bluuebunny/crossref_metadata_2025 huggingface dataset:
Factors Influencing Masculinity Ideology among Latino Men
Authors: Saez Pedro A. , Casado Adonaid , Wade Jay C.
Published: June 2009

This research study assessed the factors that affect Latino men's endorsement of hypermasculinity, an exaggerated form of traditional masculinity ideology. One hundred and one Latino men from two urban universities and surrounding neighborhoods completed measures that assessed ethnic identity, hypermasculinity, sex-role egalitarianism perceived in the home, and reference group identity dependence. It was hypothesized that hypermasculinity would be linked to traditional sex-roles taught in the home, male identity, and ethnic identity. The results indicate that hypermasculinity was associated with high ethnic identity and a male identity characterized by a lack of appreciation of differences among males.
Bacteria Coated by Polyphenols Acquire Potent Oxidant-Scavenging Capacities
Authors: Koren Erez , Kohen Ron , Ovadia Haim , Ginsburg Isaac
Published: June 2009

Several microbial species, including probiotic lactic acid bacteria, have the ability to irreversibly bind a large variety of polyphenols (flavonoids) and anthocyanidins found in many colored fruits and vegetables and to enhance their total oxidant-scavenging capacities (TOSC). The binding of flavonoids to microbial surfaces was further increased by the cationic polyelectrolytes ligands poly-L-histidine, chlorhexidine and Copaxone®. This phenomenon was confirmed visually, by the FRAP, DPPH, cyclic voltammetry, Folin-Ciocalteu as well as by luminol-dependent chemiluminescence techniques employed to assay TOSC. The possibility is considered that clinically, microbial cells in the oral cavity and in the gastro intestinal tract, complexed with antioxidant polyphenols from nutrients and with cationic ligands, might increase the protection of mammalian cells against damage induced by excessive generation of reactive oxygen species during infections and inflammation.
Lysophosphatidic Acid Stimulates Prostaglandin E2Production in Cultured Stromal Endometrial Cells Through LPA1 Receptor
Authors: Woclawek-Potocka Izabela , Kondraciuk Katarzyna , Skarzynski Dariusz Jan
Published: June 2009

Lysophosphatidic acid (LPA) has been shown to be a potent modulator of prostaglandin (PG) secretion during the luteal phase of the estrous cycle in the bovine endometrium in vivo. The aims of the present study were to determine the cell types of the bovine endometrium (epithelial or stromal cells) responsible for the secretion of PGs in response to LPA, the cellular, receptor, intracellular, and enzymatic mechanisms of LPA action. Cultured bovine epithelial and stromal cells were exposed to LPA (10−5–10−9M), tumor necrosis factor α (TNFα; 10 ng/mL) or oxytocin (OT; 10−7M) for 24 h. LPA treatment resulted in a dose-dependent increase of PGE2production in stromal cells, but not in epithelial cells. LPA did not influence PGF2αproduction in stromal or epithelial cells. To examine which type of LPA G-protein–coupled receptor (LP-GPCR; LPA1, LPA2, or LPA3) is responsible for LPA action, stromal cells were preincubated with three selected blockers of LPA receptors: NAEPA, DGPP, and Ki16425 for 0.5 h, and then stimulated with LPA. Only Ki16425 inhibited the stimulatory effect of LPA on PGE2production and cell proliferation in the stromal cells. LPA-induced intracellular calcium ion mobilization was also inhibited only by Ki16425. Finally, we examined whether LPA-induced PGE2synthesis in stromal cells is via the influence on mRNA expression for the enzymes responsible for PGE2synthesis— PGE2synthase ( PGES) and PG-endoperoxide synthase 2 ( PTGS2). We demonstrated that the stimulatory effect of LPA on PGE2production in stromal cells is via the stimulation of PTGS2 and PGES mRNA expression in the cells. The overall results indicate that LPA stimulates PGE2production, cell viability, and intracellular calcium ion mobilization in cultured stromal endometrial cells via Ki16425-sensitive LPA1 receptors. Moreover, LPA exerts a stimulatory effect on PGE2production in stromal cells via the induction of PTGS2 and PGES mRNA expression.
Adiponectin: A Key Adipokine in Alcoholic Fatty Liver
Authors: You Min , Rogers Christopher Q.
Published: June 2009

Alcoholic fatty liver is a major risk factor for advanced liver injuries such as steatohepatitis, fibrosis, and cirrhosis. While the underlying mechanisms are multiple, the development of alcoholic fatty liver has been attributed to a combined increase in the rate of de novo lipogenesis and a decrease in the rate of fatty acid oxidation in animal liver. Among various transcriptional regulators, the hepatic SIRT1 (sirtuin 1)-AMPK (AMPK-activated kinase) signaling system represents a central target for the action of ethanol in the liver. Adiponectin is one of the adipocyte-derived adipokines with potent lipid-lowering properties. Growing evidence has demonstrated that the development of alcoholic fatty liver is associated with reduced circulating adiponectin levels, decreased hepatic adiponectin receptor expression, and impaired hepatic adiponectin signaling. Adiponectin confers protection against alcoholic fatty liver via modulation of complex hepatic signaling pathways largely controlled by the central regulatory system, SIRT1-AMPK axis. This review aims to integrate the current research findings of ethanol-mediated dysregulation of adiponectin and its receptors and to provide a comprehensive point of view for understanding the role of adiponectin signaling in the development of alcoholic fatty liver.
Transcriptional Regulation of Steroidogenic Genes: STARD1, CYP11A1 and HSD3B
Authors: LaVoie Holly A. , King Steven R.
Published: June 2009

Expression of the genes that mediate the first steps in steroidogenesis, the steroidogenic acute regulatory protein (STARD1), the cholesterol side-chain cleavage enzyme, cytochrome P450scc (CYP11A1) and 3β-hydroxysteroid dehydrogenase/Δ5-Δ4 isomerase (HSD3B), is tightly controlled by a battery of transcription factors in the adrenal cortex, the gonads and the placenta. These genes generally respond to the same hormones that stimulate steroid production through common pathways such as cAMP signaling and common actions on their promoters by proteins such as NR5A and GATA family members. However, there are distinct temporal, tissue and species-specific differences in expression between the genes that are defined by combinatorial regulation and unique promoter elements. This review will provide an overview of the hormonal and transcriptional regulation of the STARD1, CYP11A1 and specific steroidogenic HSD3B genes in the adrenal, testis, ovary and placenta and discuss the current knowledge regarding the key transcriptional factors involved.
Caulis Sinomenii Extracts Activate DA/NE Transporter and Inhibit 5HT Transporter
Authors: Zhao Gang , Bi Cheng , Qin Guo-Wei , Guo Li-He
Published: June 2009

Caulis Sinomenii (QFT) has analgesic, sedative, and anxiolytic-like actions, and is proven effective for improving drug dependence that is known to be associated with abnormal monoaminergic transmission. We assessed whether QFT would be biologically active in functionally regulating monoamine transporters using CHO cells expressing dopamine transporter (DAT), norepinephrine transporter (NET), or serotonin transporter (SERT) (i.e. D8, N1, or S6 cells, respectively). Here, we showed that its primary extracts, such as QA, QC, QE, QD, and QB (QFT ethanol, chloroform, ethyl acetate, alkaloid-free chloroform, and alkaloid-containing chloroform extract, respectively), and secondary extracts, such as QE-2, − 3, − 5, − 7, QD-1, − 2, − 3, − 4, − 5, and QB-1, − 2, − 3, − 4, − 5 (fractioned from QE, QD, and QB, respectively), in differing degrees, either increased DA/ NE uptake by corresponding D8/N1 cells or decreased 5HT uptake by S6 cells; wherein, QE-2, QD-3, and QE-7 were potent DA/NE uptake activators while both QE-7 and QB-5 were potent 5HT uptake inhibitors. Furthermore, the enhancement of DA/NE uptake was dependent of DAT/NET activity, and the inhibition of 5HT uptake was typical of competition. Thus, QFT extracts, especially QE-2 and QE-7 (both with stronger potencies), are novel monoamine transporter modulators functioning as DAT/ NET activators and/or SERT inhibitors, and would likely improve neuropsychological disorders through regulating monoamine transporters.
Mesoscale Simulation of Year-to-Year Variation of Wind Power Potential over Southern China
Authors: Yim Steve  H.L. , Fung Jimmy  C.H. , Lau Alexis  K.H.
Published: June 2009

The objectives of this study are to combine historical observations and state-of-the-art numerical models (MM5/CALMET system) to map the spatial distribution of wind resources in high resolution, and to help foster a deeper understanding of the wind power potential over southern China (Guangdong). Hourly wind fields were simulated for three entire years (2004-2006). It found that almost 70% of the time, the wind speed along the coast of Guangdong is over 5 m/s, which is deemed a baseline magnitude for typical wind turbines. Spatial plots of the wind speed and power and their variations over Guangdong Province for the three years are also presented.
Extended Averaged Learning Subspace Method for Hyperspectral Data Classification
Authors: Bagan Hasi , Takeuchi Wataru , Yamagata Yoshiki , Wang Xiaohui , Yasuoka Yoshifumi
Published: June 2009

Averaged learning subspace methods (ALSM) have the advantage of being easily implemented and appear to outperform in classification problems of hyperspectral images. However, there remain some open and challenging problems, which if addressed, could further improve their performance in terms of classification accuracy. We carried out experiments mainly by using two kinds of improved subspace methods (namely, dynamic and fixed subspace methods), in conjunction with the [0,1] and [-1,+1] normalization methods. We used different performance indicators to support our experimental studies: classification accuracy, computation time, and the stability of the parameter settings. Results are presented for the AVIRIS Indian Pines data set. Experimental analysis showed that the fixed subspace method combined with the [0,1] normalization method yielded higher classification accuracy than other subspace methods. Moreover, ALSMs are easily applied: only two parameters need to be set, and they can be applied directly to hyperspectral data. In addition, they can completely identify training samples in a finite number of iterations.
POST DISASTER WASTE MANAGEMENT STRATEGIES IN DEVELOPING COUNTRIES: CASE OF SRI LANKA
Authors: Karunasena Gayani , Amaratunga Dilanthi , Haigh Richard , Lill Irene
Published: June 2009

Disasters cause substantial damage around the world. This causes serious environmental and economic burden on normal living conditions, reconstruction and general waste collection processes. Within this context, waste management has emerged as a critical issue in responding to a disaster. Thus, this paper addresses post disaster waste management strategies adopted in developing countries and applicability of best global practices in respect of challenges encountered. Comprehensive literature review and field survey among national level institutes in Sri Lanka were conducted to gather information and semi‐structured interviews were used as a method of data collection. The findings revealed that strategies, issues and challenges are varying according to type of disaster, magnitude, location, country etc. Further, poor implementation of prevailing rules and regulations; poor standards of local expertise and capacities, inadequate funds, lack of communication and coordination are identified as key issues encountered. Santruka Stichines nelaimes visame pasaulyje pridaro daug žalos. Tai labai pasunkina aplinkosaugine ir ekonomine situacija iprastomis gyvenimo salygomis, atstatant aplinka ir vykdant bendruosius atlieku rinkimo procesus. Šiame kontekste atlieku tvarkymas išryškejo kaip esmine problema, reaguojant i stichine nelaime. Taigi šiame darbe nagrinejamos atlieku tvarkymo po stichiniu nelaimiu strategijos, taikomos besivystančiose šalyse, ir geriausiu pasauliniu praktiku taikymas, imantis kilusiu iššūkiu. Siekiant surinkti informacija, išsamiai apžvelgta literatūra ir tiesiogiai ištirtos Šri Lankos valstybines institucijos, o duomenims rinkti pasitelktas pusiau struktūriniu interviu metodas. Iš rezultatu aišku, kad strategijos, problemos ir iššūkiai skiriasi priklausomai nuo stichines nelaimes pobūdžio, masto, vietos, valstybes ir pan. Be to, nustatyta, kad pagrindines problemos yra prastas visuotiniu taisykliu ir reglamentu taikymas, prasti vietines patirties standartai ir menkos galimybes, lešu trūkumas, komunikacijos ir koordinavimo trūkumas.
The Impact of Informatics on Nursing Education: A Review of the Literature
Authors: Ainsley Bonnie , Brown Abbie
Published: June 2009

On the basis of a study by the Institute of Medicine, the current health care system is facing several challenges that may be addressed by changes in health professions education. The study focused on integration of five core competencies into health professions education, one of which was informatics. This critical analysis investigates current use of technology and online instructional strategies in nursing education. It also explores the potential impact of integration of informatics into nursing education to increase the cognitive skills of nurses to promote evidence-based nursing. Advantages and disadvantages of using online education in the instruction of nursing students and recommendations for best online practices in nursing education are discussed.

J Contin Educ Nurs
2009;40(5):228–232.
Ten Ways for Provider Units to Weather This Economic Downturn
Authors: Bernard Amy
Published: June 2009

The current economic recession challenges all continuing nursing education provider units to review operational practices and explore ways to maintain and ensure financial viability. Adjustments in programs are likely, as nurses seek more cost-effective ways of meeting their continuing education requirements. Further, employers are reducing staff and budgets. As a result, provider units need to reassess operations and refocus outcomes.

J Contin Educ Nurs
2009;40(5):196–197.
Strategies for Making Oral Presentations About Clinical Issues: Part II. At Professional Conferences
Authors: Brown Janet M. , Schmidt Nola A.
Published: June 2009

This column offers strategies for making oral presentations at professional conferences. Part I, which appeared last month, offered strategies that clinicians can use to make effective oral presentations at work.

J Contin Educ Nurs
2009;40(5):198–199.
Proximal Tibia Reconstruction With a Porous Tantalum Cone in a Patient With Charcot Arthropathy
Authors: Troyer Joshua , Levine Brett R.
Published: June 2009

Neuropathic arthritis, or Charcot arthropathy, is a rapidly destructive process associated with nerve damage and periarticular insensitivity. Most commonly it is associated with diabetes mellitus, tabes dorsalis, syringomyelia, or other peripheral nerve disorders. Clinical manifestations of this disorder classically include gross deformity, crepitus, lack of proprioception, joint effusion, calor, and decreased awareness of pain in the affected joint. Often the clinical picture is difficult to distinguish from septic arthritis. Radiographic findings are typically worse than portrayed during clinical examination. Rapid destruction of the articular surface with bony fragmentation is commonly found. The incidence of neuropathic arthritis among all diabetic patients is relatively small, ranging between 0.15% and 0.4%.

Historically, there have been conflicting reports as to the efficacy of total knee arthroplasty (TKA) in patients with neuropathic arthritis. However, recent literature on the use of modern implants has been more optimistic as to the success of TKA. Difficulties associated with severe bone loss, poor bone quality, and ligamentous laxity may necessitate the use of structural allografts/augments, as well as stemmed and/or constrained TKA components. This article presents a case of a patient with Charcot arthropathy of the knee secondary to diabetes mellitus (type 2) treated successfully with a minimally constrained TKA and a porous tantalum cone (Zimmer, Warsaw, Indiana) as an “internal plate,” for reconstruction of a combined segmental/cavitary defect of the proximal tibia. At 2-year follow-up, radiographs revealed stable TKA components with reconstitution of the fragmented proximal tibia around an osseointegrated porous cone.
Bread Mold Osteomyelitis in the Femur
Authors: Wilkins Ross M. , Hahn David B. , Blum Raymond
Published: June 2009

Rhizopus osteomyelitis is an uncommon and often fatal infection that usually occurs in immunocompromised patients. The infection is commonly referred to as “bread mold.” The usual course of treatment is Amphotericin B, debridement, and, if needed, amputation of the affected limb. This article details a rare case of postoperative Rhizopus osteomyelitis in an otherwise healthy patient.

The patient originally presented at another institution for anterior cruciate ligament repair after a ski injury. Postoperatively, he developed clinical evidence of infection. He was referred to our institution with stiffness and swelling in the knee as well as weight loss and decreased range of motion. Fluid collection was visible on magnetic resonance imaging. Arthroscentesis was cultured for fungus and bacteria, and the fungal cultures were positive for Rhizopus species. An attempt at limb salvage was made. Debridement, use of a cement spacer loaded with Amphotericin B, systemic antifungal therapy, and 23 hyperbaric oxygen treatments were used to eradicate the disease. Four surgeries were needed to eradicate the disease, and 10 months after initial presentation, the patient had a distal femoral endoprosthesis placed in his leg. Laboratory tests returned to normal and frozen sections were negative for fungus. At 3-year follow-up, the patient reported a musculoskeletal functional score of 50% and had no evidence of recurrent infection.
Involvement of CD252 (CD134L) and IL-2 in the Expression of Cytotoxic Proteins in Bacterial- or Viral-Activated Human T Cells
Authors: Walch Michael , Rampini Silvana K. , Stoeckli Isabelle , Latinovic-Golic Sonja , Dumrese Claudia , Sundstrom Hanna , Vogetseder Alexander , Marino Joseph , Glauser Daniel L. , van den Broek Maries , Sander Peter , Groscurth Peter , Ziegler Urs
Published: June 2009

Regulation of cytotoxic effector molecule expression in human CTLs after viral or bacterial activation is poorly understood. By using human autologous dendritic cells (DCs) to prime T lymphocytes, we found perforin only highly up-regulated in virus- (HSV-1, vaccinia virus) but not in intracellular bacteria- (Listeria innocua, Listeria monocytogenes, Mycobacterium tuberculosis, Chlamydophila pneumoniae) activated CTLs. In contrast, larger quantities of IFN-γ and TNF-α were produced in Listeria-stimulated cultures. Granzyme B and granulysin were similarly up-regulated by all tested viruses and intracellular bacteria. DCs infected with HSV-1 showed enhanced surface expression of the costimulatory molecule CD252 (CD134L) compared with Listeria-infected DC and induced enhanced secretion of IL-2. Adding blocking CD134 or neutralizing IL-2 Abs during T cell activation reduced the HSV-dependent up-regulation of perforin. These data indicate a distinct CTL effector function in response to intracellular pathogens triggered via differing endogenous IL-2 production upon costimulation through CD252.
Myeloperoxidase Deficiency Attenuates Lipopolysaccharide-Induced Acute Lung Inflammation and Subsequent Cytokine and Chemokine Production
Authors: Haegens Astrid , Heeringa Peter , van Suylen Robert Jan , Steele Chad , Aratani Yasuaki , O'Donoghue Robert J. J. , Mutsaers Steven E. , Mossman Brooke T. , Wouters Emiel F. M. , Vernooy Juanita H. J.
Published: June 2009

Lung neutrophilia is common to a variety of lung diseases. The production of reactive oxygen and nitrogen species during neutrophil oxidative burst has been associated with protein and DNA damage. Myeloperoxidase (MPO) is an enzyme stored in the azurophilic granula of neutrophils. It is important in host defense because it generates the reactive oxidant hypochlorous acid and has been described to play a role in the activation of neutrophils during extravasation. We hypothesized that MPO contributes directly to the development of acute lung neutrophilia via stimulation of neutrophil extravasation and indirectly to the subsequent production of cytokines and chemokines in the lung. To test this hypothesis, wild-type (WT) and Mpo−/− mice were given a single LPS instillation, after which the development of neutrophil-dominated lung inflammation, oxidative stress, and cytokine and chemokine levels were examined. Mpo−/− mice demonstrated a decreased lung neutrophilia that peaked earlier than neutrophilia in WT mice, which can be explained by decreased neutrophil chemoattractant levels in LPS-exposed Mpo−/− compared with WT mice. However, oxidative stress levels were not different in LPS-exposed WT and Mpo−/− mice. Furthermore, in vivo findings were confirmed by in vitro studies, using isolated neutrophils. These results indicate that MPO promotes the development of lung neutrophilia and indirectly influences subsequent chemokine and cytokine production by other cell types in the lung.
Neutrophil-Derived IL-6 Limits Alveolar Barrier Disruption in Experimental Ventilator-Induced Lung Injury
Authors: Wolters Paul J. , Wray Charlie , Sutherland Rachel E. , Kim Sophia S. , Koff Jon , Mao Ying , Frank James A.
Published: June 2009

IL-6 is a biological marker of ventilator-associated lung injury that may contribute to alveolar barrier dysfunction in acute respiratory distress syndrome. To determine whether IL-6 affects alveolar barrier disruption in a model of ventilator-induced lung injury, we examined alveolar barrier albumin flux in wild-type (WT) mice given an IL-6-blocking Ab (IL6AB) and mice deficient in IL-6 (IL6KO). Albumin flux was significantly higher in mice given IL6AB compared with mice given a control Ab. Unexpectedly, albumin flux was similar in WT and IL6KO mice. To examine the mechanisms for these findings, lung neutrophil accumulation (myeloperoxidase activity) was compared, revealing a correlation between lung neutrophil accumulation and albumin flux. IL6AB mice had significantly more lung neutrophils than WT and IL6KO mice, which were similar. Therefore, to determine whether the cellular source of IL-6 influences neutrophil accumulation and alveolar barrier function, chimeric mice were compared. WT/KO chimeras (WT mice with IL6KO hematopoietic cells) showed significantly greater albumin flux and neutrophil accumulation with mechanical ventilation than WT/WT mice. Neutrophil depletion decreased albumin flux in WT and WT/KO mice. IL6KO neutrophils were more adherent in an in vitro assay compared with WT neutrophils. IL-6 from a hematopoietic cell source limits alveolar barrier disruption potentially by reducing neutrophil contact with the endothelium. Modulation of IL-6 signaling in a cell type-specific fashion may be a therapeutic target for patients with acute lung injury.
Tuberculosis Subunit Vaccination Provides Long-Term Protective Immunity Characterized by Multifunctional CD4 Memory T Cells
Authors: Lindenstrøm Thomas , Agger Else Marie , Korsholm Karen S. , Darrah Patricia A. , Aagaard Claus , Seder Robert A. , Rosenkrands Ida , Andersen Peter
Published: June 2009

Improved vaccines capable of promoting long-term cellular immunity are urgently required for a number of diseases that remain global health problems. In the present study, we demonstrate that a tuberculosis subunit vaccine, Ag85B-ESAT-6/CAF01 (where ESAT-6 is early secreted antigenic target of 6 kDa and CAF01 is cationic adjuvant formulation 01), induces very robust memory CD4 T cell responses that are maintained at high levels for >1 year postvaccination. This long-term, vaccine-induced memory response protects against a challenge with Mycobacterium tuberculosis at levels that are comparable to or better than those of bacillus Calmette-Guérin. Characterization of the CD4 memory T cells by multicolor flow cytometry demonstrated that the long-lived memory population consisted almost exclusively of TNF-α+IL-2+ and IFN-γ+TNF-α+IL-2+ multifunctional T cells. In addition, memory cells isolated >1 year postvaccination maintained a strong, vaccine-specific proliferative potential. Long-term memory induced by the BCG vaccine contained fewer multifunctional T cells and was biased toward effector cells mainly of the TNF-α+IFN-γ+-coexpressing subset. Ag85B-ESAT-6/CAF01 vaccination very efficiently sustained multifunctional CD4 T cells that accumulated at the site of infection after M. tuberculosis challenge, whereas the response in unvaccinated animals was characterized by CD4 effector T cells. Our data demonstrate that adjuvanted subunit vaccines can promote long-term protective immune responses characterized by high levels of persisting multifunctional T cells and that the quality and profile of this response is sustained postinfection.
Fc Receptor-Like 3 Protein Expressed on IL-2 Nonresponsive Subset of Human Regulatory T Cells
Authors: Nagata Satoshi , Ise Tomoko , Pastan Ira
Published: June 2009

Fc receptor-like 3 (FCRL3) is a cell surface protein homologous to Fc receptors. The FCRL3 gene is present in humans but not in mice. We found that FCRL3 protein is expressed on 40% of human naturally occurring CD4+ regulatory T (nTreg) cells (CD4+CD25+CD127low). Sorted nTreg cells with the surface phenotype FCRL3+ and FCRL3− were both hypoproliferative to TCR stimulation and both suppressive on proliferation of conventional T cells (CD4+CD25−) in vitro. They both expressed forkhead box p3 (Foxp3) protein, the intracellular regulatory T cell marker. However, in contrast to FCRL3− nTreg cells, FCRL3+ nTreg cells were not stimulated to proliferate by the addition of exogenous IL-2. In addition, Foxp3+ cells induced from conventional T cells by TGF-β treatment did not exhibit FCRL3 expression. These results suggest that the FCRL3+ subset of human nTreg cells identified in this study arise in vivo and Foxp3 expression alone is not sufficient to induce FCRL3 expression. FCRL3 may be involved in human-specific mechanisms to control the generation of nTreg cells.
Clinical Isolates of Streptococcus pneumoniae Bind the Complement Inhibitor C4b-Binding Protein in a PspC Allele-Dependent Fashion
Authors: Dieudonné-Vatran Antoine , Krentz Stefanie , Blom Anna M. , Meri Seppo , Henriques-Normark Birgitta , Riesbeck Kristian , Albiger Barbara
Published: June 2009

The complement system constitutes an important component of the innate immune system. To colonize their host and/or to cause disease, many pathogens have evolved strategies to avoid complement-mediated bacterial lysis and opsonophagocytosis. In this study, using a collection of 55 clinical isolates of Streptococcus pneumoniae, we demonstrate for the first time that pneumococci bind the complement inhibitor C4b-binding protein (C4BP). C4BP binding seems to be restricted to certain serotypes such as serotype 4, 6B, 7F, and 14, of which the strains of serotype 14 are the strongest binders. We show that bacteria-bound C4BP retains its functional activity and down-regulates the activation of the classical pathway. Thus, this major respiratory pathogen may escape immune recognition and eradication by the complement system. Furthermore, we show that C4BP binding varies between strains but is dependent on the expression of pneumococcal surface protein C, PspC of group 4. The study of the distribution of group 4 pspC locus shows that most of high-binder serotype 14 isolates harbor an allelic variant of group 4 pspC. Using PspC-negative mutant strains, we identified a new allelic variant of PspC (PspC4.4) as a major ligand for C4BP, revealing a new function for this important pneumococcal virulence factor. Thus pneumococci exploit host C4BP for complement evasion in a PspC allele-dependent manner.
GITR Triggering Induces Expansion of Both Effector and Regulatory CD4+ T Cells In Vivo
Authors: van Olffen Ronald W. , Koning Nathalie , van Gisbergen Klaas P. J. M. , Wensveen Felix M. , Hoek Robert M. , Boon Louis , Hamann Jörg , van Lier Rene A. W. , Nolte Martijn A.
Published: June 2009

Glucocorticoid-induced TNF receptor family-related protein (GITR) is expressed on activated and regulatory T cells, but its role on these functionally opposing cell types is not fully understood. Here we describe that transgenic expression of GITR’s unique ligand (GITRL) induces a prominent increase of both effector and regulatory CD4+ T cells, but not CD8+ T cells. Regulatory T cells from GITRL transgenic mice are phenotypically activated and retain their suppressive capacity. The accumulation of effector and regulatory T cells is not due to enhanced differentiation of naive T cells, but is a direct result of increased proliferation. Functional consequences of increased numbers of both regulatory and effector T cells were tested in an autoimmune model and show that GITR stimulation is protective, as it significantly delays disease induction. These data indicate that GITR regulates the balance between regulatory and effector CD4+ T cells by enhancing proliferation of both populations in parallel.
B Cell Receptor-Mediated Internalization of Salmonella: A Novel Pathway for Autonomous B Cell Activation and Antibody Production
Authors: Souwer Yuri , Griekspoor Alexander , Jorritsma Tineke , de Wit Jelle , Janssen Hans , Neefjes Jacques , van Ham S. Marieke
Published: June 2009

The present paradigm is that primary B cells are nonphagocytosing cells. In this study, we demonstrate that human primary B cells are able to internalize bacteria when the bacteria are recognized by the BCR. BCR-mediated internalization of Salmonella typhimurium results in B cell differentiation and secretion of anti-Salmonella Ab by the Salmonella-specific B cells. In addition, BCR-mediated internalization leads to efficient Ag delivery to the MHC class II Ag-loading compartments, even though Salmonella remains vital intracellularly in primary B cells. Consequently, BCR-mediated bacterial uptake induces efficient CD4+ T cell help, which boosts Salmonella-specific Ab production. BCR-mediated internalization of Salmonella by B cells is superior over extracellular Ag extraction to induce rapid and specific humoral immune responses and efficiently combat infection.
Lipopolysaccharide Stimulates Platelet Secretion and Potentiates Platelet Aggregation via TLR4/MyD88 and the cGMP-Dependent Protein Kinase Pathway
Authors: Zhang Guoying , Han Jingyan , Welch Emily J. , Ye Richard D. , Voyno-Yasenetskaya Tatyana A. , Malik Asrar B. , Du Xiaoping , Li Zhenyu
Published: June 2009

Bacterial LPS induces rapid thrombocytopenia, hypotension, and sepsis. Although growing evidence suggests that platelet activation plays a critical role in LPS-induced thrombocytopenia and tissue damage, the mechanism of LPS-mediated platelet activation is unclear. In this study, we show that LPS stimulates platelet secretion of dense and α granules as indicated by ATP release and P-selectin expression, and thus enhances platelet activation induced by low concentrations of platelet agonists. Platelets express components of the LPS receptor-signaling complex, including TLR (TLR4), CD14, MD2, and MyD88, and the effect of LPS on platelet activation was abolished by an anti-TLR4-blocking Ab or TLR4 knockout, suggesting that the effect of LPS on platelet aggregation requires the TLR4 pathway. Furthermore, LPS-potentiated thrombin- and collagen-induced platelet aggregation and FeCl3-induced thrombus formation were abolished in MyD88 knockout mice. LPS also induced cGMP elevation and the stimulatory effect of LPS on platelet aggregation was abolished by inhibitors of NO synthase and the cGMP-dependent protein kinase (PKG). LPS-induced cGMP elevation was inhibited by an anti-TLR4 Ab or by TLR4 deficiency, suggesting that activation of the cGMP/protein kinase G pathway by LPS involves the TLR4 pathway. Taken together, our data indicate that LPS stimulates platelet secretion and potentiates platelet aggregation through a TLR4/MyD88- and cGMP/PKG-dependent pathway.
IFN-α Enhances Peptide Vaccine-Induced CD8+ T Cell Numbers, Effector Function, and Antitumor Activity
Authors: Sikora Andrew G. , Jaffarzad Nina , Hailemichael Yared , Gelbard Alexander , Stonier Spencer W. , Schluns Kimberly S. , Frasca Loredana , Lou Yanyan , Liu Chengwen , Andersson Helen A. , Hwu Patrick , Overwijk Willem W.
Published: June 2009

Type I IFNs, including IFN-α, enhance Ag presentation and promote the expansion, survival, and effector function of CD8+ CTL during viral infection. Because these are ideal characteristics for a vaccine adjuvant, we examined the efficacy and mechanism of exogenous IFN-α as an adjuvant for antimelanoma peptide vaccination. We studied the expansion of pmel-1 transgenic CD8+ T cells specific for the gp100 melanocyte differentiation Ag after vaccination of mice with gp10025–33 peptide in IFA. IFN-α synergized with peptide vaccination in a dose-dependent manner by boosting relative and absolute numbers of gp100-specific T cells that suppressed B16 melanoma growth. IFN-α dramatically increased the accumulation of gp100-specific, IFN-γ-secreting, CD8+ T cells in the tumor through reduced apoptosis and enhanced proliferation of Ag-specific CD8+ T cells. IFN-α treatment also greatly increased the long-term maintenance of pmel-1 CD8+ T cells with an effector memory phenotype, a process that required expression of IFN-α receptor on the T cells and IL-15 in the host. These results demonstrate the efficacy of IFN-α as an adjuvant for peptide vaccination, give insight into its mechanism of action, and provide a rationale for clinical trials in which vaccination is combined with standard-of-care IFN-α therapy for melanoma.
IL-17 Receptor Signaling Is Required to Control Polymicrobial Sepsis
Authors: Freitas Andressa , Alves-Filho José C. , Victoni Tatiana , Secher Thomas , Lemos Henrique P. , Sônego Fabiane , Cunha Fernando Q. , Ryffel Bernhard
Published: June 2009

Sepsis is a systemic inflammatory response resulting from the inability of the host to contain the infection locally. Previously, we demonstrated that during severe sepsis there is a marked failure of neutrophil migration to the infection site, which contributes to dissemination of infection, resulting in high mortality. IL-17 plays an important role in neutrophil recruitment. Herein, we investigated the role of IL-17R signaling in polymicrobial sepsis induced by cecal ligation and puncture (CLP). It was observed that IL-17R-deficient mice, subjected to CLP-induced non-severe sepsis, show reduced neutrophil recruitment into the peritoneal cavity, spread of infection, and increased systemic inflammatory response as compared with C57BL/6 littermates. As a consequence, the mice showed an increased mortality rate. The ability of IL-17 to induce neutrophil migration was demonstrated in vivo and in vitro. Beside its role in neutrophil recruitment to the infection focus, IL-17 enhanced the microbicidal activity of the migrating neutrophils by a mechanism dependent on NO. Therefore, IL-17 plays a critical role in host protection during polymicrobial sepsis.
B Cell Receptor-Mediated Sustained c-Rel Activation Facilitates Late Transitional B Cell Survival through Control of B Cell Activating Factor Receptor and NF-κB2
Authors: Castro Iris , Wright Jacqueline A. , Damdinsuren Bazarragchaa , Hoek Kristen L. , Carlesso Gianluca , Shinners Nicholas P. , Gerstein Rachel M. , Woodland Robert T. , Sen Ranjan , Khan Wasif N.
Published: June 2009

Signaling from the BCR and B cell activating factor receptor (BAFF-R or BR3) differentially regulates apoptosis within early transitional (T1) and late transitional (T2; CD21int-T2) B cells during selection processes to generate mature B lymphocytes. However, molecular mechanisms underlying the differential sensitivity of transitional B cells to apoptosis remain unclear. In this study, we demonstrate that BCR signaling induced more long-term c-Rel activation in T2 and mature than in T1 B cells leading to increased expression of anti-apoptotic genes as well as prosurvival BAFF-R and its downstream substrate p100 (NF-κB2). Sustained c-Rel activation required de novo c-Rel gene transcription and translation via Btk-dependent mechanisms. Like T1 cells, mature B cells from Btk- and c-Rel-deficient mice also failed to activate these genes. These findings suggest that the gain of survival potential within transitional B cells is dependent on the ability to produce a long-term c-Rel response, which plays a critical role in T2 B cell survival and differentiation in vivo by inducing anti-apoptotic genes, BAFF-R and NF-κB2, an essential component for BAFF-R survival signaling. Thus, acquisition of resistance to apoptosis during transitional B cell maturation is achieved by integration of BCR and BAFF-R signals.
Vaccination with Aβ-Displaying Virus-Like Particles Reduces Soluble and Insoluble Cerebral Aβ and Lowers Plaque Burden in APP Transgenic Mice
Authors: Bach Patricia , Tschäpe Jakob-A. , Kopietz Ferdinand , Braun Gundula , Baade Janina K. , Wiederhold Karl-Heinz , Staufenbiel Matthias , Prinz Marco , Deller Thomas , Kalinke Ulrich , Buchholz Christian J. , Müller Ulrike C.
Published: June 2009

In transgenic animal models, humoral immunity directed against the β-amyloid peptide (Aβ), which is deposited in the brains of AD patients, can reduce Aβ plaques and restore memory. However, initial clinical trials using active immunization with Aβ1–42 (plus adjuvant) had to be stopped as a subset of patients developed meningoencephalitis, likely due to cytotoxic T cell reactions against Aβ. Previously, we demonstrated that retrovirus-like particles displaying on their surface repetitive arrays of self and foreign Ags can serve as potent immunogens. In this study, we generated retrovirus-like particles that display the 15 N-terminal residues of human Aβ (lacking known T cell epitopes) fused to the transmembrane domain of platelet-derived growth factor receptor (Aβ retroparticles). Western blot analysis, ELISA, and immunogold electron microscopy revealed efficient incorporation of the fusion proteins into the particle membrane. Without the use of adjuvants, single immunization of WT mice with Aβ retroparticles evoked high and long-lived Aβ-specific IgG titers of noninflammatory Th2 isotypes (IgG1 and IgG2b) and led to restimulatable B cell memory. Likewise, immunization of transgenic APP23 model mice induced comparable Ab levels. The CNS of immunized wild-type mice revealed neither infiltrating lymphocytes nor activated microglia, and no peripheral autoreactive T cells were detectable. Importantly, vaccination not only reduced Aβ plaque load to ∼60% of controls and lowered both insoluble Aβ40 as well as Aβ42 in APP23 brain, but also significantly reduced cerebral soluble Aβ species. In summary, Aβ retroparticle vaccination may thus hold promise as a novel efficient future candidate vaccine for active immunotherapy of Alzheimer’s disease.
Metformin Attenuated the Autoimmune Disease of the Central Nervous System in Animal Models of Multiple Sclerosis
Authors: Nath Narender , Khan Musfiquidin , Paintlia Manjeet K. , Hoda Md Nasrul , Giri Shailendra
Published: June 2009

Experimental autoimmune encephalomyelitis (EAE) is a T cell-mediated autoimmune disease of the CNS. Metformin is the most widely used drug for diabetes and mediates its action via activating AMP-activated protein kinase (AMPK). We provide evidence that metformin attenuates the induction of EAE by restricting the infiltration of mononuclear cells into the CNS, down-regulating the expression of proinflammatory cytokines (IFN-γ, TNF-α, IL-6, IL-17, and inducible NO synthase (iNOS)), cell adhesion molecules, matrix metalloproteinase 9, and chemokine (RANTES). Furthermore, the AMPK activity and lipids alterations (total phospholipids and in free fatty acids) were restored by metformin treatment in the CNS of treated EAE animals, suggesting the possible involvement of AMPK. Metformin activated AMPK in macrophages and thereby inhibited biosynthesis of phospholipids as well as neutral lipids and also down-regulated the expression of endotoxin (LPS)-induced proinflammatory cytokines and their mediators (iNOS and cyclooxygenase 2). It also attenuated IFN-γ and IL-17-induced iNOS and cyclooxygenase 2 expression in RAW267.4 cells, further supporting its anti-inflammatory property. Metformin inhibited T cell-mediated immune responses including Ag-specific recall responses and production of Th1 or Th17 cytokines, while it induced the generation of IL-10 in spleen cells of treated EAE animals. Altogether these findings reveal that metformin may have a possible therapeutic value for the treatment of multiple sclerosis and other inflammatory diseases.
Neutrophil-Derived Proteinase 3 Induces Kallikrein-Independent Release of a Novel Vasoactive Kinin
Authors: Kahn Robin , Hellmark Thomas , Leeb-Lundberg L. M. Fredrik , Akbari Nasrin , Todiras Mihail , Olofsson Tor , Wieslander Jörgen , Christensson Anders , Westman Kerstin , Bader Michael , Müller-Esterl Werner , Karpman Diana
Published: June 2009

The kinin-forming pathway is activated on endothelial cells and neutrophils when high-molecular weight kininogen (HK) is cleaved by plasma kallikrein liberating bradykinin, a potent mediator of inflammation. Kinins are released during inflammatory conditions such as vasculitis, associated with neutrophil influx around blood vessels. Some patients with vasculitis have elevated plasma levels of neutrophil-derived proteinase 3 (PR3) and anti-PR3 Abs. This study investigated if neutrophil-derived PR3 could induce activation of the kinin pathway. PR3 incubated with HK, or a synthetic peptide derived from HK, induced breakdown and release of a novel tridecapeptide termed PR3-kinin, NH2-MKRPPGFSPFRSS-COOH, consisting of bradykinin with two additional amino acids on each terminus. The reaction was specific and inhibited by anti-PR3 and α1-antitrypsin. Recombinant wild-type PR3 incubated with HK induced HK breakdown, whereas mutated PR3, lacking enzymatic activity, did not. PR3-kinin bound to and activated human kinin B1 receptors, but did not bind to B2 receptors, expressed by transfected HEK293 cells in vitro. In human plasma PR3-kinin was further processed to the B2 receptor agonist bradykinin. PR3-kinin exerted a hypotensive effect in vivo through both B1 and B2 receptors as demonstrated using wild-type and B1 overexpressing rats as well as wild-type and B2 receptor knockout mice. Neutrophil extracts from vasculitis patients and healthy controls contained comparable amounts of PR3 and induced HK proteolysis, an effect that was abolished when PR3 was immunoadsorbed. Neutrophil-derived PR3 can proteolyze HK and liberate PR3-kinin, thereby initiating kallikrein-independent activation of the kinin pathway.
The T Cell STAT Signaling Network Is Reprogrammed within Hours of Bacteremia via Secondary Signals
Authors: Hotson Andrew N. , Hardy Jonathan W. , Hale Matthew B. , Contag Christopher H. , Nolan Garry P.
Published: June 2009

The delicate balance between protective immunity and inflammatory disease is challenged during sepsis, a pathologic state characterized by aspects of both a hyperactive immune response and immunosuppression. The events driven by systemic infection by bacterial pathogens on the T cell signaling network that likely control these responses have not been illustrated in great detail. We characterized how intracellular signaling within the immune compartment is reprogrammed at the single cell level when the host is challenged with a high level of pathogen. To accomplish this, we applied flow cytometry to measure the phosphorylation potential of key signal transduction proteins during acute bacterial challenge. We modeled the onset of sepsis by i.v. administration of avirulent strains of Listeria monocytogenes and Escherichia coli to mice. Within 6 h of bacterial challenge, T cells were globally restricted in their ability to respond to specific cytokine stimulations as determined by assessing the extent of STAT protein phosphorylation. Mechanisms by which this negative feedback response occurred included SOCS1 and SOCS3 gene up-regulation and IL-6-induced endocystosis of the IL-6 receptor. Additionally, macrophages were partially tolerized in their ability to respond to TLR agonists. Thus, in contrast to the view that there is a wholesale immune activation during sepsis, one immediate host response to blood-borne bacteria was induction of a refractory period during which leukocyte activation by specific stimulations was attenuated.
Bcl-3-Regulated Transcription from Major Immediate-Early Promoter of Human Cytomegalovirus in Monocyte-Derived Macrophages
Authors: Khan Kashif Aziz , Coaquette Alain , Davrinche Christian , Herbein Georges
Published: June 2009

Monocytes/macrophages are key cells in the pathogenesis of human CMV (HCMV) infection, but the in vitro rate of viral production in primary human monocyte-derived macrophages (MDM) is considerably lower than in fibroblasts. Considering that the NF-κB signaling pathway is potentially involved in the replication strategy of HCMV through efficient transactivation of the major immediate-early promoter (MIEP), efficient viral replication, and late gene expression, we investigated the composition of the NF-κB complex in HCMV-infected MDMs and fibroblasts. Preliminary studies showed that HCMV could grow in primary MDM culture but that the viral titer in culture supernatants was lower than that observed in the supernatants of more permissive MRC5 fibroblasts. EMSA and microwell colorimetric NF-κB assay demonstrated that HCMV infection of MDMs increased p52 binding activity without activating the canonical p50/p65 complex. Moreover, Bcl-3 was up-regulated and was demonstrated to associate with p52, indicating p52/Bcl-3 complexes as the major component of the NF-κB complex in MDMs. Luciferase assays in promonocytic U937 cells transfected with an MIEP-luciferase reporter construct demonstrated MIEP activation in response to p52 and Bcl-3 overexpression. Chromatin immunoprecipitation assay demonstrated that p52 and Bcl-3 bind the MIEP in acutely HCMV-infected MDMs. In contrast, HCMV infection of MRC5 fibroblasts resulted in activation of p50/p65 heterodimers. Thus, activation of p52/Bcl-3 complexes in MDMs and p50/p65 heterodimers in fibroblasts in response to HCMV infection might explain the low-level growth of the virus in MDMs vs efficient growth in fibroblasts.
Cytokine Modulation of TLR Expression and Activation in Mesenchymal Stromal Cells Leads to a Proinflammatory Phenotype
Authors: Romieu-Mourez Raphaëlle , François Moïra , Boivin Marie-Noëlle , Bouchentouf Manaf , Spaner David E. , Galipeau Jacques
Published: June 2009

Bone marrow-derived mesenchymal stromal cells (MSC) possess an immune plasticity manifested by either an immunosuppressive or, when activated with IFN-γ, an APC phenotype. Herein, TLR expression by MSC and their immune regulatory role were investigated. We observed that human MSC and macrophages expressed TLR3 and TLR4 at comparable levels and TLR-mediated activation of MSC resulted in the production of inflammatory mediators such as IL-1β, IL-6, IL-8/CXCL8, and CCL5. IFN-α or IFN-γ priming up-regulated production of these inflammatory mediators and expression of IFNB, inducible NO synthase (iNOS), and TRAIL upon TLR activation in MSC and macrophages, but failed to induce IL-12 and TNF-α production in MSC. Nonetheless, TLR activation in MSC resulted in the formation of an inflammatory site attracting innate immune cells, as evaluated by human neutrophil chemotaxis assays and by the analysis of immune effectors retrieved from Matrigel-embedded MSC injected into mice after in vitro preactivation with cytokines and/or TLR ligands. Hence, TLR-activated MSC are capable of recruiting immune inflammatory cells. In addition, IFN priming combined with TLR activation may increase immune responses induced by Ag-presenting MSC through presentation of Ag in an inflammatory context, a mechanism that could be applied in a cell-based vaccine.