bluuebunny/crossref_metadata_2025_split huggingface dataset:
N-Linked Glycosylation of the Hemagglutinin Protein Influences Virulence and Antigenicity of the 1918 Pandemic and Seasonal H1N1 Influenza A Viruses
Authors: Sun Xiangjie , Jayaraman Akila , Maniprasad Pavithra , Raman Rahul , Houser Katherine V. , Pappas Claudia , Zeng Hui , Sasisekharan Ram , Katz Jacqueline M. , Tumpey Terrence M. 
Published: June 2013

ABSTRACT
The hemagglutinin (HA) protein is a major virulence determinant for the 1918 pandemic influenza virus; however, it encodes no known virulence-associated determinants. In comparison to seasonal influenza viruses of lesser virulence, the 1918 H1N1 virus has fewer glycosylation sequons on the HA globular head region. Using site-directed mutagenesis, we found that a 1918 HA recombinant virus, of high virulence, could be significantly attenuated in mice by adding two additional glycosylation sites (asparagine [Asn] 71 and Asn 286) on the side of the HA head. The 1918 HA recombinant virus was further attenuated by introducing two additional glycosylation sites on the top of the HA head at Asn 142 and Asn 172. In a reciprocal experimental approach, deletion of HA glycosylation sites (Asn 142 and Asn 177, but not Asn 71 and Asn 104) from a seasonal influenza H1N1 virus, A/Solomon Islands/2006 (SI/06), led to increased virulence in mice. The addition of glycosylation sites to 1918 HA and removal of glycosylation sites from SI/06 HA imposed constraints on the theoretical structure surrounding the glycan receptor binding sites, which in turn led to distinct glycan receptor binding properties. The modification of glycosylation sites for the 1918 and SI/06 viruses also caused changes in viral antigenicity based on cross-reactive hemagglutinin inhibition antibody titers with antisera from mice infected with wild-type or glycan mutant viruses. These results demonstrate that glycosylation patterns of the 1918 and seasonal H1N1 viruses directly contribute to differences in virulence and are partially responsible for their distinct antigenicity.
Quantitative Comparison of Human Parainfluenza Virus Hemagglutinin-Neuraminidase Receptor Binding and Receptor Cleavage
Authors: Tappert Mary M. , Porterfield J. Zachary , Mehta-D'Souza Padmaja , Gulati Shelly , Air Gillian M. 
Published: June 2013

ABSTRACTThe human parainfluenza virus (hPIV) hemagglutinin-neuraminidase (HN) protein binds (H) oligosaccharide receptors that containN-acetylneuraminic acid (Neu5Ac) and cleaves (N) Neu5Ac from these oligosaccharides. In order to determine if one of HN′s two functions is predominant, we measured the affinity of H for its ligands by a solid-phase binding assay with two glycoprotein substrates and by surface plasmon resonance with three monovalent glycans. We compared the dissociation constant (Kd) values from these experiments with previously determined Michaelis-Menten constants (Kms) for the enzyme activity. We found that glycoprotein substrates and monovalent glycans containing Neu5Acα2-3Galβ1-4GlcNAc bind HN withKdvalues in the 10 to 100 μM range.Kmvalues for HN were previously determined to be on the order of 1 mM (M. M. Tappert, D. F. Smith, and G. M. Air, J. Virol. 85:12146–12159, 2011). AKmvalue greater than theKdvalue indicates that cleavage occurs faster than the dissociation of binding and will dominate under N-permissive conditions. We propose, therefore, that HN is a neuraminidase that can hold its substrate long enough to act as a binding protein. The N activity can therefore regulate binding by reducing virus-receptor interactions when the concentration of receptor is high.
Pyrrolidine Dithiocarbamate Inhibits Herpes Simplex Virus 1 and 2 Replication, and Its Activity May Be Mediated through Dysregulation of the Ubiquitin-Proteasome System
Authors: Qiu Min , Chen Yu , Cheng Lin , Chu Ying , Song Hong-Yong , Wu Zhi-Wei 
Published: June 2013

ABSTRACTPyrrolidine dithiocarbamate (PDTC) is widely used as an antioxidant or an NF-κB inhibitor. It has been reported to inhibit the replication of human rhinoviruses, poliovirus, coxsackievirus, and influenza virus. In this paper, we report that PDTC could inhibit the replication of herpes simplex virus 1 and 2 (HSV-1 and HSV-2). PDTC suppressed the expression of HSV-1 and HSV-2 viral immediate early (IE) and late (membrane protein gD) genes and the production of viral progeny. This antiviral property was mediated by the dithiocarbamate moiety of PDTC and required the presence of Zn2+. Although PDTC could potently block reactive oxygen species (ROS) generation, it was found that this property did not contribute to its anti-HSV activity. PDTC showed no activity in disrupting the mitogen-activated protein kinase (MAPK) pathway activation induced by viral infection that was vital for the virus's propagation. We found that PDTC modulated cellular ubiquitination and, furthermore, influenced HSV-2-induced IκB-α degradation to inhibit NF-κB activation and enhanced PML stability in the nucleus, resulting in the inhibition of viral gene expression. These results suggested that the antiviral activity of PDTC might be mediated by its dysregulation of the cellular ubiquitin-proteasome system (UPS).
HIV-1 Gag Cytotoxic T Lymphocyte Epitopes Vary in Presentation Kinetics Relative to HLA Class I Downregulation
Authors: Balamurugan Arumugam , Ali Ayub , Boucau Julie , Le Gall Sylvie , Ng Hwee L. , Yang Otto O. 
Published: June 2013

ABSTRACT

Although CD8
+
cytotoxic T lymphocytes (CTLs) are protective in HIV-1 infection, the factors determining their antiviral efficiency are poorly defined. It is proposed that Gag targeting is superior because of very early Gag epitope presentation, allowing early killing of infected cells before Nef-mediated downregulation of human leukocyte antigen class I (HLA-I). To study Gag epitope presentation kinetics, three epitopes (SL9
77-85
, KF11
162-172
, and TW10
240-249
) were genetically translocated from their endogenous location in the Rev-dependent (late)
gag
gene into the Rev-independent (early)
nef
gene with concomitant mutation of the corresponding endogenous epitopes to nonrecognized sequences. These viruses were compared to the index virus for CTL-mediated suppression of replication and the susceptibility of this antiviral activity to Nef-mediated HLA-I downregulation. SL9-specific CTLs gained activity after SL9 translocation to Nef, going from Nef sensitive to Nef insensitive, indicating that translocation accelerated infected cell recognition from after to before HLA-I downregulation. KF11-specific CTL antiviral activity was unchanged and insensitive to HLA-I downregulation before and after KF11 translocation, suggesting that already rapid recognition of infected cells was not accelerated. However, TW10-specific CTLs that were insensitive to Nef at the baseline became sensitive with reduced antiviral activity after translocation, indicating that translocation retarded epitope expression. Cytosolic peptide processing assays suggested that TW10 was inefficiently generated after translocation to Nef, compared to SL9 and KF11. As a whole, these data demonstrate that epitope presentation kinetics play an important role in CTL antiviral efficiency, that Gag epitopes are not uniformly presented early, and that the epitope context can play a major role in presentation kinetics.
A Mutation in the Stalk of the Newcastle Disease Virus Hemagglutinin-Neuraminidase (HN) Protein Prevents Triggering of the F Protein despite Allowing Efficient HN-F Complex Formation
Authors: Mirza Anne M. , Iorio Ronald M. 
Published: June 2013

ABSTRACT
Newcastle disease virus (NDV)-induced membrane fusion requires formation of a complex between the hemagglutinin-neuraminidase (HN) and fusion (F) proteins. Substitutions for NDV HN stalk residues A89, L90, and L94 block fusion by modulating formation of the HN-F complex. Here, we demonstrate that a nearby L97A substitution, though previously shown to block fusion, allows efficient HN-F complex formation and likely acts by preventing changes in the HN stalk required for triggering of the bound F protein.
A Role for Ifit2 in Restricting West Nile Virus Infection in the Brain
Authors: Cho Hyelim , Shrestha Bimmi , Sen Ganes C. , Diamond Michael S. 
Published: June 2013

ABSTRACTPrevious studies have demonstrated that type I interferon (IFN-I) restricts West Nile virus (WNV) replication and pathogenesis in peripheral and central nervous system (CNS) tissues. However, thein vivorole of specific antiviral genes that are induced by IFN-I against WNV infection remains less well characterized. Here, usingIfit2−/−mice, we defined the antiviral function of the interferon-stimulated gene (ISG)Ifit2in limiting infection and diseasein vivoby a virulent North American strain of WNV. Compared to congenic wild-type controls,Ifit2−/−mice showed enhanced WNV infection in a tissue-restricted manner, with preferential replication in the CNS of animals lackingIfit2. Virological analysis of cultured macrophages, dendritic cells, fibroblasts, cerebellar granule cell neurons, and cortical neurons revealed cell type-specific antiviral functions of Ifit2 against WNV. In comparison, small effects of Ifit2 were observed on the induction or magnitude of innate or adaptive immune responses. Our results suggest that Ifit2 restricts WNV infection and pathogenesis in different tissues in a cell type-specific manner.
Possible Role of a Cell Surface Carbohydrate in Evolution of Resistance to Viral Infections in Old World Primates
Authors: Rodriguez Idalia A. , Welsh Raymond M. 
Published: June 2013

ABSTRACTDue to inactivation of the α1,3-galactosyltransferase gene (GGTA1, or the α1,3GT gene) approximately 28 million years ago, the carbohydrate αGal (Galα1,3Galβ1,4GlcNAc) is not expressed on the cells of Old World monkeys and apes (including humans) but is expressed in all other mammals. The proposed selective advantage of this mutation for these primates is the ability to produce anti-Gal antibodies, which may be an effective immune component in neutralizing αGal-expressing pathogens. However, loss of α1,3GT expression may have been advantageous by providing natural resistance against viral pathogens that exploited the α1,3GT pathway or cell surface αGal for infection. Infections of paired cell lines with differential expression of α1,3GT showed that Sindbis viruses (SINV) preferentially replicate in α1,3GT-positive cells, whereas herpes simplex viruses type 1 and type 2 (HSV-1 and HSV-2) preferentially grow in cells lacking α1,3GT. Viral growth and spread correlated with the ability of the different viruses to successfully initiate infection in the presence or absence of α1,3GT expression. GT knockout (KO) suckling mice infected with SINV strains (AR339 and S.A.AR86) experienced significant delay in onset of disease symptoms and mortality compared to wild-type (WT) B6 suckling mice. In contrast, HSV-2-infected GT KO mice had higher viral titers in spleen and liver and exhibited significantly more focal hepatic necrosis than WT B6 mice. This study demonstrates that α1,3GT activity plays a role in the course of infections for certain viruses. Furthermore, this study has implications for the evolution of resistance to viral infections in primates.
Positively Charged Residues at the Five-Fold Symmetry Axis of Cell Culture-Adapted Foot-and-Mouth Disease Virus Permit Novel Receptor Interactions
Authors: Berryman Stephen , Clark Stuart , Kakker Naresh K. , Silk Rhiannon , Seago Julian , Wadsworth Jemma , Chamberlain Kyle , Knowles Nick J. , Jackson Terry 
Published: June 2013

ABSTRACT

Field isolates of foot-and-mouth disease virus (FMDV) have a restricted cell tropism which is limited by the need for certain RGD-dependent integrin receptors. In contrast, cell culture-adapted viruses use heparan sulfate (HS) or other unidentified molecules as receptors to initiate infection. Here, we report several novel findings resulting from cell culture adaptation of FMDV. In cell culture, a virus with the capsid of the A/Turkey/2/2006 field isolate gained the ability to infect CHO and HS-deficient CHO cells as a result of a single glutamine (Q)-to-lysine (K) substitution at VP1-110 (VP1-
Q
110
K
). Using site-directed mutagenesis, the introduction of lysine at this same site also resulted in an acquired ability to infect CHO cells by type O and Asia-1 FMDV. However, this ability appeared to require a second positively charged residue at VP1-109. CHO cells express two RGD-binding integrins (α5β1 and αvβ5) that, although not used by FMDV, have the potential to be used as receptors; however, viruses with the VP1-
Q
110
K
substitution did not use these integrins. In contrast, the VP1-
Q
110
K
substitution appeared to result in enhanced interactions with αvβ6, which allowed a virus with KGE in place of the normal RGD integrin-binding motif to use αvβ6 as a receptor. Thus, our results confirmed the existence of nonintegrin, non-HS receptors for FMDV on CHO cells and revealed a novel, non-RGD-dependent use of αvβ6 as a receptor. The introduction of lysine at VP1-110 may allow for cell culture adaptation of FMDV by design, which may prove useful for vaccine manufacture when cell culture adaptation proves intractable.
From Integrative Genomics to Therapeutic Targets
Authors: Natrajan Rachael , Wilkerson Paul 
Published: June 2013

Abstract
Combinatorial approaches that integrate conventional pathology with genomic profiling and functional genomics have begun to enhance our understanding of the genetic basis of breast cancer. These methods have identified key genotypic–phenotypic correlations in different breast cancer subtypes that have led to the discovery of genetic dependencies that drive their behavior. Moreover, this knowledge has been applied to define novel tailored therapies for these groups of patients with cancer. With the current emphasis on characterizing the mutational repertoire of breast cancers by next-generation sequencing, the question remains as to what constitutes a driver event. By focusing efforts on homogenous subgroups of breast cancer and integrating orthogonal data-types combined with functional approaches, we can begin to unravel the heterogeneity and identify aberrations that can be therapeutically targeted. Cancer Res; 73(12); 3483–8. ©2013 AACR.
Glioma Grade Is Associated with the Accumulation and Activity of Cells Bearing M2 Monocyte Markers
Authors: Prosniak Michael , Harshyne Larry A. , Andrews David W. , Kenyon Lawrence C. , Bedelbaeva Kamila , Apanasovich Tatiyana V. , Heber-Katz Ellen , Curtis Mark T. , Cotzia Paolo , Hooper D. Craig 
Published: June 2013

AbstractPurpose: This study is directed at identifying the cell source(s) of immunomodulatory cytokines in high-grade gliomas and establishing whether the analysis of associated markers has implications for tumor grading.Experimental Design: Glioma specimens classified as WHO grade II–IV by histopathology were assessed by gene expression analysis and immunohistochemistry to identify the cells producing interleukin (IL)-10, which was confirmed by flow cytometry and factor secretion in culture. Finally, principal component analysis (PCA) and mixture discriminant analysis (MDA) were used to investigate associations between expressed genes and glioma grade.Results: The principle source of glioma-associated IL-10 is a cell type that bears phenotype markers consistent with M2 monocytes but does not express all M2-associated genes. Measures of expression of the M2 cell markers CD14, CD68, CD163, and CD204, which are elevated in high-grade gliomas, and the neutrophil/myeloid-derived suppressor cell (MDSC) subset marker CD15, which is reduced, provide the best index of glioma grade.Conclusions: Grade II and IV astrocytomas can be clearly differentiated on the basis of the expression of certain M2 markers in tumor tissues, whereas grade III astrocytomas exhibit a range of expression between the lower and higher grade specimens. The content of CD163+ cells distinguishes grade III astrocytoma subsets with different prognosis. Clin Cancer Res; 19(14); 3776–86. ©2013 AACR.
A Phase I Study of Quisinostat (JNJ-26481585), an Oral Hydroxamate Histone Deacetylase Inhibitor with Evidence of Target Modulation and Antitumor Activity, in Patients with Advanced Solid Tumors
Authors: Venugopal Balaji , Baird Richard , Kristeleit Rebecca S. , Plummer Ruth , Cowan Richard , Stewart Adam , Fourneau Nele , Hellemans Peter , Elsayed Yusri , Mcclue Steve , Smit Johan W. , Forslund Ann , Phelps Charles , Camm John , Evans T.R. Jeffry , de Bono Johann S. , Banerji Udai 
Published: June 2013

Abstract
Purpose: To determine the maximum-tolerated dose (MTD), dose-limiting toxicities (DLT), and pharmacokinetic and pharmacodynamic profile of quisinostat, a novel hydroxamate, pan-histone deacetylase inhibitor (HDACi).
Experimental Design: In this first-in-human phase I study, quisinostat was administered orally, once daily in three weekly cycles to patients with advanced malignancies, using a two-stage accelerated titration design. Three intermittent schedules were subsequently explored: four days on/three days off; every Monday, Wednesday, Friday (MWF); and every Monday and Thursday (M-Th). Toxicity, pharmacokinetics, pharmacodynamics, and clinical efficacy were evaluated at each schedule.
Results: Ninety-two patients were treated in continuous daily (2–12 mg) and three intermittent dosing schedules (6–19 mg). Treatment-emergent adverse events included: fatigue, nausea, decreased appetite, lethargy, and vomiting. DLTs observed were predominantly cardiovascular, including nonsustained ventricular tachycardia, ST/T-wave abnormalities, and other tachyarhythmias. Noncardiac DLTs were fatigue and abnormal liver function tests. The maximum plasma concentration (Cmax) and area under the plasma concentration–time curve (AUC) of quisinostat increased proportionally with dose. Pharmacodynamic evaluation showed increased acetylated histone 3 in hair follicles, skin and tumor biopsies, and in peripheral blood mononuclear cells as well as decreased Ki67 in skin and tumor biopsies. A partial response lasting five months was seen in one patient with melanoma. Stable disease was seen in eight patients (duration 4–10.5 months).
Conclusions: The adverse event profile of quisinostat was comparable with that of other HDACi. Intermittent schedules were better tolerated than continuous schedules. On the basis of tolerability, pharmacokinetic predictions, and pharmacodynamic effects, the recommended dose for phase II studies is 12 mg on the MWF schedule. Clin Cancer Res; 19(15); 4262–72. ©2013 AACR.
Energy Management by Enhanced Glycolysis in G1-phase in Human Colon Cancer Cells In Vitro and In Vivo
Authors: Bao Yan , Mukai Kuniaki , Hishiki Takako , Kubo Akiko , Ohmura Mitsuyo , Sugiura Yuki , Matsuura Tomomi , Nagahata Yoshiko , Hayakawa Noriyo , Yamamoto Takehiro , Fukuda Ryo , Saya Hideyuki , Suematsu Makoto , Minamishima Yoji Andrew 
Published: June 2013

Abstract
Activation of aerobic glycolysis in cancer cells is well known as the Warburg effect, although its relation to cell- cycle progression remains unknown. In this study, human colon cancer cells were labeled with a cell-cycle phase-dependent fluorescent marker Fucci to distinguish cells in G1-phase and those in S + G2/M phases. Fucci-labeled cells served as splenic xenograft transplants in super-immunodeficient NOG mice and exhibited multiple metastases in the livers, frozen sections of which were analyzed by semiquantitative microscopic imaging mass spectrometry. Results showed that cells in G1-phase exhibited higher concentrations of ATP, NADH, and UDP-N-acetylglucosamine than those in S and G2–M phases, suggesting accelerated glycolysis in G1-phase cells in vivo. Quantitative determination of metabolites in cells synchronized in S, G2–M, and G1 phases suggested that efflux of lactate was elevated significantly in G1-phase. By contrast, ATP production in G2–M was highly dependent on mitochondrial respiration, whereas cells in S-phase mostly exhibited an intermediary energy metabolism between G1 and G2–M phases. Isogenic cells carrying a p53-null mutation appeared more active in glycolysis throughout the cell cycle than wild-type cells. Thus, as the cell cycle progressed from G2–M to G1 phases, the dependency of energy production on glycolysis was increased while the mitochondrial energy production was reciprocally decreased.
Implications: These results shed light on distinct features of the phase-specific phenotypes of metabolic systems in cancer cells. Mol Cancer Res; 11(9); 973–85. ©2013 AACR.
Anticoagulation beyond direct thrombin and factor Xa inhibitors: indications for targeting the intrinsic pathway?
Authors: van Montfoort Maurits , Meijers Joost 
Published: June 2013

SummaryAntithrombotic drugs like vitamin K antagonists and heparin have been the gold standard for the treatment and prevention of thromboembolic disease for many years. Unfortunately, there are several disadvantages of these antithrombotic drugs: they are accompanied by serious bleeding problems, it is necessary to monitor the therapeutic window, and there are various interactions with food and other drugs. This has led to the development of new oral anticoagulants, specifically inhibiting either thrombin or factor Xa. In terms of effectiveness, these drugs are comparable to the currently available anticoagulants; however, they are still associated with issues such as bleeding, reversal of the drug and complicated laboratory monitoring. Vitamin K antagonists, heparin, direct thrombin and factor Xa inhibitors have in common that they target key proteins of the haemostatic system. In an attempt to overcome these difficulties we investigated whether the intrinsic coagulation factors (VIII, IX, XI, XII, prekallikrein and high-molecular-weight kininogen) are superior targets for anticoagulation. We analysed epidemiological data concerning thrombosis and bleeding in patients deficient in one of the intrinsic pathway proteins. Furthermore, we discuss several thrombotic models in intrinsic coagulation factor-deficient animals. The combined results suggest that intrinsic coagulation factors could be suitable targets for anticoagulant drugs.
Protease-activated receptors (PAR)-1 and -3 drive epithelial-mesenchymal transition of alveolar epithelial cells – potential role in lung fibrosis
Authors: Didiasova Miroslava , Berscheid Sebastian , Piskulak Katarzyna , Taborski Brigitte , Zakrzewicz Dariusz , Kwapiszewska Grazyna , Wygrecka Malgorzata , Preissner Klaus , Markart Philipp 
Published: June 2013

SummaryExtravascular activation of the coagulation cascade in the lung is commonly observed in pulmonary fibrosis. Coagulation proteases may exert profibrotic cellular effects via protease-activated receptors (PARs)-1 and -2. Here, we investigated the potential role of two other members of the PAR family, namely PAR-3 and PAR-4, in the pathobiology of lung fibrosis. Elevated expression of PAR-3, but not PAR-4, was detected in the lungs of idiopathic pulmonary fibrosis (IPF) patients and in bleomycin-induced lung fibrosis in mice. Increased PAR-3 expression in fibrotic lungs was mainly attributable to alveolar type II (ATII) cells. Stimulation of primary mouse ATII, MLE15 and A549 cells with thrombin (FIIa) – that may activate PAR-1, PAR-3 and PAR-4 – induced epithelial-mesenchymal transition (EMT), a process that has been suggested to be a possible mechanism underlying the expanded (myo)fibroblast pool in lung fibrosis. EMT was evidenced by morphological alterations, expression changes of epithelial and mesenchymal phenotype markers, and functional changes. Single knockdown of FIIa receptors, PAR-1, PAR-3, or PAR-4, had no major impact on FIIa-induced EMT. Simultaneous depletion of PAR-1 and PAR-3, however, almost completely inhibited this process, whereas only a partial effect on FIIa-mediated EMT was observed when PAR-1 and PAR-4, or PAR-3 and PAR-4 were knocked down. PAR-1 and PAR-3 co-localise within ATII cells with both being predominantely plasma membrane associated. In conclusion, our study indicates that PARs synergise to mediate FIIa-induced EMT and provides first evidence that PAR-3 via its ability to potentiate FIIa-triggered EMT could potentially contribute to the pathogenesis of pulmonary fibrosis.