpicomolar concentrations, exerts potent anti-inflammatory and neuroprotective effects either through the inhibition of direct microglial activation by LPS or through the inhibition of reactive microgliosis elicited by 1-methyl-4-phenylpyridinium. Furthermore, our study reveals that inhibition of PHOX is a novel site of action for the mu-opioid receptor-independent effect of morphine.
The Human Endogenous Retrovirus Envelope Glycoprotein, Syncytin-1, Regulates Neuroinflammation and Its Receptor Expression in Multiple Sclerosis: A Role for Endoplasmic Reticulum Chaperones in Astrocytes
Authors: Antony Joseph M. , Ellestad Kristofor K. , Hammond Robert , Imaizumi Kazunori , Mallet Francois , Warren Kenneth G. , Power Christopher 
Published: April 2014

Abstract
Retroviral envelopes are pathogenic glycoproteins which cause neuroinflammation, neurodegeneration, and endoplasmic reticulum stress responses. The human endogenous retrovirus (HERV-W) envelope protein, Syncytin-1, is highly expressed in CNS glia of individuals with multiple sclerosis (MS). In this study, we investigated the mechanisms by which Syncytin-1 mediated neuroimmune activation and oligodendrocytes damage. In brain tissue from individuals with MS, ASCT1, a receptor for Syncytin-1 and a neutral amino acid transporter, was selectively suppressed in astrocytes (p &lt; 0.05). Syncytin-1 induced the expression of the endoplasmic reticulum stress sensor, old astrocyte specifically induced substance (OASIS), in cultured astrocytes, similar to findings in MS brains. Overexpression of OASIS in astrocytes increased inducible NO synthase expression but concurrently down-regulated ASCT1 (p &lt; 0.01). Treatment of astrocytes with a NO donor enhanced expression of early growth response 1, with an ensuing reduction in ASCT1 expression (p &lt; 0.05). Small-interfering RNA molecules targeting Syncytin-1 selectively down-regulated its expression, preventing the suppression of ASCT1 and the release of oligodendrocyte cytotoxins by astrocytes. A Syncytin-1-transgenic mouse expressing Syncytin-1 under the glial fibrillary acidic protein promoter demonstrated neuroinflammation, ASCT1 suppression, and diminished levels of myelin proteins in the corpus callosum, consistent with observations in CNS tissues from MS patients together with neurobehavioral abnormalities compared with wild-type littermates (p &lt; 0.05). Thus, Syncytin-1 initiated an OASIS-mediated suppression of ASCT1 in astrocytes through the induction of inducible NO synthase with ensuing oligodendrocyte injury. These studies provide new insights into the role of HERV-mediated neuroinflammation and its contribution to an autoimmune disease.
A Novel Role for Defensins in Intestinal Homeostasis: Regulation of IL-1β Secretion
Authors: Shi Jishu , Aono Shelly , Lu Wuyuan , Ouellette Andre J. , Hu Xueyou , Ji Yingbiao , Wang Lei , Lenz Stephen , van Ginkel Frederik W. , Liles Mark , Dykstra Christine , Morrison Edward E. , Elson Charles O. 
Published: April 2014

Abstract
Impaired expression of α-defensin antimicrobial peptides and overproduction of the proinflammatory cytokine IL-1β have been associated with inflammatory bowel disease. In this study, we examine the interactions between α-defensins and IL-1β and the role of defensin deficiency in the pathogenesis of inflammatory bowel disease. It was found that matrix metalloproteinase-7-deficient (MMP-7−/−) mice, which produce procryptdins but not mature cryptdins (α-defensins) in the intestine, were more susceptible to dextran sulfate sodium-induced colitis. Furthermore, both baseline and dextran sulfate sodium-induced IL-1β production in the intestine were significantly up-regulated in MMP-7−/− mice compared with that in control C57BL/6 mice. To elucidate the molecular mechanism for the increased IL-1β production in defensin deficiency in vivo, we evaluated the effect of defensins on IL-1β posttranslational processing and release. It was found that α-defensins, including mouse Paneth cell defensins cryptdin-3 and cryptdin-4, human neutrophil defensin HNP-1, and human Paneth cell defensin HD-5, blocked the release of IL-1β from LPS-activated monocytes, whereas TNF-α expression and release were not affected. Unlike α-defensins, human β-defensins and mouse procryptdins do not have any effect on IL-1β processing and release. Thus, α-defensins may play an important role in intestinal homeostasis by controlling the production of IL-1β.
Therapeutic Anti-Inflammatory Effects of Myeloid Cell Adenosine Receptor A2a Stimulation in Lipopolysaccharide-Induced Lung Injury
Authors: Reutershan Jörg , Cagnina Rebecca E. , Chang Daniel , Linden Joel , Ley Klaus 
Published: April 2014

Abstract
To determine the role of the adenosine receptor A2a in a murine model of LPS-induced lung injury, migration of polymorphonuclear leukocytes (PMNs) into the different compartments of the lung was determined by flow cytometry, microvascular permeability was assessed by the extravasation of Evans blue, and the release of chemotactic cytokines into the alveolar airspace was determined by ELISA. Measurements were performed in wild-type and A2a gene-deficient mice (A2a−/−). To differentiate the role of A2a on hemopoietic and nonhemopoietic cells, we created chimeric mice by transfer of bone marrow (BM) between wild-type and A2a−/− mice and used mice that lacked A2a expression selectively on myeloid cells (A2aflox/flox × LysM-cre). A specific A2a receptor agonist (ATL202) was used to evaluate its potential to reduce lung injury in vivo. In wild-type mice, therapeutic treatment with ATL202 reduced LPS-induced PMN recruitment, and release of cytokines. Pretreatment, but not posttreatment, also reduced Evans blue extravasation. In the BM chimeric mice lacking A2a on BM-derived cells, PMN migration into the alveolar space was increased by ∼50%. These findings were confirmed in A2aflox/flox × LysM-cre mice. ATL202 was only effective when A2a was present on BM-derived cells. A2a agonists may be effective at curbing inflammatory lung tissue damage.
Pyrin Levels in Human Monocytes and Monocyte-Derived Macrophages Regulate IL-1β Processing and Release
Authors: Seshadri Sudarshan , Duncan Michelle D. , Hart Judith M. , Gavrilin Mikhail A. , Wewers Mark D. 
Published: April 2014

AbstractMacrophages and their precursors, monocytes, are key cells involved in the innate immune response. Although both monocytes and macrophages produce caspase-1, the key enzyme responsible for pro-IL-1β processing; macrophages are limited in their ability to activate the enzyme and release functional IL-1β. In this context, because mutations in the pyrin gene (MEFV) cause the inflammatory disorder familial Mediterranean fever, pyrin is believed to regulate IL-1β processing. To determine whether variations in pyrin expression explain the difference between monocytes and macrophages in IL-1β processing and release, pyrin was studied in human monocytes and monocyte-derived macrophages. Although monocytes express pyrin mRNA and protein, which is readily inducible by endotoxin, monocyte-derived macrophages express significantly less pyrin mRNA and protein. Pyrin levels directly correlated with IL-1β processing in monocytes and macrophages; therefore, we asked whether pyrin might promote IL-1β processing and release. HEK293 cells were transfected with pyrin, caspase-1, apoptotic speck protein with a caspase recruitment domain, and IL-1β. Pyrin induced IL-1β processing and release in a dose-dependent manner. Conversely, pyrin small interference RNA suppressed pro-IL-1β processing in both THP-1 cells and fresh human monocytes. In summary, both pyrin expression and IL-1β processing and release are diminished upon the maturation of monocytes to macrophages. When pyrin is ectopically expressed or silenced, IL-1β processing and release parallels the level of pyrin. In conclusion, in the context of endotoxin-induced activation of mononuclear phagocytes, pyrin augments IL-1β processing and release.
Leptin-Induced IL-6 Production Is Mediated by Leptin Receptor, Insulin Receptor Substrate-1, Phosphatidylinositol 3-Kinase, Akt, NF-κB, and p300 Pathway in Microglia
Authors: Tang Chih-Hsin , Lu Da-Yuu , Yang Rong-Sen , Tsai Huei-Yann , Kao Ming-Ching , Fu Wen-Mei , Chen Yuh-Fung 
Published: April 2014

Abstract
Leptin, the adipocyte-secreted hormone that centrally regulates weight control, is known to function as an immunomodulatory regulator. We investigated the signaling pathway involved in IL-6 production caused by leptin in microglia. Microglia expressed the long (OBRl) and short (OBRs) isoforms of the leptin receptor. Leptin caused concentration- and time-dependent increases in IL-6 production. Leptin-mediated IL-6 production was attenuated by OBRl receptor antisense oligonucleotide, PI3K inhibitor (Ly294002 and wortmannin), Akt inhibitor (1L-6-hydroxymethyl-chiro-inositol-2-((R)-2-O-methyl-3-O-octadecylcarbonate)), NF-κB inhibitor (pyrrolidine dithiocarbamate), IκB protease inhibitor (l-1-tosylamido-2-phenylenylethyl chloromethyl ketone), IκBα phosphorylation inhibitor (Bay 117082), or NF-κB inhibitor peptide. Transfection with insulin receptor substrate (IRS)-1 small-interference RNA or the dominant-negative mutant of p85 and Akt also inhibited the potentiating action of leptin. Stimulation of microglia with leptin activated IκB kinase α/IκB kinase β, IκBα phosphorylation, IκBα degradation, p65 phosphorylation at Ser276, p65 and p50 translocation from the cytosol to the nucleus, and κB-luciferase activity. Leptin-mediated an increase of IκB kinase α/IκB kinase β activity, κB-luciferase activity, and p65 and p50 binding to the NF-κB element was inhibited by wortmannin, Akt inhibitor, and IRS-1 small-interference RNA. The binding of p65 and p50 to the NF-κB elements, as well as the recruitment of p300 and the enhancement of histone H3 and H4 acetylation on the IL-6 promoter was enhanced by leptin. Our results suggest that leptin increased IL-6 production in microglia via the leptin receptor/IRS-1/PI3K/Akt/NF-κB and p300 signaling pathway.
Prevalence of Newly Generated Naive Regulatory T Cells (Treg) Is Critical for Treg Suppressive Function and Determines Treg Dysfunction in Multiple Sclerosis
Authors: Haas Jürgen , Fritzsching Benedikt , Trübswetter Petra , Korporal Mirjam , Milkova Linda , Fritz Brigitte , Vobis Diana , Krammer Peter H. , Suri-Payer Elisabeth , Wildemann Brigitte 
Published: April 2014

Abstract
The suppressive function of regulatory T cells (Treg) is impaired in multiple sclerosis (MS) patients. The mechanism underlying the Treg functional defect is unknown. Treg mature in the thymus and the majority of cells circulating in the periphery rapidly adopt a memory phenotype. Because our own previous findings suggest that the thymic output of T cells is impaired in MS, we hypothesized that an altered Treg generation may contribute to the suppressive deficiency. We therefore determined the role of Treg that enter the circulation as recent thymic emigrants (RTE) and, unlike their CD45RO+ memory counterparts, express CD31 as typical surface marker. We show that the numbers of CD31+-coexpressing CD4+CD25+CD45RA+CD45RO−FOXP3+ Treg (RTE-Treg) within peripheral blood decline with age and are significantly reduced in MS patients. The reduced de novo generation of RTE-Treg is compensated by higher proportions of memory Treg, resulting in a stable cell count of the total Treg population. Depletion of CD31+ cells from Treg diminishes the suppressive capacity of donor but not patient Treg and neutralizes the difference in inhibitory potencies between the two groups. Overall, there was a clear correlation between Treg-mediated suppression and the prevalence of RTE-Treg, indicating that CD31-expressing naive Treg contribute to the functional properties of the entire Treg population. Furthermore, patient-derived Treg, but not healthy Treg, exhibit a contracted TCR Vβ repertoire. These observations suggest that a shift in the homeostatic composition of Treg subsets related to a reduced thymic-dependent de novo generation of RTE-Treg with a compensatory expansion of memory Treg may contribute to the Treg defect associated with MS.
Omalizumab Reverses the Phenotypic and Functional Effects of IgE-Enhanced FcεRI on Human Skin Mast Cells
Authors: Gomez Gregorio , Jogie-Brahim Sherryline , Shima Mika , Schwartz Lawrence B. 
Published: April 2014

AbstractThe dramatic effects of the anti-IgE mAb omalizumab to lower free IgE levels and FcεRI levels on basophils contrast with more modest clinical effects. Accordingly, whether IgE modulates FcεRI levels and FcεRI-dependent mediator release in vitro on human skin mast cells (MCTC type) that had matured in vivo is of interest. IgE reversibly enhanced FcεRI levels on MCTC cells in a dose- and time-dependent manner (up-regulation t1/2 of 4–5 days with 1–3 μg/ml IgE), without affecting cell proliferation. A molar ratio of omalizumab to IgE of 0.9 at baseline prevented receptor up-regulation by 50%, whereas adding omalizumab to MCTC cells already with IgE-enhanced FcεRI levels at molar ratios of 5, 12.5, and 31 reduced FcεRI levels to baseline with respective t1/2 values of 8.7, 6.3, and 4.8 days. MCTC cells with IgE-enhanced FcεRI levels were more sensitive to stimulation with a low dose of anti-FcεRI mAb in terms of degranulation and production of PGD2, GM-CSF, IL-6, IL-13, and TNF-α. Reducing up-regulated FcεRI levels with omalizumab also reduced mediator release to a low dose of anti-FcεRI mAb to baseline by 3–4 wk. Thus, reducing free IgE should decrease the hypersensitivity of allergic individuals to low naturally occurring concentrations of allergens.