bluuebunny/crossref_metadata_2025 huggingface dataset:
A Takagi-Sugeno Fuzzy Dynamic Model of a Concentric-Tubes Heat Exchanger
Authors: Ruiz-Mercado Claudia , Pacheco-Vega Arturo , Torres-Chavez Gerardo
Published: May 2009

We develop a Takagi-Sugeno (TS) fuzzy model of a concentric-tubes heat exchanger. The model is structured on fuzzy logic reasoning with sets of linguistic rules describing the dynamic characteristics of the thermal system. Using a system identification technique based on adaptive neural networks and subtractive clustering, the fuzzy rules are derived from experimental data of flow rates and fluid temperatures that were previously collected in a heat exchanger test facility. The accuracy of the resulting model is assessed by comparing predictions, versus experimental measurements, of the time-dependent response of the outlet hot- and cold-water temperatures under a step-change in the mass flow rate of the cold fluid. The results indicate that the TS fuzzy model is able to estimate the behavior of the physical system with predicting errors of the order of the experimental uncertainties.
Iterative Design of Dynamic Experiments in Modeling for Optimization of Innovative Bioprocesses
Authors: Cristaldi Mariano , Grau Ricardo , Martinez Ernesto
Published: May 2009

Finding optimal operating conditions fast with a scarce budget of experimental runs is a key problem to speed up the development and scaling up of innovative bioprocesses. In this paper, a novel iterative methodology for the model-based design of dynamic experiments in modeling for optimization is developed and successfully applied to the optimization of a fed-batch bioreactor related to the production of r-interleukin-11 (rIL-11) whose DNA sequence has been cloned in an Escherichia coli strain. At each iteration, the proposed methodology resorts to a library of tendency models to increasingly bias bioreactor operating conditions towards an optimum. By selecting the most informative tendency model in the sequel, the next dynamic experiment is defined by re-optimizing the input policy and calculating optimal sampling times. Model selection is based on minimizing an error measure which distinguishes between parametric and structural uncertainty to selectively bias data gathering towards improved operating conditions. The parametric uncertainty of tendency models is iteratively reduced using Global Sensitivity Analysis (GSA) to pinpoint which parameters are keys for estimating the objective function. Results obtained after just a few iterations are very promising.
Stationary inverted Lyman populations and free-free and bound-free emission of lower-energy state hydride ion formed by an exothermic catalytic reaction of atomic hydrogen and certain group I catalysts
Authors: Mills Randell , Good William , Jansson Peter , He Jiliang
Published: May 2009

Rb+ to Rb2+ and 2K+ to K + K2+ each provide a reaction with a net enthalpy equal to the potential energy of atomic hydrogen. The presence of these gaseous ions with thermally dissociated hydrogen formed a plasma having strong VUV emission with a stationary inverted Lyman population. Significant Balmer α line broadening of 18 and 9 eV was observed from a rt-plasma of hydrogen with KNO3, and RbNO3, respectively, compared to 3 eV from a hydrogen microwave plasma. The reaction was exothermic since excess power of about 20 mW/cc was measured by Calvet calorimetry. We propose an energetic catalytic reaction involving a resonance energy transfer between hydrogen atoms and Rb+ or 2K+ to form a very stable novel hydride ion. Its predicted binding energy of 3.0471 eV with the fine structure was observed at 4071 Å, and its predicted bound-free hyperfine structure lines matched those observed for about 40 lines to within.01 percent. Characteristic emission from each catalyst was observed. This catalytic reaction may pump a CW HI laser.
Scaling behavior of earthquakes’ inter-events time series
Authors: Shadkhoo Shahriar , Ghanbarnejad Fakhteh , Jafari Gholam , Tabar Mohammad
Published: May 2009

In this paper, we investigate the statistical and scaling properties of the California earthquakes’ inter-events over a period of the recent 40 years. To detect long-term correlations behavior, we apply detrended fluctuation analysis (DFA), which can systematically detect and overcome nonstationarities in the data set at all time scales. We calculate for various earthquakes with magnitudes larger than a given M. The results indicate that the Hurst exponent decreases with increasing M; characterized by a Hurst exponent, which is given by, H = 0:34 + 1:53/M, indicating that for events with very large magnitudes M, the Hurst exponent decreases to 0:50, which is for independent events.
Dielectrophoretic mobility in the characterization of properties of microparticles
Authors: Kuokkanen Maija
Published: May 2009

The dielectric properties of microparticles were characterized by quadrupole electrode geometry. Quadruple microelectrode geometry with hyperbolic active interfaces was designed and fabricated. The dielectrophoretic mobility coefficients of the polystyrene microparticles were attained from negative dielectrophoresis. With the mobility coefficients and hypothetical inflection frequencies of the particles, the permittivity and electric conductivity of the particles in suspension were calculated. This demonstration established that dielectrophoretic mobility attained with a hyperbolic electrode can be used to characterize microparticle properties in suspension.
The differentiation of human placenta-derived mesenchymal stem cells into dopaminergic cells in vitro
Authors: Chen Li , He Dong-Mei , Zhang Yuan
Published: May 2009

Mesenchymal stem cells (MSCs) constitute an interesting cellular source to promote brain regeneration after Parkinson’s disease. MSCs have significant advantages over other stem cell types, and greater potential for immediate clinical application. The aim of this study was to investigate whether MSCs from the human placenta could be induced to differentiate into dopaminergic cells. MSCs from the human placenta were isolated by digestion and density gradient fractionation, and their cell surface glycoproteins were analyzed by flow cytometry. These MSCs were cultured under conditions promoting differetiation into adipocytes and osteoblasts. Using a cocktail that includes basic fibroblast growth factor (bFGF), all trans retinoic acid (RA), ascorbic acid (AA) and 3-isobutyl-1-methylxanthine (IBMX), the MSCs were induced in vitro to become dopamine (DA) neurons. Then, the expression of the mRNA for the Nestin and tyrosine hydroxylase (TH) genes was assayed via RT-PCR. The expression of the Nestin, dopamine transporter (DAT), neuronal nuclear protein (NeuN) and TH proteins was determined via immunofluorescence. The synthesized and secreted DA was determined via ELISA. We found that MSCs from the human placenta exhibited a fibroblastoid morphology. Flow cytometric analyses showed that the MSCs were positive for CD44 and CD29, and negative for CD34, CD45, CD106 and HLA-DR. Moreover, they could be induced into adipocytes and osteocytes. When the MSCs were induced with bFGF, RA, AA and IBMX, they showed a change in morphology to that of neuronal-like cells. The induced cells expressed Nestin and TH mRNA, and the Nestin, DAT, NeuN and TH proteins, and synthesized and secreted DA. Our results suggest that MSCs from the human placenta have the ability to differentiate into dopaminergic cells.
QSAR analysis of 1,3-diaryl-2-propen-1-ones and their indole analogs for designing potent antibacterial agents
Authors: Bhatia Neela , Mahadik Kakasaheb , Bhatia Manish
Published: May 2009

A series of 1,3-diaryl-2-propen-1-ones and their indole analogs were synthesized and evaluated for antibacterial activity. Structures of newly synthesized compounds were confirmed by physicochemical, spectral and elemental analysis. All the compounds were screened for their antibacterial activities against four different bacterial strains. The QSAR studies were performed using Vlife MDS 3.5 software. QSAR equation revealed that selected electronic, steric and lipophilic parameters have good correlation with antibacterial activity. Best equations were selected on basis of the correlation coefficient (r 2) and the predictable ability of the equations. The present findings suggest that the 1,3-diaryl-2-propen-1-ones framework is an attractive template for structure optimization to achieve higher potency, lower toxicity, and a wider spectrum of antibacterial activity.
Wettability of plasma-polymerized vinyltriethoxysilane film
Authors: Lichovníková Soňa , Studýnka Jan , Čech Vladimír
Published: May 2009

Plasma-polymerized films of vinyltriethoxysilane were surface characterized using the sessile drop technique. The surface free energy and its components were evaluated using the Owens-Wendt-Kaelble geometric mean method, Wu harmonic mean method, and van Oss, Chaudhury, and Good acid-base theory. Influence of deposition conditions on the surface free energy was demonstrated in the study. Improved wettability of the films was related to the diminished concentration of apolar methyl groups in plasma polymers. An increased concentration of carbonyl and hydroxyl groups resulted in a very small improvement of the polar component.
GC-MS analyses of flower ether extracts of Prunus domestica L. and Prunus padus L. (Rosaceae)
Authors: Radulović Niko , Đorđević Aleksandra , Zlatković Bojan , Palić Radosav
Published: May 2009

Volatiles of fresh flowers of Prunus domestica L. and Prunus padus L. (their diethyl ether extracts) were analyzed by GC and GC-MS. 110 and 33 constituents were identified in P. domestica and P. padus extracts, respectively. 32 of the identified constituents were previously unreported as metabolites of taxa belonging to the genus Prunus. Six of them (4-methoxybenzyl palmitate, isoamyl stearate, isoamyl eicosanoate, isoamyl docosanoate and penta-O-acetyl-α- and β-D-glucopyranoses) are compounds reported for the first time from a natural source and one (isoamyl tetracosanoate) is a new compound in general. The major component of P. domestica extract was kaempferol (35.0 %), while P. padus extract was found to be rich in (Z)-8-hydroxylinalool (30.4 %), benzaldehyde (19.8 %) and 2-phenylethanol (15.1 %). Both extracts (P. domestica and P. padus) contained rather large amounts of shikimate metabolites (51.7 % and 39.1 %, respectively) and anther related odd-carbon numbered alkanes (23.2 % and 27.0 %, respectively). The observed differences between P. domestica and P. padus extracts corroborate the placement of P. domestica and P. padus in separate subgenera (Prunus and Cerasus, respectively) of the genus Prunus.
Characterization of NiFe2O4 nanoparticles synthesized by various methods
Authors: Kavas Hüseyin , Kasapoğlu Nermin , Baykal Abdülhadi , Köseoğlu Yüksel
Published: May 2009

Microwave-induced combustion with glycine, CTAB-assisted hydrothermal process with NaOH and NH3, EDTA assisted-hydrothermal methods have been applied to prepare NiFe2O4 nanoparticles for the first time. Structural and magnetic properties of the products were investigated by X-ray powder diffraction (XRD), scanning electron microscopy (SEM), transmison electron microscopy (TEM), Fourier transform infrared spectroscopy (FTIR), and electron spin resonance spectrometry (EPR). TEM measurements showed that morphology of the product depends on the synthesis method employed. The average cystallite size of NiFe2O4 nanoparticles was in the range of 14–59 nm as measured by XRD. The uncoated sample (Method A) had an EPR linewidth of 1973 Oe, the coated samples reached lower values. The magnetic dipolar interactions existing among the Ni ferrite nanoparticles are reduced by the coatings, which could cause the decrease in the linewidth of the EPR signals. Additionally, the linewidth increases with an increase in the size and the size distribution of nanoparticles.
Soluble Tumor Necrosis Factor Receptor Mediates Cell Proliferation on Lipopolysaccharide-Stimulated Cultured Human Decidual Stromal Cells
Authors: Yu Xue-Wen , Zhang Xin-Wen , Li Xu
Published: May 2009

The tumor necrosis factor-alpha (TNF-α) cytokine receptor system modulates apoptosis in many cell types, so we have investigated the role of sTNFR1 in bacterial lipopolysaccharide (LPS)-induced cell death in cultured human decidual stromal cells, hypothesizing that sTNFR1 might play a central role in this action. In this work we characterized in vitro decidual stromal cell viability with LPS treatment and LPS and sTNFR1 co-treatment. We found that LPS treatment induced decidual stromal cell death in a dose-dependent manner and that sTNFR1 blocked the effect of the LPS treatment. There was a significant proliferation among cells co-incubated with LPS at 10 μg/mL and sTNFR1 at 0.1 μg/mL compared with LPS and sTNFR1 at 0.01, 0.05, 0.2 and 0.5 μg/mL (p < 0.01). This study demonstrated that LPS led to decidual stromal cell death in vitro but sTNFR1 down-regulates the cell death due to LPS under the same conditions. Taken together, these results suggested that sTNFR1 could participate in a protective mechanism against endotoxin.
Lipid profile and dietary habits in an elderly rural population in the southern Spain: the Sierra de Huelva study
Authors: Martín Francisco , Escudero-Gilete M. Luisa , Vicario Isabel M.
Published: May 2009

We have assessed serum lipids, systolic (SBP) and diastolic (DBP) blood pressure in a healthy, free living population over 70 years old residing for more than 20 years in a rural area located in the southern Spain, the Sierra de Huelva. 401 elderly, 229 women (F) and 179 men (M) mean age 79.36 ± 6.9 were included in this cross-sectional observational study. Dietary habits were assessed by means of a Modification of the Mediterranean Diet Score (MDDS), which comprised 11 components. A total score ranging from 0-44 was calculated. Mean concentration for lipids were: Total cholesterol (TC) 193.8 ± 23.1, M 195.2 ± 25.7 and F 192.7 ± 20.8 (p = 0.29); HDLc 60.3 ± 7.6 mg/dl, M 60.0 ± 8.0 and F 60.5 ± 7.2 (p = 0.49); TC/HDLc 3.3 ± 1.1 mg/dl, M 3.4 ± 1.2 and F 3.3 ± 1.1 mg/dl (p < 0.35); LDLc 127.3  30.1 mg/dl, M 129.0 ± 32.9 F 126.0 ± 27.8 mg/dl (p = 0.33); TG 137.7 ± 18.3, M 138.8 ± 19.4 and F 136 ± 17.4 (p = 0.30). Global prevalence of hypercholesterolemia (TC ≥200 mg/dl) was 8.7%, F 7.9% and M 9.9%; 10.7% had LDLc≥160 mg/dl. In this study, age was negatively correlated (p < 0.05) with TC, LDLc, TG and SBP and positively with HDLc. Pig meat consumption was negatively correlated with CT and LDLc, and positively with HDLc. According to MMDS data, 60.6 ± 6.9% of adherence to the Mediterranean diet was obtained. The MMDS was positively associated with age and negatively with TG (p < 0.05). Further studies are needed to establish the influence of local Iberian pig meat products consumption and life style on the lower incidence of risk factors for CVD and the higher life expectancy of the studied population.
Changes in SPME-extracted volatile compounds from Iberian ham during ripening
Authors: Jurado Ángela , Carrapiso Ana I. , Ventanasa Jesús , García Carmen
Published: May 2009

A headspace SPME procedure was tested to study the evolution of volatile compounds during the ripening of Iberian hams from pigs reared in a Montanera system (outdoorbased, with acorn and pasture available) and a HO-Pienso system (indoor-based, with a high oleic acid concentrate). The effect of the ripening time on volatile compounds was more marked than the effect of feeding system. Most volatile compounds affected by the ripening time were compounds that come from Strecker and Maillard reactions, which increased significantly (
Preparation and characterization of alkali-activated white belite cements
Authors: Morsli K. , De la Torre Ángeles G. , Cuberos Antonio J. M. , Zahir Mohammed , Aranda Miguel A. G.
Published: May 2009

Activated white cement clinkers with a theoretical 60% (wt) belite (dicalcium silicate) content were prepared at a temperature 100 ºC lower than used to manufacture conventional white Portland cement clinkers. Activation was achieved by adding variable amounts of K2CO 3 or Na2CO 3 to the raw mixes. Rietveld quantitative analysis of X-ray diffraction findings showed that adding the alkalis stabilized the high temperature belite polymorphs. When 2.0% (wt) of Na2O was added, the composition (by wt) found was 16.4(4)% alpha-C2S, 16.7(8)% alpha’-H-C2S, 23.2(6)% beta-C2S, 32.7(7)% total C3S, 9.5(2)% orthorhombic C3A and 1.50(5)% free lime. Due to the high volatilization rate of K2O under the experimental conditions, it stabilized the alpha-type C2S less effectively than Na2O. A calorimetric study was likewise performed to correlate the phase composition with early age hydration (behaviour).
Free Bone Graft Attenuates Acute Rejection and in Combination with Cyclosporin A Leads to Indefinite Cardiac Allograft Survival
Authors: Wang Hao , Ge Wei , Arp Jacqueline , Zassoko Roman , Liu Weihua , Ichim Thomas E. , Jiang Jifu , Jevnikar Anthony M. , Garcia Bertha
Published: May 2009

We report on a novel approach aimed at preventing acute vascular rejection (AVR), one of the major unresolved hurdles of clinical transplantation. In a C3H-to-BALB/c heterotopic heart transplant model, we demonstrate that free bone transplantation combined with cyclosporin A suppresses antidonor Ab responses, induces indefinite cardiac allograft survival (>100 days), and preserves graft architecture. In contrast, untreated- or cyclosporin A alone-treated recipients rejected their cardiac grafts on days 7.7 ± 0.6 and 15.5 ± 1.1, respectively, with graft histology indicative of AVR. Splenic dendritic cells from nonrejecting recipients expressed low levels of MHC II, CD40, and CD86, reduced ability to stimulate donor cell proliferation, and augmented IL-10 production of responding T cells in vitro. Adoptive transfer of dendritic cells from long-term surviving recipients 1 day before cardiac grafting was able to confer hyporesponsiveness to naive BALB/c recipients of cardiac allografts. To determine whether graft survival was associated with hematopoietic or stromal elements of the transplanted free bone, we administered isolated bone marrow mononuclear cells or free bone that was irradiated to deplete hematopoietic elements. Although bone marrow mononuclear cells had no effect on cardiac graft survival, irradiated free bone transplantation was capable of prolonging graft survival. Most interestingly, the prolongation effect was Ag nonspecific, because third party irradiated bone graft was also effective. Due to the fact that current immunosuppressive approaches are clinically ineffective at preventing AVR, this study provides promise for further investigations of BM components as a means of addressing a currently unmet medical need.
FcεRI and FcγRIII/CD16 Differentially Regulate Atopic Dermatitis in Mice
Authors: Abboud Georges , Staumont-Sallé Delphine , Kanda Akira , Roumier Thomas , Deruytter Nathalie , Lavogiez Céline , Fleury Sébastien , Rémy Patrick , Papin Jean-Paul , Capron Monique , Dombrowicz David
Published: May 2009

The high-affinity IgE receptor FcεRI and, in some models, the low-affinity IgG receptor FcγRIII/CD16 play an essential role in allergic diseases. In human skin, they are present on APCs and effector cells recruited into the inflamed dermis. FcRγ is a subunit shared, among other FcRs, by FcεRI and CD16 and is essential to their assembly and signal transduction. Using an experimental model reproducing some features of human atopic dermatitis and specific FcR-deficient mice, we have herein delineated the respective contribution of FcεRI and FcγRIII/CD16 to the pathology. We demonstrate that symptoms of atopic dermatitis are completely absent in FcRγ-deficient animals but only partially inhibited in either FcεRI- or FcγRIII/CD16-deficient animals. Absence or attenuation of the pathology is correlated to increased skin expression of regulatory IL-10 and Foxp3. While FcεRI controls both Th1 and Th2 skin response, mast cell recruitment into draining lymph nodes and IgE production, CD16 regulates only Th2 skin response, as well as T cell proliferation and IgG1 production. This isotype-specific regulation by the cognate FcR is associated to a differential regulation of IL-4 and IL-21 expression in the draining lymph nodes. FcεRI and CD16 thus contribute to atopic dermatitis but differentially regulate immune responses associated with the disease. Targeting both IgE/FcεRI and IgG/CD16 interactions might represent an efficient therapeutic strategy for allergic diseases.
Hepatocytes and IL-15: A Favorable Microenvironment for T Cell Survival and CD8+ T Cell Differentiation
Authors: Correia Margareta P. , Cardoso Elsa M. , Pereira Carlos F. , Neves Rui , Uhrberg Markus , Arosa Fernando A.
Published: May 2009

Human intrahepatic lymphocytes are enriched in CD1d-unrestricted T cells coexpressing NKR. Although the origin of this population remains controversial, it is possible to speculate that the hepatic microenvironment, namely epithelial cells or the cytokine milieu, may play a role in its shaping. IL-15 is constitutively expressed in the liver and has a key role in activation and survival of innate and tissue-associated immune cells. In this in vitro study, we examined whether hepatocyte cell lines and/or IL-15 could play a role in the generation of NK-like T cells. The results show that both HepG2 cells and a human immortalized hepatocyte cell line increase survival and drive basal proliferation of T cells. In addition, IL-15 was capable of inducing Ag-independent up-regulation of NKR, including NKG2A, Ig-like receptors, and de novo expression of CD56 and NKp46 in CD8+CD56− T cells. In conclusion, our study suggests that hepatocytes and IL-15 create a favorable microenvironment for T cells to growth and survive. It can be proposed that the increased percentage of intrahepatic nonclassical NKT cells could be in part due to a local CD8+ T cell differentiation.
Targeted Delivery of Immunogen to Primate M Cells with Tetragalloyl Lysine Dendrimer
Authors: Misumi Shogo , Masuyama Mitsuaki , Takamune Nobutoki , Nakayama Daisuke , Mitsumata Ryotarou , Matsumoto Hirokazu , Urata Norimitsu , Takahashi Yoshihiro , Muneoka Atsunobu , Sukamoto Takayuki , Fukuzaki Koichiro , Shoji Shozo
Published: May 2009

Effective uptake of Ags by specialized M cells of gut-associated lymphoid tissues is an important step in inducing efficient immune responses after oral vaccination. Although stable nontoxic small molecule mimetics of lectins, such as synthetic multivalent polygalloyl derivatives, may have potential in murine M cell targeting, it remains unclear whether synthetic multivalent polygalloyl derivatives effectively target nonhuman and human M cells. In this study, we evaluated the ability of a tetragalloyl derivative, the tetragalloyl-d-lysine dendrimer (TGDK), to target M cells in both in vivo nonhuman primate and in vitro human M-like cell culture models. TGDK was efficiently transported from the lumen of the intestinal tract into rhesus Peyer’s patches by M cells and then accumulated in germinal centers. Oral administration of rhesus CCR5-derived cyclopeptide conjugated with TGDK in rhesus macaque resulted in a statistically significant increase in stool IgA response against rhesus CCR5-derived cyclopeptide and induced a neutralizing activity against SIV infection. Furthermore, TGDK was specifically bound to human M-like cells and efficiently transcytosed from the apical side to the basolateral side in the M-like cell model. Thus, the TGDK-mediated vaccine delivery system represents a potential approach for enabling M cell-targeted mucosal vaccines in primates.
Notch Activation Induces the Generation of Functional NK Cells from Human Cord Blood CD34-Positive Cells Devoid of IL-15
Authors: Haraguchi Kyoko , Suzuki Takahiro , Koyama Noriko , Kumano Keiki , Nakahara Fumio , Matsumoto Akihiko , Yokoyama Yasuhisa , Sakata-Yanagimoto Mamiko , Masuda Shigeo , Takahashi Tsuyoshi , Kamijo Aki , Takahashi Koki , Takanashi Minoko , Okuyama Yoshiki , Yasutomo Koji , Sakano Seiji , Yagita Hideo , Kurokawa Mineo , Ogawa Seishi , Chiba Shigeru
Published: May 2009

The development of NK cells from hematopoietic stem cells is thought to be dependent on IL-15. In this study, we demonstrate that stimulation of human cord blood CD34+ cells by a Notch ligand, Delta4, along with IL-7, stem cell factor, and Fms-like tyrosine kinase 3 ligand, but no IL-15, in a stroma-free culture induced the generation of cells with characteristics of functional NK cells, including CD56 and CD161 Ag expression, IFN-γ secretion, and cytotoxic activity against K562 and Jurkat cells. Addition of γ-secretase inhibitor and anti-human Notch1 Ab to the culture medium almost completely blocked NK cell emergence. Addition of anti-human IL-15-neutralizing Ab did not affect NK cell development in these culture conditions. The presence of IL-15, however, augmented cytotoxicity and was required for a more mature NK cell phenotype. CD56+ cells generated by culture with IL-15, but without Notch stimulation, were negative for CD7 and cytoplasmic CD3, whereas CD56+ cells generated by culture with both Delta4 and IL-15 were CD7+ and cytoplasmic CD3+ from the beginning and therefore more similar to in vivo human NK cell progenitors. Together, these results suggest that Notch signaling is important for the physiologic development of NK cells at differentiation stages beyond those previously postulated.
Trichothecene Mycotoxins Activate Inflammatory Response in Human Macrophages
Authors: Kankkunen Päivi , Rintahaka Johanna , Aalto Annika , Leino Marina , Majuri Marja-Leena , Alenius Harri , Wolff Henrik , Matikainen Sampsa
Published: May 2009

Damp building-related illnesses have caused concern for years in many countries. Although the problem is extensive, the knowledge of the immunological reactions behind damp building-related illnesses is still quite limited. Trichothecene mycotoxins form one major group of toxins, which possibly contribute to the illnesses. Stachybotrys chartarum is a well-known, but also controversial damp building mold and many strains of this mold are capable of producing trichothecenes. In this report, we have examined the effect of S. chartarum and trichothecene mycotoxins on the proinflammatory cytokine response in human macrophages. As a result, satratoxin-positive S. chartarum activated inflammasome-associated caspase-1, which is needed for proteolytic processing of IL-1β and IL-18. Furthermore, purified trichothecene mycotoxins, roridin A, verrucarin A, and T-2 toxin activated caspase-1, and these mycotoxins also strongly enhanced LPS-dependent secretion of IL-1β and IL-18. The satratoxin-positive strain of S. chartarum and the trichothecenes also triggered the activation of caspase-3, which is an effector caspase of apoptosis. Satratoxin-negative S. chartarum was not able to activate either caspase-1 or caspase-3. In conclusion, our results indicate that human macrophages sense trichothecene mycotoxins as a danger signal, which activates caspase-1, and further enables the secretion of IL-1β and IL-18 from the LPS-primed cells.
Potent Phagocytic Activity with Impaired Antigen Presentation Identifying Lipopolysaccharide-Tolerant Human Monocytes: Demonstration in Isolated Monocytes from Cystic Fibrosis Patients
Authors: del Fresno Carlos , García-Rio Francisco , Gómez-Piña Vanesa , Soares-Schanoski Alessandra , Fernández-Ruíz Irene , Jurado Teresa , Kajiji Tasneem , Shu Chen , Marín Elvira , Gutierrez del Arroyo Ana , Prados Concepción , Arnalich Francisco , Fuentes-Prior Pablo , Biswas Subrha K. , López-Collazo Eduardo
Published: May 2009

Monocyte exposure to LPS induces a transient state in which these cells are refractory to further endotoxin stimulation. This phenomenon, termed endotoxin tolerance (ET), is characterized by a decreased production of cytokines in response to the proinflammatory stimulus. We have established a robust model of ET and have determined the time frame and features of LPS unresponsiveness in cultured human monocytes. A large number of genes transcribed in tolerant monocytes were classified as either “tolerizable” or “nontolerizable” depending on their expression levels during the ET phase. Tolerant monocytes exhibit rapid IL-1R-associated kinase-M (IRAK-M) overexpression, high levels of triggering receptor expressed on myeloid cells-1 (TREM-1) and CD64, and a marked down-regulation of MHC molecules and NF-κB2. These cells combine potent phagocytic activity with impaired capability for Ag presentation. We also show that circulating monocytes isolated from cystic fibrosis patients share all the determinants that characterize cells locked in an ET state. These findings identify a new mechanism that contributes to impaired inflammation in cystic fibrosis patients despite a high frequency of infections. Our results indicate that a tolerant phenotype interferes with timing, efficiency, and outcome of the innate immune responses against bacterial infections.
Adiponectin Promotes Endotoxin Tolerance in Macrophages by Inducing IRAK-M Expression
Authors: Zacharioudaki Vassiliki , Androulidaki Ariadne , Arranz Alicia , Vrentzos George , Margioris Andrew N. , Tsatsanis Christos
Published: May 2009

High levels of plasma adiponectin are associated with low levels of inflammatory markers and cardioprotection. The mechanism via which adiponectin exerts its anti-inflammatory effect is yet unknown. In the present study, we demonstrate that globular adiponectin (gAd) induces the expression of the inactive isoform of IL-1R-associated kinases (IRAK), IRAK-M. Homologous deletion of IRAK-M in IRAK-M−/− mice abolished the tolerogenic properties of gAd because pretreatment of IRAK-M−/− macrophages with gAd did not suppress LPS-induced proinflammatory cytokine production. GAd activated the MAPKs MEK1/2 and ERK1/2 in macrophages via their upstream regulator Tpl2. Activation of ERK1/2 via Tpl2 appeared necessary for the induction of IRAK-M because gAd did not induce IRAK-M in Tpl2−/− macrophages or in macrophages pretreated with the MEK1/2 inhibitor UO126. In addition, activation of PI3K and Akt1 also appeared necessary for the induction of IRAK-M by gAd, because treatment of Akt1−/− macrophages or pretreatment of macrophages with the PI3K inhibitor wortmannin abolished gAd-induced IRAK-M expression. Analysis of IRAK-M expression in human peripheral blood cells confirmed that serum adiponectin was negatively associated with IRAK-M and responsiveness to LPS. In conclusion, our data demonstrate that IRAK-M is a major mediator of gAd-induced endotoxin tolerance in primary macrophages, expression of which depends on the activation of Tpl2/ERK and PI3K/Akt1 signaling pathways.
Presence of Membrane-Bound TGF-β1 and Its Regulation by IL-2-Activated Immune Cell-Derived IFN-γ in Head and Neck Squamous Cell Carcinoma Cell Lines
Authors: Ahn Yong-Oon , Lee June-Chul , Sung Myung-Whun , Heo Dae Seog
Published: May 2009

The presence of membrane-bound TGF-β1 (mTGF-β1) has been recently observed in regulatory T cells, but only a few studies have reported the same phenomenon in cancer cells. In this study, we investigate the regulation of mTGF-β1 expression in five head and neck squamous cell carcinoma cell lines using FACS analysis. Through blocking Ab and exogenous cytokine treatment experiments, we found that expression of mTGF-β1 is significantly induced by the activated immune cell-derived factor IFN-γ. In addition, IFN-γ and TNF-α are shown to have a synergistic effect on mTGF-β1 expression. Moreover, we found that exogenous TNF-α induces endogenous TNF-α mRNA expression in an autocrine loop. In contrast to previous reports, we confirm that, in this model, mTGF-β1 is neither a rebound form of once-secreted TGF-β1 nor an activated form of its precursor membrane latency-associated peptide. Inhibitors of transcription (actinomycin D), translation (cycloheximide), or membrane translocation (brefeldin A) effectively block the induction of mTGF-β1, which suggests that induction of mTGF-β1 by IFN-γ and/or TNF-α occurs through de novo synthesis. These findings suggest that some cancer cells can detect immune activating cytokines, such as IFN-γ and TNF-α, and actively block antitumor immunity by induction of mTGF-β1.
T-bet Inhibits the In Vivo Differentiation of Parasite-Specific CD4+ Th17 Cells in a T Cell-Intrinsic Manner
Authors: Guo Siqi , Cobb Dustin , Smeltz Ronald B.
Published: May 2009

CD4+ Th17 cells have emerged as a new T cell subset in the Th1/Th2 paradigm, and efforts have shifted toward understanding the factors that regulate their development in vivo. To analyze the role of the transcription factor T-bet in regulation of Th17 cells, we used a murine model of Trypanosoma cruzi infection, a protozoan parasite that causes Chagas disease in humans. Infection of Tbx21−/− mice led to normal, unimpaired development of Ag-specific CD4+ T cells producing IFN-γ. However, a robust Th17 response developed concomitant with Th1 responses. Despite significant IFN-γ production, the physiological effects of Th17 responses prevailed as there was a sharp increase in Gr-1+Ly6G+ neutrophils. Adoptive transfer of T cells from infected Tbx21−/− mice into Rag-2−/− mice (Tbx21+/+) revealed that CD4+ T cells maintained their IL-17-producing phenotype, including those cells capable of producing both IFN-γ and IL-17. Furthermore, and in contrast to the effects of IL-2 on Th17 development, IL-2 had no effect on IL-17 production by primed T cells. Importantly, adoptive transfer of T cells from naive Tbx21−/− mice into infected Rag-2−/− mice recapitulated the differentiation of T. cruzi-specific Th17 cells observed in infected Tbx21−/− mice. Conversely, transfer of wild-type T cells into infected Tbx21−/− mice did not reveal an increase in Th17 development. These results demonstrate that T-bet regulates the differentiation of T. cruzi-specific Th17 cells in vivo in a T cell-intrinsic manner. These data provide important insight into the role of T-bet in regulation of parasite-specific Th17 responses.
TLR Signals Promote IL-6/IL-17-Dependent Transplant Rejection
Authors: Chen Luqiu , Ahmed Emily , Wang Tongmin , Wang Ying , Ochando Jordi , Chong Anita S. , Alegre Maria-Luisa
Published: May 2009

Acute allograft rejection has often been correlated with Th1 differentiation, whereas transplantation tolerance is frequently associated with induction of regulation. The discovery of the Th17 phenotype has prompted its scrutiny in transplant rejection. Although IL-17 has recently been observed in settings of acute allograft rejection and drives rejection in T-bet-deficient mice that have impaired type 1 T cell responses, there is little evidence of its requirement during acute rejection in wild-type animals. We and others have previously shown that TLR9 signaling by exogenous CpG at the time of transplantation is sufficient to abrogate anti-CD154-mediated acceptance of fully mismatched cardiac allografts. In this study, we investigated the mechanism by which acute rejection occurs in this inflammatory context. Our results indicate that CpG targets recipient hemopoietic cells and that its pro-rejection effects correlate both with prevention of anti-CD154-mediated conversion of conventional CD4+ T cells into induced regulatory T cells and with the expression of IFN-γ and IL-17 by intragraft CD4+ T cells. Moreover, the combined elimination of IL-6 and IL-17 signaling abrogated the ability of CpG to promote acute cardiac allograft rejection. Thus, proinflammatory signals at the time of transplantation can change the quality of the effector immune response and reveal a pathogenic function for IL-6 and IL-17 in wild-type recipients.
RhoH/TTF Negatively Regulates Leukotriene Production in Neutrophils
Authors: Daryadel Arezoo , Yousefi Shida , Troi David , Schmid Inès , Schmidt-Mende Jan , Mordasini Carlo , Dahinden Clemens A. , Ziemiecki Andrew , Simon Hans-Uwe
Published: May 2009

Leukotriene B4 (LTB4) is an important proinflammatory lipid mediator generated by neutrophils upon activation. GM-CSF stimulation is known to enhance agonist-mediated LTB4 production of neutrophils within minutes, a process called “priming”. In this study, we demonstrate that GM-CSF also limits the production of LTB4 by neutrophils via a transcriptional mechanism at later time points. We identified hemopoietic-specific Ras homologous (RhoH)/translocation three four (TTF), which was induced following GM-CSF stimulation in neutrophils, as a key regulator in this process. Neutrophils derived from RhoH/TTF-deficient (Rhoh−/−) mice demonstrated increased LTB4 production upon activation compared with normal mouse neutrophils. Moreover, neutrophils from cystic fibrosis patients expressed enhanced levels of RhoH/TTF and generated less LTB4 upon activation compared with normal human neutrophils. Taken together, these data suggest that RhoH/TTF represents an inducible feedback inhibitor in neutrophils that is involved in the limitation of innate immune responses.
Human Pregnancy Up-Regulates Tim-3 in Innate Immune Cells for Systemic Immunity
Authors: Zhao Jie , Lei Zhang , Liu Yanyan , Li Bo , Zhang Liang , Fang Haoshu , Song Chuanwang , Wang Xiaomei , Zhang Gui-Mei , Feng Zuo-Hua , Huang Bo
Published: May 2009

Pregnant women have both the local immune tolerance at the maternal-fetal interface and the systemic immune defense against pathogens. To date, regardless of the extensive investigation on the maternal-fetal immune tolerance, the maintenance of systemic immune defense in pregnant women still remains poorly understood. In the present study, we demonstrate that the immunoregulatory molecule T cell Ig and mucin domain (Tim)-3 plays important roles in innate and adaptive immunity of human pregnancy. During pregnancy, Tim-3 is strikingly up-regulated in peripheral blood of pregnant women, most by monocytes but not by T or B cells. The increased IL-4/STAT6 signaling may contribute to such up-regulation of Tim-3. In turn, the increased Tim-3 enhances not only innate immunity but also Th1-associated immune responses of pregnant women against pathogens. In contrast, our clinical data show that abnormal Tim-3 expression level might be connected to the pregnancy loss. In conclusion, our data show in this study that an immune regulatory molecule Tim-3, by virtue of its up-regulation in innate immune cells in pregnant women, enhances both innate and adaptive immune responses. Nevertheless, the abnormality of Tim-3 in pregnant woman may be deleterious to normal pregnancy.
Differential Expression of Granzyme B and C in Murine Cytotoxic Lymphocytes
Authors: Cai Sheng F. , Fehniger Todd A. , Cao Xuefang , Mayer Joshua C. , Brune Joel D. , French Anthony R. , Ley Timothy J.
Published: May 2009

Cytotoxic lymphocytes use the granule exocytosis pathway to kill pathogen-infected cells and tumor cells. Although many genes in this pathway have been extensively characterized (e.g., perforin, granzymes A and B), the role of granzyme C is less clear. We therefore developed a granzyme C-specific mAb and used flow cytometry to examine the expression of granzyme B and C in the lymphocyte compartments of wild-type and mutant GzmB−/− cre mice, which have a small deletion in the granzyme B gene. We detected granzyme B and C expression in CD4+ and CD8+ T cells activated with CD3/CD28 beads or MLRs. Stimulation of NK cells in vitro with IL-15 also induced expression of both granzymes. Granzyme C up-regulation was delayed relative to granzyme B in wild-type lymphocytes, whereas GzmB−/− cre cells expressed granzyme C earlier and more abundantly on a per-cell basis, suggesting that the deleted 350-bp region in the granzyme B gene is important for the regulation of both granzymes B and C. Quantitative RT-PCR revealed that granzyme C protein levels were regulated by mRNA abundance. In vivo, a population of wild-type CD8αα+ intraepithelial lymphocytes constitutively expressed granzyme B and GzmB−/− cre intraepithelial lymphocytes likewise expressed granzyme C. Using a model of a persistent murine CMV infection, we detected delayed expression of granzyme C in NK cells from infected hosts. Taken together, these findings suggest that granzyme C is activated with persistent antigenic stimulation, providing nonredundant backup protection for the host when granzyme B fails.
IL-17A-Expressing T Cells Are Essential for Bacterial Clearance in a Murine Model of Hypersensitivity Pneumonitis
Authors: Simonian Philip L. , Roark Christina L. , Wehrmann Fabian , Lanham Allison M. , Born Willi K. , O'Brien Rebecca L. , Fontenot Andrew P.
Published: May 2009

Hypersensitivity pneumonitis (HP) is an inflammatory lung disease characterized by a diffuse mononuclear cell infiltrate in the lung that can progress to pulmonary fibrosis with chronic exposure to an inhaled Ag. We previously reported that C57BL/6 mice repeatedly exposed to the ubiquitous microorganism Bacillus subtilis develop mononuclear infiltrates in the lung that contain Vγ6/Vδ1+ γδ T cells. In the absence of this T cell subset, mice treated with B. subtilis had significantly increased collagen deposition in the lung, suggesting a regulatory role for Vγ6/Vδ1+ γδ T cells. To further investigate the role of Vγ6/Vδ1+ γδ T cells in B. subtilis-induced lung fibrosis, we exposed transgenic Vγ6/Vδ1 mice to this microorganism and found decreased collagen content in the lung compared with wild-type C57BL/6 mice. Cytokine analysis of lung homogenates from wild-type C57BL/6 mice demonstrated increased IL-17A concentrations with repeated exposure to B. subtilis. In the absence of IL-17 receptor signaling, IL-17ra−/− mice had delayed clearance of B. subtilis with increased lung inflammation and fibrosis. Although IL-17A was predominantly expressed by Vγ6/Vδ1+ T cells, a compensatory increase in IL-17A expression by CD4+ T cells was seen in the absence of γδ T cells that resulted in similar levels of IL-17A in the lungs of TCRδ−/− and wild-type C57BL/6 mice. In combination, our data suggest an important role for IL-17A-expressing T lymphocytes, both γδ and αβ T cells, in eliminating this microorganism that prevents excessive inflammation and eventual lung fibrosis in this murine model of B. subtilis-induced hypersensitivity pneumonitis.
A Backup Role of DNA Polymerase κ in Ig Gene Hypermutation Only Takes Place in the Complete Absence of DNA Polymerase η
Authors: Faili Ahmad , Stary Anne , Delbos Frédéric , Weller Sandra , Aoufouchi Said , Sarasin Alain , Weill Jean-Claude , Reynaud Claude-Agnès
Published: May 2009

Patients with the variant form of xeroderma pigmentosum (XPV) syndrome have a genetic deficiency in DNA polymerase (Pol) η, and display accordingly an increased skin sensitivity to UV light, as well as an altered mutation pattern of their Ig V genes in memory B cells, alteration that consists in a reduced mutagenesis at A/T bases. We previously suggested that another polymerase with a different mutation signature, Pol κ, is used as backup for Ig gene hypermutation in both humans and mice in cases of complete Pol η deficiency, a proposition supported in this study by the analysis of Pol η × Pol κ double-deficient mice. We also describe a new XPV case, in which a splice site mutation of the first noncoding exon results in a decreased mRNA expression, a mRNA that otherwise encodes a normal Pol η protein. Whereas the Pol η mRNA level observed in patient’s fibroblasts is one-twentieth the value of healthy controls, it is only reduced to one-fourth of the normal level in activated B cells. Memory B cells from this patient showed a 50% reduction in A/T mutations, with a spectrum that still displays a strict Pol η signature. Pol η thus appears as a dominant enzyme in hypermutation, its presence precluding the use of a substitute enzyme even in conditions of reduced availability. Such a dominant behavior may explain the lack of Pol κ signature in Ig gene mutations of some XPV patients previously described, for whom residual Pol η activity might exist.
Regulation of Helminth-Induced Th2 Responses by Thymic Stromal Lymphopoietin
Authors: Ramalingam Thirumalai R. , Pesce John T. , Mentink-Kane Margaret M. , Madala Satish , Cheever Allen W. , Comeau Michael R. , Ziegler Steven F. , Wynn Thomas A.
Published: May 2009

Thymic stromal lymphopoietin was recently identified as a master switch for the development of allergen-driven Th2 responses. However, the role of thymic stromal lymphopoietin (TSLP) in the development of helminth-induced Th2 responses is unclear. Here, using TSLPR−/− mice, we show that while TSLPR signaling participates in the development of Schistosoma mansoni egg-induced CD4+ Th2 responses, it plays only a transient role in the development of Th2-dependent pathology in the lung, liver, and intestine. Studies conducted in a pulmonary granuloma model showed that while a reduction in IL-4/IL-13-dependent granulomatous inflammation and tissue eosinophilia was observed in TSLPR−/− mice undergoing a primary response, lesion formation was not affected during a secondary granulomatous response, even though IL-5 and IL-13 were modestly reduced in the knockout mice. To evaluate the importance of TSLPR signaling in the development of a chronic Th2-dependent response, TSLPR−/− mice were also infected with S. mansoni cercariae. Here, the only significant difference noted in TSLPR−/− mice was a modest decrease in liver fibrosis in acutely infected animals. The transient decrease in fibrosis was associated with increased production of the antifibrotic cytokine IFN-γ and decreased production of the profibrotic cytokine IL-13. Although the altered cytokine response persisted in chronically infected TSLPR−/− mice, it failed to reduce granuloma formation or fibrosis, confirming that TSLPR signaling plays a limited role in the development of chronic Th2-dependent pathology. Collectively, these findings suggest that while TSLPR signaling serves a key role in allergen-driven Th2 responses, it exerts minor regulatory activity during this chronic helminth infection.
Designing a Stable Cathode with Multiple Layers to Improve the Operational Lifetime of Polymer Light‐Emitting Diodes
Authors: Lee Tae‐Woo , Kim Mu‐Gyeom , Park Sang Hun , Kim Sang Yeol , Kwon Ohyun , Noh Taeyong , Park Jong‐Jin , Choi Tae‐Lim , Park Jong Hyeok , Chin Byung Doo
Published: May 2009

The short device lifetime of blue polymer light‐emitting diodes (PLEDs) is still a bottleneck for commercialization of self‐emissive full‐color displays. Since the cathode in the device has a dominant influence on the device lifetime, a systematic design of the cathode structure is necessary. The operational lifetime of blue PLEDs can be greatly improved by introducing a three‐layer (BaF2/Ca/Al) cathode compared with conventional two‐layer cathodes (BaF2/Al and Ba/Al). Therefore, the roles of the BaF2 and Ca layers in terms of electron injection, luminous efficiency, and device lifetime are here investigated. For efficient electron injection, the BaF2 layer should be deposited to the thickness of at least one monolayer (∼3 nm). However, it is found that the device lifetime does not show a strong relation with the electron injection or luminous efficiency. In order to prolong the device lifetime, sufficient reaction between BaF2 and the overlying Ca layer should take place during the deposition where the thickness of each layer is around that of a monolayer.