bluuebunny/crossref_metadata_2025_split huggingface dataset:
SCE1, the SUMO-Conjugating Enzyme in Plants That Interacts with NIb, the RNA-Dependent RNA Polymerase of Turnip Mosaic Virus, Is Required for Viral Infection
Authors: Xiong Ruyi , Wang Aiming 
Published: January 2013

ABSTRACT

SUMOylation, which is catalyzed by small ubiquitin-like modifier (SUMO) enzymes, is a transient, reversible posttranslational protein modification that regulates diverse cellular processes. Potyviruses, the largest group of known plant viruses, comprise many agriculturally important viruses, such as
Turnip mosaic virus
(TuMV). The potyviral genome encodes 11 mature proteins. To investigate if SUMOylation plays a role in potyvirus infection, a yeast two-hybrid screen was performed to examine possible interactions of each of the 11 viral proteins of TuMV with AtSCE1, the only SUMO-conjugating enzyme in
Arabidopsis thaliana
homologous to the key SUMO-conjugating enzyme E2 in mammalian cells or Ubc9 in yeast. A positive reaction was found between AtSCE1 and NIb, the potyviral RNA-dependent RNA polymerase. Further bimolecular fluorescence complementation (BiFC) and fluorescence resonance energy transfer (FRET) assays revealed that the NIb and AtSCE1 interaction occurred in both the cytoplasm and nuclei of epidermal cells of
Nicotiana benthamiana
. The interaction motif was mapped to a region encompassing NIb amino acids 171 to 300 which contains a potential negatively charged amino acid-dependent SUMOylation motif (NDSM). An
Escherichia coli
SUMOylation assay showed that NIb can be SUMOylated and that the lysine residue (K172) in the motif is a potent SUMOylation site. A TuMV infectious clone with an arginine (R) substitution mutation at K172 compromised TuMV infectivity in plants. In comparison with wild-type
Arabidopsis
plants,
sce1
knockdown plants exhibited increased resistance to TuMV as well as a nonrelated RNA virus. To the best of our knowledge, this is the first report showing that the host SUMO modification system plays an essential role in infection by plant RNA viruses.
Matriptase Proteolytically Activates Influenza Virus and Promotes Multicycle Replication in the Human Airway Epithelium
Authors: Beaulieu Alexandre , Gravel Émilie , Cloutier Alexandre , Marois Isabelle , Colombo Éloïc , Désilets Antoine , Verreault Catherine , Leduc Richard , Marsault Éric , Richter Martin V. 
Published: January 2013

ABSTRACT
Influenza viruses do not encode any proteases and must rely on host proteases for the proteolytic activation of their surface hemagglutinin proteins in order to fuse with the infected host cells. Recent progress in the understanding of human proteases responsible for influenza virus hemagglutinin activation has led to the identification of members of the type II transmembrane serine proteases TMPRSS2 and TMPRSS4 and human airway trypsin-like protease; however, none has proved to be the sole enzyme responsible for hemagglutinin cleavage. In this study, we identify and characterize matriptase as an influenza virus-activating protease capable of supporting multicycle viral replication in the human respiratory epithelium. Using confocal microscopy, we found matriptase to colocalize with hemagglutinin at the apical surface of human epithelial cells and within endosomes, and we showed that the soluble form of the protease was able to specifically cleave hemagglutinins from H1 virus, but not from H2 and H3 viruses, in a broad pH range. We showed that small interfering RNA (siRNA) knockdown of matriptase in human bronchial epithelial cells significantly blocked influenza virus replication in these cells. Lastly, we provide a selective, slow, tight-binding inhibitor of matriptase that significantly reduces viral replication (by 1.5 log) of H1N1 influenza virus, including the 2009 pandemic virus. Our study establishes a three-pronged model for the action of matriptase: activation of incoming viruses in the extracellular space in its shed form, upon viral attachment or exit in its membrane-bound and/or shed forms at the apical surface of epithelial cells, and within endosomes by its membrane-bound form where viral fusion takes place.
Recruitment of Brd4 to the Human Papillomavirus Type 16 DNA Replication Complex Is Essential for Replication of Viral DNA
Authors: Wang Xin , Helfer Christine M. , Pancholi Neha , Bradner James E. , You Jianxin 
Published: January 2013

ABSTRACT
Replication of the human papillomavirus (HPV) DNA genome relies on viral factors E1 and E2 and the cellular replication machinery. Bromodomain-containing protein 4 (Brd4) interacts with viral E2 protein to mediate papillomavirus (PV) genome maintenance and viral transcription. However, the functional role of Brd4 in the HPV life cycle remains to be clearly defined. In this study, we provide the first look into the E2-Brd4 interaction in the presence of other important viral factors, such as the HPV16 E1 protein and the viral genome. We show that Brd4 is recruited to actively replicating HPV16 origin foci together with HPV16 E1, E2, and a number of the cellular replication factors: replication protein A70 (RPA70), replication factor C1 (RFC1), and DNA polymerase δ. Mutagenesis disrupting the E2-Brd4 interaction abolishes the formation of the HPV16 replication complex and impairs HPV16 DNA replication in cells. Brd4 was further demonstrated to be necessary for HPV16 viral DNA replication using a cell-free replication system in which depletion of Brd4 by small interfering RNA (siRNA) silencing leads to impaired HPV16 viral DNA replication and recombinant Brd4 protein is able to rescue viral DNA replication. In addition, releasing endogenous Brd4 from cellular chromatin by using the bromodomain inhibitor JQ1(+) enhances HPV16 DNA replication, demonstrating that the role of Brd4 in HPV DNA replication could be uncoupled from its function in chromatin-associated transcriptional regulation and cell cycle control. Our study reveals a new role for Brd4 in HPV genome replication, providing novel insights into understanding the life cycle of this oncogenic DNA virus.
Alphaherpesviral US3 Kinase Induces Cofilin Dephosphorylation To Reorganize the Actin Cytoskeleton
Authors: Jacob Thary , Van den Broeke Céline , van Troys Marleen , Waterschoot Davy , Ampe Christophe , Favoreel Herman W. 
Published: January 2013

ABSTRACTThe conserved alphaherpesviral serine/threonine kinase US3 causes dramatic actin rearrangements, associated with increased viral spread. Here, we show that US3 of pseudorabies virus (PRV) leads to activation (dephosphorylation) of the central actin regulator cofilin. A mutation that impairs US3 kinase activity and the group I p21-activated kinase inhibitor IPA-3 inhibited US3-mediated cofilin activation. Additionally, expression of phosphomimetic S3D cofilin significantly suppressed the ability of US3 to cause cell projections and cell rounding. In conclusion, the US3 kinase of PRV leads to activation (dephosphorylation) of cofilin, and cofilin contributes to US3-mediated actin rearrangements.
Measles Virus Infection of Epithelial Cells in the Macaque Upper Respiratory Tract Is Mediated by Subepithelial Immune Cells
Authors: Ludlow Martin , Lemon Ken , de Vries Rory D. , McQuaid Stephen , Millar Emma L. , van Amerongen Geert , Yüksel Selma , Verburgh R. Joyce , Osterhaus Albert D. M. E. , de Swart Rik L. , Duprex W. Paul 
Published: January 2013

ABSTRACT

Measles virus (MV), one of the most contagious viruses infecting humans, causes a systemic infection leading to fever, immune suppression, and a characteristic maculopapular rash. However, the specific mechanism or mechanisms responsible for the spread of MV into the respiratory epithelium in the late stages of the disease are unknown. Here we show the crucial role of PVRL4 in mediating the spread of MV from immune to epithelial cells by generating a PVRL4 “blind” recombinant wild-type MV and developing a novel
in vitro
coculture model of B cells with primary differentiated normal human bronchial epithelial cells. We utilized the macaque model of measles to analyze virus distribution in the respiratory tract prior to and at the peak of MV replication. Expression of PVRL4 was widespread in both the lower and upper respiratory tract (URT) of macaques, indicating MV transmission can be facilitated by more than only epithelial cells of the trachea. Analysis of tissues collected at early time points after experimental MV infection demonstrated the presence of MV-infected lymphoid and myeloid cells contacting respiratory tract epithelium in the absence of infected epithelial cells, suggesting that these immune cells seed the infection
in vivo
. Thereafter, lateral cell-to-cell spread of MV led to the formation of large foci of infected cells in the trachea and high levels of MV infection in the URT, particularly in the nasal cavity. These novel findings have important implications for our understanding of the high transmissibility of measles.
HLA-B*57 versus HLA-B*81 in HIV-1 Infection: Slow and Steady Wins the Race?
Authors: Prentice Heather A. , Porter Travis R. , Price Matthew A. , Cormier Emmanuel , He Dongning , Farmer Paul K. , Kamali Anatoli , Karita Etienne , Lakhi Shabir , Sanders Eduard J. , Anzala Omu , Amornkul Pauli N. , Allen Susan , Hunter Eric , Kaslow Richard A. , Gilmour Jill , Tang Jianming 
Published: January 2013

ABSTRACT

Two human leukocyte antigen (HLA) variants, HLA-B*57 and -B*81, are consistently known as favorable host factors in human immunodeficiency virus type 1 (HIV-1)-infected Africans and African-Americans. In our analyses of prospective data from 538 recent HIV-1 seroconverters and cross-sectional data from 292 subjects with unknown duration of infection, HLA-B*57 (mostly B*57:03) and -B*81 (exclusively B*81:01) had mostly discordant associations with virologic and immunologic manifestations before antiretroviral therapy. Specifically, relatively low viral load (VL) in HLA-B*57-positive subjects (
P
≤ 0.03 in various models) did not translate to early advantage in CD4
+
T-cell (CD4) counts (
P
≥ 0.37). In contrast, individuals with HLA-B*81 showed little deviation from the normal set point VL (
P
> 0.18) while maintaining high CD4 count during early and chronic infection (
P
= 0.01). These observations suggest that discordance between VL and CD4 count can occur in the presence of certain HLA alleles and that effective control of HIV-1 viremia is not always a prerequisite for favorable prognosis (delayed immunodeficiency). Of note, steady CD4 count associated with HLA-B*81 in HIV-1-infected Africans may depend on the country of origin, as observations differed slightly between subgroups enrolled in southern Africa (Zambia) and eastern Africa (Kenya, Rwanda, and Uganda).
Structural Analysis of the Evolutionary Origins of Influenza Virus Hemagglutinin and Other Viral Lectins
Authors: Chen Lang , Li Fang 
Published: January 2013

ABSTRACT
Influenza virus and other viruses use host cell surface sugars as receptors. Here we show that the sugar-binding domains in influenza virus hemagglutinin and other viral lectins share the same structural fold as human galectins (host lectins). Unlike the easily accessible sugar-binding sites in human galectins, the sugar-binding sites in viral lectins are hidden in cavities. We propose that these viral lectins originated from host lectins but have evolved to use hidden sugar-binding sites to evade host immune attacks.
Perioperative risk stratification for a patient with severe obstructive sleep apnoea undergoing laparoscopic banding surgery
Authors: Weinberg Laurence , Tay Stan , Lai Chung Fei , Barnes Maree 
Published: January 2013

SummaryDespite the increasing prevalence of obstructive sleep apnoea (OSA), there is limited evidence to guide appropriate preoperative investigations, inpatient or outpatient surgery allocation, and the anticipated level of postoperative care. With reference to our institution's perioperative risk stratification, we describe the case of a 46-year-old Caucasian male with a body mass index of 51 kg/m2admitted for laparoscopic band insertion. Management based on our guidelines involved a preoperative polysomnography where the patient was confirmed to have severe OSA. His postoperative care was then managed in the high dependency care unit. He was discharged home on day 2 with no further sequelae. We provide evidence that adoption of this model of care can simplify clinical decision making and resource allocation with favourable patient outcomes.
Exercise during pregnancy and gestational diabetes-related adverse effects: a randomised controlled trial
Authors: Barakat Ruben , Pelaez Mireia , Lopez Carmina , Lucia Alejandro , Ruiz Jonatan R 
Published: January 2013

ObjectiveTo examine the effect of regular moderate-intensity exercise (three training sessions/week) on the incidence of gestational diabetes mellitus (GDM, primary outcome). We also examined if the exercise intervention modifies the association between GDM and birth weight and risk of macrosomia, gestational age, risk of caesarean delivery and maternal weight gain (secondary outcomes).MethodsWe randomly assigned 510 healthy gravida to either an exercise intervention or a usual care (control) group (n=255 each). The exercise programme focused on moderate-intensity resistance and aerobic exercises (three times/week, 50–55 min/session). GDM diabetes was diagnosed according to the WHO criteria and the International Association for Diabetes in Pregnancy Study Group (IADPSG).ResultsThe intervention did not reduce the risk of developing GDM (OR 0.84, 95% CI 0.50 to 1.40) when using the WHO criteria. We observed that the intervention reduced by 58% the GDM-related risk (WHO criteria) of having a newborn with macrosomia (OR 1.76, 95% CI 0.04 to 78.90 vs 4.22, 95% CI 1.35 to 13.19) in exercise and control groups, respectively), and by 34% the GDM-related risk of having acute and elective caesarean delivery (OR 1.30, 95% CI 0.44 to 3.84 vs 1.99, 95% CI 0.98 to 4.06 in exercise and control groups, respectively). Gestational age was similar across the treatment groups (control, exercise) and GDM category (GDM or non-GDM), and maternal weight gain was ∼12% lower in the exercise group independent of whether women developed GDM. The results were similar when the IADPSG criteria were used instead.ConclusionsRegular moderate-intensity exercise performed over the second-third trimesters of pregnancy can be used to attenuate important GDM-related adverse outcomes.
A specialist, second-tier response to out-of-hospital cardiac arrest: setting up TOPCAT2
Authors: Clarke Scott , Lyon Richard M , Short Steven , Crookston Colin , Clegg Gareth R 
Published: January 2013

BackgroundOut-of-hospital cardiac arrest (OHCA) is the most common, immediately life-threatening, medical emergency faced by ambulance crews. Survival from OHCA is largely dependent on quality of prehospital resuscitation. Non-technical skills, including resuscitation team leadership, communication and clinical decision-making are important in providing high quality prehospital resuscitation. We describe a pilot study (TOPCAT2, TC2) to establish a second tier, expert paramedic response to OHCA in Edinburgh, Scotland.MethodsEight paramedics were selected to undergo advanced training in resuscitation and non-technical skills. Simulation and video feedback was used during training. The designated TC2 paramedic manned a regular ambulance service response car and attended emergency calls in the usual manner. Emergency medical dispatch centre dispatchers were instructed to call the TC2 paramedic directly on receipt of a possible OHCA call. Call and dispatch timings, quality of cardiopulmonary resuscitation and return-of-spontaneous circulation were all measured prospectively.ResultsEstablishing a specialist, second-tier paramedic response was feasible. There was no overall impact on ambulance response times. From the first 40 activations, the TC2 paramedic was activated in a median of 3.2 min (IQR 1.6–5.8) and on-scene in a median of 10.8 min (8.0–17.9). Bimonthly team debrief, case review and training sessions were successfully established. OHCA attended by TC2 showed an additional trend towards improved outcome with a rate of return of spontaneous circulation of 22.5%, compared with a national average of 16%.ConclusionsEstablishing a specialist, second-tier response to OHCA is feasible, without impacting on overall ambulance response times. Improving non-technical skills, including prehospital resuscitation team leadership, has the potential to save lives and further research on the impact of the TOPCAT2 pilot programme is warranted.
Socioeconomic development and girl child survival in rural North India: solution or problem?
Authors: Krishnan Anand , Dwivedi Purva , Gupta Vivek , Byass Peter , Pandav Chandrakant S , Ng Nawi 
Published: January 2013

BackgroundSocioeconomic development has been considered as a solution to the problem of sex differentials at birth and under-five mortality. This paper analyses longitudinal data from the Ballabgarh Health and Demographic Surveillance System (HDSS) site in north India to check its veracity.MethodsA cohort of children born between 1 January 2006 and 31 December 2011 at Ballabgarh HDSS were followed till death, emigration, 3 years of age or end of the study. Socioeconomic status (SES) was measured by caste, parental combined years of schooling and wealth index and divided into low, mid and high strata for each of them. Sex ratio at birth (SRB) was reported as the number of girls per 1000 boys. The Kaplan-Meier survival curves were drawn and a Cox Proportional HR of girls over boys was estimated.ResultsA total of 12 517 native born children (25 797 child years) were enrolled of which 710 died (death rate of 56.7/1000-live births and 27.5/1000 child-years. Socioeconomically advantaged children had significantly lower death rates. The SRB (10–16% lower) and neonatal death rate were consistently adverse for girls in the advantaged groups by all the three indicators of SES. The first month survival rates were better for girls in the lower SES categories (significant only in caste (HR 0.58; 0.37 to 0.91). High SES categories consistently showed adverse survival rates for girls (HR of 1.22 to 1.59).ConclusionsBetter socioeconomic situation worsened the sex differentials, especially at birth. Therefore, specific interventions targeting gender issues are required, at least as a short-term measure.
Prospects for the measurement of the Higgs Yukawa couplings to b and c quarks, and muons at CLIC
Authors: Grefe Christian , Laštovička Tomáš , Strube Jan 
Published: January 2013

AbstractThe investigation of the properties of the Higgs boson, especially a test of the predicted linear dependence of the branching ratios on the mass of the final state is going to be an integral part of the physics program at colliders at the energy frontier for the foreseeable future. The large Higgs boson production cross section at a 3 TeV CLIC machine allows for a precision measurement of the Higgs branching ratios. The cross section times branching ratio of the decays $\mathrm {H}\to \mathrm {b}\overline {\mathrm {b}}$, $\mathrm {H}\to \mathrm {c}\overline {\mathrm {c}}$ and H→μ+μ− of a Standard Model Higgs boson with a mass of 120 GeV can be measured with a statistical uncertainty of 0.23 %, 3.1 % and 15 %, respectively, assuming an integrated luminosity of 2 ab−1.
TGF-β Mediates Homing of Bone Marrow–Derived Human Mesenchymal Stem Cells to Glioma Stem Cells
Authors: Shinojima Naoki , Hossain Anwar , Takezaki Tatsuya , Fueyo Juan , Gumin Joy , Gao Feng , Nwajei Felix , Marini Frank C. , Andreeff Michael , Kuratsu Jun-Ichi , Lang Frederick F. 
Published: January 2013

Abstract
Although studies have suggested that bone marrow human mesenchymal stem cells (BM-hMSC) may be used as delivery vehicles for cancer therapy, it remains unclear whether BM-hMSCs are capable of targeting cancer stem cells, including glioma stem cells (GSC), which are the tumor-initiating cells responsible for treatment failures. Using standard glioma models, we identify TGF-β as a tumor factor that attracts BM-hMSCs via TGF-β receptors (TGFβR) on BM-hMSCs. Using human and rat GSCs, we then show for the first time that intravascularly administered BM-hMSCs home to GSC-xenografts that express TGF-β. In therapeutic studies, we show that BM-hMSCs carrying the oncolytic adenovirus Delta-24-RGD prolonged the survival of TGF-β–secreting GSC xenografts and that the efficacy of this strategy can be abrogated by inhibition of TGFβR on BM-hMSCs. These findings reveal the TGF-β/TGFβR axis as a mediator of the tropism of BM-hMSCs for GSCs and suggest that TGF-β predicts patients in whom BM-hMSC delivery will be effective. Cancer Res; 73(7); 2333–44. ©2012 AACR.
SHP2 Is Overexpressed and Inhibits pSTAT1-Mediated APM Component Expression, T-cell Attracting Chemokine Secretion, and CTL Recognition in Head and Neck Cancer Cells
Authors: Leibowitz Michael S. , Srivastava Raghvendra M. , Andrade Filho Pedro A. , Egloff Ann Marie , Wang Lin , Seethala Raja R. , Ferrone Soldano , Ferris Robert L. 
Published: January 2013

Abstract
Purpose: Human leukocyte antigen (HLA) class I antigen processing machinery (APM) component downregulation permits escape of malignant cells from recognition by cytotoxic T lymphocytes (CTL) and correlates with poor prognosis in patients with head and neck cancer (HNC). Activated STAT1 (pSTAT1) is necessary for APM component expression in HNC cells. We investigated whether an overexpressed phosphatase was responsible for basal suppression of pSTAT1 and subsequent APM component-mediated immune escape in HNC cells.
Experimental Design: Immunohistochemical staining and reverse transcription PCR of paired HNC tumors was performed for the phosphatases src homology domain-containing phosphatase (SHP)–1 and SHP2. Depletion of phosphatase activity in HNC and STAT1−/− tumor cells was achieved by siRNA knockdown. HLA class I–restricted, tumor antigen-specific CTL were used in IFN-γ ELISPOT assays against HNC cells. Chemokine secretion was measured after SHP2 depletion in HNC cells.
Results: SHP2, but not SHP1, was significantly upregulated in HNC tissues. In HNC cells, SHP2 depletion significantly upregulated expression of pSTAT1 and HLA class I APM components. Overexpression of SHP2 in nonmalignant keratinocytes inhibited IFN-γ–mediated STAT1 phosphorylation, and SHP2 depletion in STAT1−/− tumor cells did not significantly induce IFN-γ–mediated APM component expression, verifying STAT1 dependence of SHP2 activity. SHP2 depletion induced recognition of HNC cells by HLA class I–restricted CTL and secretion of inflammatory, T-cell attracting chemokines, RANTES and IP10.
Conclusion: These findings suggest for the first time an important role for SHP2 in APM-mediated escape of HNC cells from CTL recognition. Targeting SHP2 could enhance T-cell–based cancer immunotherapy. Clin Cancer Res; 19(4); 798–808. ©2012 AACR.