bluuebunny/crossref_metadata_2025 huggingface dataset:
The Validity of Subjects in Korean Dental Technicians' Licensing Examination
Authors: Kim Woong-chul , Lee Won-chul , Sohn Young-seok , Oh Sae-yoon , Kim Bu-sob , Yu Chin-ho , Kim Ji-hwan
Published: February 2009

This study prepared a basic framework for the development and improvement of Korean Dental Technicians' Licensing Examination, based on actual test questions. A peer review was conducted to ensure relevance to current practices in dental technology. For the statistical analysis, 1000 dental laboratory technicians were selected; specialists in dental laboratory technology (laboratory owners, educators, etc.) were involved in creating valid and reliable questions. Results indicated that examination subjects should be divided into three categories: basic dental laboratory theory, dental laboratory specialties, and a practical examination. To ensure relevance to current practice, there should be less emphasis on basic dental laboratory theory, including health-related laws, and more emphasis on dental laboratory specialties. Introduction to dental anatomy should be separated from oral anatomy and tooth morphology; and fixed prosthodontics should be separated from crown and bridge technology and dental ceramics technology. Removable orthodontic appliance technology should be renamed 'orthodontic laboratory technology'. There should be less questions related to health related law, oral anatomy, dental hygiene, dental materials science and inlay, while the distribution ratio of questions related to tooth morphology should be maintained. There should be a decrease in the distribution ratio of questions related to crown and bridge technology, dental ceramics technology, complete dentures and removable partial dentures technology, and orthodontic laboratory technology. In the practical examination, the current multiple choice test should be replaced with tooth carving using wax or plaster. In dental laboratory specialties, subjects related to contemporary dental laboratory technology should be included in the test items.
The New Horizon for Evaluations in Medical Education in Korea
Authors: Baik Sang-Ho
Published: February 2009

Over the last two decades, there have been a number of significant changes in the evaluation system in medical education in Korea. One major improvement in this respect has been the listing of learning objectives at medical schools and the construction of a content outline for the Korean Medical Licensing Examination that can be used as a basis of evaluation. Item analysis has become a routine method for obtaining information that often provides valuable feedback concerning test items after the completion of a written test. The use of item response theory in analyzing test items has been spreading in medical schools as a way to evaluate performance tests and computerized adaptive testing. A series of recent studies have documented an upward trend in the adoption of the objective structured clinical examination (OSCE) and clinical practice examination (CPX) for measuring skill and attitude domains, in addition to tests of the knowledge domain. There has been an obvious increase in regional consortiums involving neighboring medical schools that share the planning and administration of the OSCE and CPX; this includes recruiting and training standardized patients. Such consortiums share common activities, such as case development and program evaluation. A short history and the pivotal roles of four organizations that have brought about significant changes in the examination system are discussed briefly.
Proposal of the Implementation of an International Pharmacy Graduate Preliminary Examination
Authors: Kwon Kyenghee , Park Jeoung Hill , Kim Jinwoong , Lee Seung Ki
Published: February 2009

At present, graduates of international pharmacy schools can apply to take the Korean Pharmacist Licensing Examination after passing a review by the Accreditation Board of the Pharmacy Schools and Licenses. However, since the educational content of different schools and the roles of pharmacists differ from country to country, a preliminary examination might be necessary before the Pharmacist Licensing Examination. To prepare to implement a preliminary examination for foreign pharmacy graduates in Korea, we summarized the preliminary examinations used in four other countries and presented a proposal for a preliminary examination. Data were collected via the internet and through telephone interviews with appropriate persons. The proposal was revised after a public forum. There are preliminary examinations in the USA, Canada, Australia, and the United Kingdom, and these involve written, oral, practice, and English proficiency tests. We proposed that the Korean preliminary examination consist of a written test on basic pharmacy, a test in the Korean language, and an interview. The preliminary examination should include suitable items that effectively evaluate international graduates. Graduates of international pharmacy schools who have an ability equivalent to graduates of Korean pharmacy schools should be eligible to write the Korean Licensing Examination.
Students' Evaluation of a Team-based Course on Research and Publication Ethics: Attitude Change in Medical School Graduate Students
Authors: Kim Soo Young
Published: February 2009

In response to a growing need for students to appreciate ethical issues in medical research and publication, a brief team-based learning (TBL) course was presented to graduate students in the medical school of Hallym University in October and November 2007. To gather information as a basis for improving the course, questionnaires were distributed to 19 students and the feedback was evaluated. The questionnaire consisted of four categories: general course content (7 items), changes in attitudes toward research and publication ethics (6 items), the TBL format (6 items), and an open-ended question about the class (1 item). The most positive response had to do with the importance of the material. Students reported that their knowledge about ethical issues increased, and they expressed satisfaction regarding the communication with their tutors within the TBL format. Most students showed positive responses to the subject as well as to TBL. Since this was the first trial offering of this material in the graduate program at this medical school, it may have been novel to the students. The attitude change and the knowledge acquisition reported by students reflect a very positive outcome of this class. After adjustments to improve weaknesses, such as the short time allocation and students??lack of prior background, the outcomes of this TBL course on research and publication ethics provide a good basis for its continuation.
Experimental Investigations of Extracted Rapeseed Combustion Emissions in a Small Scale Stationary Fluidized Bed Combustor
Authors: Dinh Tung Nguyen , Steinbrecht Dieter , Vincent Tristan
Published: February 2009

The objective of this study was to observe the combustion process of extracted rapeseed (ER) grist in a stationary fluidized bed combustor (SFBC) and evaluate the chemical compositions of the flue gas emissions. The experimental tests of ER combustion in the 90 to 200 kW (Kilowatt) SFB combustion test facility show that the optimal ER combustion temperature is within the range from 850 to 880° C. Temperature and the concentration of exhausted emissions (e.g. O2, CO, CO2, NO, NO2, SO2, Corg) were measured with dedicated sensors distributed within the combustor, along its height and in the flue gas duct. The experimental results showed that with respect to German emission limits the concentration of SO2 and NOx in the flue gas were high whereas that of CO was low. This study furthermore is applicable for the abundant biomass residue resources in Vietnam (rice husk, rice straw, bagasse, cassava residues, coconut shell etc.), which have similar chemical compositions to ER.
Effect of Nanoparticles on Protein Folding and Fibrillogenesis
Authors: Fei Li , Perrett Sarah
Published: February 2009

The large surface area and small size of nanoparticles provide properties and applications that are distinct from those of bulk materials. The ability of nanoparticles to influence protein folding and aggregation is interesting, not only because of the potential beneficial applications, but also the potential risks to human health and the environment. This makes it essential that we understand the effect of nanoparticles on fundamental biological process, like protein folding. Here, we review studies that have examined the effect of nanoparticles on protein folding and aggregation, providing insight both into the mechanisms of these processes and how they may be controlled.
Bioactive Metabolites from Spilanthes acmella Murr.
Authors: Prachayasittikul Supaluk , Suphapong Saowapa , Worachartcheewan Apilak , Lawung Ratana , Ruchirawat Somsak , Prachayasittikul Virapong
Published: February 2009

Spilanthes acmella Murr. (Compositae) has been used as a traditional medicine for toothache, rheumatism and fever. Its extracts had been shown to exhibit vasorelaxant and antioxidant activities. Herein, its antimicrobial, antioxidant and cytotoxic activities were evaluated. Agar dilution method assays against 27 strains of microorganisms were performed. Results showed that fractions from the chloroform and methanol extracts inhibited the growth of many tested organisms, e.g. Corynebacterium diphtheriae NCTC 10356 with minimum inhibitory concentration (MIC) of 64-256 mg/mL and Bacillus subtilis ATCC 6633 with MIC of 128-256 mg/mL. The tested fractions all exhibited antioxidant properties in both DPPH and SOD assays. Potent radical scavenging activity was observed in the DPPH assay. No cytotoxic effects of the extracts against KB and HuCCA-1 cell lines were evident. Bioassay-guided isolation resulted in a diverse group of bioactive compounds such as phenolics [vanillic acid (2), trans-ferulic acid (5) and trans-isoferulic acid (6)], coumarin (scopoletin, 4) and triterpenoids like 3-acetylaleuritolic acid (1), b-sitostenone (3), stigmasterol and stigmasteryl-3-O-b-D-glucopyranosides, in addition to a mixture of stigmasteryl-and b-sitosteryl-3-O-b-D-glucopyranosides. The compounds 1–6 represent bioactive metabolites of S. acmella Murr. that were never previously reported. Our findings demonstrate for the first time the potential benefits of this medicinal plant as a rich source of high therapeutic value compounds for medicines, cosmetics, supplements and as a health food.
Design, Synthesis and Anti-HIV Integrase Evaluation of 4-Oxo-4H-quinolizine-3-carboxylic Acid Derivatives
Authors: Xu Yi-Sheng , Zeng Cheng-Chu , Jiao Zi-Guo , Hu Li-Ming , Zhong Ru-gang
Published: February 2009

4-Oxo-4H-quinolizine-3-carboxylic acid derivatives bearing sulfamido, carboxylamido, benzimidazole and benzothiazole substituents have been designed and synthesized. The structures of these new compounds were confirmed by 1H-NMR, 13C- NMR, IR and ESI (or HRMS) spectra. Compounds were screened for possible HIV integrase inhibitory activity.
Enhanced Photoelectrochemical Detection of Bioaffinity Reactions by Vertically Oriented Au Nanobranches Complexed with a Biotinylated Polythiophene Derivative
Authors: Zhou Huiqiong , Tang Yanli , Zhai Jin , Wang Shu , Tang Zhiyong , Jiang Lei
Published: February 2009

Four nanostructured Au electrodes were prepared by a simple and templateless electrochemical deposition technique. After complexing with a biotinylated polythiophene derivative (PTBL), photocurrent generation and performance of PTBL/Au-nanostructured electrodes as photoelectrochemical biosensors were investigated. Among these four nanostructured Au electrodes, vertically oriented nanobranches on the electrode significantly improved the photoelectric conversion, because the vertically oriented nanostructures not only benefit light harvesting but also the transfer of the photogenerated charge carriers. Owing to this advantaged nanostructure, the PTBL/Au-nanobranch electrode showed higher sensitivity and faster response times in the photoelectrochemical detection of a streptavidin-biotin affinity reaction compared to a PTBL/Au-nanoparticle electrode.
3D Digital Surveying and Modelling of Cave Geometry: Application to Paleolithic Rock Art
Authors: González-Aguilera Diego , Muñoz-Nieto Angel , Gómez-Lahoz Javier , Herrero-Pascual Jesus , Gutierrez-Alonso Gabriel
Published: February 2009

3D digital surveying and modelling of cave geometry represents a relevant approach for research, management and preservation of our cultural and geological legacy. In this paper, a multi-sensor approach based on a terrestrial laser scanner, a high-resolution digital camera and a total station is presented. Two emblematic caves of Paleolithic human occupation and situated in northern Spain, “Las Caldas” and “Peña de Candamo”, have been chosen to put in practise this approach. As a result, an integral and multi-scalable 3D model is generated which may allow other scientists, pre-historians, geologists…, to work on two different levels, integrating different Paleolithic Art datasets: (1) a basic level based on the accurate and metric support provided by the laser scanner; and (2) a advanced level using the range and image-based modelling.
An Updating System for the Gridded Population Database of China Based on Remote Sensing, GIS and Spatial Database Technologies
Authors: Yang Xiaohuan , Huang Yaohuan , Dong Pinliang , Jiang Dong , Liu Honghui
Published: February 2009

The spatial distribution of population is closely related to land use and land cover (LULC) patterns on both regional and global scales. Population can be redistributed onto geo-referenced square grids according to this relation. In the past decades, various approaches to monitoring LULC using remote sensing and Geographic Information Systems (GIS) have been developed, which makes it possible for efficient updating of geo-referenced population data. A Spatial Population Updating System (SPUS) is developed for updating the gridded population database of China based on remote sensing, GIS and spatial database technologies, with a spatial resolution of 1 km by 1 km. The SPUS can process standard Moderate Resolution Imaging Spectroradiometer (MODIS L1B) data integrated with a Pattern Decomposition Method (PDM) and an LULC-Conversion Model to obtain patterns of land use and land cover, and provide input parameters for a Population Spatialization Model (PSM). The PSM embedded in SPUS is used for generating 1 km by 1 km gridded population data in each population distribution region based on natural and socio-economic variables. Validation results from finer township-level census data of Yishui County suggest that the gridded population database produced by the SPUS is reliable.
HIV-1 Tat Addresses Dendritic Cells to Induce a Predominant Th1-Type Adaptive Immune Response That Appears Prevalent in the Asymptomatic Stage of Infection
Authors: Fanales-Belasio Emanuele , Moretti Sonia , Fiorelli Valeria , Tripiciano Antonella , Pavone Cossut Maria R. , Scoglio Arianna , Collacchi Barbara , Nappi Filomena , Macchia Iole , Bellino Stefania , Francavilla Vittorio , Caputo Antonella , Barillari Giovanni , Magnani Mauro , Laguardia Maria Elena , Cafaro Aurelio , Titti Fausto , Monini Paolo , Ensoli Fabrizio , Ensoli Barbara
Published: February 2009

Tat is an early regulatory protein that plays a major role in human HIV-1 replication and AIDS pathogenesis, and therefore, it represents a key target for the host immune response. In natural infection, however, Abs against Tat are produced only by a small fraction (∼20%) of asymptomatic individuals and are rarely seen in progressors, suggesting that Tat may possess properties diverting the adaptive immunity from generating humoral responses. Here we show that a Th1-type T cell response against Tat is predominant over a Th2-type B cell response in natural HIV-1 infection. This is likely due to the capability of Tat to selectively target and very efficiently enter CD1a-expressing monocyte-derived dendritic cells (MDDC), which represent a primary target for the recognition and response to virus Ag. Upon cellular uptake, Tat induces MDDC maturation and Th1-associated cytokines and β-chemokines production and polarizes the immune response in vitro to the Th1 pattern through the transcriptional activation of TNF-α gene expression. This requires the full conservation of Tat transactivation activity since neither MDDC maturation nor TNF-α production are found with either an oxidized Tat, which does not enter MDDC, or with a Tat protein mutated in the cysteine-rich region (cys22 Tat), which enters MDDC as the wild-type Tat but is transactivation silent. Consistently with these data, inoculation of monkeys with the native wild-type Tat induced a predominant Th1 response, whereas cys22 Tat generated mostly Th2 responses, therefore providing evidence that Tat induces a predominant Th1 polarized adaptive immune response in the host.
Human Dendritic Cells Produce TGF-β1 under the Influence of Lung Carcinoma Cells and Prime the Differentiation of CD4+CD25+Foxp3+ Regulatory T Cells
Authors: Dumitriu Ingrid E. , Dunbar Donald R. , Howie Sarah E. , Sethi Tariq , Gregory Christopher D.
Published: February 2009

Dendritic cells (DCs) have a central role in the development of adaptive immune responses, including antitumor immunity. Factors present in the tumor milieu can alter the maturation of DCs and inhibit their capacity to activate T cells. Using gene expression analysis, we found that human DCs increased the expression of TGF-β1 transcripts following culture with human lung carcinoma cells (LCCs). These DCs produced increased amounts of TGF-β1 protein compared with DCs not exposed to tumor cells. LCCs also decreased the expression of CD86 and HLA-DR by immature DCs. Furthermore, LCCs decreased CD86 expression and the production of TNF-α and IL-12 p70 by mature DCs. Moreover, LCCs also converted mature DCs into cells producing TGF-β1. These TGF-β1-producing DCs were poor at eliciting the activation of naive CD4+ T cells and sustaining their proliferation and differentiation into Th1 (IFN-γ+) effectors. Instead, TGF-β1-producing DCs demonstrated an increased ability to generate CD4+CD25+Foxp3+ regulatory T cells that suppress the proliferation of T lymphocytes. These results identify a novel mechanism by which the function of human DCs is altered by tumor cells and contributes to the evasion of the immune response.
Inhibition of CCR6 Function Reduces the Severity of Experimental Autoimmune Encephalomyelitis via Effects on the Priming Phase of the Immune Response
Authors: Liston Adrian , Kohler Rachel E. , Townley Scott , Haylock-Jacobs Sarah , Comerford Iain , Caon Adriana C. , Webster Julie , Harrison Jodie M. , Swann Jeremy , Clark-Lewis Ian , Korner Heinrich , McColl Shaun R.
Published: February 2009

Chemokines are essential for homeostasis and activation of the immune system. The chemokine ligand/receptor pairing CCL20/CCR6 is interesting because these molecules display characteristics of both homeostatic and activation functions. These dual characteristics suggest a role for CCR6 in the priming and effector phases of the immune response. However, while CCR6 has been implicated in the effector phase in several models, a role in the priming phase is less clear. Herein we analyze the role of CCR6 in these two important arms of the immune response during experimental autoimmune encephalomyelitis (EAE). Both CCR6 and its chemokine ligand CCL20 were up-regulated in the draining lymph nodes and spinal cord during EAE, and CCR6 was up-regulated on CD4+ T cells that had divided following induction of EAE. The functional role of this expression was demonstrated by impaired development of EAE in gene-targeted CCR6-deficient mice and in mice treated either with a neutralizing anti-CCR6 Ab or with a novel receptor antagonist. Inhibition of EAE was due to reduced priming of autoreactive CD4+ T cells probably as a result of impaired late-stage influx of dendritic cells into draining lymph nodes. This was accompanied by reduced egress of activated lymphocytes from the lymph nodes. These results demonstrate a novel role for CCR6 in the mechanism of autoreactive lymphocyte priming and emigration to the efferent lymphatics.
IL-17 Promotes Progression of Cutaneous Leishmaniasis in Susceptible Mice
Authors: Lopez Kostka Susanna , Dinges Stephanie , Griewank Klaus , Iwakura Yoichiro , Udey Mark C. , von Stebut Esther
Published: February 2009

Resistance to leishmaniasis in C57BL/6 mice depends on Th1/Tc1 cells. BALB/c mice preferentially develop Th2 immunity and succumb to infection. We now assessed the role of IL-17 in cutaneous leishmaniasis. During the course of Leishmania major infection, BALB/c CD4 cells and neutrophils produced increased amounts of IL-17 as compared with cells from C57BL/6 mice. This increase was associated with significantly increased IL-23 release from L. major-infected BALB/c dendritic cells (DC), whereas IL-6 and TGF-β1 production by BALB/c and C57BL/6 DC were comparable. Interestingly, lesion sizes in infected IL-17-deficient BALB/c mice were dramatically smaller and failed to progress as compared with those in control mice. Similar amounts of IL-4, IL-10, and IFN-γ were produced by T cells from IL-17-deficient mice and control mice consistent with development of Th2-predominant immunity in all animals. Improved disease outcome was associated with decreased CXCL2-accumulation in lesion sites and decreased neutrophil immigration into lesions of infected IL-17-deficient mice confirming prior observations that enhanced neutrophil recruitment contributes to disease susceptibility in BALB/c mice. This study excludes an important facilitating role for IL-17 in Th1/Th2 development in L. major-infected BALB/c mice, and suggests that IL-23 production by L. major-infected DC maintains IL-17+ cells that influence disease progression via regulation of neutrophil recruitment.
Stabilized β-Catenin in Thymic Epithelial Cells Blocks Thymus Development and Function
Authors: Zuklys Saulius , Gill Jason , Keller Marcel P. , Hauri-Hohl Mathias , Zhanybekova Saule , Balciunaite Gina , Na Kyung-Jae , Jeker Lukas T. , Hafen Katrin , Tsukamoto Noriyuki , Amagai Takashi , Taketo Makoto M. , Krenger Werner , Holländer Georg A.
Published: February 2009

Thymic T cell development is dependent on a specialized epithelial microenvironment mainly composed of cortical and medullary thymic epithelial cells (TECs). The molecular programs governing the differentiation and maintenance of TECs remain largely unknown. Wnt signaling is central to the development and maintenance of several organ systems but a specific role of this pathway for thymus organogenesis has not yet been ascertained. In this report, we demonstrate that activation of the canonical Wnt signaling pathway by a stabilizing mutation of β-catenin targeted exclusively to TECs changes the initial commitment of endodermal epithelia to a thymic cell fate. Consequently, the formation of a correctly composed and organized thymic microenvironment is prevented, thymic immigration of hematopoietic precursors is restricted, and intrathymic T cell differentiation is arrested at a very early developmental stage causing severe immunodeficiency. These results suggest that a precise regulation of canonical Wnt signaling in thymic epithelia is essential for normal thymus development and function.
Tumor-Specific Bacteriophages Induce Tumor Destruction through Activation of Tumor-Associated Macrophages
Authors: Eriksson Fredrik , Tsagozis Panagiotis , Lundberg Kajsa , Parsa Roham , Mangsbo Sara M. , Persson Mats A. A. , Harris Robert A. , Pisa Pavel
Published: February 2009

We recently reported that administration of tumor-specific bacteriophages initiates infiltration of neutrophilic granulocytes with subsequent regression of established B16 tumors. The aim of the current study was to investigate the mechanism of action of bacteriophage-induced tumor regression and to examine possible stimulatory effects of bacteriophages on macrophages. We observed that the mechanism of phage-induced tumor regression is TLR dependent as no signs of tumor destruction or neutrophil infiltration were observed in tumors in MyD88−/− mice in which TLR signaling is abolished. The microenvironment of bacteriophage-treated tumors was further analyzed by gene profiling through applying a low-density array preferentially designed to detect genes expressed by activated APCs, which demonstrated that the M2-polarized tumor microenvironment switched to a more M1-polarized milieu following phage treatment. Bacteriophage stimulation induced secretion of proinflammatory cytokines in both normal mouse macrophages and tumor-associated macrophages (TAMs) and increased expression of molecules involved in Ag presentation and costimulation. Furthermore, mouse neutrophils selectively migrated toward mediators secreted by bacteriophage-stimulated TAMs. Under these conditions, the neutrophils also exhibited increased cytotoxicity toward B16 mouse melanoma target cells. These results describe a close interplay of the innate immune system in which bacteriophages, located to the tumor microenvironment due to their specificity, stimulate TAMs to secrete factors that promote recruitment of neutrophils and potentiate neutrophil-mediated tumor destruction.
ELR-CXC Chemokine Receptor Antagonism Targets Inflammatory Responses at Multiple Levels
Authors: Zhao Xixing , Town Jennifer R. , Li Fang , Zhang Xiaobei , Cockcroft Donald W. , Gordon John R.
Published: February 2009

The ELR-CXC chemokines play important roles in neutrophilic inflammation. We report in this study that a fully human ELR-CXC chemokine antagonist that we have generated, CXCL8(3–72)K11R/G31P (G31P), has potent anti-inflammatory effects that arise through its actions at multiple levels. G31P inhibited CXCL8-induced chemotactic responses and intracellular Ca2+ flux in CXCR1-transfected HEK cells and neutrophils, and responses of neutrophils to CXCR2-exclusive ligands. G31P desensitized heterologous G protein-coupled receptors on neutrophils, 52–86% reducing their Ca2+ flux and chemotactic responses to leukotriene B4, C5a, and the bacterial tripeptide fMLP. G31P also 60–90% blocked neutrophil chemotactic responses to mediators present in 10 of 12 sputum samples from cystic fibrosis or bronchiectasis subjects with bacterial pneumonia. Moreover, whereas A549 bronchial epithelial cells (which expressed CXCR1) secreted ≈29,000 pg/ml CXCL8 in response to in vitro endotoxin challenge, G31P reduced this response by up to 98%, presumably by interrupting an autocrine inflammatory loop. The anti-inflammatory effects of G31P extended also to reversing the antiapoptotic influence of ELR-CXC chemokines on neutrophils. That these effects were relevant in vivo was confirmed in a guinea pig model of airway endotoxemia, wherein the human form of G31P >95% blocked neutrophil infiltration into and activation within the airways, as determined by airway levels of the neutrophil primary, secondary, and tertiary granule markers myeloperoxidase, lactoferrin, and matrix metalloproteinase-9, respectively, and the epithelial cell marker matrix metalloproteinase-2. These data suggest that the beneficial effects of ELR-CXC chemokine antagonism arise through effects that occur at multiple levels, including epithelial cells, neutrophils, and alternate G protein-coupled receptors.
An Unusual Insertion in Jak2 Is Crucial for Kinase Activity and Differentially Affects Cytokine Responses
Authors: Haan Claude , Kroy Daniela C. , Wüller Stefan , Sommer Ulrike , Nöcker Tanja , Rolvering Catherine , Behrmann Iris , Heinrich Peter C. , Haan Serge
Published: February 2009

The Janus kinases, Jaks, constitutively associate with the cytoplasmic region of cytokine receptors and play an important role in a multitude of biological processes. Jak2 dysfunction has been implicated in myeloproliferative diseases and leukemia. Although Jaks were studied extensively for many years, the molecular mechanism of Jak activation upon cytokine stimulation of cells is still incompletely understood. In this study, we investigated the importance of an unusual insertion located within the kinase domain in Jak2. We found that the deletion of this insertion, which we named the Jak-specific insertion (JSI), totally abrogates Jak2 autophosphorylation. We further point mutated four residues within the JSI that are conserved in all Jak family members. Three of these mutants showed abrogated or reduced autophosphorylation, whereas the fourth displayed increased autophosphorylation. We found that the phosphorylation state of these mutants is not influenced by other domains of the kinase. Our data further suggest that the JSI is not required for the negative regulation of kinase activity by the suppressor of cytokine signaling proteins, SOCS. Most importantly, we show that mutations in this region differentially affect IFN-γ and erythropoietin signal transduction. Taken together, the dramatic effects on the phosphorylation status of Jak2 as well as the differential effects on the signaling via different cytokines highlight the importance of this unusual region for the catalytic activity of Jaks.
Disseminated and Rapidly Fatal Tuberculosis in Mice Bearing a Defective Allele at IFN Regulatory Factor 8
Authors: Marquis Jean-François , LaCourse Ronald , Ryan Lynn , North Robert J. , Gros Philippe
Published: February 2009

The interferon regulatory factor (IRF) family member IRF-8 participates in IFN-γ-dependent transcriptional activation of genes containing in their promoter regions IFN-stimulated response element or IFN-γ activation site elements. To test the role of IRF-8 in host defenses against tuberculosis, BXH-2 mice, which bear a defective IRF-8R294C allele, were challenged with low doses of virulent Mycobacterium tuberculosis via the i.v. and aerosol routes. BXH-2 mice were found to be extremely susceptible to M. tuberculosis, as demonstrated by rapid and uncontrolled microbial replication in spleen, liver, and lungs leading to very early death. The BXH-2 defect was expressed very early (10 days postinfection) as uncontrolled intracellular pathogen replication in NOS2-expressing lung macrophages, impaired granuloma formation, rapid dissemination of the infection to distant sites, and rapid necrosis of infected tissues. There was complete absence of IL-12p40 induction, severely reduced IFN-γ production, and impaired T cell priming in the lungs of infected BXH-2, highlighting the critical role of IRF-8 in this process. Collectively, these results identify IRF-8 as a critical regulator of host defenses against tuberculosis.
Gap Junction Communication between Autologous Endothelial and Tumor Cells Induce Cross-Recognition and Elimination by Specific CTL
Authors: Benlalam Houssem , Jalil Abdelali , Hasmim Meriem , Pang Baoxu , Tamouza Ryad , Mitterrand Michèle , Godet Yann , Lamerant Nathalie , Robert Caroline , Avril Marie-Françoise , Neefjes Jacques , Tursz Thomas , Mami-Chouaib Fathia , Kieda Claudine , Chouaib Salem
Published: February 2009

Cellular interactions in the tumor stroma play a major role in cancer progression but can also induce tumor rejection. To explore the role of endothelial cells in these interactions, we used an in vitro three-dimensional collagen matrix model containing a cytotoxic T lymphocyte CTL clone (M4.48), autologous tumor cells (M4T), and an endothelial cell (M4E) line that are all derived from the same tumor. We demonstrate in this study that specific killing of the endothelial cells by the CTL clone required the autologous tumor cells and involved Ag cross-presentation. The formation of gap junctions between endothelial and tumor cells is required for antigenic peptide transfer to endothelial cells that are then recognized and eliminated by CTL. Our results indicate that gap junctions facilitate an effective CTL-mediated destruction of endothelial cells from the tumor microenvironment that may contribute to the control of tumor progression.
Suppression of Autoimmune Diabetes by Soluble Galectin-1
Authors: Perone Marcelo J. , Bertera Suzanne , Shufesky William J. , Divito Sherrie J. , Montecalvo Angela , Mathers Alicia R. , Larregina Adriana T. , Pang Mabel , Seth Nilufer , Wucherpfennig Kai W. , Trucco Massimo , Baum Linda G. , Morelli Adrian E.
Published: February 2009

Type 1 diabetes (T1D) is a T cell-mediated autoimmune disease that targets the β-cells of the pancreas. We investigated the ability of soluble galectin-1 (gal-1), an endogenous lectin that promotes T cell apoptosis, to down-regulate the T cell response that destroys the pancreatic β-cells. We demonstrated that in nonobese diabetic (NOD) mice, gal-1 therapy reduces significantly the amount of Th1 cells, augments the number of T cells secreting IL-4 or IL-10 specific for islet cell Ag, and causes peripheral deletion of β-cell-reactive T cells. Administration of gal-1 prevented the onset of hyperglycemia in NOD mice at early and subclinical stages of T1D. Preventive gal-1 therapy shifted the composition of the insulitis into an infiltrate that did not invade the islets and that contained a significantly reduced number of Th1 cells and a higher percentage of CD4+ T cells with content of IL-4, IL-5, or IL-10. The beneficial effects of gal-1 correlated with the ability of the lectin to trigger apoptosis of the T cell subsets that cause β-cell damage while sparing naive T cells, Th2 lymphocytes, and regulatory T cells in NOD mice. Importantly, gal-1 reversed β-cell autoimmunity and hyperglycemia in NOD mice with ongoing T1D. Because gal-1 therapy did not cause major side effects or β-cell toxicity in NOD mice, the use of gal-1 to control β-cell autoimmunity represents a novel alternative for treatment of subclinical or ongoing T1D.
NK-Dependent Increases in CCL22 Secretion Selectively Recruits Regulatory T Cells to the Tumor Microenvironment
Authors: Mailloux Adam W. , Young M. Rita I.
Published: February 2009

Tumor-induced immune suppression involves the accumulation of immune-suppressive infiltrates in the microenvironment. This study demonstrates increased numbers of CD4+CD25+FoxP3+ regulatory T cells (Tregs) in the lungs of C57BL/6 mice bearing a metastatic Lewis lung carcinoma (LLC) variant. These Tregs suppressed the proliferation of endogenous CD4+CD25− cells and expressed higher levels of the chemokine receptor CCR4 than other types of T cells. LLC-bearing lungs secreted elevated levels of the CCR4-associated chemokine CCL22 compared with normal lungs. However, CCL22 was not secreted by LLC or normal epithelial controls, suggesting that CCL22 is secreted by a nonepithelial component of the microenvironment. Migration assays revealed that medium conditioned by LLC-bearing lungs selectively recruited Tregs at higher frequencies than did medium conditioned by normal lungs. Neutralization of CCL22 significantly reduced this selective recruitment toward both conditioned media. A series of immunomagnetic isolations, FACS, and flow cytometric analyses were used to isolate different cellular fractions from both normal and LLC-bearing lungs. When isolated, only the NK-containing fractions secreted CCL22, and the same fraction isolated from LLC-bearing lungs secreted higher levels. Depletion of NK cells from both normal and LLC-bearing lung tissue significantly reduced CCL22 secretion, suggesting that a large portion of secreted CCL22 is NK cell dependent. Flow cytometric analysis of the lung NK compartments revealed no significant increase in NK cell numbers across LLC-bearing lung tissue as a whole as compared with normal tissue. However, immunofluorescent staining revealed an increased frequency of NK cells at the tumor periphery that were closely associated with the elevated FoxP3+ infiltrate.
NAD+ and ATP Released from Injured Cells Induce P2X7-Dependent Shedding of CD62L and Externalization of Phosphatidylserine by Murine T Cells
Authors: Scheuplein Felix , Schwarz Nicole , Adriouch Sahil , Krebs Christian , Bannas Peter , Rissiek Björn , Seman Michel , Haag Friedrich , Koch-Nolte Friedrich
Published: February 2009

Extracellular NAD+ and ATP trigger the shedding of CD62L and the externalization of phosphatidylserine on murine T cells. These events depend on the P2X7 ion channel. Although ATP acts as a soluble ligand to activate P2X7, gating of P2X7 by NAD+ requires ecto-ADP-ribosyltransferase ART2.2-catalyzed transfer of the ADP-ribose moiety from NAD+ onto Arg125 of P2X7. Steady-state concentrations of NAD+ and ATP in extracellular compartments are highly regulated and usually are well below the threshold required for activating P2X7. The goal of this study was to identify possible endogenous sources of these nucleotides. We show that lysis of erythrocytes releases sufficient levels of NAD+ and ATP to induce activation of P2X7. Dilution of erythrocyte lysates or incubation of lysates at 37°C revealed that signaling by ATP fades more rapidly than that by NAD+. We further show that the routine preparation of primary lymph node and spleen cells induces the release of NAD+ in sufficient concentrations for ART2.2 to ADP-ribosylate P2X7, even at 4°C. Gating of P2X7 occurs when T cells are returned to 37°C, rapidly inducing CD62L-shedding and PS-externalization by a substantial fraction of the cells. The “spontaneous” activation of P2X7 during preparation of primary T cells could be prevented by i.v. injection of either the surrogate ART substrate etheno-NAD or ART2.2-inhibitory single domain Abs 10 min before sacrificing mice.
Influenza Virus and Poly(I:C) Inhibit MHC Class I-Restricted Presentation of Cell-Associated Antigens Derived from Infected Dead Cells Captured by Human Dendritic Cells
Authors: Frleta Davor , Yu Chun I. , Klechevsky Eynav , Flamar Anne-Laure , Zurawski Gerard , Banchereau Jacques , Palucka A. Karolina
Published: February 2009

During viral infection, dendritic cells (DCs) capture infected cells and present viral Ags to CD8+ T cells. However, activated DCs might potentially present cell-associated Ags derived from captured dead cells. In this study, we find that human DCs that captured dead cells containing the TLR3 agonist poly(I:C) produced cytokines and underwent maturation, but failed to elicit autologous CD8+ T cell responses against Ags of dead cells. Accordingly, DCs that captured dead cells containing poly(I:C), or influenza virus, are unable to activate CD8+ T cell clones specific to cell-associated Ags of captured dead cells. CD4+ T cells are expanded with DCs that have captured poly(I:C)-containing dead cells, indicating the inhibition is specific for MHC class I-restricted cross-presentation. Furthermore, these DCs can expand naive allogeneic CD8+ T cells. Finally, soluble or targeted Ag is presented when coloaded onto DCs that have captured poly(I:C)-containing dead cells, indicating the inhibition is specific for dead cell cargo that is accompanied by viral or poly(I:C) stimulus. Thus, DCs have a mechanism that prevents MHC class I-restricted cross-presentation of cell-associated Ag when they have captured dead infected cells.
Nonresolving Inflammation in gp91phox−/− Mice, a Model of Human Chronic Granulomatous Disease, Has Lower Adenosine and Cyclic Adenosine 5′-Monophosphate
Authors: Rajakariar Ravindra , Newson Justine , Jackson Edwin K. , Sawmynaden Precilla , Smith Andrew , Rahman Farooq , Yaqoob Muhammad M. , Gilroy Derek W.
Published: February 2009

In chronic granulomatous disease (CGD), there is failure to generate reactive oxygen metabolites, resulting in recurrent infections and persistent inflammatory events. Because responses to sterile stimuli in murine models of CGD also result in nonresolving inflammation, we investigated whether defects in endogenous counterregulatory mechanisms and/or proresolution pathways contribute to the etiology of CGD. To this end, we conducted a series of experiments finding, in the first instance that adenosine and cAMP, which dampen innate immune-mediated responses, show a biphasic profile in resolving peritonitis; peaking at onset, waning as inflammation progresses, and rising again at resolution. We also found elevations in adenosine and cAMP in resolving human peritonitis. In gp91phox−/− mice, an experimental model of CGD, levels of adenosine and cAMP were significantly lower at onset and again at resolution. Corroborating the finding of others, we show that adenosine, signaling through its A2A receptor and therefore elevating cAMP, is not only anti-inflammatory, but, importantly, it does not impair proresolution pathways, properties typical of nonsteroidal anti-inflammatory drugs. Conversely, antagonizing the A2A receptor worsens acute inflammation and prolongs resolution. Taking this further, activating the A2A receptor in gp91phox−/− mice was dramatically anti-inflammatory regardless of the phase the inflammatory response A2A agonists were administered, i.e., onset or resolution, demonstrating wide and robust pharmacological flexibility that is unlikely to subvert proresolution pathways. Therefore, we describe the biphasic profile of adenosine and cAMP throughout the time course of acute inflammation that is dysregulated in CGD.
Chemotaxis and Phagocytosis in Neutrophils Is Independent of Coronin 1
Authors: Combaluzier Benoit , Pieters Jean
Published: February 2009

The WD repeat protein family member coronin 1 is exclusively expressed in leukocytes, where it colocalizes with the cortical cytoskeleton. Although initially coronin 1 was believed to regulate F-actin dynamics such as leukocyte motility, phagocytosis, and membrane ruffling, recent work showed that in macrophages, T cells, and B cells, coronin 1 is dispensable for these F-actin dependent processes, instead being involved in the regulation of calcium dependent signaling reactions. In this study, we show that in mice lacking coronin 1 neutrophil populations developed normally, and that coronin 1-deficient neutrophils are fully functional with respect to adherence, membrane dynamics, migration, phagocytosis and the oxidative burst. Therefore, these data argue against a role for coronin 1 in the modulation of F-actin and suggest that coronin 1 is dispensable for neutrophil functioning.
Genome-Wide Comparison between IL-17A- and IL-17F-Induced Effects in Human Rheumatoid Arthritis Synoviocytes
Authors: Zrioual Saloua , Ecochard René , Tournadre Anne , Lenief Vanina , Cazalis Marie-Angélique , Miossec Pierre
Published: February 2009

IL-17A is implicated in rheumatoid arthritis (RA) pathogenesis; however, the contribution of IL-17F remains to be clarified. Using microarrays and gene-specific expression assays, we compared the regulatory effects of IL-17A and IL-17F alone or in combination with TNF-α on RA synoviocytes. IL-17A and IL-17F expression was studied in osteoarthritis and RA synovium by immunohistochemistry. The comparison between the IL-17A and IL-17F stimulatory effect on RA synoviocytes was assessed at the protein level by ELISA and at the mRNA level by microarrays and real-time RT-PCR. TNFRII expression was studied by real-time RT-PCR and immunofluorescence, and neutralizing Ab was used to analyze its contribution to CCL20 secretion. IL-17A and IL-17F were detected in plasma cell-like cells from RA but not osteoarthritis synovium. In microarrays, IL-17A and IL-17F alone had similar regulatory effects, IL-17F being quantitatively less active. Both cytokines induced a similar expression pattern in the presence of TNF-α. Based on a cooperation index, 130 and 203 genes were synergistically induced by IL-17A or IL-17F plus TNF-α, respectively. Among these, the new target genes CXCR4, LPL, and IL-32 were validated by real-time RT-PCR. IL-17A and IL-17F up-regulated TNFRII expression, but had no effects on TNFRI, IL-17RA or IL-17RC. TNFRII blockade inhibited the synergistic induction of CCL20 by IL-17A or IL-17F and TNF-α. IL-17A and IL-17F are both expressed in RA synovium. In the presence of TNF-α, they induced a similar expression pattern in RA synoviocytes. Accordingly, IL-17F appears as a target in Th17-mediated diseases such as RA.
Polymorphisms in Mannan-Binding Lectin (MBL)-Associated Serine Protease 2 Affect Stability, Binding to MBL, and Enzymatic Activity
Authors: Thiel Steffen , Kolev Martin , Degn Søren , Steffensen Rudi , Hansen Annette G. , Ruseva Marieta , Jensenius Jens C.
Published: February 2009

Mannan-binding lectin-associated serine protease 2 (MASP-2) is an enzyme of the innate immune system. MASP-2 forms complexes with the pattern recognition molecules mannan-binding lectin (MBL), H-ficolin, L-ficolin, or M-ficolin, and is activated when one of these proteins recognizes microorganisms and subsequently cleaves complement factors C4 and C2, thus initiating the activation of the complement system. Missense polymorphisms of MASP-2 exist in different ethnic populations. To further characterize the nature of these, we have produced and characterized rMASP-2s representing the following naturally occurring polymorphisms: R99Q, D120G, P126L, H155R, 156_159dupCHNH (CHNHdup), V377A, and R439H. Only very low levels of CHNHdup were secreted from the cells, whereas quantities similar to wild-type MASP-2 were found intracellularly, indicating that this mutation results in a misfolded protein. We found that D120G and CHNHdup could not associate with MBL, whereas R99Q, P126L, H155R, V377A, R439H, and wild-type MASP-2 bound equally well to MBL. Accordingly, when D120G and CHNHdup were mixed with MBL, no activation of complement factor C4 was observed, whereas R99Q, P126L, and V377A cleaved C4 with an activity comparable to wild-type MASP-2 and H155R slightly better. In contrast, the R439H variant was deficient in this process despite its normal binding to MBL. This variant was also not able to autoactivate in the presence of MBL and mannan. We find the R439H variant is common in Sub-Saharan Africans with a gene frequency of 10%. Our results indicate that individuals with different types of MASP-2 defects may be identified through genotyping.
IL-17 Signaling-Independent Central Nervous System Autoimmunity Is Negatively Regulated by TGF-β
Authors: Gonzalez-García Ines , Zhao Yani , Ju Songguang , Gu Qin , Liu Lin , Kolls Jay K. , Lu Binfeng
Published: February 2009

Recent studies have established an important role of Th17 in induction of autoimmune diseases. We have found that although IL-17 receptor A (IL-17RA)−/− mice were resistant to experimental autoimmune encephalomyelitis, a small number of them developed milder clinical signs of this autoimmune disease. In addition, blockade of TGF-β in IL-17RA−/− mice resulted in much more severe clinical signs of experimental autoimmune encephalomyelitis and significantly increased parenchymal lymphocyte infiltration in the CNS. Furthermore, the number of autoreactive Th1 cells was greatly increased in the inflamed spinal cord of IL-17RA−/− mice. These data support a role of IL-17RA-independent mechanisms in causing autoimmunity and its regulation by TGF-β.