bluuebunny/crossref_metadata_2025 huggingface dataset:
A nuclear export signal within the structural Gag protein is required for prototype foamy virus replication
Authors: Renault Noémie , Tobaly-Tapiero Joelle , Paris Joris , Giron Marie-Lou , Coiffic Audrey , Roingeard Philippe , Saïb Ali
Published: January 2011

Background

The Gag polyproteins play distinct roles during the replication cycle of retroviruses, hijacking many cellular machineries to fulfill them. In the case of the prototype foamy virus (PFV), Gag structural proteins undergo transient nuclear trafficking after their synthesis, returning back to the cytoplasm for capsid assembly and virus egress. The functional role of this nuclear stage as well as the molecular mechanism(s) responsible for Gag nuclear export are not understood.

Results

We have identified a leptomycin B (LMB)-sensitive nuclear export sequence (NES) within the N-terminus of PFV Gag that is absolutely required for the completion of late stages of virus replication. Point mutations of conserved residues within this motif lead to nuclear redistribution of Gag, preventing subsequent virus egress. We have shown that a NES-defective PFV Gag acts as a dominant negative mutant by sequestrating its wild-type counterpart in the nucleus. Trans-complementation experiments with the heterologous NES of HIV-1 Rev allow the cytoplasmic redistribution of FV Gag, but fail to restore infectivity.

Conclusions

PFV Gag-Gag interactions are finely tuned in the cytoplasm to regulate their functions, capsid assembly, and virus release. In the nucleus, we have shown Gag-Gag interactions which could be involved in the nuclear export of Gag and viral RNA. We propose that nuclear export of unspliced and partially spliced PFV RNAs relies on two complementary mechanisms, which take place successively during the replication cycle.
Identification and Characterization of Seven New Exon 11-Associated Splice Variants of the Rat Mu Opioid Receptor Gene, OPRM1
Authors: Xu Jin , Xu Mingming , Rossi Grace C , Pasternak Gavril W , Pan Ying-Xian
Published: January 2011

Background:

The mouse mu opioid receptor (OPRM1) gene undergoes extensive alternative splicing at both the 3'- and 5'-ends of the gene. Previously, several C-terminal variants generated through 3' splicing have been identified in the rat OPRM1 gene. In both mice and humans 5' splicing generates a number of exon 11-containing variants. Studies in an exon 11 knockout mouse suggest the functional importance of these exon 11-associated variants in mediating the analgesic actions of a subset of mu opioids, including morphine-6β-glucuronide (M6G) and heroin, but not others such as morphine and methadone. We now have examined 5' splicing in the rat.

Results:

The current studies identified in the rat a homologous exon 11 and seven exon 11-associated variants, suggesting conservation of exon 11 and its associated variants among mouse, rat and human. RT-PCR revealed marked differences in the expression of these variants across several brain regions, implying region-specific mRNA processing of the exon 11-associated variants. Of the seven rat exon 11-associated variants, four encoded the identical protein as found in rMOR-1, two predicted 6 TM variants, and one, rMOR-1H2, generated a novel N-terminal variant in which a stretch of an additional 50 amino acids was present at the N-terminus of the previously established rMOR-1 sequence. When expressed in CHO cells, the presence of the additional 50 amino acids in rMOR-1H2 significantly altered agonist-induced G protein activation with little effect on opioid binding.

Conclusion:

The identification of the rat exon 11 and its associated variants further demonstrated conservation of 5′ splicing in OPRM1 genes among rodents and humans. The functional relevance of these exon 11 associated variants was suggested by the region-specific expression of their mRNAs and the influence of the N-terminal sequence on agonist-induced G protein coupling in the novel N-terminal variant, rMOR-1H2. The importance of the exon 11-associated variants in mice in M6G and heroin analgesia revealed in the exon 11 knockout mouse implies that these analogous rat variants may also play similar roles in rat. The complexity created by alternative splicing of the rat OPRM1 gene may provide important insights of understanding the diverse responses to the various mu opioids seen in rats.
Immunohistochemical profiles of claudin-3 in primary and metastatic prostatic adenocarcinoma
Authors: Bartholow Tanner L , Chandran Uma R , Becich Michael J , Parwani Anil V
Published: January 2011

Background

Claudins are integral membrane proteins that are involved in forming cellular tight junctions. One member of the claudin family, claudin-3, has been shown to be overexpressed in breast, ovarian, and pancreatic cancer. Here we use immunohistochemistry to evaluate its expression in benign prostatic hyperplasia (BPH), prostatic intraepithelial neoplasia (PIN), normal tissue adjacent to prostatic adenocarcinoma (NAC), primary prostatic adenocarcinoma (PCa), and metastatic prostatic adenocarcinoma (Mets).

Methods

Tissue microarrays were immunohistochemically stained for claudin-3, with the staining intensities subsequently quantified and statistically analyzed using a one-way ANOVA with subsequent Tukey tests for multiple comparisons or a nonparametric equivalent. Fifty-three cases of NAC, 17 cases of BPH, 35 cases of PIN, 107 cases of PCa, and 55 cases of Mets were analyzed in the microarrays.

Results

PCa and Mets had the highest absolute staining for claudin-3. Both had significantly higher staining than BPH (p < 0.05 in both cases) and NAC (p < 0.05 in both cases). PIN had a lower, but non-significant, staining score than PCa and Mets, but a statistically higher score than both BPH and NAC (p < 0.05 for both cases). No significant differences were observed between PCa, Mets, and PIN.

Conclusions

To our knowledge, this represents one of the first studies comparing the immunohistochemical profiles of claudin-3 in PCa and NAC to specimens of PIN, BPH, and Mets. These findings provide further evidence that claudin-3 may serve as an important biomarker for prostate cancer, both primary and metastatic, but does not provide evidence that claudin-3 can be used to predict risk of metastasis.
How Peer Influence Affects Attribute Preferences: A Bayesian Updating Mechanism
Authors: Narayan Vishal , Rao Vithala R. , Saunders Carolyne
Published: January 2011

We study how multiattribute product choices are affected by peer influence. We propose a two-stage conjoint-based approach to examine three behavioral mechanisms of peer influence. We find that when faced with information on peer choices, consumers update their attribute preferences in a Bayesian manner. This suggests that greater uncertainty in the attribute preferences of a focal consumer and lesser uncertainty in preferences of peers both lead to greater preference revision. Greater number of peers is associated with greater preference revision, although the extent of preference revision diminishes with increasing number of peers. Furthermore, to address the significant time and costs associated with collecting sociometric data, we estimate the accuracy of predicted consumer choices when peer influence data are unavailable. Online social network membership and frequency of peer interactions provide better proxies than more common demographic similarity measures. These findings have key implications, especially for word-of-mouth marketing.
Profitability of the Name-Your-Own-Price Channel in the Case of Risk-Averse Buyers
Authors: Shapiro Dmitry
Published: January 2011

In this paper, I study profitability of the name-your-own-price channel (NYOP) in the presence of risk-averse buyers. First, I provide conditions that guarantee that for the monopolistic seller the NYOP is more profitable than the posted price. Second, I consider a more competitive framework where buyers with rejected bids have access to an alternative option. I show that if under the posted-price scenario there are unserved customers with low valuations, then NYOP is more profitable than the posted price. Finally, I study whether adding the posted-price option to the NYOP will further increase the seller's profit and show that for the decreasing absolute risk-aversion utility and a monopolistic seller it does not. In the presence of an alternative option, the answer depends on whether buyers consider the posted-price option and the alternative option to be close substitutes or not. Adding the posted-price option will increase the profit in the former case and will not in the latter.
Predictably Non-Bayesian: Quantifying Salience Effects in Physician Learning About Drug Quality
Authors: Camacho Nuno , Donkers Bas , Stremersch Stefan
Published: January 2011

Experimental and survey-based research suggests that consumers often rely on their intuition and cognitive shortcuts to make decisions. Intuition and cognitive shortcuts can lead to suboptimal decisions and, especially in high-stakes decisions, to legitimate welfare concerns. In this paper, we propose an extension of a Bayesian learning model that allows us to quantify the impact of salience—the fact that some pieces of information are easier to retrieve from memory than others—on physician learning. We show, using data on actual prescriptions for real patients, that physicians' belief formation is strongly influenced by salience effects. Feedback from switching patients—the ones the physician decided to switch to a clinically equivalent treatment—receives considerably more weight than feedback from other patients. In the category we study, salience effects slowed down physicians' speed of learning and the adoption of a new treatment, which raises welfare concerns. For managers, our findings suggest that firms that are able to eliminate, or at least reduce, salience effects to a greater extent than their competitors can speed up the adoption of new treatments. We explore the implications of these results and suggest alternative applications of our model that are relevant for policy makers and managers.
Regret in Overbooking and Fare-Class Allocation for Single Leg
Authors: Lan Yingjie , Ball Michael O. , Karaesmen Itir Z.
Published: January 2011

Focusing on a seller's regret in not acting optimally, we develop a model of overbooking and fare-class allocation in the multifare, single-resource problem in revenue management. We derive optimal static overbooking levels and booking limits, in closed form, that minimize the maximum relative regret (i.e., maximize competitive ratio). We prove that the optimal booking limits are nested. Our work addresses a number of important issues. (i) We use partial information, which is critical because of the difficulty in forecasting fare-class demand. Demand and no-shows are characterized using interval uncertainty in our model. (ii) We make joint overbooking and fare-class allocation decisions. (iii) We obtain conservative but practical overbooking levels that improve the service quality without sacrificing profits. Using computational experiments, we benchmark our methods to existing ones and show that our model leads to effective, consistent, and robust decisions.
The Role of Component Commonality in Product Assortment Decisions
Authors: Bernstein Fernando , Kök A. Gürhan , Xie Lei
Published: January 2011

We consider a firm that produces multiple variants of a product. Products are assembled using a combination of common and dedicated components. We characterize the optimal assortment and derive the optimal inventory levels for the common and dedicated components under various bill-of-material configurations. We investigate the effect of commonality on product variety and compare its benefits under different demand characteristics. Commonality always leads to increased profits, but its effect on the level of product variety depends on the type of commonality. If all common components are used for the production of the entire set of products, then the optimal variety level increases relative to the system with no commonality. However, if the common components are used by a subset of the final products, then the optimal variety level may decrease with commonality. We find that the effects of commonality on profit and variety level are stronger under a demand model in which product demands are more variable and exhibit pairwise negative correlation relative to a model with independent demands.
The Newsvendor Problem with Advertising Revenue
Authors: Wu Zhengping , Zhu Wanshan , Crama Pascale
Published: January 2011

We study a modified newsvendor model in which the newsvendor obtains a revenue from sales to end users as well as from an advertiser paying to obtain access to those end users. We study the optimal decisions for both a price-taking and a price-setting newsvendor when the advertiser has private information about its willingness to pay for advertisements. We find that the newsvendor's optimal policy excludes advertisers with low willingness to pay and distorts the price and quantity from its system-efficient level to screen the advertiser. Our analysis reveals the different roles that pricing and production quantity play as screening instruments. We perform a numerical analysis to investigate the value of information and the impact of the model parameters.
Evaluation of the respective influence of thyroid hormones and TSH on blood coagulation parameters after total thyroidectomy
Authors: Yango John , Alexopoulou Orsalia , Eeckhoudt Stephane , Hermans Cedric , Daumerie Chantal
Published: January 2011

Background

Several hemostatic abnormalities have been described in hypothyroidism, such as modification of coagulation proteins and bleeding tendency. Although thyroid hormone deficiency is considered to be responsible for these changes, the underlying mechanisms have not yet been established.

Objective

To evaluate the respective influence of peripheral thyroid hormones (free thyroxine) and TSH on blood clotting by assessing coagulation parameters in patients with a history of total thyroidectomy for thyroid cancer, under three different conditions: induced hypothyroidism, euthyroid state, and following recombinant human TSH (rhTSH) administration.

Methods

Coagulation parameters (platelet count, fibrinogen, international normalized ratio, prothrombin time, thrombin time, activated partial thromboplastin time (APTT), factor VIII activity ((FVIII:C), as well as von Willebrand factor antigen (VWF:Ag) and VWF activity using collagen binding assay (VWF:CBA)) were measured in patients with severe hypothyroidism following withdrawal of thyroid hormone replacement therapy, and in the same patients with euthyroidism after restoring replacement treatment (group A), and before and after administering rhTSH (group B).

Results

FVIII:C, VWF:Ag, and VWF:CBA were significantly decreased (P<0.001), whereas APTT was significantly increased (P<0.001) in patients with severe hypothyroidism compared with patients in the euthyroid state. No changes in clotting parameters were observed in patients who received rhTSH therapy.

Conclusion

This prospective study shows that severe short-term hypothyroidism is associated with significantly lower levels of VWF:Ag, VWF:CBA, and FVIII:C. Administration of exogenous TSH has no effect on coagulation parameters. These findings suggest that thyroid hormone deficiency is likely to be the main cause of coagulation alterations in patients with hypothyroidism.
FABP 4 is associated with inflammatory markers and metabolic syndrome in morbidly obese women
Authors: Terra Ximena , Quintero Yunuen , Auguet Teresa , Porras Jose Antonio , Hernández Mercé , Sabench Fátima , Aguilar Carmen , Luna Anna María , del Castillo Daniel , Richart Cristobal
Published: January 2011

Objective

The adipocyte/macrophage fatty acid-binding protein 4 (FABP4) has been described as a biomarker for adiposity and metabolic syndrome (MS). The aims of this study were to assess the relationship between FABP4 and inflammatory cytokines related to obesity, and to evaluate FABP4 mRNA expression in visceral and subcutaneous adipose tissue in non-diabetic morbidly obese women versus healthy lean women.

Methods

We analyzed circulating levels of FABP4 in 81 Spanish women: 38 lean (body mass index (BMI)<25 kg/m2) and 43 morbidly obese (BMI>40 kg/m2). We took 30 follow-up blood samples at 6 and 12 months after bariatric surgery. We assessed FABP4 gene expression in samples of subcutaneous abdominal and visceral adipose tissue. Adipose tissue mRNA expression was determined by real-time RT-PCR.

Results

In morbidly obese women, plasma FABP4 levels were significantly higher than in non-obese patients. These levels positively correlated with BMI, homeostasis model assessment of insulin resistance (HOMA2-IR), and plasma glucose and insulin levels. Post-operative FABP4 levels decreased by a maximum of 30% after 12 months. We also found an inverse association between FABP4 and adiponectin levels, and positive correlations between FABP4 and circulating leptin, tumor necrosis factor (TNF) receptors, C-reactive protein (CRP) and interleukin 6 levels. Linear regression analysis revealed that FABP4 was more closely related to HOMA2-IR than adiponectin, CRP, TNF-RI, or leptin. Furthermore, high circulating FABP4 levels were associated with the presence of MS. FABP4 mRNA expression in visceral adipose tissue was related to its circulating levels in morbidly obese women.

Conclusions

Our results indicate that serum FABP4 is associated with inflammatory factors related to obesity and MS in non-diabetic morbidly obese women.
What Do Prostate Cancer Patients Die Of?
Authors: Riihimäki Matias , Thomsen Hauke , Brandt Andreas , Sundquist Jan , Hemminki Kari
Published: January 2011

Background.

A recent rise in the incidence of prostate cancer and a more favorable outcome have increased the proportions of other causes of death in affected men. Extending the survival of prostate cancer patients thus requires knowledge of all causes of death.

Methods.

Data on the population, cancers, and causes of death were gathered from the nationwide Swedish Family-Cancer Database. A Cox regression model, comparing prostate cancer patients with all other men, was applied. Hazard ratios (HR) were calculated both for the underlying cause and for dying with a specific cause listed among multiple causes of death.

Findings.

Among 686,500 observed deaths, 62,500 were prostate cancer patients. For underlying causes other than prostate cancer, the highest cause-specific HRs were found for external causes (HR, 1.24; 95% confidence interval [CI], 1.16–1.31), diseases of the pulmonary circulation (HR, 1.22; 95% CI, 1.09–1.37), and heart failure (HR, 1.18; 95% CI, 1.11–1.24). For specific multiple causes, the highest HRs were found for anemia (HR, 2.28; 95% CI, 2.14–2.42), diseases of the pulmonary circulation (HR, 1.61; 95% CI, 1.55–1.68), and urinary system disease (HR, 1.90; 95% CI, 1.84–1.96).

Interpretations.

Prostate cancer patients have a higher risk for dying from various causes other than prostate cancer, including external causes and heart failure. Mechanisms have been proposed linking these elevated risks to both cancer and treatment. More attention should be paid to comorbidities in men with prostate cancer. The present study fulfills a gap in the knowledge of death causes in prostate cancer patients.
A Three Component Latent Class Model for Robust Semiparametric Gene Discovery
Authors: Alfo' Marco , Farcomeni Alessio , Tardella Luca
Published: January 2011

We propose a robust model for discovering differentially expressed genes which directly incorporates biological significance, i.e., effect dimension. Using the so-called c-fold rule, we transform the expressions into a nominal observed random variable with three categories: below a fixed lower threshold, above a fixed upper threshold or within the two thresholds. Gene expression data is then transformed into a nominal variable with three levels possibly originated by three different distributions corresponding to under expressed, not differential, and over expressed genes. This leads to a statistical model for a 3-component mixture of trinomial distributions with suitable constraints on the parameter space. In order to obtain the MLE estimates, we show how to implement a constrained EM algorithm with a latent label for the corresponding component of each gene. Different strategies for a statistically significant gene discovery are discussed and compared. We illustrate the method on a little simulation study and a real dataset on multiple sclerosis.
Polymorphic microsatellite markers in the invasive shrub Buddleja davidii (Scrophulariaceae)1
Authors: Schreiter Susanne , Ebeling Susan K. , Durka Walter
Published: January 2011

• Premise of the study: Microsatellite primers were developed for the invasive plant Buddleja davidii, a Chinese shrub that is an invader in most other continents.

• Methods and Results: An invasive population was analyzed using eight di‐ and tetranucleotide microsatellite loci. The number of alleles per locus ranged from 5 to 14. Due to polyploidy, exact genotypes could not be determined. Progeny arrays were used to study the outcrossing rate using presence/absence data of alleles resulting in an estimate of multilocus outcrossing rate of 93%. The markers were successfully tested in five congeneric species.

• Conclusions: The results indicate the utility of these loci in future studies of population genetics and breeding systems in B. davidii and in congeneric species.
Development and characterization of microsatellite markers for Sagittaria trifolia var. sinensis (Alismataceae)
Authors: Wu Zhi‐Hua , Wang Shu‐Zhen , Hu Ji‐Hong , Li Feng , Ke Wei‐Dong , Ding Yi
Published: January 2011

• Premise of the study: Microsatellite markers were developed for the aquatic plant Sagittaria trifolia var. sinensis to assess its genetic diversity and population structure. Cross‐species transferability was assayed in eight congeneric species.

• Methods and Results: Seventeen microsatellite markers were isolated and characterized in Sagittaria trifolia var. sinensis using Fast Isolation by AFLP of Sequence COntaining Repeats (FIASCO) protocol. Across the evaluated populations, 14 of the markers showed polymorphisms with 3 to 11 alleles per locus; the observed and expected heterozygosity (Ho and HE) ranged from 0.0000 to 0.6364 and from 0.0000 to 0.8386, respectively. Nine of the loci were successfully amplified in the congeneric species.

• Conclusions: These markers will be useful for further investigation of population genetics in Sagittaria trifolia var. sinensis and related research in Sagittaria species.
La dimension culturelle du développement territorial
Authors: Kahn René
Published: January 2011

La prise en compte des aspects culturels du développement correspond à une évolution de la réalité économique mais aussi à une évolution épistémologique en économie spatiale et régionale. Après avoir identifié les différentes acceptions de la notion de territoire dans la littérature, nous privilégions celle qui le définit comme une construction d’acteurs partageant une même culture du développement. La dimension culturelle qui est désormais partie prenante de toute politique de développement n’est cependant pas totalement intégrable dans le cadre de l’analyse économique standard. La poursuite du dialogue économie - culture reste par conséquent souhaitable.
L'évolution du débat sur les SYAL : le regard d'un économiste
Authors: Requier-Desjardins Denis
Published: January 2011

Cet article fait un bilan de l’approche économique de la notion de système agroalimentaire localisé (SYAL) apparu depuis environ une dizaine d’années. Il cherche notamment à la positionner par rapport à la notion de Système Productif Local : s’agit-il d’une simple déclinaison sectorielle du concept de SPL ou identifie-t-elle des dimensions spécifiques de l’ancrage territorial. La thèse défendue est que, si les deux notions entretiennent une parenté évidente, l’analyse des SYAL fait apparaître une relation spécifique au territoire, à travers les processus de qualification des produits agroalimentaires notamment et la relation au développement durable.
La territorialisation : proposition pour la compréhension du phénomène par une entrée systémique
Authors: Wœssner Raymond
Published: January 2011

La mondialisation conduit à une recomposition rapide et profonde des territoires. Choisis dans le contexte du Rhin supérieur, trois exemples concrets viennent tester la pertinence de la notion de territorialisation : Mulhouse en tant que modèle industriel historique, le réseau technologique et scientifique BioValley et le Pôle de Compétitivité Véhicule du Futur. Sur cette base, est proposé un cheminement type qui définit les manières et les étapes de la territorialisation de manière générale. Il cherche à préciser les contours d’un certain nombre de notions, comme la bifurcation ou l’émergence.
L'imbrication spatiale dans l'analyse des territoires : formalisation, modélisation, simulation
Authors: Voiron-Canicio Christine , Dutozia Jérôme , Basse Reine-Maria , Dubus Nathalie , Maignant Gilles , Saint-Amand Pascale , Sevenet Marie
Published: January 2011

Cet article situe l’imbrication spatiale dans le cadre du fonctionnement systémique du territoire. L’articulation des systèmes territoriaux imbriqués est analysée dans l’optique de la durabilité et d’une meilleure anticipation des dynamiques territoriales. Au cours de ces dynamiques, les possibilités de changement d’état des systèmes territoriaux résultent d’interactions et d’imbrications à la fois spatiales, réticulaires et scalaires qui peuvent opérer, aussi bien dans des temporalités longues que courtes. L’intérêt d’une démarche croisant analyse spatiale et simulation sera développé à partir de deux applications : la première porte sur l’imbrication des vulnérabilités territoriales dans un système de risques générés par le réseau électrique ; la seconde appréhende les futurs possibles de l’espace transfrontalier franco-italo-monégasque dont la partie française devrait être desservie en 2020 par une ligne ferroviaire à grande vitesse.
Ville durable, ville mutable : quelle convergence en France et en Suisse ?
Authors: Andres Lauren , Bochet Béatrice
Published: January 2011

Cet article confronte la notion de mutabilité à celle de durabilité au travers de l’analyse des transformations des territoires urbains en France et en Suisse. Il analyse les positionnements antagonistes, convergents, ou synonymes, inhérents aux interactions entre ces deux champs de l’action publique. L’intérêt du propos réside dans la confrontation, peu fréquente, des deux termes. En effet, la durabilité constitue un des référentiels incontournables de l’action publique depuis quinze ans, alors que la notion de mutabilité désigne l’ensemble des processus de requalification des territoires en déshérence en d’autres termes, en friches. La mutabilité semble être associée à des processus dits de durabilité au travers du principe de reconstruction de la ville sur la ville ; toutefois, trois études de cas montrent que la mutabilité n’est pas toujours « synonyme » de durabilité.
Mesurer le développement durable : jeux d'indicateurs et enjeux locaux
Authors: Decamps Mélanie , Vicard Fanny
Published: January 2011

Alors que la définition même du développement durable fait débat, un consensus semble avoir émergé sur la nécessité d’agir localement pour résoudre un problème global. Cela implique, notamment pour les scientifiques, de concevoir de nouveaux outils de mesure du développement durable à l’échelle des territoires. Plusieurs études empiriques ont été menées en ce sens sur des territoires multiples, aux caractéristiques parfois proches (villes, régions, etc.). L’objectif de cet article est de déterminer si l’hétérogénéité des territoires étudiés résulte nécessairement en une hétérogénéité des systèmes d’indicateurs proposés. A partir d’une revue de la littérature académique internationale, nous montrons que, en l’état actuel des recherches, on ne peut établir de liens entre les caractéristiques des territoires et les systèmes d’indicateurs proposés.
Investissement direct étranger, régimes fiscaux, modes de financement et politique économique régionale
Authors: Laurent Hélène , Mignolet Michel , Meunier Olivier
Published: January 2011

Les autorités publiques régionales ou nationales désireuses de stimuler l’investissement direct étranger sur leur territoire doivent composer avec les règles fiscales internationales et les stratégies d’optimisation fiscale des groupes multinationaux. Prenant appui sur la théorie de la taxation effective, cette contribution montre comment l’efficience des incitants à l’investissement offerts par le pays de la filiale est affectée par la structure de financement du groupe (financements simples et plus complexes, notamment utilisation d’instruments hybrides, ou interposition d’une société établie dans un pays tiers) et par les régimes d’atténuation de la double imposition internationale (exemption ou imputation) appliqués par le pays (ou la région) de la maison mère.
Enhanced and Sustained CD8+ T Cell Responses with an Adenoviral Vector-Based Hepatitis C Virus Vaccine Encoding NS3 Linked to the MHC Class II Chaperone Protein Invariant Chain
Authors: Mikkelsen Marianne , Holst Peter Johannes , Bukh Jens , Thomsen Allan Randrup , Christensen Jan Pravsgaard
Published: January 2011

Potent and broad cellular immune responses against the nonstructural (NS) proteins of hepatitis C virus (HCV) are associated with spontaneous viral clearance. In this study, we have improved the immunogenicity of an adenovirus (Ad)-based HCV vaccine by fusing NS3 from HCV (Strain J4; Genotype 1b) to the MHC class II chaperone protein invariant chain (Ii). We found that, after a single vaccination of C57BL/6 or BALB/c mice with Ad-IiNS3, the HCV NS3-specific CD8+ T cell responses were significantly enhanced, accelerated, and prolonged compared with the vaccine encoding NS3 alone. The AdIiNS3 vaccination induced polyfunctional CD8+ T cells characterized by coproduction of IFN-γ, TNF-α and IL-2, and this cell phenotype is associated with good viral control. The memory CD8+ T cells also expressed high levels of CD27 and CD127, which are markers of long-term survival and maintenance of T cell memory. Functionally, the AdIiNS3-vaccinated mice had a significantly increased cytotoxic capacity compared with the AdNS3 group. The AdIiNS3-induced CD8+ T cells protected mice from infection with recombinant vaccinia virus expressing HCV NS3 of heterologous 1b strains, and studies in knockout mice demonstrated that this protection was mediated primarily through IFN-γ production. On the basis of these promising results, we suggest that this vaccination technology should be evaluated further in the chimpanzee HCV challenge model.
Recognition of Cytoplasmic RNA Results in Cathepsin-Dependent Inflammasome Activation and Apoptosis in Human Macrophages
Authors: Rintahaka Johanna , Lietzén Niina , Öhman Tiina , Nyman Tuula A. , Matikainen Sampsa
Published: January 2011

dsRNA is an important pathogen-associated molecular pattern that is primarily recognized by cytosolic pattern-recognition receptors of the innate-immune system during virus infection. This recognition results in the activation of inflammasome-associated caspase-1 and apoptosis of infected cells. In this study, we used high-throughput proteomics to identify secretome, the global pattern of secreted proteins, in human primary macrophages that had been activated through the cytoplasmic dsRNA-recognition pathway. The secretome analysis revealed cytoplasmic dsRNA-recognition pathway-induced secretion of several exosome-associated proteins, as well as basal and dsRNA-activated secretion of lysosomal protease cathepsins and cysteine protease inhibitors (cystatins). Inflammasome activation was almost completely abolished by cathepsin inhibitors in response to dsRNA stimulation, as well as encephalomyocarditis virus and vesicular stomatitis virus infections. Interestingly, Western blot analysis showed that the mature form of cathepsin D, but not cathepsin B, was secreted simultaneously with IL-18 and inflammasome components ASC and caspase-1 in cytoplasmic dsRNA-stimulated cells. Furthermore, small interfering RNA-mediated silencing experiments confirmed that cathepsin D has a role in inflammasome activation. Caspase-1 activation was followed by proteolytic processing of caspase-3, indicating that inflammasome activation precedes apoptosis in macrophages that had recognized cytoplasmic RNA. Like inflammasome activation, apoptosis triggered by dsRNA stimulation and virus infection was effectively blocked by cathepsin inhibition. In conclusion, our results emphasize the importance of cathepsins in the innate immune response to virus infection.
Marginal Zone B Cells Regulate Antigen Capture by Marginal Zone Macrophages
Authors: You Yuying , Myers Riley C. , Freeberg Larry , Foote Jeremy , Kearney John F. , Justement Louis B. , Carter Robert H.
Published: January 2011

The marginal zone (MZ) of the mouse spleen contains macrophages that express receptors that trap pathogens, including the scavenger receptor macrophage receptor with a collagenous structure and the C-type lectin specific intracellular adhesion molecule-grabbing nonintegrin receptor 1 (SIGN-R1). We previously reported that expression of SIGN-R1 was decreased in CD19-deficient mice. In this study, we demonstrate that SIGN-R1 is expressed on a subset of macrophage receptor with a collagenous structure (MARCO)+ macrophages. This subset is diminished when MZ B cells are absent due to either genetic developmental defects or following transient migration of B cells out of the MZ. When B cells return to the MZ, there is a delay in recovery of SIGN-R1–expressing macrophages. During this period, capture of Ficoll, which for the macrophages requires SIGN-R1, remains defective not only by the macrophages, but also by the B cells. Thus, MZ B cells regulate expression of molecules on macrophages that are important for trapping Ag, which, in turn, is required for Ag capture by the B cells.
Class IA Phosphoinositide 3-Kinase β and δ Regulate Neutrophil Oxidase Activation in Response toAspergillus fumigatusHyphae
Authors: Boyle Keith B. , Gyori David , Sindrilaru Anca , Scharffetter-Kochanek Karin , Taylor Philip R. , Mócsai Attila , Stephens Len R. , Hawkins Phillip T.
Published: January 2011

An effective immune response to the ubiquitous fungus Aspergillus fumigatus is dependent upon production of reactive oxygen species (ROS) by the NADPH oxidase. This is evidenced by the acute sensitivity of oxidase-deficient humans and mice to invasive aspergillosis. Neutrophils are recruited to the lungs shortly postinfection and respond by phagocytosing conidia and mediating extracellular killing of germinated hyphae in a ROS-dependent manner. However, the signaling mechanisms regulating the generation of ROS in response to hyphae are poorly understood. PI3Ks are important regulators of numerous cellular processes, with much recent work describing unique roles for the different class I PI3K isoforms. We showed by live-cell imaging that the lipid products of class I PI3Ks accumulated at the hyphal-bound neutrophil plasma membrane. Further, we used pharmacological and genetic approaches to demonstrate essential, but overlapping, roles for PI3Kβ and PI3Kδ in the ROS and spreading responses of murine neutrophils to Aspergillus hyphae. Hyphal-induced ROS responses were substantially inhibited by deletion of the common β2-integrin subunit CD18, with only a minor, redundant role for Dectin-1. However, addition of soluble algal glucans plus the genetic deletion of CD18 were required to significantly inhibit activation of the PI3K-effector protein kinase B. Hyphal ROS responses were also totally dependent on the presence of Syk, but not its ITAM-containing adaptor proteins FcRγ or DAP12, and the Vav family of Rac-guanine nucleotide exchange factors. These results start to define the signaling network controlling neutrophil ROS responses to A. fumigatus hyphae.
Rhesus Macaque Inhibitory and Activating KIR3D Interact with Mamu-A–Encoded Ligands
Authors: Rosner Cornelia , Kruse Philip H. , Hermes Meike , Otto Nicole , Walter Lutz
Published: January 2011

Specific interactions between killer cell Ig-like receptors (KIRs) and MHC class I ligands have not been described in rhesus macaques despite their importance in biomedical research. Using KIR–Fc fusion proteins, we detected specific interactions for three inhibitory KIRs (3DLW03, 3DL05, 3DL11) and one activating KIR (3DS05). As ligands we identified Macaca mulatta MHC (Mamu)-A1– and Mamu-A3–encoded allotypes, among them Mamu-A1*001:01, which is well known for association with slow progression to AIDS in the rhesus macaque experimental SIV infection model. Interactions with Mamu-B or Mamu-I molecules were not found. KIR3DLW03 and KIR3DL05 differ in their binding sites to their shared ligand Mamu-A1*001:01, with 3DLW03 depending on presence of the α1 domain, whereas 3DL05 depends on both the α1 and α2 domains. Fine-mapping studies revealed that binding of KIR3DLW03 is influenced by presence of the complete Bw4 epitope (positions 77, 80–83), whereas that of KIR3DL05 is mainly influenced by amino acid position 77 of Bw4 and positions 80–83 of Bw6. Our findings allowed the successful prediction of a further ligand of KIR3DL05, Mamu-A1*002:01. These functional differences of rhesus macaque KIR3DL molecules are in line with the known genetic diversification of lineage II KIRs in macaques.
Differential Expression of NLRP3 among Hematopoietic Cells
Authors: Guarda Greta , Zenger Manuel , Yazdi Amir S. , Schroder Kate , Ferrero Isabel , Menu Philippe , Tardivel Aubry , Mattmann Chantal , Tschopp Jürg
Published: January 2011

Although the importance of the NOD-like receptor family, pyrin domain containing 3 (NLRP3) inflammasome in health and disease is well appreciated, a precise characterization of NLRP3 expression is yet undetermined. To this purpose, we generated a knock-in mouse in which the Nlrp3 coding sequence was substituted for the GFP (enhanced GFP [egfp]) gene. In this way, the expression of eGFP is driven by the endogenous regulatory elements of the Nlrp3 gene. In this study, we show that eGFP expression indeed mirrors that of NLRP3. Interestingly, splenic neutrophils, macrophages, and, in particular, monocytes and conventional dendritic cells showed robust eGFP fluorescence, whereas lymphoid subsets, eosinophils, and plasmacytoid dendritic cells showed negligible eGFP levels. NLRP3 expression was highly inducible in macrophages, both by MyD88- and Trif-dependent pathways. In vivo, when mice were challenged with diverse inflammatory stimuli, differences in both the number of eGFP-expressing cells and fluorescence intensity were observed in the draining lymph node. Thus, NLRP3 levels at the site of adaptive response initiation are controlled by recruitment of NLRP3-expressing cells and by NLRP3 induction.
A Single Nucleotide Polymorphism in NF-κB Inducing Kinase Is Associated with Mortality in Septic Shock
Authors: Thair Simone A. , Walley Keith R. , Nakada Taka-aki , McConechy Melissa K. , Boyd John H. , Wellman Hugh , Russell James A.
Published: January 2011

We tested the hypothesis that single nucleotide polymorphisms (SNPs) within genes of the NF-κB pathway are associated with altered clinical outcome of septic shock patients. We genotyped 59 SNPs in the NF-κB pathway in a discovery cohort of septic shock patients (St. Paul’s Hospital [SPH], N = 589), which identified the C allele of rs7222094 T/C within MAP3K14 (NF-κB inducing kinase; NIK) associated with increased 28-d mortality (uncorrected p = 0.00024, Bonferroni corrected p = 0.014). This result was replicated in a second cohort of septic shock patients (Vasopressin and Septic Shock Trial [VASST; N = 616]) in which the CC genotype of rs7222094 was associated with increased 28-d mortality (Cox regression: SPH cohort hazard ratio [HR], 1.35; 95% confidence interval [CI], 1.12–1.64; p = 0.002 Caucasian only; and VASST cohort HR, 1.24; 95% CI, 1.00–1.52; p = 0.048 Caucasian only). Patients having the CC genotype of rs7222094 in SPH experienced more renal and hematological dysfunction (p = 0.003 and p = 0.011), while patients of the VASST cohort with the rs7222094 CC genotype showed the same trend toward more renal dysfunction. In lymphoblastoid cell lines, we found the rs7222094 genotype most strongly associated with mRNA expression of CXCL10, a chemokine regulated by NF-κB. Accordingly, we measured CXCL10 protein levels and found that the CC genotype of rs7222094 was associated with significantly lower levels than those of the TT genotype in lymphoblastoid cell lines (p < 0.05) and in septic shock patients (p = 0.017). This suggests that the CC genotype of NIK rs7222094 is associated with increased mortality and organ dysfunction in septic shock patients, perhaps due to altered regulation of NF-κB pathway genes, including CXCL10.
Intrinsic IL-21 Signaling Is Critical for CD8 T Cell Survival and Memory Formation in Response to Vaccinia Viral Infection
Authors: Novy Patricia , Huang Xiaopei , Leonard Warren J. , Yang Yiping
Published: January 2011

CD4 T cell help plays an important role in promoting CD8 T cell immunity to pathogens. In models of infection with vaccinia virus (VV) and Listeria monocytogenes, CD4 T cell help is critical for the survival of activated CD8 T cells during both the primary and memory recall responses. Still unclear, however, is how CD4 T cell help promotes CD8 T cell survival. In this study, we first showed that CD4 T cell help for the CD8 T cell response to VV infection was mediated by IL-21, a cytokine produced predominantly by activated CD4 T cells, and that direct action of IL-21 on CD8 T cells was critical for the VV-specific CD8 T cell response in vivo. We next demonstrated that this intrinsic IL-21 signaling was essential for the survival of activated CD8 T cells and the generation of long-lived memory cells. We further revealed that IL-21 promoted CD8 T cell survival in a mechanism dependent on activation of the STAT1 and STAT3 pathways and subsequent upregulation of the prosurvival molecules Bcl-2 and Bcl-xL. These results identify a critical role for intrinsic IL-21 signaling in CD8 T cell responses to an acute viral infection in vivo and may help design effective vaccine strategies.
Two Unique Human Decidual Macrophage Populations
Authors: Houser Brandy L. , Tilburgs Tamara , Hill Jonathan , Nicotra Matthew L. , Strominger Jack L.
Published: January 2011

Several important events occur at the maternal–fetal interface, including generation of maternal–fetal tolerance, remodeling of the uterine smooth muscle and its spiral arteries and glands, and placental construction. Fetal-derived extravillous trophoblasts come in direct contact with maternal decidual leukocytes. Macrophages represent ∼20% of the leukocytes at this interface. In this study, two distinct subsets of CD14+ decidual macrophages (dMɸs) are found to be present in first-trimester decidual tissue, CD11cHI and CD11cLO. Gene expression analysis by RNA microarray revealed that 379 probes were differentially expressed between these two populations. Analysis of the two subsets revealed several clusters of coregulated genes that suggest distinct functions for these subsets in tissue remodeling, growth, and development. CD11cHI dMɸs express genes associated with lipid metabolism and inflammation, whereas CD11cLO dMɸs express genes associated with extracellular matrix formation, muscle regulation, and tissue growth. The CD11cHI dMɸs also differ from CD11cLO dMɸs in their ability to process protein Ag and are likely to be the major APCs in the decidua. Moreover, these populations each secrete both proinflammatory and anti-inflammatory cytokines that may contribute to the balance that establishes fetal–maternal tolerance. Thus, they do not fit the conventional M1/M2 categorization.
A Novel Human IgA Monoclonal Antibody Protects against Tuberculosis
Authors: Balu Sucharitha , Reljic Rajko , Lewis Melanie J. , Pleass Richard J. , McIntosh Richard , van Kooten Cees , van Egmond Marjolein , Challacombe Stephen , Woof Jenny M. , Ivanyi Juraj
Published: January 2011

Abs have been shown to be protective in passive immunotherapy of tuberculous infection using mouse experimental models. In this study, we report on the properties of a novel human IgA1, constructed using a single-chain variable fragment clone (2E9), selected from an Ab phage library. The purified Ab monomer revealed high binding affinities for the mycobacterial α-crystallin Ag and for the human FcαRI (CD89) IgA receptor. Intranasal inoculations with 2E9IgA1 and recombinant mouse IFN-γ significantly inhibited pulmonary H37Rv infection in mice transgenic for human CD89 but not in CD89-negative littermate controls, suggesting that binding to CD89 was necessary for the IgA-imparted passive protection. 2E9IgA1 added to human whole-blood or monocyte cultures inhibited luciferase-tagged H37Rv infection although not for all tested blood donors. Inhibition by 2E9IgA1 was synergistic with human rIFN-γ in cultures of purified human monocytes but not in whole-blood cultures. The demonstration of the mandatory role of FcαRI (CD89) for human IgA-mediated protection is important for understanding of the mechanisms involved and also for translation of this approach toward development of passive immunotherapy of tuberculosis.
NF-κB– and AP-1–Mediated DNA Looping Regulates Osteopontin Transcription in Endotoxin-Stimulated Murine Macrophages
Authors: Zhao Wei , Wang Lijuan , Zhang Meng , Wang Peng , Zhang Lei , Yuan Chao , Qi Jianni , Qiao Yu , Kuo Paul C. , Gao Chengjiang
Published: January 2011

Osteopontin (OPN) is expressed by various immune cells and modulates both innate and adaptive immune responses. However, the molecular mechanisms that control opn gene expression, especially at the chromatin level, remain largely unknown. We have previously demonstrated many specific cis- and trans-regulatory elements that determine the extent of endotoxin (LPS)-mediated induction of OPN synthesis in murine macrophages. In the present study, we confirm that NF-κB also plays an important role in the setting of LPS-stimulated OPN expression through binding to a distal regulatory element. Importantly, we demonstrate that LPS stimulates chromosomal loops in the OPN promoter between NF-κB binding site and AP-1 binding site using chromosome conformation capture technology. The crucial role of NF-κB and AP-1 in LPS-stimulated DNA looping was confirmed, as small interfering RNA knock-down of NF-κB p65 and AP-1 c-Jun exhibited decreased levels of DNA looping. Furthermore, we demonstrate that p300 can form a complex with NF-κB and AP-1 and is involved in DNA looping and LPS-induced OPN expression. Therefore, we have identified an essential mechanism to remodel the local chromatin structures and spatial conformations to regulate LPS-induced OPN expression.
Case report: Combined transarterial and direct approaches for embolization of a large mandibular arteriovenous malformation
Authors: Koshy Chiramel George , Keshava Shyamkumar N , Moses Vinu , Sen Sudipta
Published: January 2011

Arteriovenous malformations (AVMs) that involve the mandible are difficult lesions to treat, with traditional options being surgery and embolization. This article describes a large mandibular AVM that was treated with embolization using transarterial as well as direct puncture approaches. Follow-up imaging showed thrombosis of the vascular spaces of the malformation. There were no complications. The patient is doing well and is on follow-up.
Case report: Complex internal mammary to pulmonary artery fistula as a cause of hemoptysis in tuberculosis: Diagnosis and endovascular management using ethylene vinyl alcohol copolymer (Onyx)
Authors: Pierce Gregory , Ahuja Chaitanya , Chadha Meghna
Published: January 2011

A complex right internal mammary to right pulmonary artery fistula resulting in hemoptysis was successfully treated by embolization with a liquid, nonadhesive, embolic agent - ethylene vinyl alcohol copolymer (Onyx). There were no procedural complications and no recurrence of symptoms has been seen after 2 years of follow-up.