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Sample records for envelope glycoprotein gene

  1. HIV-1 envelope glycoprotein

    Science.gov (United States)

    Caulfield, Michael; Cupo, Albert; Dean, Hansi; Hoffenberg, Simon; King, C. Richter; Klasse, P. J.; Marozsan, Andre; Moore, John P.; Sanders, Rogier W.; Ward, Andrew; Wilson, Ian; Julien, Jean-Philippe

    2017-08-22

    The present application relates to novel HIV-1 envelope glycoproteins, which may be utilized as HIV-1 vaccine immunogens, and antigens for crystallization, electron microscopy and other biophysical, biochemical and immunological studies for the identification of broad neutralizing antibodies. The present invention encompasses the preparation and purification of immunogenic compositions, which are formulated into the vaccines of the present invention.

  2. Identifying the Viral Genes Encoding Envelope Glycoproteins for Differentiation of Cyprinid herpesvirus 3 Isolates

    Directory of Open Access Journals (Sweden)

    Se Chang Park

    2013-01-01

    Full Text Available Cyprinid herpes virus 3 (CyHV-3 diseases have been reported around the world and are associated with high mortalities of koi (Cyprinus carpio. Although little work has been conducted on the molecular analysis of this virus, glycoprotein genes identified in the present study seem to be valuable targets for genetic comparison of this virus. Three envelope glycoprotein genes (ORF25, 65 and 116 of the CyHV-3 isolates from the USA, Israel, Japan and Korea were compared, and interestingly, sequence insertions or deletions were observed in these target regions. In addition, polymorphisms were presented in microsatellite zones from two glycoprotein genes (ORF65 and 116. In phylogenetic tree analysis, the Korean isolate was remarkably distinguished from USA, Israel, Japan isolates. These findings may be suitable for many applications including isolates differentiation and phylogeny studies.

  3. Identifying the Viral Genes Encoding Envelope Glycoproteins for Differentiation of Cyprinid herpesvirus 3 Isolates

    Science.gov (United States)

    Han, Jee Eun; Kim, Ji Hyung; Renault, Tristan; Choresca, Casiano; Shin, Sang Phil; Jun, Jin Woo; Park, Se Chang

    2013-01-01

    Cyprinid herpes virus 3 (CyHV-3) diseases have been reported around the world and are associated with high mortalities of koi (Cyprinus carpio). Although little work has been conducted on the molecular analysis of this virus, glycoprotein genes identified in the present study seem to be valuable targets for genetic comparison of this virus. Three envelope glycoprotein genes (ORF25, 65 and 116) of the CyHV-3 isolates from the USA, Israel, Japan and Korea were compared, and interestingly, sequence insertions or deletions were observed in these target regions. In addition, polymorphisms were presented in microsatellite zones from two glycoprotein genes (ORF65 and 116). In phylogenetic tree analysis, the Korean isolate was remarkably distinguished from USA, Israel, Japan isolates. These findings may be suitable for many applications including isolates differentiation and phylogeny studies. PMID:23435236

  4. Comprehensive analysis of the codon usage patterns in the envelope glycoprotein E2 gene of the classical swine fever virus.

    Directory of Open Access Journals (Sweden)

    Ye Chen

    Full Text Available The classical swine fever virus (CSFV, circulating worldwide, is a highly contagious virus. Since the emergence of CSFV, it has caused great economic loss in swine industry. The envelope glycoprotein E2 gene of the CSFV is an immunoprotective antigen that induces the immune system to produce neutralizing antibodies. Therefore, it is essential to study the codon usage of the E2 gene of the CSFV. In this study, 140 coding sequences of the E2 gene were analyzed. The value of effective number of codons (ENC showed low codon usage bias in the E2 gene. Our study showed that codon usage could be described mainly by mutation pressure ENC plot analysis combined with principal component analysis (PCA and translational selection-correlation analysis between the general average hydropathicity (Gravy and aromaticity (Aroma, and nucleotides at the third position of codons (A3s, T3s, G3s, C3s and GC3s. Furthermore, the neutrality analysis, which explained the relationship between GC12s and GC3s, revealed that natural selection had a key role compared with mutational bias during the evolution of the E2 gene. These results lay a foundation for further research on the molecular evolution of CSFV.

  5. A Functional Henipavirus Envelope Glycoprotein Pseudotyped Lentivirus Assay System

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    Broder Christopher C

    2010-11-01

    Full Text Available Abstract Background Hendra virus (HeV and Nipah virus (NiV are newly emerged zoonotic paramyxoviruses discovered during outbreaks in Queensland, Australia in 1994 and peninsular Malaysia in 1998/9 respectively and classified within the new Henipavirus genus. Both viruses can infect a broad range of mammalian species causing severe and often-lethal disease in humans and animals, and repeated outbreaks continue to occur. Extensive laboratory studies on the host cell infection stage of HeV and NiV and the roles of their envelope glycoproteins have been hampered by their highly pathogenic nature and restriction to biosafety level-4 (BSL-4 containment. To circumvent this problem, we have developed a henipavirus envelope glycoprotein pseudotyped lentivirus assay system using either a luciferase gene or green fluorescent protein (GFP gene encoding human immunodeficiency virus type-1 (HIV-1 genome in conjunction with the HeV and NiV fusion (F and attachment (G glycoproteins. Results Functional retrovirus particles pseudotyped with henipavirus F and G glycoproteins displayed proper target cell tropism and entry and infection was dependent on the presence of the HeV and NiV receptors ephrinB2 or B3 on target cells. The functional specificity of the assay was confirmed by the lack of reporter-gene signals when particles bearing either only the F or only G glycoprotein were prepared and assayed. Virus entry could be specifically blocked when infection was carried out in the presence of a fusion inhibiting C-terminal heptad (HR-2 peptide, a well-characterized, cross-reactive, neutralizing human mAb specific for the henipavirus G glycoprotein, and soluble ephrinB2 and B3 receptors. In addition, the utility of the assay was also demonstrated by an examination of the influence of the cytoplasmic tail of F in its fusion activity and incorporation into pseudotyped virus particles by generating and testing a panel of truncation mutants of NiV and HeV F

  6. Bioinformatics Analysis of Envelope Glycoprotein E epitopes of ...

    African Journals Online (AJOL)

    The E glycoprotein of dengue virus is responsible for the viral binding to the receptor. The crystal structure of envelope glycoprotein has already been determined. However, where the well-defined Bcell and T-cell epitopes are located is still a question. Because of the large variations among the four dengue genotypes, it is ...

  7. Solubilization of glycoproteins of envelope viruses by detergents

    International Nuclear Information System (INIS)

    Berezin, V.E.; Zaides, V.M.; Artamsnov, A.F.; Isaeva, E.S.; Zhdanov, V.M.

    1986-01-01

    The action of a number of known ionic and nonionic detergents, as well as the new nonionic detergent MESK, on envelope viruses was investigated. It was shown that the nonionic detergents MESK, Triton X-100, and octyl-β-D-glucopyranoside selectively solubilize the outer glycoproteins of the virus particles. The nonionic detergent MESK has the mildest action. Using MESK, purified glycoproteins of influenza, parainfluenza, Venezuelan equine encephalomyelitis, vesicular stomatitis, rabies, and herpes viruses were obtained. The procedure for obtaining glycoproteins includes incubation of the virus suspension with the detergent MESK, removal of subvirus structures by centrifuging, and purification of glycoproteins from detergents by dialysis. Isolated glycoproteins retain a native structure and biological activity and possess high immunogenicity. The detergent MESK is promising for laboratory tests and with respect to the production of subunit vaccines

  8. Evidence for a novel coding sequence overlapping the 5'-terminal ~90 codons of the Gill-associated and Yellow head okavirus envelope glycoprotein gene

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    Atkins John F

    2009-12-01

    Full Text Available Abstract The genus Okavirus (order Nidovirales includes a number of viruses that infect crustaceans, causing major losses in the shrimp industry. These viruses have a linear positive-sense ssRNA genome of ~26-27 kb, encoding a large replicase polyprotein that is expressed from the genomic RNA, and several additional proteins that are expressed from a nested set of 3'-coterminal subgenomic RNAs. In this brief report, we describe the bioinformatic discovery of a new, apparently coding, ORF that overlaps the 5' end of the envelope glycoprotein encoding sequence, ORF3, in the +2 reading frame. The new ORF has a strong coding signature and, in fact, is more conserved at the amino acid level than the overlapping region of ORF3. We propose that translation of the new ORF initiates at a conserved AUG codon separated by just 2 nt from the ORF3 AUG initiation codon, resulting in a novel 86 amino acid protein.

  9. Determinants of foamy virus envelope glycoprotein mediated resistance to superinfection

    International Nuclear Information System (INIS)

    Berg, Angelika; Pietschmann, Thomas; Rethwilm, Axel; Lindemann, Dirk

    2003-01-01

    Little is known about the nature of foamy virus (FV) receptor molecules on target cells and their interaction with the viral glycoproteins. Similar to other viruses, cellular expression of the FV Env protein is sufficient to induce resistance to exogenous FV, a phenomenon called superinfection resistance (SIR). In this study we define determinants of the FV Env protein essential for mediating SIR. FV Env requires the extracellular domains of the SU and the TM subunits as well as membrane anchorage, efficient cell surface transport, and most probably correct subunit processing. This is in contrast to murine leukemia virus where secreted proteins comprising the receptor-binding domain in SU are sufficient to induce SIR. Furthermore, we demonstrate that cellular expression of the prototype FV envelope proteins induces SIR against pseudotypes with glycoproteins of other FV species, including of simian, feline, bovine, and equine origin. This implies that all of them use the same receptor molecules for viral entry

  10. Humoral immune response to the entire human immunodeficiency virus envelope glycoprotein made in insect cells

    Energy Technology Data Exchange (ETDEWEB)

    Rusche, J.R.; Lynn, D.L.; Robert-Guroff, M.; Langlois, A.J.; Lyerly, H.K.; Carson, H.; Krohn, K.; Ranki, A.; Gallo, R.C.; Bolognesi, D.P.; Putney, S.D.

    1987-10-01

    The human immunodeficiency virus envelope gene was expressed in insect cells by using a Baculovirus expression vector. The protein has an apparent molecular mass of 160 kDa, appears on the surface of infected insect cells, and does not appear to be cleaved to glycoproteins gp120 and gp41. Goats immunized with the 160-kDa protein have high titers of antibody that neutralizes virus infection as measured by viral gene expression or cell cytolysis. In addition, immune sera can block fusion of human immunodeficiency virus-infected cells in culture. Both neutralization and fusion-blocking activities are bound to and eluted from immobilized gp120.

  11. Humoral immune response to the entire human immunodeficiency virus envelope glycoprotein made in insect cells

    International Nuclear Information System (INIS)

    Rusche, J.R.; Lynn, D.L.; Robert-Guroff, M.

    1987-01-01

    The human immunodeficiency virus envelope gene was expressed in insect cells by using a Baculovirus expression vector. The protein has an apparent molecular mass of 160 kDa, appears on the surface of infected insect cells, and does not appear to be cleaved to glycoproteins gp120 and gp41. Goats immunized with the 160-kDa protein have high titers of antibody that neutralizes virus infection as measured by viral gene expression or cell cytolysis. In addition, immune sera can block fusion of human immunodeficiency virus-infected cells in culture. Both neutralization and fusion-blocking activities are bound to and eluted from immobilized gp120

  12. Hepatitis C Virus E2 Envelope Glycoprotein Core Structure

    Energy Technology Data Exchange (ETDEWEB)

    Kong, Leopold; Giang, Erick; Nieusma, Travis; Kadam, Rameshwar U.; Cogburn, Kristin E.; Hua, Yuanzi; Dai, Xiaoping; Stanfield, Robyn L.; Burton, Dennis R.; Ward, Andrew B.; Wilson, Ian A.; Law, Mansun

    2014-08-26

    Hepatitis C virus (HCV), a Hepacivirus, is a major cause of viral hepatitis, liver cirrhosis, and hepatocellular carcinoma. HCV envelope glycoproteins E1 and E2 mediate fusion and entry into host cells and are the primary targets of the humoral immune response. The crystal structure of the E2 core bound to broadly neutralizing antibody AR3C at 2.65 angstroms reveals a compact architecture composed of a central immunoglobulin-fold β sandwich flanked by two additional protein layers. The CD81 receptor binding site was identified by electron microscopy and site-directed mutagenesis and overlaps with the AR3C epitope. The x-ray and electron microscopy E2 structures differ markedly from predictions of an extended, three-domain, class II fusion protein fold and therefore provide valuable information for HCV drug and vaccine design.

  13. Membrane topology analysis of HIV-1 envelope glycoprotein gp41

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    Xiao Dan

    2010-11-01

    Full Text Available Abstract Background The gp41 subunit of the HIV-1 envelope glycoprotein (Env has been widely regarded as a type I transmembrane protein with a single membrane-spanning domain (MSD. An alternative topology model suggested multiple MSDs. The major discrepancy between the two models is that the cytoplasmic Kennedy sequence in the single MSD model is assigned as the extracellular loop accessible to neutralizing antibodies in the other model. We examined the membrane topology of the gp41 subunit in both prokaryotic and mammalian systems. We attached topological markers to the C-termini of serially truncated gp41. In the prokaryotic system, we utilized a green fluorescent protein (GFP that is only active in the cytoplasm. The tag protein (HaloTag and a membrane-impermeable ligand specific to HaloTag was used in the mammalian system. Results In the absence of membrane fusion, both the prokaryotic and mammalian systems (293FT cells supported the single MSD model. In the presence of membrane fusion in mammalian cells (293CD4 cells, the data obtained seem to support the multiple MSD model. However, the region predicted to be a potential MSD is the highly hydrophilic Kennedy sequence and is least likely to become a MSD based on several algorithms. Further analysis revealed the induction of membrane permeability during membrane fusion, allowing the membrane-impermeable ligand and antibodies to cross the membrane. Therefore, we cannot completely rule out the possible artifacts. Addition of membrane fusion inhibitors or alterations of the MSD sequence decreased the induction of membrane permeability. Conclusions It is likely that a single MSD model for HIV-1 gp41 holds true even in the presence of membrane fusion. The degree of the augmentation of membrane permeability we observed was dependent on the membrane fusion and sequence of the MSD.

  14. A Directed Molecular Evolution Approach to Improved Immunogenicity of the HIV-1 Envelope Glycoprotein

    Science.gov (United States)

    Du, Sean X.; Xu, Li; Zhang, Wenge; Tang, Susan; Boenig, Rebecca I.; Chen, Helen; Mariano, Ellaine B.; Zwick, Michael B.; Parren, Paul W. H. I.; Burton, Dennis R.; Wrin, Terri; Petropoulos, Christos J.; Ballantyne, John A.; Chambers, Michael; Whalen, Robert G.

    2011-01-01

    A prophylactic vaccine is needed to slow the spread of HIV-1 infection. Optimization of the wild-type envelope glycoproteins to create immunogens that can elicit effective neutralizing antibodies is a high priority. Starting with ten genes encoding subtype B HIV-1 gp120 envelope glycoproteins and using in vitro homologous DNA recombination, we created chimeric gp120 variants that were screened for their ability to bind neutralizing monoclonal antibodies. Hundreds of variants were identified with novel antigenic phenotypes that exhibit considerable sequence diversity. Immunization of rabbits with these gp120 variants demonstrated that the majority can induce neutralizing antibodies to HIV-1. One novel variant, called ST-008, induced significantly improved neutralizing antibody responses when assayed against a large panel of primary HIV-1 isolates. Further study of various deletion constructs of ST-008 showed that the enhanced immunogenicity results from a combination of effective DNA priming, an enhanced V3-based response, and an improved response to the constant backbone sequences. PMID:21738594

  15. Enhancement of feline immunodeficiency virus infection after immunization with envelope glycoprotein subunit vaccines.

    NARCIS (Netherlands)

    C.H.J. Siebelink (Kees); E.J. Tijhaar (Edwin); R.C. Huisman (Robin); W. Huisman (Willem); A. de Ronde; I.H. Darby; M.J. Francis; G.F. Rimmelzwaan (Guus); A.D.M.E. Osterhaus (Albert)

    1995-01-01

    textabstractCats were immunized three times with different recombinant feline immunodeficiency virus (FIV) candidate vaccines. Recombinant vaccinia virus (rVV)-expressed envelope glycoprotein with (vGR657) or without (vGR657 x 15) the cleavage site and an FIV envelope bacterial fusion protein

  16. Feline immunodeficiency virus envelope glycoproteins antagonize tetherin through a distinctive mechanism that requires virion incorporation.

    Science.gov (United States)

    Morrison, James H; Guevara, Rebekah B; Marcano, Adriana C; Saenz, Dyana T; Fadel, Hind J; Rogstad, Daniel K; Poeschla, Eric M

    2014-03-01

    BST2/tetherin inhibits the release of enveloped viruses from cells. Primate lentiviruses have evolved specific antagonists (Vpu, Nef, and Env). Here we characterized tetherin proteins of species representing both branches of the order Carnivora. Comparison of tiger and cat (Feliformia) to dog and ferret (Caniformia) genes demonstrated that the tiger and cat share a start codon mutation that truncated most of the tetherin cytoplasmic tail early in the Feliformia lineage (19 of 27 amino acids, including the dual tyrosine motif). Alpha interferon (IFN-α) induced tetherin and blocked feline immunodeficiency virus (FIV) replication in lymphoid and nonlymphoid feline cells. Budding of bald FIV and HIV particles was blocked by carnivore tetherins. However, infectious FIV particles were resistant, and spreading FIV replication was uninhibited. Antagonism mapped to the envelope glycoprotein (Env), which rescued FIV from carnivore tetherin restriction when expressed in trans but, in contrast to known antagonists, did not rescue noncognate particles. Also unlike the primate lentiviral antagonists, but similar to the Ebola virus glycoprotein, FIV Env did not reduce intracellular or cell surface tetherin levels. Furthermore, FIV-enveloped FIV particles actually required tetherin for optimal release from cells. The results show that FIV Envs mediate a distinctive tetherin evasion. Well adapted to a phylogenetically ancient tetherin tail truncation in the Felidae, it requires functional virion incorporation of Env, and it shields the budding particle without downregulating plasma membrane tetherin. Moreover, FIV has evolved dependence on this protein: particles containing FIV Env need tetherin for optimal release from the cell, while Env(-) particles do not. HIV-1 antagonizes the restriction factor tetherin with the accessory protein Vpu, while HIV-2 and the filovirus Ebola use their envelope (Env) glycoproteins for this purpose. It turns out that the FIV tetherin antagonist is

  17. Bioinformatics Analysis of Envelope Glycoprotein E epitopes of ...

    African Journals Online (AJOL)

    User

    2011-05-02

    May 2, 2011 ... 1National Centre of Excellence in Molecular Biology, University of the Punjab Lahore, Pakistan. 2Department of ..... E glycoprotein and its interaction with antibody with the method of molecular dynamics and molecular model ...

  18. Identification of active pocket and protein druggability within envelope glycoprotein GP2 from Ebola virus

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    Beuy Joob

    2014-12-01

    Full Text Available The drug searching for combating the present outbreak of Ebola virus infection is the urgent activity at present. Finding the new effective drug at present must base on the molecular analysis of the pathogenic virus. The in-depth analysis of the viral protein to find the binding site, active pocket is needed. Here, the authors analyzed the envelope glycoprotein GP2 from Ebola virus. Identification of active pocket and protein druggability within envelope glycoprotein GP2 from Ebola virus was done. According to this assessment, 7 active pockets with varied druggability could be identified.

  19. Secretion of hepatitis C virus envelope glycoproteins depends on assembly of apolipoprotein B positive lipoproteins.

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    Vinca Icard

    Full Text Available The density of circulating hepatitis C virus (HCV particles in the blood of chronically infected patients is very heterogeneous. The very low density of some particles has been attributed to an association of the virus with apolipoprotein B (apoB positive and triglyceride rich lipoproteins (TRL likely resulting in hybrid lipoproteins known as lipo-viro-particles (LVP containing the viral envelope glycoproteins E1 and E2, capsid and viral RNA. The specific infectivity of these particles has been shown to be higher than the infectivity of particles of higher density. The nature of the association of HCV particles with lipoproteins remains elusive and the role of apolipoproteins in the synthesis and assembly of the viral particles is unknown. The human intestinal Caco-2 cell line differentiates in vitro into polarized and apoB secreting cells during asymmetric culture on porous filters. By using this cell culture system, cells stably expressing E1 and E2 secreted the glycoproteins into the basal culture medium after one week of differentiation concomitantly with TRL secretion. Secreted glycoproteins were only detected in apoB containing density fractions. The E1-E2 and apoB containing particles were unique complexes bearing the envelope glycoproteins at their surface since apoB could be co-immunoprecipitated with E2-specific antibodies. Envelope protein secretion was reduced by inhibiting the lipidation of apoB with an inhibitor of the microsomal triglyceride transfer protein. HCV glycoproteins were similarly secreted in association with TRL from the human liver cell line HepG2 but not by Huh-7 and Huh-7.5 hepatoma cells that proved deficient for lipoprotein assembly. These data indicate that HCV envelope glycoproteins have the intrinsic capacity to utilize apoB synthesis and lipoprotein assembly machinery even in the absence of the other HCV proteins. A model for LVP assembly is proposed.

  20. Dysfunction of bovine endogenous retrovirus K2 envelope glycoprotein is related to unsuccessful intracellular trafficking.

    Science.gov (United States)

    Nakaya, Yuki; Miyazawa, Takayuki

    2014-06-01

    Endogenous retroviruses (ERVs) are the remnants of retroviral infection of ancestral germ cells. Mutations introduced into ERVs halt the production of infectious agents, but their effects on the function of retroviral proteins are not fully understood. Retroviral envelope glycoproteins (Envs) are utilized in membrane fusion during viral entry, and we recently identified intact coding sequences for bovine endogenous retrovirus K1 (BERV-K1) and BERV-K2 Envs. Amino acid sequences of BERV-K1 Env (also called Fematrin-1) and BERV-K2 Env are similar, and both viruses are classified in the genus Betaretrovirus. While Fematrin-1 plays an important role in cell-to-cell fusion in bovine placenta, the BERV-K2 envelope gene is marginally expressed in vivo, and its recombinant Env protein is defective in membrane fusion due to inefficient cleavage of surface (SU) and transmembrane subunits. Here, we conducted chimeric analyses of Fematrin-1 and BERV-K2 Envs and revealed that defective maturation of BERV-K2 Env contributed to failed intracellular trafficking. Fluorescence microscopy and flow cytometric analysis suggested that in contrast to Fematrin-1 Env, BERV-K2 Env could not be transported from the endoplasmic reticulum to the trans-Golgi network, where cellular proteases required for processing retroviral Envs are localized. We also identified that one of the responsive regions of this phenomenon resided within a 65-amino-acid region of BERV-K2 SU. This is the first report to identify that retroviral Env SU is involved in the regulation of intracellular trafficking, and it may help to elucidate the maturation process of Fematrin-1 and other related Envs. Retroviruses utilize envelope glycoproteins (Envs) to enter host target cells. Mature retroviral Env is a heterodimer, which consists of surface (SU) and transmembrane (TM) subunits that are generated by the cleavage of an Env precursor protein in the trans-Golgi network. SU and TM mediate the recognition of the entry

  1. Mechanism of feline immunodeficiency virus envelope glycoprotein-mediated fusion

    International Nuclear Information System (INIS)

    Garg, Himanshu; Fuller, Frederick J.; Tompkins, Wayne A.F.

    2004-01-01

    Feline immunodeficiency virus (FIV) shares remarkable homology to primate lentiviruses, human immunodeficiency virus (HIV) and simian immunodeficiency virus (SIV). The process of lentiviral env glycoprotein-mediated fusion of membranes is essential for viral entry and syncytia formation. A detailed understanding of this phenomenon has helped identify new targets for antiviral drug development. Using a model based on syncytia formation between FIV env-expressing cells and a feline CD4+ T cell line we have studied the mechanism of FIV env-mediated fusion. Using this model we show that FIV env-mediated fusion mechanism and kinetics are similar to HIV env. Syncytia formation could be blocked by CXCR4 antagonist AMD3100, establishing the importance of this receptor in FIV gp120 binding. Interestingly, CXCR4 alone was not sufficient to allow fusion by a primary isolate of FIV, as env glycoprotein from FIV-NCSU 1 failed to induce syncytia in several feline cell lines expressing CXCR4. Syncytia formation could be inhibited at a post-CXCR4 binding step by synthetic peptide T1971, which inhibits interaction of heptad repeat regions of gp41 and formation of the hairpin structure. Finally, using site-directed mutagenesis, we also show that a conserved tryptophan-rich region in the membrane proximal ectodomain of gp41 is critical for fusion, possibly at steps post hairpin structure formation

  2. Structure of a Pestivirus Envelope Glycoprotein E2 Clarifies Its Role in Cell Entry

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    Kamel El Omari

    2013-01-01

    Full Text Available Enveloped viruses have developed various adroit mechanisms to invade their host cells. This process requires one or more viral envelope glycoprotein to achieve cell attachment and membrane fusion. Members of the Flaviviridae such as flaviviruses possess only one envelope glycoprotein, E, whereas pestiviruses and hepacivirus encode two glycoproteins, E1 and E2. Although E2 is involved in cell attachment, it has been unclear which protein is responsible for membrane fusion. We report the crystal structures of the homodimeric glycoprotein E2 from the pestivirus bovine viral diarrhea virus 1 (BVDV1 at both neutral and low pH. Unexpectedly, BVDV1 E2 does not have a class II fusion protein fold, and at low pH the N-terminal domain is disordered, similarly to the intermediate postfusion state of E2 from sindbis virus, an alphavirus. Our results suggest that the pestivirus and possibly the hepacivirus fusion machinery are unlike any previously observed.

  3. Structure of a Pestivirus Envelope Glycoprotein E2 Clarifies Its Role in Cell Entry

    Science.gov (United States)

    El Omari, Kamel; Iourin, Oleg; Harlos, Karl; Grimes, Jonathan M.; Stuart, David I.

    2013-01-01

    Summary Enveloped viruses have developed various adroit mechanisms to invade their host cells. This process requires one or more viral envelope glycoprotein to achieve cell attachment and membrane fusion. Members of the Flaviviridae such as flaviviruses possess only one envelope glycoprotein, E, whereas pestiviruses and hepacivirus encode two glycoproteins, E1 and E2. Although E2 is involved in cell attachment, it has been unclear which protein is responsible for membrane fusion. We report the crystal structures of the homodimeric glycoprotein E2 from the pestivirus bovine viral diarrhea virus 1 (BVDV1) at both neutral and low pH. Unexpectedly, BVDV1 E2 does not have a class II fusion protein fold, and at low pH the N-terminal domain is disordered, similarly to the intermediate postfusion state of E2 from sindbis virus, an alphavirus. Our results suggest that the pestivirus and possibly the hepacivirus fusion machinery are unlike any previously observed. PMID:23273918

  4. Glycosylation in HIV-1 envelope glycoprotein and its biological implications

    KAUST Repository

    Ho, Yung Shwen

    2013-08-01

    Glycosylation of HIV-1 envelope proteins (Env gp120/gp41) plays a vital role in viral evasion from the host immune response, which occurs through the masking of key neutralization epitopes and the presentation of the Env glycosylation as \\'self\\' to the host immune system. Env glycosylation is generally conserved, yet its continual evolution plays an important role in modulating viral infectivity and Env immunogenicity. Thus, it is believed that Env glycosylation, which is a vital part of the HIV-1 architecture, also controls intra- and inter-clade genetic variations. Discerning intra- and inter-clade glycosylation variations could therefore yield important information for understanding the molecular and biological differences between HIV clades and may assist in effectively designing Env-based immunogens and in clearly understanding HIV vaccines. This review provides an in-depth perspective of various aspects of Env glycosylation in the context of HIV-1 pathogenesis. © 2013 Future Medicine Ltd.

  5. Host cell tropism mediated by Australian bat lyssavirus envelope glycoproteins.

    Science.gov (United States)

    Weir, Dawn L; Smith, Ina L; Bossart, Katharine N; Wang, Lin-Fa; Broder, Christopher C

    2013-09-01

    Australian bat lyssavirus (ABLV) is a rhabdovirus of the lyssavirus genus capable of causing fatal rabies-like encephalitis in humans. There are two variants of ABLV, one circulating in pteropid fruit bats and another in insectivorous bats. Three fatal human cases of ABLV infection have been reported with the third case in 2013. Importantly, two equine cases also arose in 2013; the first occurrence of ABLV in a species other than bats or humans. We examined the host cell entry of ABLV, characterizing its tropism and exploring its cross-species transmission potential using maxGFP-encoding recombinant vesicular stomatitis viruses that express ABLV G glycoproteins. Results indicate that the ABLV receptor(s) is conserved but not ubiquitous among mammalian cell lines and that the two ABLV variants can utilize alternate receptors for entry. Proposed rabies virus receptors were not sufficient to permit ABLV entry into resistant cells, suggesting that ABLV utilizes an unknown alternative receptor(s). Published by Elsevier Inc.

  6. Palmitoylation of the feline immunodeficiency virus envelope glycoprotein and its effect on fusion activity and envelope incorporation into virions

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Silvia A.; Paladino, Monica G. [Laboratorio de Virologia, CONICET-Universidad de Belgrano (UB), Villanueva 1324 (C1426BMJ), Buenos Aires (Argentina); Affranchino, Jose L., E-mail: jose.affranchino@comunidad.ub.edu.ar [Laboratorio de Virologia, CONICET-Universidad de Belgrano (UB), Villanueva 1324 (C1426BMJ), Buenos Aires (Argentina)

    2012-06-20

    The feline immunodeficiency virus (FIV) envelope glycoprotein (Env) possesses a short cytoplasmic domain of 53 amino acids containing four highly conserved cysteines at Env positions 804, 811, 815 and 848. Since palmitoylation of transmembrane proteins occurs at or near the membrane anchor, we investigated whether cysteines 804, 811 and 815 are acylated and analyzed the relevance of these residues for Env functions. Replacement of cysteines 804, 811 and 815 individually or in combination by serine residues resulted in Env glycoproteins that were efficiently expressed and processed. However, mutations C804S and C811S reduced Env fusogenicity by 93% and 84%, respectively, compared with wild-type Env. By contrast, mutant C815S exhibited a fusogenic capacity representing 50% of the wild-type value. Remarkably, the double mutation C804S/C811S abrogated both Env fusion activity and Env incorporation into virions. Finally, by means of Click chemistry assays we demonstrated that the four FIV Env cytoplasmic cysteines are palmitoylated.

  7. Palmitoylation of the feline immunodeficiency virus envelope glycoprotein and its effect on fusion activity and envelope incorporation into virions

    International Nuclear Information System (INIS)

    González, Silvia A.; Paladino, Mónica G.; Affranchino, José L.

    2012-01-01

    The feline immunodeficiency virus (FIV) envelope glycoprotein (Env) possesses a short cytoplasmic domain of 53 amino acids containing four highly conserved cysteines at Env positions 804, 811, 815 and 848. Since palmitoylation of transmembrane proteins occurs at or near the membrane anchor, we investigated whether cysteines 804, 811 and 815 are acylated and analyzed the relevance of these residues for Env functions. Replacement of cysteines 804, 811 and 815 individually or in combination by serine residues resulted in Env glycoproteins that were efficiently expressed and processed. However, mutations C804S and C811S reduced Env fusogenicity by 93% and 84%, respectively, compared with wild-type Env. By contrast, mutant C815S exhibited a fusogenic capacity representing 50% of the wild-type value. Remarkably, the double mutation C804S/C811S abrogated both Env fusion activity and Env incorporation into virions. Finally, by means of Click chemistry assays we demonstrated that the four FIV Env cytoplasmic cysteines are palmitoylated.

  8. Understanding the Process of Envelope Glycoprotein Incorporation into Virions in Simian and Feline Immunodeficiency Viruses

    Directory of Open Access Journals (Sweden)

    José L. Affranchino

    2014-01-01

    Full Text Available The lentiviral envelope glycoproteins (Env mediate virus entry by interacting with specific receptors present at the cell surface, thereby determining viral tropism and pathogenesis. Therefore, Env incorporation into the virions formed by assembly of the viral Gag polyprotein at the plasma membrane of the infected cells is a key step in the replication cycle of lentiviruses. Besides being useful models of human immunodeficiency virus (HIV infections in humans and valuable tools for developing AIDS therapies and vaccines, simian and feline immunodeficiency viruses (SIV and FIV, respectively are relevant animal retroviruses; the study of which provides important information on how lentiviral replication strategies have evolved. In this review, we discuss the molecular mechanisms underlying the incorporation of the SIV and FIV Env glycoproteins into viral particles.

  9. Reduction of cerebral glucose utilization by the HIV envelope glycoprotein Gp-120

    Energy Technology Data Exchange (ETDEWEB)

    Kimes, A.S.; London, E.D.; Szabo, G.; Raymon, L.; Tabakoff, B. (Neuropharmacology Laboratory, National Institute on Drug Abuse, Baltimore, MD (USA))

    1991-05-01

    Gp-120 is a glycoprotein constituent of the human immunodeficiency virus (HIV) envelope. The effects of gp-120 on cerebral glucose utilization in rats were studied by the quantitative 2-deoxy-D-(1-14C) glucose method. Intracerebroventricular injection of gp-120 significantly reduced glucose utilization in the lateral habenula and the suprachiasmatic nucleus and decreased the global cerebral metabolic rate for glucose. The findings suggest that gp-120 and closely related peptides can alter neuronal function, thereby contributing to the sequelae of HIV infection.

  10. Reduction of cerebral glucose utilization by the HIV envelope glycoprotein Gp-120

    International Nuclear Information System (INIS)

    Kimes, A.S.; London, E.D.; Szabo, G.; Raymon, L.; Tabakoff, B.

    1991-01-01

    Gp-120 is a glycoprotein constituent of the human immunodeficiency virus (HIV) envelope. The effects of gp-120 on cerebral glucose utilization in rats were studied by the quantitative 2-deoxy-D-[1-14C] glucose method. Intracerebroventricular injection of gp-120 significantly reduced glucose utilization in the lateral habenula and the suprachiasmatic nucleus and decreased the global cerebral metabolic rate for glucose. The findings suggest that gp-120 and closely related peptides can alter neuronal function, thereby contributing to the sequelae of HIV infection

  11. Enhanced Gene Transfer with Fusogenic Liposomes Containing Vesicular Stomatitis Virus G Glycoprotein

    Science.gov (United States)

    Abe, Akihiro; Miyanohara, Atsushi; Friedmann, Theodore

    1998-01-01

    Exposure of Lipofectin-DNA complexes to the partially purified G glycoprotein of the vesicular stomatitis virus envelope (VSV-G) results in loss of serum-mediated inhibition and in enhanced efficiency of gene transfer. Sucrose density gradient sedimentation analysis indicated that the VSV-G associates physically with the DNA-lipid complex to produce a VSV-G liposome. The ability to incorporate surrogate viral or cellular envelope components such as VSV-G into liposomes may allow more-efficient and possibly targeted gene delivery by lipofection, both in vitro and in vivo. PMID:9621082

  12. Determining the Structure of an Unliganded and Fully Glycosylated SIV gp120 Envelope Glycoprotein

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Bing; Vogan, Erik M.; Gong, Haiyun; Skehel, John J.; Wiley, Don C.; Harrison, Stephen C. (Harvard-Med); (NIMR)

    2010-07-13

    HIV/SIV envelope glycoproteins mediate the first steps in viral infection. They are trimers of a membrane-anchored polypeptide chain, cleaved into two fragments known as gp120 and gp41. The structure of HIV gp120 bound with receptor (CD4) has been known for some time. We have now determined the structure of a fully glycosylated SIV gp120 envelope glycoprotein in an unliganded conformation by X-ray crystallography at 4.0 {angstrom} resolution. We describe here our experimental and computational approaches, which may be relevant to other resolution-limited crystallographic problems. Key issues were attention to details of beam geometry mandated by small, weakly diffracting crystals, and choice of strategies for phase improvement, starting with two isomorphous derivatives and including multicrystal averaging. We validated the structure by analyzing composite omit maps, averaged among three distinct crystal lattices, and by calculating model-based, SeMet anomalous difference maps. There are at least four ordered sugars on many of the thirteen oligosaccharides.

  13. Human broadly neutralizing antibodies to the envelope glycoprotein complex of hepatitis C virus

    DEFF Research Database (Denmark)

    Giang, Erick; Dorner, Marcus; Prentoe, Jannick C

    2012-01-01

    , and an effective vaccine should target conserved T- and B-cell epitopes of the virus. Conserved B-cell epitopes overlapping the CD81 receptor-binding site (CD81bs) on the E2 viral envelope glycoprotein have been reported previously and provide promising vaccine targets. In this study, we isolated 73 human m......Abs recognizing five distinct antigenic regions on the virus envelope glycoprotein complex E1E2 from an HCV-immune phage-display antibody library by using an exhaustive-panning strategy. Many of these mAbs were broadly neutralizing. In particular, the mAb AR4A, recognizing a discontinuous epitope outside the CD81......bs on the E1E2 complex, has an exceptionally broad neutralizing activity toward diverse HCV genotypes and protects against heterologous HCV challenge in a small animal model. The mAb panel will be useful for the design and development of vaccine candidates to elicit broadly neutralizing antibodies...

  14. Co-assembly of viral envelope glycoproteins regulates their polarized sorting in neurons.

    Directory of Open Access Journals (Sweden)

    Rafael Mattera

    2014-05-01

    Full Text Available Newly synthesized envelope glycoproteins of neuroinvasive viruses can be sorted in a polarized manner to the somatodendritic and/or axonal domains of neurons. Although critical for transneuronal spread of viruses, the molecular determinants and interregulation of this process are largely unknown. We studied the polarized sorting of the attachment (NiV-G and fusion (NiV-F glycoproteins of Nipah virus (NiV, a paramyxovirus that causes fatal human encephalitis, in rat hippocampal neurons. When expressed individually, NiV-G exhibited a non-polarized distribution, whereas NiV-F was specifically sorted to the somatodendritic domain. Polarized sorting of NiV-F was dependent on interaction of tyrosine-based signals in its cytosolic tail with the clathrin adaptor complex AP-1. Co-expression of NiV-G with NiV-F abolished somatodendritic sorting of NiV-F due to incorporation of NiV-G•NiV-F complexes into axonal transport carriers. We propose that faster biosynthetic transport of unassembled NiV-F allows for its proteolytic activation in the somatodendritic domain prior to association with NiV-G and axonal delivery of NiV-G•NiV-F complexes. Our study reveals how interactions of viral glycoproteins with the host's transport machinery and between themselves regulate their polarized sorting in neurons.

  15. HIV-1 Envelope Glycoprotein Trafficking through the Endosomal Recycling Compartment Is Required for Particle Incorporation.

    Science.gov (United States)

    Kirschman, Junghwa; Qi, Mingli; Ding, Lingmei; Hammonds, Jason; Dienger-Stambaugh, Krista; Wang, Jaang-Jiun; Lapierre, Lynne A; Goldenring, James R; Spearman, Paul

    2018-03-01

    The human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env) encodes specific trafficking signals within its long cytoplasmic tail (CT) that regulate incorporation into HIV-1 particles. Rab11-family interacting protein 1C (FIP1C) and Rab14 are host trafficking factors required for Env particle incorporation, suggesting that Env undergoes sorting from the endosomal recycling compartment (ERC) to the site of particle assembly on the plasma membrane. We disrupted outward sorting from the ERC by expressing a C-terminal fragment of FIP1C (FIP1C 560-649 ) and examined the consequences on Env trafficking and incorporation into particles. FIP1C 560-649 reduced cell surface levels of Env and prevented its incorporation into HIV-1 particles. Remarkably, Env was trapped in an exaggerated perinuclear ERC in a CT-dependent manner. Mutation of either the Yxxϕ endocytic motif or the YW 795 motif in the CT prevented Env trapping in the ERC and restored incorporation into particles. In contrast, simian immunodeficiency virus SIVmac239 Env was not retained in the ERC, while substitution of the HIV-1 CT for the SIV CT resulted in SIV Env retention in this compartment. These results provide the first direct evidence that Env traffics through the ERC and support a model whereby HIV-1 Env is specifically targeted to the ERC prior to FIP1C- and CT-dependent outward sorting to the particle assembly site on the plasma membrane. IMPORTANCE The HIV envelope protein is an essential component of the viral particle. While many aspects of envelope protein structure and function have been established, the pathway it follows in the cell prior to reaching the site of particle assembly is not well understood. The envelope protein has a very long cytoplasmic tail that interacts with the host cell trafficking machinery. Here, we utilized a truncated form of the trafficking adaptor FIP1C protein to arrest the intracellular transport of the envelope protein, demonstrating that it becomes

  16. Stabilization of the soluble, cleaved, trimeric form of the envelope glycoprotein complex of human immunodeficiency virus type 1

    NARCIS (Netherlands)

    Sanders, Rogier W.; Vesanen, Mika; Schuelke, Norbert; Master, Aditi; Schiffner, Linnea; Kalyanaraman, Roopa; Paluch, Maciej; Berkhout, Ben; Maddon, Paul J.; Olson, William C.; Lu, Min; Moore, John P.

    2002-01-01

    The envelope glycoprotein (Env) complex of human immunodeficiency virus type I has evolved a structure that is minimally immunogenic while retaining its natural function of receptor-mediated virus-cell fusion. The Env complex is trimeric; its six individual subunits (three gp120 and three gp41

  17. Chimeric HIV-1 envelope glycoproteins with potent intrinsic granulocyte-macrophage colony-stimulating factor (GM-CSF) activity

    NARCIS (Netherlands)

    Isik, Gözde; van Montfort, Thijs; Boot, Maikel; Cobos Jiménez, Viviana; Kootstra, Neeltje A.; Sanders, Rogier W.

    2013-01-01

    HIV-1 acquisition can be prevented by broadly neutralizing antibodies (BrNAbs) that target the envelope glycoprotein complex (Env). An ideal vaccine should therefore be able to induce BrNAbs that can provide immunity over a prolonged period of time, but the low intrinsic immunogenicity of HIV-1 Env

  18. Stable 293 T and CHO cell lines expressing cleaved, stable HIV-1 envelope glycoprotein trimers for structural and vaccine studies

    NARCIS (Netherlands)

    Chung, Nancy P. Y.; Matthews, Katie; Kim, Helen J.; Ketas, Thomas J.; Golabek, Michael; de Los Reyes, Kevin; Korzun, Jacob; Yasmeen, Anila; Sanders, Rogier W.; Klasse, Per Johan; Wilson, Ian A.; Ward, Andrew B.; Marozsan, Andre J.; Moore, John P.; Cupo, Albert

    2014-01-01

    Recombinant soluble, cleaved HIV-1 envelope glycoprotein SOSIP.664 gp140 trimers based on the subtype A BG505 sequence are being studied structurally and tested as immunogens in animals. For these trimers to become a vaccine candidate for human trials, they would need to be made in appropriate

  19. Conglutinin binds the HIV-1 envelope glycoprotein gp 160 and inhibits its interaction with cell membrane CD4

    DEFF Research Database (Denmark)

    Andersen, Ove; Sørensen, A M; Svehag, S E

    1991-01-01

    The highly glycosylated envelope glycoprotein (gp 160) of human immunodeficiency virus (HIV) interacts with the CD4 molecule present on the membrane of CD4+ cells and is involved in the pathobiology of HIV infection. Lectins bind glycoproteins through non-covalent interactions with specific hexose...... residues. The mammalian C-type lectin bovine conglutinin was examined for its ability to interact with recombinant gp160 (rgp160) produced in vaccinia virus-infected BHK21 cells. Specific binding of conglutinin to rgp160 was demonstrated by ELISA. The interaction of bovine conglutinin with rgp160...... of the binding of rgp160 to the CD4 receptor on CEM 13 cells, as demonstrated by FACS analyses. These results indicate that conglutinin may inhibit the infection with HIV-1 through its interaction with the viral envelope glycoprotein....

  20. IFITM Proteins Restrict HIV-1 Infection by Antagonizing the Envelope Glycoprotein

    Directory of Open Access Journals (Sweden)

    Jingyou Yu

    2015-10-01

    Full Text Available The interferon-induced transmembrane (IFITM proteins have been recently shown to restrict HIV-1 and other viruses. Here, we provide evidence that IFITM proteins, particularly IFITM2 and IFITM3, specifically antagonize the HIV-1 envelope glycoprotein (Env, thereby inhibiting viral infection. IFITM proteins interact with HIV-1 Env in viral producer cells, leading to impaired Env processing and virion incorporation. Notably, the level of IFITM incorporation into HIV-1 virions does not strictly correlate with the extent of inhibition. Prolonged passage of HIV-1 in IFITM-expressing T lymphocytes leads to emergence of Env mutants that overcome IFITM restriction. The ability of IFITMs to inhibit cell-to-cell infection can be extended to HIV-1 primary isolates, HIV-2 and SIVs; however, the extent of inhibition appears to be virus-strain dependent. Overall, our study uncovers a mechanism by which IFITM proteins specifically antagonize HIV-1 Env to restrict HIV-1 infection and provides insight into the specialized role of IFITMs in HIV infection.

  1. Composition and Antigenic Effects of Individual Glycan Sites of a Trimeric HIV-1 Envelope Glycoprotein

    Directory of Open Access Journals (Sweden)

    Anna-Janina Behrens

    2016-03-01

    Full Text Available The HIV-1 envelope glycoprotein trimer is covered by an array of N-linked glycans that shield it from immune surveillance. The high density of glycans on the trimer surface imposes steric constraints limiting the actions of glycan-processing enzymes, so that multiple under-processed structures remain on specific areas. These oligomannose glycans are recognized by broadly neutralizing antibodies (bNAbs that are not thwarted by the glycan shield but, paradoxically, target it. Our site-specific glycosylation analysis of a soluble, recombinant trimer (BG505 SOSIP.664 maps the extremes of simplicity and diversity of glycan processing at individual sites and reveals a mosaic of dense clusters of oligomannose glycans on the outer domain. Although individual sites usually minimally affect the global integrity of the glycan shield, we identify examples of how deleting some glycans can subtly influence neutralization by bNAbs that bind at distant sites. The network of bNAb-targeted glycans should be preserved on vaccine antigens.

  2. Elite suppressor-derived HIV-1 envelope glycoproteins exhibit reduced entry efficiency and kinetics.

    Directory of Open Access Journals (Sweden)

    Kara G Lassen

    2009-04-01

    Full Text Available Elite suppressors (ES are a rare subset of HIV-1-infected individuals who are able to maintain HIV-1 viral loads below the limit of detection by ultra-sensitive clinical assays in the absence of antiretroviral therapy. Mechanism(s responsible for this elite control are poorly understood but likely involve both host and viral factors. This study assesses ES plasma-derived envelope glycoprotein (env fitness as a function of entry efficiency as a possible contributor to viral suppression. Fitness of virus entry was first evaluated using a novel inducible cell line with controlled surface expression levels of CD4 (receptor and CCR5 (co-receptor. In the context of physiologic CCR5 and CD4 surface densities, ES envs exhibited significantly decreased entry efficiency relative to chronically infected viremic progressors. ES envs also demonstrated slow entry kinetics indicating the presence of virus with reduced entry fitness. Overall, ES env clones were less efficient at mediating entry than chronic progressor envs. Interestingly, acute infection envs exhibited an intermediate phenotypic pattern not distinctly different from ES or chronic progressor envs. These results imply that lower env fitness may be established early and may directly contribute to viral suppression in ES individuals.

  3. Engineering and Characterization of a Fluorescent Native-Like HIV-1 Envelope Glycoprotein Trimer

    Directory of Open Access Journals (Sweden)

    Kwinten Sliepen

    2015-10-01

    Full Text Available Generation of a stable, soluble mimic of the HIV-1 envelope glycoprotein (Env trimer on the virion surface has been considered an important first step for developing a successful HIV-1 vaccine. Recently, a soluble native-like Env trimer (BG505 SOSIP.664 has been described. This protein has facilitated major advances in the HIV-1 vaccine field, since it was the first Env immunogen that induced consistent neutralizing antibodies against a neutralization-resistant (tier 2 virus. Moreover, BG505 SOSIP.664 enabled elucidation of the atomic resolution structure of the Env trimer and facilitated the isolation and characterization of new broadly neutralizing antibodies against HIV-1. Here, we designed and characterized the BG505 SOSIP.664 trimer fused to fluorescent superfolder GFP (sfGFP, a GFP variant that allows efficient folding (BG505 SOSIP.664-sfGFP. Despite the presence of the sfGFP, the Env protein largely retained its morphology, antigenicity, glycan composition, and thermostability. In addition, we show that BG505 SOSIP.664-sfGFP can be used for fluorescence-based assays, such as flow cytometry.

  4. Importance of the short cytoplasmic domain of the feline immunodeficiency virus transmembrane glycoprotein for fusion activity and envelope glycoprotein incorporation into virions

    International Nuclear Information System (INIS)

    Celma, Cristina C.P.; Paladino, Monica G.; Gonzalez, Silvia A.; Affranchino, Jose L.

    2007-01-01

    The mature form of the envelope (Env) glycoprotein of lentiviruses is a heterodimer composed of the surface (SU) and transmembrane (TM) subunits. Feline immunodeficiency virus (FIV) possesses a TM glycoprotein with a cytoplasmic tail of approximately 53 amino acids which is unusually short compared with that of the other lentiviral glycoproteins (more than 100 residues). To investigate the relevance of the FIV TM cytoplasmic domain to Env-mediated viral functions, we characterized the biological properties of a series of Env glycoproteins progressively shortened from the carboxyl terminus. All the mutant Env proteins were efficiently expressed in feline cells and processed into the SU and TM subunits. Deletion of 5 or 11 amino acids from the TM C-terminus did not significantly affect Env surface expression, fusogenic activity or Env incorporation into virions, whereas removal of 17 or 23 residues impaired Env-mediated cell-to-cell fusion. Further truncation of the FIV TM by 29 residues resulted in an Env glycoprotein that was poorly expressed at the cell surface, exhibited only 20% of the wild-type Env fusogenic capacity and was inefficiently incorporated into virions. Remarkably, deletion of the TM C-terminal 35 or 41 amino acids restored or even enhanced Env biological functions. Indeed, these mutant Env glycoproteins bearing cytoplasmic domains of 18 or 12 amino acids were found to be significantly more fusogenic than the wild-type Env and were efficiently incorporated into virions. Interestingly, truncation of the TM cytoplasmic domain to only 6 amino acids did not affect Env incorporation into virions but abrogated Env fusogenicity. Finally, removal of the entire TM cytoplasmic tail or deletion of as many as 6 amino acids into the membrane-spanning domain led to a complete loss of Env functions. Our results demonstrate that despite its relatively short length, the FIV TM cytoplasmic domain plays an important role in modulating Env-mediated viral functions

  5. Mutations altering the gammaretrovirus endoproteolytic motif affect glycosylation of the envelope glycoprotein and early events of the virus life cycle

    Energy Technology Data Exchange (ETDEWEB)

    Argaw, Takele; Wilson, Carolyn A., E-mail: carolyn.wilson@fda.hhs.gov

    2015-01-15

    Previously, we found that mutation of glutamine to proline in the endoproteolytic cleavage signal of the PERV-C envelope (RQKK to RPKK) resulted in non-infectious vectors. Here, we show that RPKK results in a non-infectious vector when placed in not only a PERV envelope, but also the envelope of a related gammaretrovirus, FeLV-B. The amino acid substitutions do not prevent envelope precursor cleavage, viral core and genome assembly, or receptor binding. Rather, the mutations result in the formation of hyperglycosylated glycoprotein and a reduction in the reverse transcribed minus strand synthesis and undetectable 2-LTR circular DNA in cells exposed to vectors with these mutated envelopes. Our findings suggest novel functions associated with the cleavage signal sequence that may affect trafficking through the glycosylation machinery of the cell. Further, the glycosylation status of the envelope appears to impact post-binding events of the viral life cycle, either membrane fusion, internalization, or reverse transcription. - Highlights: • Env cleavage signal impacts infectivity of gammaretroviruses. • Non-infectious mutants have hyper-glycosylated envelope that bind target cells. • Non-infectious mutants have defects in the formation of the double-stranded DNA. • Env cleavage motif has functions beyond cleavage of the env precursor.

  6. Humoral immune response to hypervariable region 1 of the putative envelope glycoprotein (gp70) of hepatitis C virus.

    OpenAIRE

    Kato, N; Sekiya, H; Ootsuyama, Y; Nakazawa, T; Hijikata, M; Ohkoshi, S; Shimotohno, K

    1993-01-01

    We recently found that alterations of amino acids in hypervariable region 1 (HVR1) of the putative envelope glycoprotein (gp70) of hepatitis C virus (HCV) occurred sequentially in the chronic phase of hepatitis at intervals of several months. This finding suggests that mutations in HVR1 are involved in the mechanism of persistent chronic HCV infection involving escape from the immunosurveillance system. To explore this possibility, we examined the humoral immune response to HVR1 with our assa...

  7. Prediction of exposed domains of envelope glycoprotein in Indian HIV-1 isolates and experimental confirmation of their immunogenicity in humans

    Directory of Open Access Journals (Sweden)

    Mohabatkar H.

    2004-01-01

    Full Text Available We describe the impact of subtype differences on the seroreactivity of linear antigenic epitopes in envelope glycoprotein of HIV-1 isolates from different geographical locations. By computer analysis, we predicted potential antigenic sites of envelope glycoprotein (gp120 and gp4l of this virus. For this purpose, after fetching sequences of proteins of interest from data banks, values of hydrophilicity, flexibility, accessibility, inverted hydrophobicity, and secondary structure were considered. We identified several potential antigenic epitopes in a B subtype strain of envelope glycoprotein of HIV-1 (IIIB. Solid- phase peptide synthesis methods of Merrifield and Fmoc chemistry were used for synthesizing peptides. These synthetic peptides corresponded mainly to the C2, V3 and CD4 binding sites of gp120 and some parts of the ectodomain of gp41. The reactivity of these peptides was tested by ELISA against different HIV-1-positive sera from different locations in India. For two of these predicted epitopes, the corresponding Indian consensus sequences (LAIERYLKQQLLGWG and DIIGDIRQAHCNISEDKWNET (subtype C were also synthesized and their reactivity was tested by ELISA. These peptides also distinguished HIV-1-positive sera of Indians with C subtype infections from sera from HIV-negative subjects.

  8. A mechanistic understanding of allosteric immune escape pathways in the HIV-1 envelope glycoprotein.

    Directory of Open Access Journals (Sweden)

    Anurag Sethi

    Full Text Available The HIV-1 envelope (Env spike, which consists of a compact, heterodimeric trimer of the glycoproteins gp120 and gp41, is the target of neutralizing antibodies. However, the high mutation rate of HIV-1 and plasticity of Env facilitates viral evasion from neutralizing antibodies through various mechanisms. Mutations that are distant from the antibody binding site can lead to escape, probably by changing the conformation or dynamics of Env; however, these changes are difficult to identify and define mechanistically. Here we describe a network analysis-based approach to identify potential allosteric immune evasion mechanisms using three known HIV-1 Env gp120 protein structures from two different clades, B and C. First, correlation and principal component analyses of molecular dynamics (MD simulations identified a high degree of long-distance coupled motions that exist between functionally distant regions within the intrinsic dynamics of the gp120 core, supporting the presence of long-distance communication in the protein. Then, by integrating MD simulations with network theory, we identified the optimal and suboptimal communication pathways and modules within the gp120 core. The results unveil both strain-dependent and -independent characteristics of the communication pathways in gp120. We show that within the context of three structurally homologous gp120 cores, the optimal pathway for communication is sequence sensitive, i.e. a suboptimal pathway in one strain becomes the optimal pathway in another strain. Yet the identification of conserved elements within these communication pathways, termed inter-modular hotspots, could present a new opportunity for immunogen design, as this could be an additional mechanism that HIV-1 uses to shield vulnerable antibody targets in Env that induce neutralizing antibody breadth.

  9. Multiple genes encode the major surface glycoprotein of Pneumocystis carinii

    DEFF Research Database (Denmark)

    Kovacs, J A; Powell, F; Edman, J C

    1993-01-01

    hydrophobic region at the carboxyl terminus. The presence of multiple related msg genes encoding the major surface glycoprotein of P. carinii suggests that antigenic variation is a possible mechanism for evading host defenses. Further characterization of this family of genes should allow the development......The major surface antigen of Pneumocystis carinii, a life-threatening opportunistic pathogen in human immunodeficiency virus-infected patients, is an abundant glycoprotein that functions in host-organism interactions. A monoclonal antibody to this antigen is protective in animals, and thus...... blot studies using chromosomal or restricted DNA, the major surface glycoproteins are the products of a multicopy family of genes. The predicted protein has an M(r) of approximately 123,000, is relatively rich in cysteine residues (5.5%) that are very strongly conserved, and contains a well conserved...

  10. Interaction and inhibition of dengue envelope glycoprotein with mammalian receptor DC-sign, an in-silico approach.

    Directory of Open Access Journals (Sweden)

    Masaud Shah

    Full Text Available Membrane fusion is the central molecular event during the entry of enveloped viruses into cells. The critical agents of this process are viral surface proteins, primed to facilitate cell bilayer fusion. The important role of Dendritic-cell-specific ICAM3-grabbing non-integrin (DC-SIGN in Dengue virus transmission makes it an attractive target to interfere with Dengue virus Propagation. Receptor mediated endocytosis allows the entry of virions due to the presence of endosomal membranes and low pH-induced fusion of the virus. DC-SIGN is the best characterized molecule among the candidate protein receptors and is able to mediate infection with the four serotypes of dengue virus (DENV. Unrestrained pair wise docking was used for the interaction of dengue envelope protein with DC-SIGN and monoclonal antibody 2G12. Pre-processed the PDB coordinates of dengue envelope glycoprotein and other candidate proteins were prepared and energy minimized through AMBER99 force field distributed in MOE software. Protein-protein interaction server, ZDOCK was used to find molecular interaction among the candidate proteins. Based on these interactions it was found that antibody successfully blocks the glycosylation site ASN 67 and other conserved residues present at DC-SIGN-Den-E complex interface. In order to know for certain, the exact location of the antibody in the envelope protein, co-crystallize of the envelope protein with these compounds is needed so that their exact docking locations can be identified with respect to our results.

  11. Genetic Diversity Underlying the Envelope Glycoproteins of Hepatitis C Virus: Structural and Functional Consequences and the Implications for Vaccine Design

    Directory of Open Access Journals (Sweden)

    Alexander W. Tarr

    2015-07-01

    Full Text Available In the 26 years since the discovery of Hepatitis C virus (HCV a major global research effort has illuminated many aspects of the viral life cycle, facilitating the development of targeted antivirals. Recently, effective direct-acting antiviral (DAA regimens with >90% cure rates have become available for treatment of chronic HCV infection in developed nations, representing a significant advance towards global eradication. However, the high cost of these treatments results in highly restricted access in developing nations, where the disease burden is greatest. Additionally, the largely asymptomatic nature of infection facilitates continued transmission in at risk groups and resource constrained settings due to limited surveillance. Consequently a prophylactic vaccine is much needed. The HCV envelope glycoproteins E1 and E2 are located on the surface of viral lipid envelope, facilitate viral entry and are the targets for host immunity, in addition to other functions. Unfortunately, the extreme global genetic and antigenic diversity exhibited by the HCV glycoproteins represents a significant obstacle to vaccine development. Here we review current knowledge of HCV envelope protein structure, integrating knowledge of genetic, antigenic and functional diversity to inform rational immunogen design.

  12. Replacement of the murine leukemia virus (MLV) envelope gene with a truncated HIV envelope gene in MLV generates a virus with impaired replication capacity

    International Nuclear Information System (INIS)

    Nack, Ursula; Schnierle, Barbara S.

    2003-01-01

    Murine leukemia virus (MLV) capsid particles can be efficiently pseudotyped with a variant of the HIV-1 envelope protein (Env) containing the surface glycoprotein gp120-SU and a carboxyl-terminally truncated transmembrane (TM) protein, with only seven cytoplasmic amino acids. MLV/HIV pseudotyped vector particles acquire the natural host tropism of HIV-1 and their entry is dependent on the presence of CD4 and an appropriate co-receptor on the surface of the target cell. We describe here the construction of chimeric MLV/HIV proviruses containing the truncated HIV envelope gene. The MLV/HIV provirus was generated by direct replacement of the MLV envelope gene with HIV Env coding sequences either with or without the additional inclusion of the woodchuck hepatitis virus posttranscriptional regulatory element (WPRE). Chimeric MLV/HIV particles could be generated from transfected 293T cells and were able to infect CD4/CXCR4-positive target cells. However, the second round of infection of target cells was severely impaired, despite the fact that the WPRE element enhanced the amount of viral mRNA detected. Viral particles released from infected cells showed reduced HIV Env incorporation, indicating that additional factors required for efficient replication of MLV/HIV pseudotyped viruses are missing

  13. Genetic signatures in the envelope glycoproteins of HIV-1 that associate with broadly neutralizing antibodies.

    Directory of Open Access Journals (Sweden)

    S Gnanakaran

    Full Text Available A steady increase in knowledge of the molecular and antigenic structure of the gp120 and gp41 HIV-1 envelope glycoproteins (Env is yielding important new insights for vaccine design, but it has been difficult to translate this information to an immunogen that elicits broadly neutralizing antibodies. To help bridge this gap, we used phylogenetically corrected statistical methods to identify amino acid signature patterns in Envs derived from people who have made potently neutralizing antibodies, with the hypothesis that these Envs may share common features that would be useful for incorporation in a vaccine immunogen. Before attempting this, essentially as a control, we explored the utility of our computational methods for defining signatures of complex neutralization phenotypes by analyzing Env sequences from 251 clonal viruses that were differentially sensitive to neutralization by the well-characterized gp120-specific monoclonal antibody, b12. We identified ten b12-neutralization signatures, including seven either in the b12-binding surface of gp120 or in the V2 region of gp120 that have been previously shown to impact b12 sensitivity. A simple algorithm based on the b12 signature pattern was predictive of b12 sensitivity/resistance in an additional blinded panel of 57 viruses. Upon obtaining these reassuring outcomes, we went on to apply these same computational methods to define signature patterns in Env from HIV-1 infected individuals who had potent, broadly neutralizing responses. We analyzed a checkerboard-style neutralization dataset with sera from 69 HIV-1-infected individuals tested against a panel of 25 different Envs. Distinct clusters of sera with high and low neutralization potencies were identified. Six signature positions in Env sequences obtained from the 69 samples were found to be strongly associated with either the high or low potency responses. Five sites were in the CD4-induced coreceptor binding site of gp120, suggesting an

  14. Effect of partial and complete variable loop deletions of the human immunodeficiency virus type 1 envelope glycoprotein on the breadth of gp160-specific immune responses

    International Nuclear Information System (INIS)

    Gzyl, Jaroslaw; Bolesta, Elizabeth; Wierzbicki, Andrew; Kmieciak, Dariusz; Naito, Toshio; Honda, Mitsuo; Komuro, Katsutoshi; Kaneko, Yutaro; Kozbor, Danuta

    2004-01-01

    Induction of cross-reactive cellular and humoral responses to the HIV-1 envelope (env) glycoprotein was examined after DNA immunization of BALB/c mice with gp140 89.6 -derived constructs exhibiting partial or complete deletions of the V1, V2, and V3 domains. It was demonstrated that specific modification of the V3 loop (mV3) in combination with the V2-modified (mV2) or V1/V2-deleted (ΔV1/V2) region elicited increased levels of cross-reactive CD8 + T cell responses. Mice immunized with the mV2/mV3 or ΔV1/V2/mV3 gp140 89.6 plasmid DNA were greater than 50-fold more resistant to challenge with recombinant vaccinia virus (rVV) expressing heterologous env gene products than animals immunized with the wild-type (WT) counterpart. Sera from mV2/mV3- and ΔV1/V2/mV3-immunized mice exhibited the highest cross-neutralizing activity and displayed intermediate antibody avidity values which were further enhanced by challenge with rVV expressing the homologous gp160 glycoprotein. In contrast, complete deletion of the variable regions had little or no effect on the cross-reactive antibody responses. The results of these experiments indicate that the breadth of antibody responses to the HIV-1 env glycoprotein may not be increased by removal of the variable domains. Instead, partial deletions within these regions may redirect specific responses toward conserved epitopes and facilitate approaches for boosting cross-reactive cellular and antibody responses to the env glycoprotein

  15. An alternative conformation of the gp41 heptad repeat 1 region coiled coil exists in the human immunodeficiency virus (HIV-1) envelope glycoprotein precursor

    International Nuclear Information System (INIS)

    Mische, Claudia C.; Yuan Wen; Strack, Bettina; Craig, Stewart; Farzan, Michael; Sodroski, Joseph

    2005-01-01

    The human immunodeficiency virus (HIV-1) transmembrane envelope glycoprotein, gp41, which mediates virus-cell fusion, exists in at least three different conformations within the trimeric envelope glycoprotein complex. The structures of the prefusogenic and intermediate states are unknown; structures representing the postfusion state have been solved. In the postfusion conformation, three helical heptad repeat 2 (HR2) regions pack in an antiparallel fashion into the hydrophobic grooves on the surface of a triple-helical coiled coil formed by the heptad repeat 1 (HR1) regions. We studied the prefusogenic conformation of gp41 by mutagenic alteration of membrane-anchored and soluble forms of the HIV-1 envelope glycoproteins. Our results indicate that, in the HIV-1 envelope glycoprotein precursor, the gp41 HR1 region is in a conformation distinct from that of a trimeric coiled coil. Thus, the central gp41 coiled coil is formed during the transition of the HIV-1 envelope glycoproteins from the precursor state to the receptor-bound intermediate

  16. Glycoprotein is enough for sindbis virus-derived DNA vector to express heterogenous genes

    Directory of Open Access Journals (Sweden)

    Fu Juanjuan

    2011-07-01

    Full Text Available Abstract To investigate the necessity and potential application of structural genes for expressing heterogenous genes from Sindbis virus-derived vector, the DNA-based expression vector pVaXJ was constructed by placing the recombinant genome of sindbis-like virus XJ-160 under the control of the human cytomegalovirus (CMV promoter of the plasmid pVAX1, in which viral structural genes were replaced by a polylinker cassette to allow for insertion of heterologous genes. The defect helper plasmids pVaE or pVaC were developed by cloning the gene of glycoprotein E3E26KE1 or capsid protein of XJ-160 virus into pVAX1, respectively. The report gene cassette pVaXJ-EGFP or pV-Gluc expressing enhanced green fluorescence protein (EGFP or Gaussia luciferase (G.luc were constructed by cloning EGFP or G.luc gene into pVaXJ. EGFP or G.luc was expressed in the BHK-21 cells co-transfected with report gene cassettes and pVaE at levels that were comparable to those produced by report gene cassettes, pVaC and pVaE and were much higher than the levels produced by report gene cassette and pVaC, suggesting that glycoprotein is enough for Sindbis virus-derived DNA vector to express heterogenous genes in host cells. The method of gene expression from Sindbis virus-based DNA vector only co-transfected with envelop E gene increase the conveniency and the utility of alphavirus-based vector systems in general.

  17. Genetic analysis of heptad-repeat regions in the G2 fusion subunit of the Junin arenavirus envelope glycoprotein

    International Nuclear Information System (INIS)

    York, Joanne; Agnihothram, Sudhakar S.; Romanowski, Victor; Nunberg, Jack H.

    2005-01-01

    The G2 fusion subunit of the Junin virus envelope glycoprotein GP-C contains two hydrophobic heptad-repeat regions that are postulated to form a six-helix bundle structure required for the membrane fusion activity of Class I viral fusion proteins. We have investigated the role of these heptad-repeat regions and, specifically, the importance of the putative interhelical a and d position sidechains by using alanine-scanning mutagenesis. All the mutant glycoproteins were expressed and transported to the cell surface. Proteolytic maturation at the subtilisin kexin isozyme-1/site-1-protease (SKI-1/S1P) cleavage site was observed in all but two of the mutants. Among the adequately cleaved mutant glycoproteins, four positions in the N-terminal region (I333, L336, L347 and L350) and two positions in the C-terminal region (R392 and W395) were shown to be important determinants of cell-cell fusion. Taken together, our results indicate that α-helical coiled-coil structures are likely critical in promoting arenavirus membrane fusion. These findings support the inclusion of the arenavirus GP-C among the Class I viral fusion proteins and suggest pharmacologic and immunologic strategies for targeting arenavirus infection and hemorrhagic fever

  18. Feline immunodeficiency virus envelope glycoprotein mediates apoptosis in activated PBMC by a mechanism dependent on gp41 function

    International Nuclear Information System (INIS)

    Garg, Himanshu; Joshi, Anjali; Tompkins, Wayne A.

    2004-01-01

    Feline Immunodeficiency Virus (FIV) is a lentivirus that causes immunodeficiency in cats, which parallels HIV-1-induced immunodeficiency in humans. It has been established that HIV envelope (Env) glycoprotein mediates T cell loss via a mechanism that requires CXCR4 binding. The Env glycoprotein of FIV, similar to HIV, requires CXCR4 binding for viral entry, as well as inducing membrane fusion leading to syncytia formation. However, the role of FIV Env in T cell loss and the molecular mechanisms governing this process have not been elucidated. We studied the role of Env glycoprotein in FIV-mediated T cell apoptosis in an in vitro model. Our studies demonstrate that membrane-expressed FIV Env induces apoptosis in activated feline peripheral blood mononuclear cells (PBMC) by a mechanism that requires CXCR4 binding, as the process was inhibited by CXCR4 antagonist AMD3100 in a dose-dependent manner. Interestingly, studies regarding the role of CD134, the recently identified primary receptor of FIV, suggest that binding to CD134 may not be important for induction of apoptosis in PBMC. However, inhibiting Env-mediated fusion post CXCR4 binding by FIV gp41-specific fusion inhibitor also inhibited apoptosis. Under similar conditions, a fusion-defective gp41 mutant was unable to induce apoptosis in activated PBMC. Our findings are the first report suggesting the potential of FIV Env to mediate apoptosis in bystander cells by a process that is dependent on gp41 function

  19. Inhibition of human immunodeficiency virus (HIV) infection in vitro by anticarbohydrate monoclonal antibodies: peripheral glycosylation of HIV envelope glycoprotein gp120 may be a target for virus neutralization

    DEFF Research Database (Denmark)

    Hansen, J E; Clausen, H; Nielsen, C

    1990-01-01

    ), and the cell type used as the infection target (MT4, PMC, or selected T4 lymphocytes). Inhibition was observed when viruses were preincubated with MAbs but not when cells were preincubated with MAbs before inoculation, and the MAbs were shown to precipitate 125I-labeled gp120. The MAbs therefore define...... carbohydrate structures expressed by the viral envelope glycoprotein gp120, indicating that glycans of the viral envelope are possible targets for immunotherapy or vaccine development or both....

  20. Expression, purification and crystallization of the ectodomain of the envelope glycoprotein E2 from Bovine viral diarrhoea virus

    International Nuclear Information System (INIS)

    Iourin, Oleg; Harlos, Karl; El Omari, Kamel; Lu, Weixian; Kadlec, Jan; Iqbal, Munir; Meier, Christoph; Palmer, Andrew; Jones, Ian; Thomas, Carole; Brownlie, Joe; Grimes, Jonathan M.; Stuart, David I.

    2012-01-01

    The cloning, expression, purification, crystallization and preliminary X-ray diffraction analysis of the ectodomain of BVDV E2 are described. Bovine viral diarrhoea virus (BVDV) is an economically important animal pathogen which is closely related to Hepatitis C virus. Of the structural proteins, the envelope glycoprotein E2 of BVDV is the major antigen which induces neutralizing antibodies; thus, BVDV E2 is considered as an ideal target for use in subunit vaccines. Here, the expression, purification of wild-type and mutant forms of the ectodomain of BVDV E2 and subsequent crystallization and data collection of two crystal forms grown at low and neutral pH are reported. Native and multiple-wavelength anomalous dispersion (MAD) data sets have been collected and structure determination is in progress

  1. A Molecular Sensor To Characterize Arenavirus Envelope Glycoprotein Cleavage by Subtilisin Kexin Isozyme 1/Site 1 Protease

    Science.gov (United States)

    Oppliger, Joel; da Palma, Joel Ramos; Burri, Dominique J.; Khatib, Abdel-Majid; Spiropoulou, Christina F.

    2015-01-01

    ABSTRACT Arenaviruses are emerging viruses including several causative agents of severe hemorrhagic fevers in humans. The advent of next-generation sequencing technology has greatly accelerated the discovery of novel arenavirus species. However, for many of these viruses, only genetic information is available, and their zoonotic disease potential remains unknown. During the arenavirus life cycle, processing of the viral envelope glycoprotein precursor (GPC) by the cellular subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P) is crucial for productive infection. The ability of newly emerging arenaviruses to hijack human SKI-1/S1P appears, therefore, to be a requirement for efficient zoonotic transmission and human disease potential. Here we implement a newly developed cell-based molecular sensor for SKI-1/S1P to characterize the processing of arenavirus GPC-derived target sequences by human SKI-1/S1P in a quantitative manner. We show that only nine amino acids flanking the putative cleavage site are necessary and sufficient to accurately recapitulate the efficiency and subcellular location of arenavirus GPC processing. In a proof of concept, our sensor correctly predicts efficient processing of the GPC of the newly emergent pathogenic Lujo virus by human SKI-1/S1P and defines the exact cleavage site. Lastly, we employed our sensor to show efficient GPC processing of a panel of pathogenic and nonpathogenic New World arenaviruses, suggesting that GPC cleavage represents no barrier for zoonotic transmission of these pathogens. Our SKI-1/S1P sensor thus represents a rapid and robust test system for assessment of the processing of putative cleavage sites derived from the GPCs of newly discovered arenavirus by the SKI-1/S1P of humans or any other species, based solely on sequence information. IMPORTANCE Arenaviruses are important emerging human pathogens that can cause severe hemorrhagic fevers with high mortality in humans. A crucial step in productive arenavirus

  2. Identification of a mouse synaptic glycoprotein gene in cultured neurons.

    Science.gov (United States)

    Yu, Albert Cheung-Hoi; Sun, Chun Xiao; Li, Qiang; Liu, Hua Dong; Wang, Chen Ran; Zhao, Guo Ping; Jin, Meilei; Lau, Lok Ting; Fung, Yin-Wan Wendy; Liu, Shuang

    2005-10-01

    Neuronal differentiation and aging are known to involve many genes, which may also be differentially expressed during these developmental processes. From primary cultured cerebral cortical neurons, we have previously identified various differentially expressed gene transcripts from cultured cortical neurons using the technique of arbitrarily primed PCR (RAP-PCR). Among these transcripts, clone 0-2 was found to have high homology to rat and human synaptic glycoprotein. By in silico analysis using an EST database and the FACTURA software, the full-length sequence of 0-2 was assembled and the clone was named as mouse synaptic glycoprotein homolog 2 (mSC2). DNA sequencing revealed transcript size of mSC2 being smaller than the human and rat homologs. RT-PCR indicated that mSC2 was expressed differentially at various culture days. The mSC2 gene was located in various tissues with higher expression in brain, lung, and liver. Functions of mSC2 in neurons and other tissues remain elusive and will require more investigation.

  3. Identification of new genes in a cell envelope-cell division gene cluster of Escherichia coli: cell envelope gene murG.

    Science.gov (United States)

    Salmond, G P; Lutkenhaus, J F; Donachie, W D

    1980-01-01

    We report the identification, cloning, and mapping of a new cell envelope gene, murG. This lies in a group of five genes of similar phenotype (in the order murE murF murG murC ddl) all concerned with peptidoglycan biosynthesis. This group is in a larger cluster of at least 10 genes, all of which are involved in some way with cell envelope growth. Images PMID:6998962

  4. Structural models of the membrane anchors of envelope glycoproteins E1 and E2 from pestiviruses

    International Nuclear Information System (INIS)

    Wang, Jimin; Li, Yue; Modis, Yorgo

    2014-01-01

    The membrane anchors of viral envelope proteins play essential roles in cell entry. Recent crystal structures of the ectodomain of envelope protein E2 from a pestivirus suggest that E2 belongs to a novel structural class of membrane fusion machinery. Based on geometric constraints from the E2 structures, we generated atomic models of the E1 and E2 membrane anchors using computational approaches. The E1 anchor contains two amphipathic perimembrane helices and one transmembrane helix; the E2 anchor contains a short helical hairpin stabilized in the membrane by an arginine residue, similar to flaviviruses. A pair of histidine residues in the E2 ectodomain may participate in pH sensing. The proposed atomic models point to Cys987 in E2 as the site of disulfide bond linkage with E1 to form E1–E2 heterodimers. The membrane anchor models provide structural constraints for the disulfide bonding pattern and overall backbone conformation of the E1 ectodomain. - Highlights: • Structures of pestivirus E2 proteins impose constraints on E1, E2 membrane anchors. • Atomic models of the E1 and E2 membrane anchors were generated in silico. • A “snorkeling” arginine completes the short helical hairpin in the E2 membrane anchor. • Roles in pH sensing and E1–E2 disulfide bond formation are proposed for E1 residues. • Implications for E1 ectodomain structure and disulfide bonding pattern are discussed

  5. Sequence variation and phylogenetic analysis of envelope glycoprotein of hepatitis G virus.

    Science.gov (United States)

    Lim, M Y; Fry, K; Yun, A; Chong, S; Linnen, J; Fung, K; Kim, J P

    1997-11-01

    A transfusion-transmissible agent provisionally designated hepatitis G virus (HGV) was recently identified. In this study, we examined the variability of the HGV genome by analysing sequences in the putative envelope region from 72 isolates obtained from diverse geographical sources. The 1561 nucleotide sequence of the E1/E2/NS2a region of HGV was determined from 12 isolates, and compared with three published sequences. The most variability was observed in 400 nucleotides at the N terminus of E2. We next analysed this 400 nucleotide envelope variable region (EV) from an additional 60 HGV isolates. This sequence varied considerably among the 75 isolates, with overall identity ranging from 79.3% to 99.5% at the nucleotide level, and from 83.5% to 100% at the amino acid level. However, hypervariable regions were not identified. Phylogenetic analyses indicated that the 75 HGV isolates belong to a single genotype. A single-tier distribution of evolutionary distances was observed among the 15 E1/E2/NS2a sequences and the 75 EV sequences. In contrast, 11 isolates of HCV were analysed and showed a three-tiered distribution, representing genotypes, subtypes, and isolates. The 75 isolates of HGV fell into four clusters on the phylogenetic tree. Tight geographical clustering was observed among the HGV isolates from Japan and Korea.

  6. Structural models of the membrane anchors of envelope glycoproteins E1 and E2 from pestiviruses

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jimin, E-mail: jimin.wang@yale.edu; Li, Yue; Modis, Yorgo, E-mail: yorgo.modis@yale.edu

    2014-04-15

    The membrane anchors of viral envelope proteins play essential roles in cell entry. Recent crystal structures of the ectodomain of envelope protein E2 from a pestivirus suggest that E2 belongs to a novel structural class of membrane fusion machinery. Based on geometric constraints from the E2 structures, we generated atomic models of the E1 and E2 membrane anchors using computational approaches. The E1 anchor contains two amphipathic perimembrane helices and one transmembrane helix; the E2 anchor contains a short helical hairpin stabilized in the membrane by an arginine residue, similar to flaviviruses. A pair of histidine residues in the E2 ectodomain may participate in pH sensing. The proposed atomic models point to Cys987 in E2 as the site of disulfide bond linkage with E1 to form E1–E2 heterodimers. The membrane anchor models provide structural constraints for the disulfide bonding pattern and overall backbone conformation of the E1 ectodomain. - Highlights: • Structures of pestivirus E2 proteins impose constraints on E1, E2 membrane anchors. • Atomic models of the E1 and E2 membrane anchors were generated in silico. • A “snorkeling” arginine completes the short helical hairpin in the E2 membrane anchor. • Roles in pH sensing and E1–E2 disulfide bond formation are proposed for E1 residues. • Implications for E1 ectodomain structure and disulfide bonding pattern are discussed.

  7. Structural models of the membrane anchors of envelope glycoproteins E1 and E2 from pestiviruses

    Science.gov (United States)

    Wang, Jimin; Li, Yue; Modis, Yorgo

    2014-01-01

    The membrane anchors of viral envelope proteins play essential roles in cell entry. Recent crystal structures of the ectodomain of envelope protein E2 from a pestivirus suggest that E2 belongs to a novel structural class of membrane fusion machinery. Based on geometric constraints from the E2 structures, we generated atomic models of the E1 and E2 membrane anchors using computational approaches. The E1 anchor contains two amphipathic perimembrane helices and one transmembrane helix; the E2 anchor contains a short helical hairpin stabilized in the membrane by an arginine residue, similar to flaviviruses. A pair of histidine residues in the E2 ectodomain may participate in pH sensing. The proposed atomic models point to Cys987 in E2 as the site of disulfide bond linkage with E1 to form E1–E2 heterodimers. The membrane anchor models provide structural constraints for the disulfide bonding pattern and overall backbone conformation of the E1 ectodomain. PMID:24725935

  8. Venezuelan equine encephalitis emergence: Enhanced vector infection from a single amino acid substitution in the envelope glycoprotein

    Science.gov (United States)

    Brault, Aaron C.; Powers, Ann M.; Ortiz, Diana; Estrada-Franco, Jose G.; Navarro-Lopez, Roberto; Weaver, Scott C.

    2004-01-01

    In 1993 and 1996, subtype IE Venezuelan equine encephalitis (VEE) virus caused epizootics in the Mexican states of Chiapas and Oaxaca. Previously, only subtype IAB and IC VEE virus strains had been associated with major outbreaks of equine and human disease. The IAB and IC epizootics are believed to emerge via adaptation of enzootic (sylvatic, equine-avirulent) strains for high titer equine viremia that results in efficient infection of mosquito vectors. However, experimental equine infections with subtype IE equine isolates from the Mexican outbreaks demonstrated neuro-virulence but little viremia, inconsistent with typical VEE emergence mechanisms. Therefore, we hypothesized that changes in the mosquito vector host range might have contributed to the Mexican emergence. To test this hypothesis, we evaluated the susceptibility of the most abundant mosquito in the deforested Pacific coastal locations of the VEE outbreaks and a proven epizootic vector, Ochlerotatus taeniorhynchus. The Mexican epizootic equine isolates exhibited significantly greater infectivity compared with closely related enzootic strains, supporting the hypothesis that adaptation to an efficient epizootic vector contributed to disease emergence. Reverse genetic studies implicated a Ser → Asn substitution in the E2 envelope glycoprotein as the major determinant of the increased vector infectivity phenotype. Our findings underscore the capacity of RNA viruses to alter their vector host range through minor genetic changes, resulting in the potential for disease emergence. PMID:15277679

  9. Antigenicity of peptides comprising the immunosuppressive domain of the retroviral envelope glycoprotein [version 1; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Bryony Jenkins

    2016-12-01

    Full Text Available To achieve persistent infection of the host, viruses often subvert or suppress host immunity through mechanisms that are not entirely understood. The envelope glycoprotein of several retroviruses is thought to possess potent immunosuppressive activity, mapped to a 17-amino acid residue conserved domain. Synthetic peptides corresponding to this immunosuppressive domain can inhibit lymphocyte activation, whereas mutation of key domain residues can increase the lymphocyte response to linked antigenic epitopes. Using three T cell receptors (TCRs of defined specificity, we examine the effect of the immunosuppressive domain on the T cell response to their respective antigenic peptides. We find that fusion of a T cell epitope to the immunosuppressive domain can greatly modulate its potency. However, the effects heavily depend on the particular combination of TCR and peptide-major histocompatibility complex class II (pMHC II, and are mimicked by sequence-scrambled peptides of similar length, suggesting they operate at the level of TCR-pMHC interaction. These results offer an alternative explanation for the immunogenicity of T cell epitopes comprising the putative immunosuppressive domain, which is more consistent with an effect on peptide antigenicity than true immunosuppressive activity.

  10. Antigenicity of peptides comprising the immunosuppressive domain of the retroviral envelope glycoprotein [version 2; referees: 2 approved

    Directory of Open Access Journals (Sweden)

    Bryony Jenkins

    2017-02-01

    Full Text Available To achieve persistent infection of the host, viruses often subvert or suppress host immunity through mechanisms that are not entirely understood. The envelope glycoprotein of several retroviruses is thought to possess potent immunosuppressive activity, mapped to a 17-amino acid residue conserved domain. Synthetic peptides corresponding to this immunosuppressive domain can inhibit lymphocyte activation, whereas mutation of key domain residues can increase the lymphocyte response to linked antigenic epitopes. Using three T cell receptors (TCRs of defined specificity, we examine the effect of the immunosuppressive domain on the T cell response to their respective antigenic peptides. We find that fusion of a T cell epitope to the immunosuppressive domain can greatly modulate its potency. However, the effects heavily depend on the particular combination of TCR and peptide-major histocompatibility complex class II (pMHC II, and are mimicked by sequence-scrambled peptides of similar length, suggesting they operate at the level of pMHC formation or TCR-pMHC interaction. These results offer an alternative explanation for the immunogenicity of T cell epitopes comprising the putative immunosuppressive domain, which is more consistent with an effect on peptide antigenicity than true immunosuppressive activity.

  11. Residues in the membrane-spanning domain core modulate conformation and fusogenicity of the HIV-1 envelope glycoprotein

    International Nuclear Information System (INIS)

    Shang Liang; Hunter, Eric

    2010-01-01

    The membrane-spanning domain (MSD) of human immunodeficiency virus type I (HIV-1) envelope glycoprotein (Env) is critical for its biological activity. Initial studies have defined an almost invariant 'core' structure in the MSD and demonstrated that it is crucial for anchoring Env in the membrane and virus entry. We show here that amino acid substitutions in the MSD 'core' do not influence specific virus-cell attachment, nor CD4 receptor and CXCR4 coreceptor recognition by Env. However, substitutions within the MSD 'core' delayed the kinetics and reduced the efficiency of cell-cell fusion mediated by Env. Although we observed no evidence that membrane fusion mediated by the MSD core mutants was arrested at a hemifusion stage, impaired Env fusogenicity was correlated with minor conformational changes in the V2, C1, and C5 regions in gp120 and the immunodominant loop in gp41. These changes could delay initiation of the conformational changes required in the fusion process.

  12. Distinct requirements for signal peptidase processing and function in the stable signal peptide subunit of the Junin virus envelope glycoprotein

    International Nuclear Information System (INIS)

    York, Joanne; Nunberg, Jack H.

    2007-01-01

    The arenavirus envelope glycoprotein (GP-C) retains a cleaved and stable signal peptide (SSP) as an essential subunit of the mature complex. This 58-amino-acid residue peptide serves as a signal sequence and is additionally required to enable transit of the assembled GP-C complex to the Golgi, and for pH-dependent membrane fusion activity. We have investigated the C-terminal region of the Junin virus SSP to study the role of the cellular signal peptidase (SPase) in generating SSP. Site-directed mutagenesis at the cleavage site (positions - 1 and - 3) reveals a pattern of side-chain preferences consistent with those of SPase. Although position - 2 is degenerate for SPase cleavage, this residue in the arenavirus SSP is invariably a cysteine. In the Junin virus, this cysteine is not involved in disulfide bonding. We show that replacement with alanine or serine is tolerated for SPase cleavage but prevents the mutant SSP from associating with GP-C and enabling transport to the cell surface. Conversely, an arginine mutation at position - 1 that prevents SPase cleavage is fully compatible with GP-C-mediated membrane fusion activity when the mutant SSP is provided in trans. These results point to distinct roles of SSP sequences in SPase cleavage and GP-C biogenesis. Further studies of the unique structural organization of the GP-C complex will be important in identifying novel opportunities for antiviral intervention against arenaviral hemorrhagic disease

  13. Crystal structure of the pestivirus envelope glycoprotein E(rns) and mechanistic analysis of its ribonuclease activity.

    Science.gov (United States)

    Krey, Thomas; Bontems, Francois; Vonrhein, Clemens; Vaney, Marie-Christine; Bricogne, Gerard; Rümenapf, Till; Rey, Félix A

    2012-05-09

    Pestiviruses, which belong to the Flaviviridae family of RNA viruses, are important agents of veterinary diseases causing substantial economical losses in animal farming worldwide. Pestivirus particles display three envelope glycoproteins at their surface: E(rns), E1, and E2. We report here the crystal structure of the catalytic domain of E(rns), the ribonucleolytic activity of which is believed to counteract the innate immunity of the host. The structure reveals a three-dimensional fold corresponding to T2 ribonucleases from plants and fungi. Cocrystallization experiments with mono- and oligonucleotides revealed the structural basis for substrate recognition at two binding sites previously identified for T2 RNases. A detailed analysis of poly-U cleavage products using (31)P-NMR and size exclusion chromatography, together with molecular docking studies, provides a comprehensive mechanistic picture of E(rns) activity on its substrates and reveals the presence of at least one additional nucleotide binding site. Copyright © 2012 Elsevier Ltd. All rights reserved.

  14. Feline tetherin is characterized by a short N-terminal region and is counteracted by the feline immunodeficiency virus envelope glycoprotein.

    Science.gov (United States)

    Celestino, Michele; Calistri, Arianna; Del Vecchio, Claudia; Salata, Cristiano; Chiuppesi, Flavia; Pistello, Mauro; Borsetti, Alessandra; Palù, Giorgio; Parolin, Cristina

    2012-06-01

    Tetherin (BST2) is the host cell factor that blocks the particle release of some enveloped viruses. Two putative feline tetherin proteins differing at the level of the N-terminal coding region have recently been described and tested for their antiviral activity. By cloning and comparing the two reported feline tetherins (called here cBST2(504) and cBST2*) and generating specific derivative mutants, this study provides evidence that feline tetherin has a shorter intracytoplasmic domain than those of other known homologues. The minimal tetherin promoter was identified and assayed for its ability to drive tetherin expression in an alpha interferon-inducible manner. We also demonstrated that cBST2(504) is able to dimerize, is localized at the cellular membrane, and impairs human immunodeficiency virus type 1 (HIV-1) particle release, regardless of the presence of the Vpu antagonist accessory protein. While cBST2(504) failed to restrict wild-type feline immunodeficiency virus (FIV) egress, FIV mutants, bearing a frameshift at the level of the envelope-encoding region, were potently blocked. The transient expression of the FIV envelope glycoprotein was able to rescue mutant particle release from feline tetherin-positive cells but did not antagonize human BST2 activity. Moreover, cBST2(504) was capable of specifically immunoprecipitating the FIV envelope glycoprotein. Finally, cBST2(504) also exerted its function on HIV-2 ROD10 and on the simian immunodeficiency virus SIVmac239. Taken together, these results show that feline tetherin does indeed have a short N-terminal region and that the FIV envelope glycoprotein is the predominant factor counteracting tetherin restriction.

  15. HIV-1 tropism for the central nervous system: Brain-derived envelope glycoproteins with lower CD4 dependence and reduced sensitivity to a fusion inhibitor

    International Nuclear Information System (INIS)

    Martin-Garcia, Julio; Cao, Wei; Varela-Rohena, Angel; Plassmeyer, Matthew L.; Gonzalez-Scarano, Francisco

    2006-01-01

    We previously described envelope glycoproteins of an HIV-1 isolate adapted in vitro for growth in microglia that acquired a highly fusogenic phenotype and lower CD4 dependence, as well as resistance to inhibition by anti-CD4 antibodies. Here, we investigated whether similar phenotypic changes are present in vivo. Envelope clones from the brain and spleen of an HIV-1-infected individual with neurological disease were amplified, cloned, and sequenced. Phylogenetic analysis demonstrated clustering of sequences according to the tissue of origin, as expected. Functional clones were then used in cell-to-cell fusion assays to test for CD4 and co-receptor utilization and for sensitivity to various antibodies and inhibitors. Both brain- and spleen-derived envelope clones mediated fusion in cells expressing both CD4 and CCR5 and brain envelopes also used CCR3 as co-receptor. We found that the brain envelopes had a lower CD4 dependence, since they efficiently mediated fusion in the presence of low levels of CD4 on the target cell membrane, and they were significantly more resistant to blocking by anti-CD4 antibodies than the spleen-derived envelopes. In contrast, we observed no difference in sensitivity to the CCR5 antagonist TAK-779. However, brain-derived envelopes were significantly more resistant than those from spleen to the fusion inhibitor T-1249 and concurrently showed slightly greater fusogenicity. Our results suggest an increased affinity for CD4 of brain-derived envelopes that may have originated from in vivo adaptation to replication in microglial cells. Interestingly, we note the presence of envelopes more resistant to a fusion inhibitor in the brain of an untreated, HIV-1-infected individual

  16. Herpes simplex virus glycoproteins gB and gH function in fusion between the virion envelope and the outer nuclear membrane.

    Science.gov (United States)

    Farnsworth, Aaron; Wisner, Todd W; Webb, Michael; Roller, Richard; Cohen, Gary; Eisenberg, Roselyn; Johnson, David C

    2007-06-12

    Herpesviruses must traverse the nuclear envelope to gain access to the cytoplasm and, ultimately, to exit cells. It is believed that herpesvirus nucleocapsids enter the perinuclear space by budding through the inner nuclear membrane (NM). To reach the cytoplasm these enveloped particles must fuse with the outer NM and the unenveloped capsids then acquire a second envelope in the trans-Golgi network. Little is known about the process by which herpesviruses virions fuse with the outer NM. Here we show that a herpes simplex virus (HSV) mutant lacking both the two putative fusion glycoproteins gB and gH failed to cross the nuclear envelope. Enveloped virions accumulated in the perinuclear space or in membrane vesicles that bulged into the nucleoplasm (herniations). By contrast, mutants lacking just gB or gH showed only minor or no defects in nuclear egress. We concluded that either HSV gB or gH can promote fusion between the virion envelope and the outer NM. It is noteworthy that fusion associated with HSV entry requires the cooperative action of both gB and gH, suggesting that the two types of fusion (egress versus entry) are dissimilar processes.

  17. Chimeric HIV-1 Envelope Glycoproteins with Potent Intrinsic Granulocyte-Macrophage Colony-Stimulating Factor (GM-CSF) Activity*

    Science.gov (United States)

    Boot, Maikel; Cobos Jiménez, Viviana; Kootstra, Neeltje A.; Sanders, Rogier W.

    2013-01-01

    HIV-1 acquisition can be prevented by broadly neutralizing antibodies (BrNAbs) that target the envelope glycoprotein complex (Env). An ideal vaccine should therefore be able to induce BrNAbs that can provide immunity over a prolonged period of time, but the low intrinsic immunogenicity of HIV-1 Env makes the elicitation of such BrNAbs challenging. Co-stimulatory molecules can increase the immunogenicity of Env and we have engineered a soluble chimeric Env trimer with an embedded granulocyte-macrophage colony-stimulating factor (GM-CSF) domain. This chimeric molecule induced enhanced B and helper T cell responses in mice compared to Env without GM-CSF. We studied whether we could optimize the activity of the embedded GM-CSF as well as the antigenic structure of the Env component of the chimeric molecule. We assessed the effect of truncating GM-CSF, removing glycosylation-sites in GM-CSF, and adjusting the linker length between GM-CSF and Env. One of our designed EnvGM-CSF chimeras improved GM-CSF-dependent cell proliferation by 6-fold, reaching the same activity as soluble recombinant GM-CSF. In addition, we incorporated GM-CSF into a cleavable Env trimer and found that insertion of GM-CSF did not compromise Env cleavage, while Env cleavage did not compromise GM-CSF activity. Importantly, these optimized EnvGM-CSF proteins were able to differentiate human monocytes into cells with a macrophage-like phenotype. Chimeric EnvGM-CSF should be useful for improving humoral immunity against HIV-1 and these studies should inform the design of other chimeric proteins. PMID:23565193

  18. Chimeric HIV-1 envelope glycoproteins with potent intrinsic granulocyte-macrophage colony-stimulating factor (GM-CSF activity.

    Directory of Open Access Journals (Sweden)

    Gözde Isik

    Full Text Available HIV-1 acquisition can be prevented by broadly neutralizing antibodies (BrNAbs that target the envelope glycoprotein complex (Env. An ideal vaccine should therefore be able to induce BrNAbs that can provide immunity over a prolonged period of time, but the low intrinsic immunogenicity of HIV-1 Env makes the elicitation of such BrNAbs challenging. Co-stimulatory molecules can increase the immunogenicity of Env and we have engineered a soluble chimeric Env trimer with an embedded granulocyte-macrophage colony-stimulating factor (GM-CSF domain. This chimeric molecule induced enhanced B and helper T cell responses in mice compared to Env without GM-CSF. We studied whether we could optimize the activity of the embedded GM-CSF as well as the antigenic structure of the Env component of the chimeric molecule. We assessed the effect of truncating GM-CSF, removing glycosylation-sites in GM-CSF, and adjusting the linker length between GM-CSF and Env. One of our designed Env(GM-CSF chimeras improved GM-CSF-dependent cell proliferation by 6-fold, reaching the same activity as soluble recombinant GM-CSF. In addition, we incorporated GM-CSF into a cleavable Env trimer and found that insertion of GM-CSF did not compromise Env cleavage, while Env cleavage did not compromise GM-CSF activity. Importantly, these optimized Env(GM-CSF proteins were able to differentiate human monocytes into cells with a macrophage-like phenotype. Chimeric Env(GM-CSF should be useful for improving humoral immunity against HIV-1 and these studies should inform the design of other chimeric proteins.

  19. CTA1-DD adjuvant promotes strong immunity against human immunodeficiency virus type 1 envelope glycoproteins following mucosal immunization.

    Science.gov (United States)

    Sundling, Christopher; Schön, Karin; Mörner, Andreas; Forsell, Mattias N E; Wyatt, Richard T; Thorstensson, Rigmor; Karlsson Hedestam, Gunilla B; Lycke, Nils Y

    2008-12-01

    Strategies to induce potent and broad antibody responses against the human immunodeficiency virus type 1 (HIV-1) envelope glycoproteins (Env) at both systemic and mucosal sites represent a central goal for HIV-1 vaccine development. Here, we show that the non-toxic CTA1-DD adjuvant promoted mucosal and systemic humoral and cell-mediated immune responses following intranasal (i.n.) immunizations with trimeric or monomeric forms of HIV-1 Env in mice and in non-human primates. Env-specific IgG subclasses in the serum of immunized mice reflected a balanced Th1/Th2 type of response. Strikingly, i.n. immunizations with Env and the CTA1-DD adjuvant induced substantial levels of mucosal anti-Env IgA in bronchial alveolar lavage and also detectable levels in vaginal secretions. By contrast, parenteral immunizations of Env formulated in Ribi did not stimulate mucosal IgA responses, while the two adjuvants induced a similar distribution of Env-specific IgG-subclasses in serum. A single parenteral boost with Env in Ribi adjuvant into mice previously primed i.n. with Env and CTA1-DD, augmented the serum anti-Env IgG levels to similar magnitudes as those observed after three intraperitoneal immunizations with Env in Ribi. The augmenting potency of CTA1-DD was similar to that of LTK63 or CpG oligodeoxynucleotides (ODN). However, in contrast to CpG ODN, the effect of CTA1-DD and LTK63 appeared to be independent of MyD88 and toll-like receptor signalling. This is the first demonstration that CTA1-DD augments specific immune responses also in non-human primates, suggesting that this adjuvant could be explored further as a clinically safe mucosal vaccine adjuvant for humoral and cell-mediated immunity against HIV-1 Env.

  20. Molecular Characterization of the Processing of Arenavirus Envelope Glycoprotein Precursors by Subtilisin Kexin Isozyme-1/Site-1 Protease

    Science.gov (United States)

    Burri, Dominique J.; Pasqual, Giulia; Rochat, Cylia; Seidah, Nabil G.

    2012-01-01

    A crucial step in the life cycle of arenaviruses is the biosynthesis of the mature fusion-active viral envelope glycoprotein (GP) that is essential for virus-host cell attachment and entry. The maturation of the arenavirus GP precursor (GPC) critically depends on proteolytic processing by the cellular proprotein convertase (PC) subtilisin kexin isozyme-1 (SKI-1)/site-1 protease (S1P). Here we undertook a molecular characterization of the SKI-1/S1P processing of the GPCs of the prototypic arenavirus lymphocytic choriomeningitis virus (LCMV) and the pathogenic Lassa virus (LASV). Previous studies showed that the GPC of LASV undergoes processing in the endoplasmic reticulum (ER)/cis-Golgi compartment, whereas the LCMV GPC is cleaved in a late Golgi compartment. Herein we confirm these findings and provide evidence that the SKI-1/S1P recognition site RRLL, present in the SKI-1/S1P prodomain and LASV GPC, but not in the LCMV GPC, is crucial for the processing of the LASV GPC in the ER/cis-Golgi compartment. Our structure-function analysis revealed that the cleavage of arenavirus GPCs, but not cellular substrates, critically depends on the autoprocessing of SKI-1/S1P, suggesting differences in the processing of cellular and viral substrates. Deletion mutagenesis showed that the transmembrane and intracellular domains of SKI-1/S1P are dispensable for arenavirus GPC processing. The expression of a soluble form of the protease in SKI-I/S1P-deficient cells resulted in the efficient processing of arenavirus GPCs and rescued productive virus infection. However, exogenous soluble SKI-1/S1P was unable to process LCMV and LASV GPCs displayed at the surface of SKI-I/S1P-deficient cells, indicating that GPC processing occurs in an intracellular compartment. In sum, our study reveals important differences in the SKI-1/S1P processing of viral and cellular substrates. PMID:22357276

  1. The mitochondrial translocator protein, TSPO, inhibits HIV-1 envelope glycoprotein biosynthesis via the endoplasmic reticulum-associated protein degradation pathway.

    Science.gov (United States)

    Zhou, Tao; Dang, Ying; Zheng, Yong-Hui

    2014-03-01

    The HIV-1 Env glycoprotein is folded in the endoplasmic reticulum (ER), which is necessary for viral entry and replication. Currently, it is still unclear how this process is regulated. The glycoprotein folding in the ER is controlled by the ER-associated protein degradation (ERAD) pathway, which specifically targets misfolded proteins for degradation. Previously, we reported that HIV-1 replication is restricted in the human CD4(+) T cell line CEM.NKR (NKR). To understand this mechanism, we first analyzed cellular protein expression in NKR cells and discovered that levels of the mitochondrial translocator protein TSPO were upregulated by ∼64-fold. Notably, when NKR cells were treated with TSPO antagonist PK-11195, Ro5-4864, or diazepam, HIV restriction was completely disrupted, and TSPO knockdown by short hairpin RNAs (shRNAs) achieved a similar effect. We next analyzed viral protein expression, and, interestingly, we discovered that Env expression was specifically inhibited. Both TSPO knockdown and treatment with TSPO antagonist could restore Env expression in NKR cells. We further discovered that Env proteins were rapidly degraded and that kifunensine, an ERAD pathway inhibitor, could restore Env expression and viral replication, indicating that Env proteins were misfolded and degraded through the ERAD pathway in NKR cells. We also knocked out the TSPO gene in 293T cells using CRISPR/Cas9 (clustered, regularly interspaced, short palindromic repeat [CRISPR]/CRISPR-associated-9) technology and found that TSPO could similarly inhibit Env expression in these cells. Taken together, these results demonstrate that TSPO inhibits Env protein expression through the ERAD pathway and suggest that mitochondria play an important role in regulating the Env folding process. The HIV-1 Env glycoprotein is absolutely required for viral infection, and an understanding of its expression pathway in infected cells will identify new targets for antiretroviral therapies. Env proteins

  2. Envelope gene sequences encoding variable regions 3 and 4 are involved in macrophage tropism of feline immunodeficiency virus

    NARCIS (Netherlands)

    Horzinek, M.C.; Vahlenkamp, T.W.; Ronde, A. de; Schuurman, N.M.P.; Vliet, A.L.W. van; Drunen, J. van; Egberink, H.F.

    1999-01-01

    The envelope is of cardinal importance for the entry of feline immunodeficiency virus (FIV) into its host cells, which consist of cells of the immune system including macrophages. To characterize the envelope glycoprotein determinants involved in macrophage tropism, chimeric infectious molecular

  3. Antigenic properties of the human immunodeficiency virus envelope glycoprotein gp120 on virions bound to target cells.

    Directory of Open Access Journals (Sweden)

    Meron Mengistu

    2015-03-01

    Full Text Available The HIV-1 envelope glycoprotein, gp120, undergoes multiple molecular interactions and structural rearrangements during the course of host cell attachment and viral entry, which are being increasingly defined at the atomic level using isolated proteins. In comparison, antigenic markers of these dynamic changes are essentially unknown for single HIV-1 particles bound to target cells. Such markers should indicate how neutralizing and/or non-neutralizing antibodies might interdict infection by either blocking infection or sensitizing host cells for elimination by Fc-mediated effector function. Here we address this deficit by imaging fluorescently labeled CCR5-tropic HIV-1 pseudoviruses using confocal and superresolution microscopy to track the exposure of neutralizing and non-neutralizing epitopes as they appear on single HIV-1 particles bound to target cells. Epitope exposure was followed under conditions permissive or non-permissive for viral entry to delimit changes associated with virion binding from those associated with post-attachment events. We find that a previously unexpected array of gp120 epitopes is exposed rapidly upon target cell binding. This array comprises both neutralizing and non-neutralizing epitopes, the latter being hidden on free virions yet capable of serving as potent targets for Fc-mediated effector function. Under non-permissive conditions for viral entry, both neutralizing and non-neutralizing epitope exposures were relatively static over time for the majority of bound virions. Under entry-permissive conditions, epitope exposure patterns changed over time on subsets of virions that exhibited concurrent variations in virion contents. These studies reveal that bound virions are distinguished by a broad array of both neutralizing and non-neutralizing gp120 epitopes that potentially sensitize a freshly engaged target cell for destruction by Fc-mediated effector function and/or for direct neutralization at a post-binding step

  4. Use of whole genome deep sequencing to define emerging minority variants in virus envelope genes in herpesvirus treated with novel antimicrobial K21.

    Science.gov (United States)

    Tweedy, Joshua G; Prusty, Bhupesh K; Gompels, Ursula A

    2017-10-01

    New antivirals are required to prevent rising antimicrobial resistance from replication inhibitors. The aim of this study was to analyse the range of emerging mutations in herpesvirus by whole genome deep sequencing. We tested human herpesvirus 6 treatment with novel antiviral K21, where evidence indicated distinct effects on virus envelope proteins. We treated BACmid cloned virus in order to analyse mechanisms and candidate targets for resistance. Illumina based next generation sequencing technology enabled analyses of mutations in 85 genes to depths of 10,000 per base detecting low prevalent minority variants (<1%). After four passages in tissue culture the untreated virus accumulated mutations in infected cells giving an emerging mixed population (45-73%) of non-synonymous SNPs in six genes including two envelope glycoproteins. Strikingly, treatment with K21 did not accumulate the passage mutations; instead a high frequency mutation was selected in envelope protein gQ2, part of the gH/gL complex essential for herpesvirus infection. This introduced a stop codon encoding a truncation mutation previously observed in increased virion production. There was reduced detection of the glycoprotein complex in infected cells. This supports a novel pathway for K21 targeting virion envelopes distinct from replication inhibition. Copyright © 2017 The Authors. Published by Elsevier B.V. All rights reserved.

  5. Generation of a non-transmissive Borna disease virus vector lacking both matrix and glycoprotein genes.

    Science.gov (United States)

    Fujino, Kan; Yamamoto, Yusuke; Daito, Takuji; Makino, Akiko; Honda, Tomoyuki; Tomonaga, Keizo

    2017-09-01

    Borna disease virus (BoDV), a prototype of mammalian bornavirus, is a non-segmented, negative strand RNA virus that often causes severe neurological disorders in infected animals, including horses and sheep. Unique among animal RNA viruses, BoDV transcribes and replicates non-cytopathically in the cell nucleus, leading to establishment of long-lasting persistent infection. This striking feature of BoDV indicates its potential as an RNA virus vector system. It has previously been demonstrated by our team that recombinant BoDV (rBoDV) lacking an envelope glycoprotein (G) gene develops persistent infections in transduced cells without loss of the viral genome. In this study, a novel non-transmissive rBoDV, rBoDV ΔMG, which lacks both matrix (M) and G genes in the genome, is reported. rBoDV-ΔMG expressing green fluorescence protein (GFP), rBoDV ΔMG-GFP, was efficiently generated in Vero/MG cells stably expressing both BoDV M and G proteins. Infection with rBoDV ΔMG-GFP was persistently maintained in the parent Vero cells without propagation within cell culture. The optimal ratio of M and G for efficient viral particle production by transient transfection of M and G expression plasmids into cells persistently infected with rBoDV ΔMG-GFP was also demonstrated. These findings indicate that the rBoDV ΔMG-based BoDV vector may provide an extremely safe virus vector system and could be a novel strategy for investigating the function of M and G proteins and the host range of bornaviruses. © 2017 The Societies and John Wiley & Sons Australia, Ltd.

  6. Multiple genes encode the major surface glycoprotein of Pneumocystis carinii

    DEFF Research Database (Denmark)

    Kovacs, J A; Powell, F; Edman, J C

    1993-01-01

    The major surface antigen of Pneumocystis carinii, a life-threatening opportunistic pathogen in human immunodeficiency virus-infected patients, is an abundant glycoprotein that functions in host-organism interactions. A monoclonal antibody to this antigen is protective in animals, and thus this a...

  7. Molecular cloning of S1 glycoprotein gene of infectious bronchitis ...

    African Journals Online (AJOL)

    In vitro protein expression is an important method of obtaining large amounts of viral proteins to investigate their biological properties. The S1 glycoprotein of infectious bronchitis virus, due to its effective immune-dominant role is an appropriate candidate for production of recombinant vaccine against infectious bronchitis ...

  8. The promoter for a variant surface glycoprotein gene expression site in Trypanosoma brucei

    NARCIS (Netherlands)

    Zomerdijk, J. C.; Ouellette, M.; ten Asbroek, A. L.; Kieft, R.; Bommer, A. M.; Clayton, C. E.; Borst, P.

    1990-01-01

    The variant-specific surface glycoprotein (VSG) gene 221 of Trypanosoma brucei is transcribed as part of a 60 kb expression site (ES). We have identified the promoter controlling this multigene transcription unit by the use of 221 chromosome-enriched DNA libraries and VSG gene 221 expression site

  9. N-terminal substitutions in HIV-1 gp41 reduce the expression of non-trimeric envelope glycoproteins on the virus

    International Nuclear Information System (INIS)

    Dey, Antu K.; David, Kathryn B.; Ray, Neelanjana; Ketas, Thomas J.; Klasse, Per J.; Doms, Robert W.; Moore, John P.

    2008-01-01

    The native, functional HIV-1 envelope glycoprotein (Env) complex is a trimer of two non-covalently associated subunits: the gp120 surface glycoprotein and the gp41 transmembrane glycoprotein. However, various non-functional forms of Env are present on virus particles and HIV-1-infected cells, some of which probably arise as the native complex decays. The aberrant forms include gp120-gp41 monomers and oligomers, as well as gp41 subunits from which gp120 has dissociated. The presence of non-functional Env creates binding sites for antibodies that do not recognize native Env complexes and that are, therefore, non-neutralizing. Non-native Env forms (monomers, dimers, tetramers and aggregates) can also arise when soluble gp140 proteins, lacking the cytoplasmic and transmembrane domains of gp41, are expressed for vaccine studies. We recently identified five amino acids in the gp41 N-terminal region (I535, Q543, S553, K567 and R588) that promote gp140 trimerization. We have now studied their influence on the function and antigenic properties of JR-FL Env expressed on the surfaces of pseudoviruses and Env-transfected cells. The 5 substitutions in gp41 reduce the expression of non-trimeric gp160s, without affecting trimer levels. Pseudovirions bearing the mutant Env are fully infectious with similar kinetics of Env-mediated fusion. Various non-neutralizing antibodies bind less strongly to the Env mutant, but neutralizing antibody binding is unaffected. Hence the gp41 substitutions do not adversely affect Env structure, supporting their use for making new Env-based vaccines. The mutant Env might also help in studies intended to correlate antibody binding to virus neutralization. Of note is that the 5 residues are much more frequent, individually or collectively, in viruses from subtypes other than B

  10. Ninety-five- and 25-kDa fragments of the human immunodeficiency virus envelope glycoprotein gp120 bind to the CD4 receptor

    International Nuclear Information System (INIS)

    Nygren, A.; Bergman, T.; Matthews, T.; Joernvall, H.; Wigzell, H.

    1988-01-01

    Iodine-125-labeled gp120 (120-kDa envelope glycoprotein) from the BH10 isolate of human immunodeficiency virus is cleaved to a limited extend with the glutamate-specific protease from Staphylococcus aureus. After disulfide bond reduction, fragments with approximate molecular masses of 95, 60, 50, and 25 kDa are produced. Tests for binding to CD4-positive cells show that only two fragments, the 95- and 25- kDa peptides, are observed in cleavage products that retain the selective binding capacity of gp120. Radiosequence analysis of the fragments after sodium dodecyl sulfate/polyacrylamide gel electrophoresis and electroblotting demonstrates that the 95-kDa fragment lacks the N-terminal region of gp120 and starts at position 143 of the mature envelope protein. The 50-kDa fragment starts at the same position. The 25-kDa binding fragment was similarly deduced to be generated as a small fragment from a cleavage site in the C-terminal part of gp120. The identifications of these fragments demonstrate that radiosequence analysis utilizing 125 I-labeled tyrosine residues can function as a useful and reliable method for small-scale determination of cleavage sites in proteins. Combined, the data suggest domain-like subdivisions of gp120, define at least two intervening segments especially sensitive to proteolytic cleavage, and demonstrate the presence of a functional region for receptor binding in the C-terminal part of the molecule

  11. Variations in Spike Glycoprotein Gene of MERS-CoV, South Korea, 2015.

    Science.gov (United States)

    Kim, Dae-Won; Kim, You-Jin; Park, Sung Han; Yun, Mi-Ran; Yang, Jeong-Sun; Kang, Hae Ji; Han, Young Woo; Lee, Han Saem; Kim, Heui Man; Kim, Hak; Kim, A-Reum; Heo, Deok Rim; Kim, Su Jin; Jeon, Jun Ho; Park, Deokbum; Kim, Joo Ae; Cheong, Hyang-Min; Nam, Jeong-Gu; Kim, Kisoon; Kim, Sung Soon

    2016-01-01

    An outbreak of nosocomial infections with Middle East respiratory syndrome coronavirus occurred in South Korea in May 2015. Spike glycoprotein genes of virus strains from South Korea were closely related to those of strains from Riyadh, Saudi Arabia. However, virus strains from South Korea showed strain-specific variations.

  12. Highly efficient retrograde gene transfer into motor neurons by a lentiviral vector pseudotyped with fusion glycoprotein.

    Directory of Open Access Journals (Sweden)

    Miyabi Hirano

    Full Text Available The development of gene therapy techniques to introduce transgenes that promote neuronal survival and protection provides effective therapeutic approaches for neurological and neurodegenerative diseases. Intramuscular injection of adenoviral and adeno-associated viral vectors, as well as lentiviral vectors pseudotyped with rabies virus glycoprotein (RV-G, permits gene delivery into motor neurons in animal models for motor neuron diseases. Recently, we developed a vector with highly efficient retrograde gene transfer (HiRet by pseudotyping a human immunodeficiency virus type 1 (HIV-1-based vector with fusion glycoprotein B type (FuG-B or a variant of FuG-B (FuG-B2, in which the cytoplasmic domain of RV-G was replaced by the corresponding part of vesicular stomatitis virus glycoprotein (VSV-G. We have also developed another vector showing neuron-specific retrograde gene transfer (NeuRet with fusion glycoprotein C type, in which the short C-terminal segment of the extracellular domain and transmembrane/cytoplasmic domains of RV-G was substituted with the corresponding regions of VSV-G. These two vectors afford the high efficiency of retrograde gene transfer into different neuronal populations in the brain. Here we investigated the efficiency of the HiRet (with FuG-B2 and NeuRet vectors for retrograde gene transfer into motor neurons in the spinal cord and hindbrain in mice after intramuscular injection and compared it with the efficiency of the RV-G pseudotype of the HIV-1-based vector. The main highlight of our results is that the HiRet vector shows the most efficient retrograde gene transfer into both spinal cord and hindbrain motor neurons, offering its promising use as a gene therapeutic approach for the treatment of motor neuron diseases.

  13. Induction of antibodies against epitopes inaccessible on the HIV type 1 envelope oligomer by immunization with recombinant monomeric glycoprotein 120

    DEFF Research Database (Denmark)

    Schønning, Kristian; Bolmstedt, A; Novotny, J

    1998-01-01

    An N-glycan (N306) at the base of the V3 loop of HIV-BRU gp120 is shielding a linear neutralization epitope at the tip of the V3 loop on oligomeric Env. In contrast, this epitope is readily antigenic on monomeric gp120. Immunization with recombinant monomeric HIV-BRU gp120 may thus be expected...... immunogenic structures inaccessible on the envelope oligomer. The limited ability of recombinant gp120 vaccines to induce neutralizing antibodies against primary isolates may thus not exclusively reflect genetic variation....

  14. Host cell virus entry mediated by Australian bat lyssavirus G envelope glycoprotein occurs through a clathrin-mediated endocytic pathway that requires actin and Rab5.

    Science.gov (United States)

    Weir, Dawn L; Laing, Eric D; Smith, Ina L; Wang, Lin-Fa; Broder, Christopher C

    2014-02-27

    Australian bat lyssavirus (ABLV), a rhabdovirus of the genus Lyssavirus which circulates in both pteropid fruit bats and insectivorous bats in mainland Australia, has caused three fatal human infections, the most recent in February 2013, manifested as acute neurological disease indistinguishable from clinical rabies. Rhabdoviruses infect host cells through receptor-mediated endocytosis and subsequent pH-dependent fusion mediated by their single envelope glycoprotein (G), but the specific host factors and pathways involved in ABLV entry have not been determined. ABLV internalization into HEK293T cells was examined using maxGFP-encoding recombinant vesicular stomatitis viruses (rVSV) that express ABLV G glycoproteins. A combination of chemical and molecular approaches was used to investigate the contribution of different endocytic pathways to ABLV entry. Dominant negative Rab GTPases were used to identify the endosomal compartment utilized by ABLV to gain entry into the host cell cytosol. Here we show that ABLV G-mediated entry into HEK293T cells was significantly inhibited by the dynamin-specific inhibitor dynasore, chlorpromazine, a drug that blocks clathrin-mediated endocytosis, and the actin depolymerizing drug latrunculin B. Over expression of dominant negative mutants of Eps15 and Rab5 also significantly reduced ABLV G-mediated entry into HEK293T cells. Chemical inhibitors of caveolae-dependent endocytosis and macropinocytosis and dominant negative mutants of Rab7 and Rab11 had no effect on ABLV entry. The predominant pathway utilized by ABLV for internalization into HEK293T cells is clathrin-and actin-dependent. The requirement of Rab5 for productive infection indicates that ABLV G-mediated fusion occurs within the early endosome compartment.

  15. Molecular characterisation of the nucleocapsid protein gene, glycoprotein gene and gene junctions of rhabdovirus 903/87, a novel fish pathogenic rhabdovirus

    DEFF Research Database (Denmark)

    Johansson, Tove; Nylund, S.; Olesen, Niels Jørgen

    2001-01-01

    , M, G and L genes it was determined that transcription start and stop codons were conserved between virus 903/87 and the vesiculo viruses. Virus 903/87 has no open reading frame coding for a non-virion gene between the glycoprotein and the polymerase gene. Phylogenetic studies based on rhabdovirus...

  16. Identification of glycosylation sites in the SU component of the Avian Sarcoma/Leukosis virus Envelope Glycoprotein (Subgroup A) by mass spectrometry

    International Nuclear Information System (INIS)

    Kvaratskhelia, Mamuka; Clark, Patrick K.; Hess, Sonja; Melder, Deborah C.; Federspiel, Mark J.; Hughes, Stephen H.

    2004-01-01

    We used enzymatic digestion and mass spectrometry to identify the sites of glycosylation on the SU component of the Avian Sarcoma/Leukosis virus (ASLV) Envelope Glycoprotein (Subgroup A). The analysis was done with an SU(A)-rIgG fusion protein that binds the cognate receptor (Tva) specifically. PNGase F removed all the carbohydrate from the SU(A)-rIgG fusion. PNGase F is specific for N-linked carbohydrates; this shows that all the carbohydrate on SU(A) is N-linked. There are 10 modified aspargines in SU(A) (N17, N59, N80, N97, N117, N196, N230, N246, N254, and N330). All conform to the consensus site for N-linked glycosylation NXS/T. There is one potential glycosylation site (N236) that is not modified. Removing most of the carbohydrate from the mature SU(A)-rIgG by PNGase F treatment greatly reduces the ability of the protein to bind Tva, suggesting that carbohydrate may play a direct role in receptor binding

  17. The impact of envelope glycoprotein cleavage on the antigenicity, infectivity, and neutralization sensitivity of Env-pseudotyped human immunodeficiency virus type 1 particles

    International Nuclear Information System (INIS)

    Herrera, Carolina; Klasse, Per Johan; Michael, Elizabeth; Kake, Shivani; Barnes, Kelly; Kibler, Christopher W.; Campbell-Gardener, Lila; Si, Zhihai; Sodroski, Joseph; Moore, John P.; Beddows, Simon

    2005-01-01

    Endoproteolytic processing of the human immunodeficiency virus type 1 (HIV-1) envelope (Env) glycoproteins is an obligate part of the biosynthetic pathway that generates functional, fusion-competent Env complexes, which are then incorporated into infectious virions. We have examined the influence of cleavage on Env-specific antibody reactivity, Env incorporation into pseudovirions, and the infectivity and neutralization sensitivity of Env-pseudotyped viruses. To do so, we have used both incompletely processed wild-type (Wt) Env and engineered, cleavage-defective Env mutants. We find that there is no simple association between antibody reactivity to cell surface-expressed Env, and the ability of the same antibody to neutralize virus pseudotyped with the same Env proteins. One explanation for the absence of such an association is the diverse array of Env species present on the surface of transiently transfected cells. We also confirm that cleavage-defective mutants are antigenically different from Wt Env. These findings have implications for the use of Env binding assays as predictors of neutralizing activity, and for the development of cleavage-defective Env trimers for use as subunit immunogens

  18. Mechanistic Insight into Bunyavirus-Induced Membrane Fusion from Structure-Function Analyses of the Hantavirus Envelope Glycoprotein Gc.

    Directory of Open Access Journals (Sweden)

    Pablo Guardado-Calvo

    2016-10-01

    Full Text Available Hantaviruses are zoonotic viruses transmitted to humans by persistently infected rodents, giving rise to serious outbreaks of hemorrhagic fever with renal syndrome (HFRS or of hantavirus pulmonary syndrome (HPS, depending on the virus, which are associated with high case fatality rates. There is only limited knowledge about the organization of the viral particles and in particular, about the hantavirus membrane fusion glycoprotein Gc, the function of which is essential for virus entry. We describe here the X-ray structures of Gc from Hantaan virus, the type species hantavirus and responsible for HFRS, both in its neutral pH, monomeric pre-fusion conformation, and in its acidic pH, trimeric post-fusion form. The structures confirm the prediction that Gc is a class II fusion protein, containing the characteristic β-sheet rich domains termed I, II and III as initially identified in the fusion proteins of arboviruses such as alpha- and flaviviruses. The structures also show a number of features of Gc that are distinct from arbovirus class II proteins. In particular, hantavirus Gc inserts residues from three different loops into the target membrane to drive fusion, as confirmed functionally by structure-guided mutagenesis on the HPS-inducing Andes virus, instead of having a single "fusion loop". We further show that the membrane interacting region of Gc becomes structured only at acidic pH via a set of polar and electrostatic interactions. Furthermore, the structure reveals that hantavirus Gc has an additional N-terminal "tail" that is crucial in stabilizing the post-fusion trimer, accompanying the swapping of domain III in the quaternary arrangement of the trimer as compared to the standard class II fusion proteins. The mechanistic understandings derived from these data are likely to provide a unique handle for devising treatments against these human pathogens.

  19. Phage-Displayed Peptides Selected to Bind Envelope Glycoprotein Show Antiviral Activity against Dengue Virus Serotype 2

    Directory of Open Access Journals (Sweden)

    Carolina de la Guardia

    2017-01-01

    Full Text Available Dengue virus is a growing public health threat that affects hundreds of million peoples every year and leave huge economic and social damage. The virus is transmitted by mosquitoes and the incidence of the disease is increasing, among other causes, due to the geographical expansion of the vector’s range and the lack of effectiveness in public health interventions in most prevalent countries. So far, no highly effective vaccine or antiviral has been developed for this virus. Here we employed phage display technology to identify peptides able to block the DENV2. A random peptide library presented in M13 phages was screened with recombinant dengue envelope and its fragment domain III. After four rounds of panning, several binding peptides were identified, synthesized, and tested against the virus. Three peptides were able to block the infectivity of the virus while not being toxic to the target cells. Blind docking simulations were done to investigate the possible mode of binding, showing that all peptides appear to bind domain III of the protein and may be mostly stabilized by hydrophobic interactions. These results are relevant to the development of novel therapeutics against this important virus.

  20. Recurrent signature patterns in HIV-1 B clade envelope glycoproteins associated with either early or chronic infections.

    Directory of Open Access Journals (Sweden)

    S Gnanakaran

    2011-09-01

    Full Text Available Here we have identified HIV-1 B clade Envelope (Env amino acid signatures from early in infection that may be favored at transmission, as well as patterns of recurrent mutation in chronic infection that may reflect common pathways of immune evasion. To accomplish this, we compared thousands of sequences derived by single genome amplification from several hundred individuals that were sampled either early in infection or were chronically infected. Samples were divided at the outset into hypothesis-forming and validation sets, and we used phylogenetically corrected statistical strategies to identify signatures, systematically scanning all of Env. Signatures included single amino acids, glycosylation motifs, and multi-site patterns based on functional or structural groupings of amino acids. We identified signatures near the CCR5 co-receptor-binding region, near the CD4 binding site, and in the signal peptide and cytoplasmic domain, which may influence Env expression and processing. Two signatures patterns associated with transmission were particularly interesting. The first was the most statistically robust signature, located in position 12 in the signal peptide. The second was the loss of an N-linked glycosylation site at positions 413-415; the presence of this site has been recently found to be associated with escape from potent and broad neutralizing antibodies, consistent with enabling a common pathway for immune escape during chronic infection. Its recurrent loss in early infection suggests it may impact fitness at the time of transmission or during early viral expansion. The signature patterns we identified implicate Env expression levels in selection at viral transmission or in early expansion, and suggest that immune evasion patterns that recur in many individuals during chronic infection when antibodies are present can be selected against when the infection is being established prior to the adaptive immune response.

  1. Sequential and Simultaneous Immunization of Rabbits with HIV-1 Envelope Glycoprotein SOSIP.664 Trimers from Clades A, B and C

    NARCIS (Netherlands)

    Klasse, P. J.; LaBranche, Celia C.; Ketas, Thomas J.; Ozorowski, Gabriel; Cupo, Albert; Pugach, Pavel; Ringe, Rajesh P.; Golabek, Michael; van Gils, Marit J.; Guttman, Miklos; Lee, Kelly K.; Wilson, Ian A.; Butera, Salvatore T.; Ward, Andrew B.; Montefiori, David C.; Sanders, Rogier W.; Moore, John P.

    2016-01-01

    We have investigated the immunogenicity in rabbits of native-like, soluble, recombinant SOSIP.664 trimers based on the env genes of four isolates of human immunodeficiency virus type 1 (HIV-1); specifically BG505 (clade A), B41 (clade B), CZA97 (clade C) and DU422 (clade C). The various trimers were

  2. Conditional expression of the vesicular stomatitis virus glycoprotein gene in Escherichia coli.

    OpenAIRE

    Rose, J K; Shafferman, A

    1981-01-01

    Bacterial plasmids that directed expression of the vesicular stomatitis virus glycoprotein (G-protein) gene under control of the tryptophan operon regulatory region were constructed. A plasmid directing the synthesis of a G-protein-like protein (containing the NH2-terminal segment of seven amino acids encoded by the trpE gene fused to the complete G-protein sequence lacking only its NH2-terminal methionine) could be transformed into trpR+ (repressed) but not into trpR- (derepressed) cells. Th...

  3. Genetic characterization of complete open reading frame of glycoprotein C gene of bovine herpesvirus 1

    Directory of Open Access Journals (Sweden)

    Saurabh Majumder

    2013-10-01

    Full Text Available Aim: To characterize one of the major glycoprotein genes viz., glycoprotein C (gC; UL44, unique long region 44 of bovineherpesvirus 1(BoHV1 of Indian origin at genetic and phylogenetic level.Materials and Methods: A bovine herpesvirus 1 isolate viz., (BoHV1/IBR 216 II/ 1976/ India maintained at Division ofVirology, IVRI, Mukteswar was used for the current study. The DNA was extracted using commercial kit and the completeORF of gC gene was amplified, cloned, and sequenced by conventional Sanger sequencing method. The sequence wasgenetically and phylogenetically analysed using various bioinformatic tools. The sequence was submitted in the Genbankwith accession number Kc756965.Results: The complete ORF of gC gene was amplified and sequenced. It showed 100% sequence homology with referencecooper strain of BoHV1 and divergence varied from 0% to 2.7% with other isolates of BoHV1. The isolate under study haddivergence of 9.2%, 13%, 26.6%, and 9.2% with BoHV5 (Bovine herpesvirus 5, CvHV1 (Cervid herpesvirus 1, CpHV1(Caprine herpesvirus 1, and BuHV1 (Bubaline herpesvirus 1, respectively.Conclusion: This is the first genetic characterization of complete open reading frame (ORF of glycoprotein C gene (UL44 ofIndian isolate of BoHV1. The gC gene of BoHV1 is highly conserved among all BoHV1 isolates and it can be used as a targetfor designing diagnostic primers for the specific detection of BoHV1.

  4. Fusion proteins of HIV-1 envelope glycoprotein gp120 with CD4-induced antibodies showed enhanced binding to CD4 and CD4 binding site antibodies

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Weizao, E-mail: chenw3@mail.nih.gov [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Feng, Yang [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Wang, Yanping [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); The Basic Research Program, Science Applications International Corporation-Frederick, Inc., National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States); Zhu, Zhongyu; Dimitrov, Dimiter S. [Protein Interactions Group, Frederick National Laboratory for Cancer Research, National Cancer Institute, National Institutes of Health, Frederick, MD 21702 (United States)

    2012-09-07

    Highlights: Black-Right-Pointing-Pointer Some recombinant HIV-1 gp120s do not preserve their conformations on gp140s. Black-Right-Pointing-Pointer We hypothesize that CD4i antibodies could induce conformational changes in gp120. Black-Right-Pointing-Pointer CD4i antibodies enhance binding of CD4 and CD4bs antibodies to gp120. Black-Right-Pointing-Pointer CD4i antibody-gp120 fusion proteins could have potential as vaccine immunogens. -- Abstract: Development of successful AIDS vaccine immunogens continues to be a major challenge. One of the mechanisms by which HIV-1 evades antibody-mediated neutralizing responses is the remarkable conformational flexibility of its envelope glycoprotein (Env) gp120. Some recombinant gp120s do not preserve their conformations on gp140s and functional viral spikes, and exhibit decreased recognition by CD4 and neutralizing antibodies. CD4 binding induces conformational changes in gp120 leading to exposure of the coreceptor-binding site (CoRbs). In this study, we test our hypothesis that CD4-induced (CD4i) antibodies, which target the CoRbs, could also induce conformational changes in gp120 leading to better exposed conserved neutralizing antibody epitopes including the CD4-binding site (CD4bs). We found that a mixture of CD4i antibodies with gp120 only weakly enhanced CD4 binding. However, such interactions in single-chain fusion proteins resulted in gp120 conformations which bound to CD4 and CD4bs antibodies better than the original or mutagenically stabilized gp120s. Moreover, the two molecules in the fusion proteins synergized with each other in neutralizing HIV-1. Therefore, fusion proteins of gp120 with CD4i antibodies could have potential as components of HIV-1 vaccines and inhibitors of HIV-1 entry, and could be used as reagents to explore the conformational flexibility of gp120 and mechanisms of entry and immune evasion.

  5. Dominant-negative effect of hetero-oligomerization on the function of the human immunodeficiency virus type 1 envelope glycoprotein complex

    International Nuclear Information System (INIS)

    Herrera, Carolina; Klasse, Per Johan; Kibler, Christopher W.; Michael, Elizabeth; Moore, John P.; Beddows, Simon

    2006-01-01

    The human immunodeficiency virus type 1 (HIV-1) envelope (Env) glycoprotein forms trimers that mediate interactions with the CD4 receptor and a co-receptor on the target cell surface, thereby triggering viral fusion with the cell membrane. Cleavage of Env into its surface, gp120, and transmembrane, gp41, moieties is necessary for activation of its fusogenicity. Here, we produced pseudoviruses with phenotypically mixed wild-type (Wt) and mutant, cleavage-incompetent Env in order to quantify the effects of incorporating uncleaved Env on virion infectivity, antigenicity and neutralization sensitivity. We modeled the relative infectivity of three such phenotypically mixed viral strains, JR-FL, HXBc2 and a derivative of the latter, 3.2P, as a function of the relative amount of Wt Env. The data were fit very closely (R 2 > 0.99) by models which assumed that only Wt homotrimers were functional, with different approximate thresholds of critical numbers of functional trimers per virion for the three strains. We also produced 3.2P pseudoviruses containing both a cleavage-competent Env that is defective for binding the neutralizing monoclonal antibody (NAb) 2G12, and a cleavage-incompetent Env that binds 2G12. The 2G12 NAb was not able to reduce the infectivity of these pseudoviruses detectably. Their neutralization by the CD4-binding site-directed agents CD4-IgG2 and NAb b12 was also unaffected by 2G12 binding to uncleaved Env. These results further strengthen the conclusion that only homotrimers consisting of cleaved Env are functional. They also imply that the function of a trimer is unaffected sterically by the binding of an antibody to an adjacent trimer

  6. Differential Recognition of Old World and New World Arenavirus Envelope Glycoproteins by Subtilisin Kexin Isozyme 1 (SKI-1)/Site 1 Protease (S1P)

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    Burri, Dominique J.; Ramos da Palma, Joel; Seidah, Nabil G.; Zanotti, Giuseppe; Cendron, Laura

    2013-01-01

    The arenaviruses are an important family of emerging viruses that includes several causative agents of severe hemorrhagic fevers in humans that represent serious public health problems. A crucial step of the arenavirus life cycle is maturation of the envelope glycoprotein precursor (GPC) by the cellular subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P). Comparison of the currently known sequences of arenavirus GPCs revealed the presence of a highly conserved aromatic residue at position P7 relative to the SKI-1/S1P cleavage side in Old World and clade C New World arenaviruses but not in New World viruses of clades A and B or cellular substrates of SKI-1/S1P. Using a combination of molecular modeling and structure-function analysis, we found that residueY285 of SKI-1/S1P, distal from the catalytic triad, is implicated in the molecular recognition of the aromatic “signature residue” at P7 in the GPC of Old World Lassa virus. Using a quantitative biochemical approach, we show that Y285 of SKI-1/S1P is crucial for the efficient processing of peptides derived from Old World and clade C New World arenavirus GPCs but not of those from clade A and B New World arenavirus GPCs. The data suggest that during coevolution with their mammalian hosts, GPCs of Old World and clade C New World viruses expanded the molecular contacts with SKI-1/S1P beyond the classical four-amino-acid recognition sequences and currently occupy an extended binding pocket. PMID:23536681

  7. A single site for N-linked glycosylation in the envelope glycoprotein of feline immunodeficiency virus modulates the virus-receptor interaction

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    Samman Ayman

    2008-08-01

    Full Text Available Abstract Feline immunodeficiency virus (FIV targets helper T cells by attachment of the envelope glycoprotein (Env to CD134, a subsequent interaction with CXCR4 then facilitating the process of viral entry. As the CXCR4 binding site is not exposed until CD134-binding has occurred then the virus is protected from neutralising antibodies targeting the CXCR4-binding site on Env. Prototypic FIV vaccines based on the FL4 strain of FIV contain a cell culture-adapted strain of FIV Petaluma, a CD134-independent strain of FIV that interacts directly with CXCR4. In addition to a characteristic increase in charge in the V3 loop homologue of FIVFL4, we identified two mutations in potential sites for N-linked glycosylation in the region of FIV Env analogous to the V1–V2 region of HIV and SIV Env, T271I and N342Y. When these mutations were introduced into the primary GL8 and CPG41 strains of FIV, the T271I mutation was found to alter the nature of the virus-CD134 interaction; primary viruses carrying the T271I mutation no longer required determinants in cysteine-rich domain (CRD 2 of CD134 for viral entry. The T271I mutation did not confer CD134-independent infection upon GL8 or CPG41, nor did it increase the affinity of the CXCR4 interaction, suggesting that the principal effect was targeted at reducing the complexity of the Env-CD134 interaction.

  8. Use of λgt11 to isolate genes for two pseudorabies virus glycoproteins with homology to herpes simplex virus and varicella-zoster virus glycoproteins

    International Nuclear Information System (INIS)

    Petrovskis, E.A.; Timmins, J.G.; Post, L.E.

    1986-01-01

    A library of pseudorabies virus (PRV) DNA fragments was constructed in the expression cloning vector λgt11. The library was screened with antisera which reacted with mixtures of PRV proteins to isolate recombinant bacteriophages expressing PRV proteins. By the nature of the λgt11 vector, the cloned proteins were expressed in Escherichia coli as β-galactosidase fusion proteins. The fusion proteins from 35 of these phages were purified and injected into mice to raise antisera. The antisera were screened by several different assays, including immunoprecipitation of [ 14 C]glucosamine-labeled PRV proteins. This method identified phages expressing three different PRV glycoproteins: the secreted glycoprotein, gX; gI; and a glycoprotein that had not been previously identified, which we designate gp63. The gp63 and gI genes map adjacent to each other in the small unique region of the PRV genome. The DNA sequence was determined for the region of the genome encoding gp63 and gI. It was found that gp63 has a region of homology with a herpes simplex virus type 1 (HSV-1) protein, encoded by US7, and also with varicella-zoster virus (VZV) gpIV. The gI protein sequence has a region of homology with HSV-1 gE and VZV gpI. It is concluded that PRV, HSV, and VZV all have a cluster of homologous glycoprotein genes in the small unique components of their genomes and that the organization of these genes is conserved

  9. The glycoprotein genes and gene junctions of the fish rhabdoviruses spring viremia of carp virus and hirame rhabdovirus: Analysis of relationships with other rhabdoviruses

    Science.gov (United States)

    Bjorklund, H.V.; Higman, K.H.; Kurath, G.

    1996-01-01

    The nucleotide sequences of the glycoprotein genes and all of the internal gene junctions of the fish pathogenic rhabdoviruses spring viremia of carp virus (SVCV) and hirame rhabdovirus (HIRRV) have been determined from cDNA clones generated from viral genomic RNA. The SVCV glycoprotein gene sequence is 1588 nucleotides (nt) long and encodes a 509 amino acid (aa) protein. The HIRRV glycoprotein gene sequence comprises 1612 nt, coding for a 508 aa protein. In sequence comparisons of 15 rhabdovirus glycoproteins, the SVCV glycoprotein gene showed the highest amino acid sequence identity (31.2–33.2%) with vesicular stomatitis New Jersey virus (VSNJV), Chandipura virus (CHPV) and vesicular stomatitis Indiana virus (VSIV). The HIRRV glycoprotein gene showed a very high amino acid sequence identity (74.3%) with the glycoprotein gene of another fish pathogenic rhabdovirus, infectious hematopoietic necrosis virus (IHNV), but no significant similarity with glycoproteins of VSIV or rabies virus (RABV). In phylogenetic analyses SVCV was grouped consistently with VSIV, VSNJV and CHPV in the Vesiculovirus genus of Rhabdoviridae. The fish rhabdoviruses HIRRV, IHNV and viral hemorrhagic septicemia virus (VHSV) showed close relationships with each other, but only very distant relationships with mammalian rhabdoviruses. The gene junctions are highly conserved between SVCV and VSIV, well conserved between IHNV and HIRRV, but not conserved between HIRRV/IHNV and RABV. Based on the combined results we suggest that the fish lyssa-type rhabdoviruses HIRRV, IHNV and VHSV may be grouped in their own genus within the family Rhabdoviridae. Aquarhabdovirus has been proposed for the name of this new genus.

  10. Asn 362 in gp120 contributes to enhanced fusogenicity by CCR5-restricted HIV-1 envelope glycoprotein variants from patients with AIDS

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    Wang Bin

    2007-12-01

    Full Text Available Abstract Background CCR5-restricted (R5 human immunodeficiency virus type 1 (HIV-1 variants cause CD4+ T-cell loss in the majority of individuals who progress to AIDS, but mechanisms underlying the pathogenicity of R5 strains are poorly understood. To better understand envelope glycoprotein (Env determinants contributing to pathogenicity of R5 viruses, we characterized 37 full-length R5 Envs from cross-sectional and longitudinal R5 viruses isolated from blood of patients with asymptomatic infection or AIDS, referred to as pre-AIDS (PA and AIDS (A R5 Envs, respectively. Results Compared to PA-R5 Envs, A-R5 Envs had enhanced fusogenicity in quantitative cell-cell fusion assays, and reduced sensitivity to inhibition by the fusion inhibitor T-20. Sequence analysis identified the presence of Asn 362 (N362, a potential N-linked glycosylation site immediately N-terminal to CD4-binding site (CD4bs residues in the C3 region of gp120, more frequently in A-R5 Envs than PA-R5 Envs. N362 was associated with enhanced fusogenicity, faster entry kinetics, and increased sensitivity of Env-pseudotyped reporter viruses to neutralization by the CD4bs-directed Env mAb IgG1b12. Mutagenesis studies showed N362 contributes to enhanced fusogenicity of most A-R5 Envs. Molecular models indicate N362 is located adjacent to the CD4 binding loop of gp120, and suggest N362 may enhance fusogenicity by promoting greater exposure of the CD4bs and/or stabilizing the CD4-bound Env structure. Conclusion Enhanced fusogenicity is a phenotype of the A-R5 Envs studied, which was associated with the presence of N362, enhanced HIV-1 entry kinetics and increased CD4bs exposure in gp120. N362 contributes to fusogenicity of R5 Envs in a strain dependent manner. Our studies suggest enhanced fusogenicity of A-R5 Envs may contribute to CD4+ T-cell loss in subjects who progress to AIDS whilst harbouring R5 HIV-1 variants. N362 may contribute to this effect in some individuals.

  11. Mutations increasing exposure of a receptor binding site epitope in the soluble and oligomeric forms of the caprine arthritis-encephalitis lentivirus envelope glycoprotein

    International Nuclear Information System (INIS)

    Hoetzel, Isidro; Cheevers, William P.

    2005-01-01

    The caprine arthritis-encephalitis (CAEV) and ovine maedi-visna (MVV) viruses are resistant to antibody neutralization, a feature shared with all other lentiviruses. Whether the CAEV gp135 receptor binding site(s) (RBS) in the functional surface envelope glycoprotein (Env) is protected from antibody binding, allowing the virus to resist neutralization, is not known. Two CAEV gp135 regions were identified by extrapolating a gp135 structural model that could affect binding of antibodies to the RBS: the V1 region and a short sequence analogous in position to the human immunodeficiency virus type 1 gp120 loop B postulated to be located between two major domains of CAEV gp135. Mutation of isoleucine-166 to alanine in the putative loop B of gp135 increased the affinity of soluble gp135 for the CAEV receptor(s) and goat monoclonal antibody (Mab) F7-299 which recognizes an epitope overlapping the gp135 RBS. The I166A mutation also stabilized or exposed the F7-299 epitope in anionic detergent buffers, indicating that the I166A mutation induces conformational changes and stabilizes the RBS of soluble gp135 and enhances Mab F7-299 binding. In contrast, the affinity of a V1 deletion mutant of gp135 for the receptor and Mab F7-299 and its structural stability did not differ from that of the wild-type gp135. However, both the I166A mutation and the V1 deletion of gp135 increased cell-to-cell fusion activity and binding of Mab F7-299 to the oligomeric Env. Therefore, the CAEV gp135 RBS is protected from antibody binding by mechanisms both dependent and independent of Env oligomerization which are disrupted by the V1 deletion and the I166A mutation, respectively. In addition, we found a correlation between side-chain β-branching at amino acid position 166 and binding of Mab F7-299 to oligomeric Env and cell-to-cell fusion, suggesting local secondary structure constraints in the region around isoleucine-166 as one determinant of gp135 RBS exposure and antibody binding

  12. Immunization of rabbits with highly purified, soluble, trimeric human immunodeficiency virus type 1 envelope glycoprotein induces a vigorous B cell response and broadly cross-reactive neutralization.

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    Gerald V Quinnan

    Full Text Available Previously we described induction of cross-reactive HIV-1 neutralizing antibody responses in rabbits using a soluble HIV-1 gp140 envelope glycoprotein (Env in an adjuvant containing monophosphoryl lipid A (MPL and QS21 (AS02A. Here, we compared different forms of the same HIV-1 strain R2 Env for antigenic and biophysical characteristics, and in rabbits characterized the extent of B cell induction for specific antibody expression and secretion and neutralizing responses. The forms of this Env that were produced in and purified from stably transformed 293T cells included a primarily dimeric gp140, a trimeric gp140 appended to a GCN4 trimerization domain (gp140-GCN4, gp140-GCN4 with a 15 amino acid flexible linker between the gp120 and gp41 ectodomain (gp140-GCN4-L, also trimeric, and a gp140 with the flexible linker purified from cell culture supernatants as either dimer (gp140-L(D or monomer (gp140-L(M. Multimeric states of the Env proteins were assessed by native gel electrophoresis and analytical ultracentrifugation. The different forms of gp140 bound broadly cross-reactive neutralizing (BCN human monoclonal antibodies (mAbs similarly in ELISA and immunoprecipitation assays. All Envs bound CD4i mAbs in the presence and absence of sCD4, as reported for the R2 Env. Weak neutralization of some strains of HIV-1 was seen after two additional doses in AS02A. Rabbits that were given a seventh dose of gp140-GCN4-L developed BCN responses that were weak to moderate, similar to our previous report. The specificity of these responses did not appear similar to that of any of the known BCN human mAbs. Induction of spleen B cell and plasma cells producing immunoglobulins that bound trimeric gp140-GCN4-L was vigorous, based on ELISpot and flow cytometry analyses. The results demonstrate that highly purified gp140-GCN4-L trimer in adjuvant elicits BCN responses in rabbits accompanied by vigorous B cell induction.

  13. Critical amino acids within the human immunodeficiency virus type 1 envelope glycoprotein V4 N- and C-terminals contribute to virus entry.

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    Yan Li

    Full Text Available The importance of the fourth variable (V4 region of the human immunodeficiency virus 1 (HIV-1 envelope glycoprotein (Env in virus infection has not been well clarified, though the polymorphism of this region has been found to be associated with disease progression to acquired immunodeficiency syndrome (AIDS. In the present work, we focused on the correlation between HIV-1 gp120 V4 region polymorphism and the function of the region on virus entry, and the possible mechanisms for how the V4 region contributes to virus infectivity. Therefore, we analyzed the differences in V4 sequences along with coreceptor usage preference from CCR5 to CXCR4 and examined the importance of the amino acids within the V4 region for CCR5- and CXCR4-tropic virus entry. In addition, we determined the influence of the V4 amino acids on Env expression and gp160 processing intracellularly, as well as the amount of Env on the pseudovirus surface. The results indicated that V4 tended to have a shorter length, fewer potential N-linked glycosylation sites (PNGS, greater evolutionary distance, and a lower negative net charge when HIV-1 isolates switched from a coreceptor usage preference for CCR5 to CXCR4. The N- and C-terminals of the HIV-1 V4 region are highly conserved and critical to maintain virus entry ability, but only the mutation at position 417 in the context of ADA (a R5-tropic HIV-1 strain resulted in the ability to utilize CXCR4. In addition, 390L, 391F, 414I, and 416L are critical to maintain gp160 processing and maturation. It is likely that the hydrophobic properties and the electrostatic surface potential of gp120, rather than the conformational structure, greatly contribute to this V4 functionality. The findings provide information to aid in the understanding of the functions of V4 in HIV-1 entry and offer a potential target to aid in the development of entry inhibitors.

  14. Positive evolution of the glycoprotein (GP) gene is related to transmission of the Ebola virus.

    Science.gov (United States)

    Jing, Y X; Wang, L N; Wu, X M; Song, C X

    2016-03-28

    Ebola hemorrhagic fever is a fatal disease caused by the negative-strand RNA of the Ebola virus. A high-intensity outbreak of this fever was reported in West Africa last year; however, there is currently no definitive treatment strategy available for this disease. In this study, we analyzed the molecular evolutionary history and attempted to determine the positive selection sites in the Ebola genes using multiple-genomic sequences of the various Ebola virus subtypes, in order to gain greater clarity into the evolution of the virus and its various subtypes. Only the glycoprotein (GP) gene was positively selected among the 8 Ebola genes, with the other genes remaining in the purification stage. The positive selection sites in the GP gene were identified by a random-site model; these sites were found to be located in the mucin-like region, which is associated with transmembrane protein binding. Additionally, different branches of the phylogenetic tree displayed different positive sites, which in turn was responsible for differences in the cell adhesion ability of the virus. In conclusion, the pattern of positive sites in the GP gene is associated with the epidemiology and prevalence of Ebola in different areas.

  15. Murine and human b locus pigmentation genes encode a glycoprotein (gp75) with catalase activity

    International Nuclear Information System (INIS)

    Halaban, R.; Moellmann, G.

    1990-01-01

    Melanogenesis is regulated in large part by tyrosinase, and defective tyrosinase leads to albinism. The mechanisms for other pigmentation determinants (e.g., those operative in tyrosinase-positive albinism and in murine coat-color mutants) are not yet known. One murine pigmentation gene, the brown (b) locus, when mutated leads to a brown (b/b) or hypopigmentated (B lt /B lt ) coat versus the wild-type black (B/B). The authors show that the b locus codes for a glycoprotein with the activity of a catalase (catalase B). Only the c locus protein is a tyrosinase. Because peroxides may be by-products of melanogenic activity and hydrogen peroxide in particular is known to destroy melanin precursors and melanin, they conclude that pigmentation is controlled not only by tyrosinase but also by a hydroperoxidase. The studies indicate that catalase B is identical with gp75, a known human melanosomal glycoprotein; that the b mutation is in a heme-associated domain; and that the B lt mutation renders the protein susceptible to rapid proteolytic degradation

  16. Glycoprotein gene truncation in avian metapneumovirus subtype C isolates from the United States.

    Science.gov (United States)

    Velayudhan, Binu T; Yu, Qingzhong; Estevez, Carlos N; Nagaraja, Kakambi V; Halvorson, David A

    2008-10-01

    The length of the published glycoprotein (G) gene sequences of avian metapneumovirus subtype-C (aMPV-C) isolated from domestic turkeys and wild birds in the United States (1996-2003) remains controversial. To explore the G gene size variation in aMPV-C by the year of isolation and cell culture passage levels, we examined 21 turkey isolates of aMPV-C at different cell culture passages. The early domestic turkey isolates of aMPV-C (aMPV/CO/1996, aMPV/MN/1a-b, and 2a-b/97) had a G gene of 1,798 nucleotides (nt) that coded for a predicted protein of 585 amino acids (aa) and showed >97% nt similarity with that of aMPV-C isolated from Canada geese. This large G gene got truncated upon serial passages in Vero cell cultures by deletion of 1,015 nt near the end of the open reading frame. The recent domestic turkey isolates of aMPV-C lacked the large G gene but instead had a small G gene of 783 nt, irrespective of cell culture passage levels. In some cultures, both large and small genes were detected, indicating the existence of a mixed population of the virus. Apparently, serial passage of aMPV-C in cell cultures and natural passage in turkeys in the field led to truncation of the G gene, which may be a mechanism of virus evolution for survival in a new host or environment.

  17. ERManI (Endoplasmic Reticulum Class I α-Mannosidase) Is Required for HIV-1 Envelope Glycoprotein Degradation via Endoplasmic Reticulum-associated Protein Degradation Pathway.

    Science.gov (United States)

    Zhou, Tao; Frabutt, Dylan A; Moremen, Kelley W; Zheng, Yong-Hui

    2015-09-04

    Previously, we reported that the mitochondrial translocator protein (TSPO) induces HIV-1 envelope (Env) degradation via the endoplasmic reticulum (ER)-associated protein degradation (ERAD) pathway, but the mechanism was not clear. Here we investigated how the four ER-associated glycoside hydrolase family 47 (GH47) α-mannosidases, ERManI, and ER-degradation enhancing α-mannosidase-like (EDEM) proteins 1, 2, and 3, are involved in the Env degradation process. Ectopic expression of these four α-mannosidases uncovers that only ERManI inhibits HIV-1 Env expression in a dose-dependent manner. In addition, genetic knock-out of the ERManI gene MAN1B1 using CRISPR/Cas9 technology disrupts the TSPO-mediated Env degradation. Biochemical studies show that HIV-1 Env interacts with ERManI, and between the ERManI cytoplasmic, transmembrane, lumenal stem, and lumenal catalytic domains, the catalytic domain plays a critical role in the Env-ERManI interaction. In addition, functional studies show that inactivation of the catalytic sites by site-directed mutagenesis disrupts the ERManI activity. These studies identify ERManI as a critical GH47 α-mannosidase in the ER-associated protein degradation pathway that initiates the Env degradation and suggests that its catalytic domain and enzymatic activity play an important role in this process. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  18. A Novel Nonviral Gene Delivery System: Multifunctional Envelope-Type Nano Device

    Science.gov (United States)

    Hatakeyama, Hiroto; Akita, Hidetaka; Kogure, Kentaro; Harashima, Hideyoshi

    In this review we introduce a new concept for developing a nonviral gene delivery system which we call "Programmed Packaging." Based on this concept, we succeeded in developing a multifunctional envelope-type nano device (MEND), which exerts high transfection activities equivalent to those of an adenovirus in a dividing cell. The use of MEND has been extended to in vivo applications. PEG/peptide/DOPE ternary conjugate (PPD)-MEND, a new in vivo gene delivery system for the targeting of tumor cells that dissociates surface-modified PEG in tumor tissue by matrix metalloproteinase (MMP) and exerts significant transfection activities, was developed. In parallel with the development of MEND, a quantitative gene delivery system, Confocal Image-assisted 3-dimensionally integrated quantification (CIDIQ), also was developed. This method identified the rate-limiting step of the nonviral gene delivery system by comparing it with adenoviral-mediated gene delivery. The results of this analysis provide a new direction for the development of rational nonviral gene delivery systems.

  19. The V1-V3 region of a brain-derived HIV-1 envelope glycoprotein determines macrophage tropism, low CD4 dependence, increased fusogenicity and altered sensitivity to entry inhibitors

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    Martín-García Julio

    2008-10-01

    Full Text Available Abstract Background HIV-1 infects macrophages and microglia in the brain and can cause neurological disorders in infected patients. We and others have shown that brain-derived envelope glycoproteins (Env have lower CD4 dependence and higher avidity for CD4 than those from peripheral isolates, and we have also observed increased fusogenicity and reduced sensitivity to the fusion inhibitor T-1249. Due to the genetic differences between brain and spleen env from one individual throughout gp120 and in gp41's heptad repeat 2 (HR2, we investigated the viral determinants for the phenotypic differences by performing functional studies with chimeric and mutant Env. Results Chimeric Env showed that the V1/V2-C2-V3 region in brain's gp120 determines the low CD4 dependence and high avidity for CD4, as well as macrophage tropism and reduced sensitivity to the small molecule BMS-378806. Changes in brain gp41's HR2 region did not contribute to the increased fusogenicity or to the reduced sensitivity to T-1249, since a T-1249-based peptide containing residues found in brain's but not in spleen's HR2 had similar potency than T-1249 and interacted similarly with an immobilized heptad repeat 1-derived peptide in surface plasmon resonance analysis. However, the increased fusogenicity and reduced T-1249 sensitivity of brain and certain chimeric Env mostly correlated with the low CD4 dependence and high avidity for CD4 determined by brain's V1-V3 region. Remarkably, most but not all of these low CD4-dependent, macrophage tropic envelopes glycoproteins also had increased sensitivity to the novel allosteric entry inhibitor HNG-105. The gp120's C2 region asparagine 283 (N283 has been previously associated with macrophage tropism, brain infection, lower CD4 dependence and higher CD4 affinity. Therefore, we introduced the N283T mutation into an env clone from a brain-derived isolate and into a brain tissue-derived env clone, and the T283N change into a spleen-derived env

  20. Genetic diversity of perch rhabdoviruses isolates based on the nucleoprotein and glycoprotein genes.

    Science.gov (United States)

    Talbi, Chiraz; Cabon, Joelle; Baud, Marine; Bourjaily, Maya; de Boisséson, Claire; Castric, Jeannette; Bigarré, Laurent

    2011-12-01

    Despite the increasing impact of rhabdoviruses in European percid farming, the diversity of the viral populations is still poorly investigated. To address this issue, we sequenced the partial nucleoprotein (N) and complete glycoprotein (G) genes of nine rhabdoviruses isolated from perch (Perca fluviatilis) between 1999 and 2010, mostly from France, and analyzed six of them by immunofluorescence antibody test (IFAT). Using two rabbit antisera raised against either the reference perch rhabdovirus (PRhV) isolated in 1980 or the perch isolate R6146, two serogroups were distinguished. Meanwhile, based on partial N and complete G gene analysis, perch rhabdoviruses were divided into four genogroups, A-B-D and E, with a maximum of 32.9% divergence (G gene) between isolates. A comparison of the G amino acid sequences of isolates from the two identified serogroups revealed several variable regions that might account for antigenic differences. Comparative analysis of perch isolates with other rhabdoviruses isolated from black bass, pike-perch and pike showed some strong phylogenetic relationships, suggesting cross-host transmission. Similarly, striking genetic similarities were shown between perch rhabdoviruses and isolates from other European countries and various ecological niches, most likely reflecting the circulation of viruses through fish trade as well as putative transfers from marine to freshwater fish. Phylogenetic relationships of the newly characterized viruses were also determined within the family Rhabdoviridae. The analysis revealed a genetic cluster containing only fish viruses, including all rhabdoviruses from perch, as well as siniperca chuatsi rhabdovirus (SCRV) and eel virus X (EVEX). This cluster was distinct from the one represented by spring viraemia of carp vesiculovirus (SVCV), pike fry rhabdovirus (PFRV) and mammalian vesiculoviruses. The new genetic data provided in the present study shed light on the diversity of rhabdoviruses infecting perch in

  1. The herpes simplex virus 1-encoded envelope glycoprotein B activates NF-κB through the Toll-like receptor 2 and MyD88/TRAF6-dependent signaling pathway.

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    Mingsheng Cai

    Full Text Available The innate immune response plays a critical role in the host defense against invading pathogens, and TLR2, a member of the Toll-like receptor (TLR family, has been implicated in the immune response and initiation of inflammatory cytokine secretion against several human viruses. Previous studies have demonstrated that infectious and ultraviolet-inactivated herpes simplex virus 1 (HSV-1 virions lead to the activation of nuclear factor kappa B (NF-κB and secretion of proinflammatory cytokines via TLR2. However, except for the envelope glycoprotein gH and gL, whether there are other determinants of HSV-1 responsible for TLR2 mediated biological effects is not known yet. Here, we demonstrated that the HSV-1-encoded envelope glycoprotein gB displays as molecular target recognized by TLR2. gB coimmunoprecipitated with TLR2, TLR1 and TLR6 in transfected and infected human embryonic kidney (HEK 293T cells. Treatment of TLR2-transfected HEK293T (HEK293T-TLR2 cells with purified gB results in the activation of NF-κB reporter, and this activation requires the recruitment of the adaptor molecules myeloid differentiation primary-response protein 88 (MyD88 and tumor necrosis factor receptor-associated factor 6 (TRAF6 but not CD14. Furthermore, activation of NF-κB was abrogated by anti-gB and anti-TLR2 blocking antibodies. In addition, the expression of interleukin-8 induced by gB was abrogated by the treatment of the human monocytic cell line THP-1 with anti-TLR2 blocking antibody or by the incubation of gB with anti-gB antibody. Taken together, these results indicate the importance and potency of HSV-1 gB as one of pathogen-associated molecular patterns (PAMPs molecule recognized by TLR2 with immediate kinetics.

  2. Processing, fusogenicity, virion incorporation and CXCR4-binding activity of a feline immunodeficiency virus envelope glycoprotein lacking the two conserved N-glycosylation sites at the C-terminus of the V3 domain.

    Science.gov (United States)

    González, Silvia A; Affranchino, José L

    2016-07-01

    The process of feline immunodeficiency virus (FIV) entry into its target cells is initiated by the association of the surface (SU) subunit of the viral envelope glycoprotein (Env) with the cellular receptors CD134 and CXCR4. This event is followed by the fusion of the viral and cellular membranes, which is mediated by the transmembrane (TM) subunit of Env. We and others have previously demonstrated that the V3 domain of the SU subunit of Env is essential for CXCR4 binding. Of note, there are two contiguous and highly conserved potential N-glycosylation sites ((418)NST(420) and (422)NLT(424)) located at the C-terminal side of the V3 domain. We therefore decided to study the relevance for Env functions of these N-glycosylation motifs and found that disruption of both of them by introducing the N418Q/N422Q double amino acid substitution drastically impairs Env processing into the SU and TM subunits. Moreover, the simultaneous mutation of these N-glycosylation sites prevents Env incorporation into virions and Env-mediated cell-to-cell fusion. Notably, a recombinant soluble version of the SU glycoprotein carrying the double amino acid replacement N418Q/N422Q at the V3 C-terminal side binds to CXCR4 with an efficiency similar to that of wild-type SU.

  3. Functional and structural analysis of GP64, the major envelope glycoprotein of the Budded Virus phenotype of Autographa californica and Orgyia pseudotsugata Multicapsid Nucleopolyhedroviruses

    NARCIS (Netherlands)

    Oomens, A.G.P.

    1999-01-01

    The Baculoviridae are a family of large, enveloped, double-stranded DNA viruses, that cause severe disease in the larvae of mostly lepidopteran insects. Baculoviruses have been studied with the aim of developing alternatives to chemical pest control, and later for their potential as systems

  4. The HP0256 gene product is involved in motility and cell envelope architecture of Helicobacter pylori

    LENUS (Irish Health Repository)

    Douillard, Francois P

    2010-04-08

    Abstract Background Helicobacter pylori is the causative agent for gastritis, and peptic and duodenal ulcers. The bacterium displays 5-6 polar sheathed flagella that are essential for colonisation and persistence in the gastric mucosa. The biochemistry and genetics of flagellar biogenesis in H. pylori has not been fully elucidated. Bioinformatics analysis suggested that the gene HP0256, annotated as hypothetical, was a FliJ homologue. In Salmonella, FliJ is a chaperone escort protein for FlgN and FliT, two proteins that themselves display chaperone activity for components of the hook, the rod and the filament. Results Ablation of the HP0256 gene in H. pylori significantly reduced motility. However, flagellin and hook protein synthesis was not affected in the HP0256 mutant. Transmission electron transmission microscopy revealed that the HP0256 mutant cells displayed a normal flagellum configuration, suggesting that HP0256 was not essential for assembly and polar localisation of the flagella in the cell. Interestingly, whole genome microarrays of an HP0256 mutant revealed transcriptional changes in a number of genes associated with the flagellar regulon and the cell envelope, such as outer membrane proteins and adhesins. Consistent with the array data, lack of the HP0256 gene significantly reduced adhesion and the inflammatory response in host cells. Conclusions We conclude that HP0256 is not a functional counterpart of FliJ in H. pylori. However, it is required for full motility and it is involved, possibly indirectly, in expression of outer membrane proteins and adhesins involved in pathogenesis and adhesion.

  5. Nucleotide and deduced amino acid sequence of the envelope gene of the Vasilchenko strain of TBE virus; comparison with other flaviviruses.

    Science.gov (United States)

    Gritsun, T S; Frolova, T V; Pogodina, V V; Lashkevich, V A; Venugopal, K; Gould, E A

    1993-02-01

    A strain of tick-borne encephalitis virus known as Vasilchenko (Vs) exhibits relatively low virulence characteristics in monkeys, Syrian hamsters and humans. The gene encoding the envelope glycoprotein of this virus was cloned and sequenced. Alignment of the sequence with those of other known tick-borne flaviviruses and identification of the recognised amino acid genetic marker EHLPTA confirmed its identity as a member of the TBE complex. However, Vs virus was distinguishable from eastern and western tick-borne serotypes by the presence of the sequence AQQ at amino acid positions 232-234 and also by the presence of other specific amino acid substitutions which may be genetic markers for these viruses and could determine their pathogenetic characteristics. When compared with other tick-borne flaviviruses, Vs virus had 12 unique amino acid substitutions including an additional potential glycosylation site at position (315-317). The Vs virus strain shared closest nucleotide and amino acid homology (84.5% and 95.5% respectively) with western and far eastern strains of tick-borne encephalitis virus. Comparison with the far eastern serotype of tick-borne encephalitis virus, by cross-immunoelectrophoresis of Vs virions and PAGE analysis of the extracted virion proteins, revealed differences in surface charge and virus stability that may account for the different virulence characteristics of Vs virus. These results support and enlarge upon previous data obtained from molecular and serological analysis.

  6. Adenoviral vectors expressing fusogenic membrane glycoproteins activated via matrix metalloproteinase cleavable linkers have significant antitumor potential in the gene therapy of gliomas.

    Science.gov (United States)

    Allen, Cory; McDonald, Cari; Giannini, Caterina; Peng, Kah Whye; Rosales, Gabriela; Russell, Stephen J; Galanis, Evanthia

    2004-11-01

    Fusogenic membrane glycoproteins (FMG) such as the gibbon ape leukemia virus envelope (GALV) glycoprotein are potent therapeutic transgenes with potential utility in the gene therapy of gliomas. Transfection of glioma cell lines with FMG expression constructs results in fusion with massive syncytia formation followed by cytotoxic cell death. Nevertheless, ubiquitous expression of the GALV receptor, Pit-1, makes targeting desirable in order to increase the specificity of the observed cytopathic effect. Here we report on use of matrix metalloproteinase (MMP)-cleavable linkers to target the cytotoxicity of FMG-expressing adenoviral vectors against gliomas. Replication-defective adenoviruses (Ad) were constructed expressing the hyperfusogenic version of the GALV glycoprotein linked to a blocking ligand (C-terminal extracellular domain of CD40 ligand) through either an MMP-cleavable linker (AdM40) or a non-cleavable linker (AdN40). Both viruses also co-expressed the green fluorescent protein (GFP) via an internal ribosomal entry site. The glioma cell lines U87, U118, and U251 characterized by zymography and MMP-2 activity assay as high, medium and low MMP expressors, respectively, the MMP-poor cell lines TE671 and normal human astrocytes were infected with AdM40 and AdN40 at different multiplicities of infection (MOIs) from 1-30. Fusion was quantitated by counting both number and size of syncytia. Infection of these cell lines with AdN40 did not result in fusion or cytotoxic cell death, despite the presence of infection, as demonstrated by GFP positivity, therefore indicating that the displayed CD40 ligand blocked GALV-induced fusion. Fusion was restored after infection of glioma cells with AdM40 at an MOI as low as 1 to an extent dependent on MMP expression and coxsackie adenovirus receptor (CAR) expression in the specific cell line. Western immunoblotting demonstrated the presence of the cleaved CD40 ligand in the supernatant of fused glioma cells. Use of the MMP

  7. N-Glycans on the Rift Valley Fever Virus Envelope Glycoproteins Gn and Gc Redundantly Support Viral Infection via DC-SIGN

    Science.gov (United States)

    Phoenix, Inaia; Nishiyama, Shoko; Lokugamage, Nandadeva; Hill, Terence E.; Huante, Matthew B.; Slack, Olga A.L.; Carpio, Victor H.; Freiberg, Alexander N.; Ikegami, Tetsuro

    2016-01-01

    Rift Valley fever is a mosquito-transmitted, zoonotic disease that infects humans and ruminants. Dendritic cell specific intercellular adhesion molecule 3 (ICAM-3) grabbing non-integrin (DC-SIGN) acts as a receptor for members of the phlebovirus genus. The Rift Valley fever virus (RVFV) glycoproteins (Gn/Gc) encode five putative N-glycan sequons (asparagine (N)–any amino acid (X)–serine (S)/threonine (T)) at positions: N438 (Gn), and N794, N829, N1035, and N1077 (Gc). The N-glycosylation profile and significance in viral infection via DC-SIGN have not been elucidated. Gc N-glycosylation was first evaluated by using Gc asparagine (N) to glutamine (Q) mutants. Subsequently, we generated a series of recombinant RVFV MP-12 strain mutants, which encode N-to-Q mutations, and the infectivity of each mutant in Jurkat cells stably expressing DC-SIGN was evaluated. Results showed that Gc N794, N1035, and N1077 were N-glycosylated but N829 was not. Gc N1077 was heterogeneously N-glycosylated. RVFV Gc made two distinct N-glycoforms: “Gc-large” and “Gc-small”, and N1077 was responsible for “Gc-large” band. RVFV showed increased infection of cells expressing DC-SIGN compared to cells lacking DC-SIGN. Infection via DC-SIGN was increased in the presence of either Gn N438 or Gc N1077. Our study showed that N-glycans on the Gc and Gn surface glycoproteins redundantly support RVFV infection via DC-SIGN. PMID:27223297

  8. Comprehensive search for intra- and inter-specific sequence polymorphisms among coding envelope genes of retroviral origin found in the human genome: genes and pseudogenes

    Directory of Open Access Journals (Sweden)

    Vasilescu Alexandre

    2005-09-01

    Full Text Available Abstract Background The human genome carries a high load of proviral-like sequences, called Human Endogenous Retroviruses (HERVs, which are the genomic traces of ancient infections by active retroviruses. These elements are in most cases defective, but open reading frames can still be found for the retroviral envelope gene, with sixteen such genes identified so far. Several of them are conserved during primate evolution, having possibly been co-opted by their host for a physiological role. Results To characterize further their status, we presently sequenced 12 of these genes from a panel of 91 Caucasian individuals. Genomic analyses reveal strong sequence conservation (only two non synonymous Single Nucleotide Polymorphisms [SNPs] for the two HERV-W and HERV-FRD envelope genes, i.e. for the two genes specifically expressed in the placenta and possibly involved in syncytiotrophoblast formation. We further show – using an ex vivo fusion assay for each allelic form – that none of these SNPs impairs the fusogenic function. The other envelope proteins disclose variable polymorphisms, with the occurrence of a stop codon and/or frameshift for most – but not all – of them. Moreover, the sequence conservation analysis of the orthologous genes that can be found in primates shows that three env genes have been maintained in a fully coding state throughout evolution including envW and envFRD. Conclusion Altogether, the present study strongly suggests that some but not all envelope encoding sequences are bona fide genes. It also provides new tools to elucidate the possible role of endogenous envelope proteins as susceptibility factors in a number of pathologies where HERVs have been suspected to be involved.

  9. High-Mannose Specific Lectin and Its Recombinants from a Carrageenophyta Kappaphycus alvarezii Represent a Potent Anti-HIV Activity Through High-Affinity Binding to the Viral Envelope Glycoprotein gp120.

    Science.gov (United States)

    Hirayama, Makoto; Shibata, Hiromi; Imamura, Koji; Sakaguchi, Takemasa; Hori, Kanji

    2016-02-01

    We previously reported that a high-mannose binding lectin KAA-2 from the red alga Kappaphycus alvarezii, which is an economically important species and widely cultivated as a source of carrageenans, had a potent anti-influenza virus activity. In this study, the full-length sequences of two KAA isoforms, KAA-1 and KAA-2, were elucidated by a combination of peptide mapping and complementary DNA (cDNA) cloning. They consisted of four internal tandem-repeated domains, which are conserved in high-mannose specific lectins from lower organisms, including a cyanobacterium Oscillatoria agardhii and a red alga Eucheuma serra. Using an Escherichia coli expression system, an active recombinant form of KAA-1 (His-tagged rKAA-1) was successfully generated in the yield of 115 mg per liter of culture. In a detailed oligosaccharide binding analysis by a centrifugal ultrafiltration-HPLC method with 27 pyridylaminated oligosaccharides, His-tagged rKAA-1 and rKAA-1 specifically bound to high-mannose N-glycans with an exposed α1-3 mannose in the D2 arm as the native lectin did. Predicted from oligosaccharide binding specificity, a surface plasmon resonance analysis revealed that the recombinants exhibit strong interaction with gp120, a heavily glycosylated envelope glycoprotein of HIV with high association constants (1.48 - 1.61 × 10(9) M(-1)). Native KAAs and the recombinants inhibited the HIV-1 entry at IC50s of low nanomolar levels (7.3-12.9 nM). Thus, the recombinant proteins would be useful as antiviral reagents targeting the viral surface glycoproteins with high-mannose N-glycans, and the cultivated alga K. alvarezii could also be a good source of not only carrageenans but also this functional lectin(s).

  10. The C-terminal tail of the gp41 transmembrane envelope glycoprotein of HIV-1 clades A, B, C, and D may exist in two conformations: an analysis of sequence, structure, and function

    International Nuclear Information System (INIS)

    Hollier, Mark J.; Dimmock, Nigel J.

    2005-01-01

    In addition to the major ectodomain, the gp41 transmembrane glycoprotein of HIV-1 is now known to have a minor ectodomain that is part of the long C-terminal tail. Both ectodomains are highly antigenic, carry neutralizing and non-neutralizing epitopes, and are involved in virus-mediated fusion activity. However, data have so far been biologically based, and derived solely from T cell line-adapted (TCLA), B clade viruses. Here we have carried out sequence and theoretically based structural analyses of 357 gp41 C-terminal sequences of mainly primary isolates of HIV-1 clades A, B, C, and D. Data show that all these viruses have the potential to form a tail loop structure (the minor ectodomain) supported by three, β-sheet, membrane-spanning domains (MSDs). This means that the first (N-terminal) tyrosine-based sorting signal of the gp41 tail is situated outside the cell membrane and is non-functional, and that gp41 that reaches the cell surface may be recycled back into the cytoplasm through the activity of the second tyrosine-sorting signal. However, we suggest that only a minority of cell-associated gp41 molecules - those destined for incorporation into virions - has 3 MSDs and the minor ectodomain. Most intracellular gp41 has the conventional single MSD, no minor ectodomain, a functional first tyrosine-based sorting signal, and in line with current thinking is degraded intracellularly. The gp41 structural diversity suggested here can be viewed as an evolutionary strategy to minimize HIV-1 envelope glycoprotein expression on the cell surface, and hence possible cytotoxicity and immune attack on the infected cell

  11. The Escherichia coli Cpx envelope stress response regulates genes of diverse function that impact antibiotic resistance and membrane integrity.

    Science.gov (United States)

    Raivio, Tracy L; Leblanc, Shannon K D; Price, Nancy L

    2013-06-01

    The Cpx envelope stress response mediates adaptation to stresses that cause envelope protein misfolding. Adaptation is partly conferred through increased expression of protein folding and degradation factors. The Cpx response also plays a conserved role in the regulation of virulence determinant expression and impacts antibiotic resistance. We sought to identify adaptive mechanisms that may be involved in these important functions by characterizing changes in the transcriptome of two different Escherichia coli strains when the Cpx response is induced. We show that, while there is considerable strain- and condition-specific variability in the Cpx response, the regulon is enriched for proteins and functions that are inner membrane associated under all conditions. Genes that were changed by Cpx pathway induction under all conditions were involved in a number of cellular functions and included several intergenic regions, suggesting that posttranscriptional regulation is important during Cpx-mediated adaptation. Some Cpx-regulated genes are centrally involved in energetics and play a role in antibiotic resistance. We show that a number of small, uncharacterized envelope proteins are Cpx regulated and at least two of these affect phenotypes associated with membrane integrity. Altogether, our work suggests new mechanisms of Cpx-mediated envelope stress adaptation and antibiotic resistance.

  12. Expression of the MDR1 gene and P-glycoprotein in canine mast cell tumor cell lines

    OpenAIRE

    NAKAICHI, Munekazu; TAKESHITA, Yoko; OKUDA, Masaru; NAKAMOTO, Yuya; ITAMOTO, Kazuhito; UNE, Satoshi; SASAKI, Nobuo; KADOSAWA, Tsuyoshi; TAKAHASHI, Tomoko; TAURA, Yasuho

    2007-01-01

    Cellular drug resistance to antineoplastic drugs is often due to the presence of a drug efflux pump that reduces intracellular drug accumulation and chemosensitivity. P-glycoprotein (P-gp), which is encoded by the MDR1 gene, is considered to function as an ATP-driven membrane drug efflux pump and appears to play an important role in tumor cell resistance. In the present report, we assessed the expression of MDR1 by RT-PCR in three canine mast cell tumor cell lines, TiMC, CoMS and LuMC, origin...

  13. Absence of cytotoxic antibody to human immunodeficiency virus-infected cells in humans and its induction in animals after infection or immunization with purified envelope glycoprotein gp120

    International Nuclear Information System (INIS)

    Nara, P.L.; Robey, W.G.; Gonda, M.A.; Carter, S.G.; Fischinger, P.J.

    1987-01-01

    The presence of antibody-dependent complement-mediated cytotoxicity (ACC) was assessed in humans and chimpanzees, which are capable of infection with human immunodeficiency virus isolate HTLV-IIIb, and examined in the goat after immunization with the major viral glycoprotein (gp120) of HTLV-IIIb. In infected humans no antibody mediating ACC was observed regardless of the status of disease. Even healthy individuals with high-titer, broadly reactive, neutralizing antibodies has no ACC. In contrast, chimpanzees infected with HTLV-IIIb, from whom virus could be isolated, not only had neutralizing antibody but also antibodies broadly reactive in ACC, even against distantly related human immunodeficiency virus isolates, as well as against their own reisolated virus. In the goat, the gp120 of HTLV-IIIb induced a highly type-specific response as measured by both ACC and flow cytofluorometry of live infected H9 cells. Normal human cells were not subject to ACC by animal anti-HTLV-III gp120-specific sera. Induction of ACC and neutralizing antibody were closely correlated in the animal experimental models but not in humans. The presence of ACC in gp120-inoculated goats and HTLV-III-infected chimpanzees represent a qualitative difference that may be important in the quest for the elicitation of a protective immunity in humans

  14. Specific interaction of CXCR4 with CD4 and CD8α: Functional analysis of the CD4/CXCR4 interaction in the context of HIV-1 envelope glycoprotein-mediated membrane fusion

    International Nuclear Information System (INIS)

    Basmaciogullari, Stephane; Pacheco, Beatriz; Bour, Stephan; Sodroski, Joseph

    2006-01-01

    We investigated possible interactions between HIV-1 receptor (CD4) and the main coreceptors CXCR4 and CCR5. We found that CD4 and CXCR4 coexpressed in 293T cells form a complex that can be immunoprecipitated with antibodies directed against the extracellular domain of either protein. Mutagenesis revealed that the CD4/CXCR4 interaction maps to two previously uncharacterized basic motifs in the cytoplasmic domain of CD4. HIV-1 envelope glycoprotein-mediated membrane fusion was found to be independent of the ability of CD4 and CXCR4 to interact, whether fusion was studied in a virus-cell or a cell-cell model. However, this interaction might explain the adaptation of HIV-1 to CXCR4 as an alternative to CCR5. We found that CXCR4 also interacts with the cytoplasmic domain of CD8α in a way that is similar to the CD4/CXCR4 interaction. The CD4/CXCR4 and CD8α/CXCR4 interactions may thus be involved in cellular signaling pathways shared by the CD4 and CD8α molecules

  15. Evolution of the HIV-1 Envelope Glycoprotein Genes and Neutralizing Antibody Response in an Individual with Broadly Cross Neutralizing Antibodies

    Science.gov (United States)

    2010-08-31

    1994, 140: 1 05-130. 51. Pantaleo G, Graziosi C, Demarest JF, Butini L, Montroni M, Fox CH, Orenstein JM, Kotler DP, Fauci AS: HIV infection is...Pizzo PA, Schnittman SM, Kotler DP, Fauci AS: Lymphoid organs function as major reservoirs for human immunodeficiency virus. Proc Natl Acad Sci US

  16. Characterization of retrovirus-based reporter viruses pseudotyped with the precursor membrane and envelope glycoproteins of four serotypes of dengue viruses

    International Nuclear Information System (INIS)

    Hu, H.-P.; Hsieh, S.-C.; King, C.-C.; Wang, W.-K.

    2007-01-01

    In this study, we successfully established retrovirus-based reporter viruses pseudotyped with the precursor membrane and envelope (PrM/E) proteins of each of the four serotypes of dengue viruses, which caused the most important arboviral diseases in this century. Co-sedimentation of the dengue E protein and HIV-1 core proteins by sucrose gradient analysis of the pseudotype reporter virus of dengue virus type 2, D2(HIVluc), and detection of HIV-1 core proteins by immunoprecipitation with anti-E monoclonal antibody suggested that dengue viral proteins were incorporated into the pseudotype viral particles. The infectivity in target cells, as assessed by the luciferase activity, can be inhibited by the lysosomotropic agents, suggesting a pH-dependent mechanism of entry. Amino acid substitutions of the leucine at position 107, a critical residue at the fusion loop of E protein, with lysine resulted in severe impairment in infectivity, suggesting that entry of the pseudotype reporter virus is mediated through the fusogenic properties of E protein. With more and more dengue viral sequences available from different outbreaks worldwide, this sensitive and convenient tool has the potential to facilitate molecular characterization of the PrM/E proteins of dengue field isolates

  17. Stability of the glycoprotein gene of avian metapneumovirus (Canada goose isolate 15a/01) after serial passages in cell cultures.

    Science.gov (United States)

    Chockalingam, Ashok K; Chander, Yogesh; Halvorson, David A; Goyal, Sagar M

    2010-06-01

    The glycoprotein (G) gene sequences of avian metapneumovirus (aMPV) subtypes A, B, C, and D are variable in size and number of nucleotides. The G gene of early U.S. turkey isolates of aMPV-C have been reported to be 1798 nucleotides (nt) (585 aa) in length, whereas the G genes of more recent turkey isolates have been reported to be 783 nucleotides. In some studies, the G gene of aMPV-C turkey isolates was found to be truncated to a smaller G gene of 783 nt (261 aa) upon serial passages in Vero cells. This is believed to be due to the deletion of 1015 nt near the end of the open reading frame. The purpose of this study was to determine variation, if any, in the G gene of an aMPV-C isolated from a wild bird (Canada goose [Branta canadensis]) following serial passages in Vero cells. No size variation was observed for up to 50 passages, except for a few amino acid changes in the extracellular domain at the 50th passage level. The G gene of this wild bird isolate appears to be unique from subtype C metapneumoviruses of turkeys.

  18. Variants in linkage disequilibrium with the late cornified envelope gene cluster deletion are associated with susceptibility to psoriatic arthritis.

    LENUS (Irish Health Repository)

    Bowes, John

    2010-12-01

    A common deletion mapping to the psoriasis susceptibility locus 4 on chromosome 1q21, encompassing two genes of the late cornified envelope (LCE) gene cluster, has been associated with an increased risk of psoriasis vulgaris (PsV). One previous report found no association of the deletion with psoriatic arthritis (PsA), suggesting it may be a specific risk factor for PsV. Given the genetic overlap between PsA and PsV, a study was undertaken to investigate whether single nucleotide polymorphisms (SNPs) mapping to this locus are risk factors for PsA in a UK and Irish population.

  19. Second site escape of a T20-dependent HIV-1 variant by a single amino acid change in the CD4 binding region of the envelope glycoprotein

    Directory of Open Access Journals (Sweden)

    Berkhout Ben

    2006-11-01

    Full Text Available Abstract Background We previously described the selection of a T20-dependent human immunodeficiency virus type-1 (HIV-1 variant in a patient on T20 therapy. The fusion inhibitor T20 targets the viral envelope (Env protein by blocking a conformational switch that is critical for viral entry into the host cell. T20-dependent viral entry is the result of 2 mutations in Env (GIA-SKY, creating a protein that undergoes a premature conformational switch, and the presence of T20 prevents this premature switch and rescues viral entry. In the present study, we performed 6 independent evolution experiments with the T20-dependent HIV-1 variant in the absence of T20, with the aim to identify second site compensatory changes, which may provide new mechanistic insights into Env function and the T20-dependence mechanism. Results Escape variants with improved replication capacity appeared within 42 days in 5 evolution cultures. Strikingly, 3 cultures revealed the same single amino acid change in the CD4 binding region of Env (glycine at position 431 substituted for arginine: G431R. This mutation was sufficient to abolish the T20-dependence phenotype and restore viral replication in the absence of T20. The GIA-SKY-G431R escape variant produces an Env protein that exhibits reduced syncytia formation and reduced cell-cell fusion activity. The escape variant was more sensitive to an antibody acting on an early gp41 intermediate, suggesting that the G431R mutation helps preserve a pre-fusion Env conformation, similar to T20 action. The escape variant was also less sensitive to soluble CD4, suggesting a reduced CD4 receptor affinity. Conclusion The forced evolution experiments indicate that the premature conformational switch of the T20-dependent HIV-1 Env variant (GIA-SKY can be corrected by a second site mutation in Env (GIA-SKY-G431R that affects the interaction with the CD4 receptor.

  20. Enhancement of antitumor activity of gammaretrovirus carrying IL-12 gene through genetic modification of envelope targeting HER2 receptor: a promising strategy for bladder cancer therapy.

    Science.gov (United States)

    Tsai, Y-S; Shiau, A-L; Chen, Y-F; Tsai, H-T; Tzai, T-S; Wu, C-L

    2010-01-01

    The objective of this study was to develop an HER2-targeted, envelope-modified Moloney murine leukemia virus (MoMLV)-based gammaretroviral vector carrying interleukin (IL)-12 gene for bladder cancer therapy. It displayed a chimeric envelope protein containing a single-chain variable fragment (scFv) antibody to the HER2 receptor and carried the mouse IL-12 gene. The fragment of anti-erbB2scFv was constructed into the proline-rich region of the viral envelope of the packaging vector lacking a transmembrane subunit of the carboxyl terminal region of surface subunit. As compared with envelope-unmodified gammaretroviruses, envelope-modified ones had extended viral tropism to human HER2-expressing bladder cancer cell lines, induced apoptosis, and affected cell cycle progression despite lower viral titers. Moreover, animal studies showed that envelope-modified gammaretroviruses carrying IL-12 gene exerted higher antitumor activity in terms of retarding tumor growth and prolonging the survival of tumor-bearing mice than unmodified ones, which were associated with enhanced tumor cell apoptosis as well as increased intratumoral levels of IL-12, interferon-gamma, IL-1beta, and tumor necrosis factor-alpha proteins. Therefore, the antitumor activity of gammaretroviruses carrying the IL-12 gene was enhanced through genetic modification of the envelope targeting HER2 receptor, which may be a promising strategy for bladder cancer therapy.

  1. Characterization of the bovine pregnancy-associated glycoprotein gene family – analysis of gene sequences, regulatory regions within the promoter and expression of selected genes

    Directory of Open Access Journals (Sweden)

    Walker Angela M

    2009-04-01

    Full Text Available Abstract Background The Pregnancy-associated glycoproteins (PAGs belong to a large family of aspartic peptidases expressed exclusively in the placenta of species in the Artiodactyla order. In cattle, the PAG gene family is comprised of at least 22 transcribed genes, as well as some variants. Phylogenetic analyses have shown that the PAG family segregates into 'ancient' and 'modern' groupings. Along with sequence differences between family members, there are clear distinctions in their spatio-temporal distribution and in their relative level of expression. In this report, 1 we performed an in silico analysis of the bovine genome to further characterize the PAG gene family, 2 we scrutinized proximal promoter sequences of the PAG genes to evaluate the evolution pressures operating on them and to identify putative regulatory regions, 3 we determined relative transcript abundance of selected PAGs during pregnancy and, 4 we performed preliminary characterization of the putative regulatory elements for one of the candidate PAGs, bovine (bo PAG-2. Results From our analysis of the bovine genome, we identified 18 distinct PAG genes and 14 pseudogenes. We observed that the first 500 base pairs upstream of the translational start site contained multiple regions that are conserved among all boPAGs. However, a preponderance of conserved regions, that harbor recognition sites for putative transcriptional factors (TFs, were found to be unique to the modern boPAG grouping, but not the ancient boPAGs. We gathered evidence by means of Q-PCR and screening of EST databases to show that boPAG-2 is the most abundant of all boPAG transcripts. Finally, we provided preliminary evidence for the role of ETS- and DDVL-related TFs in the regulation of the boPAG-2 gene. Conclusion PAGs represent a relatively large gene family in the bovine genome. The proximal promoter regions of these genes display differences in putative TF binding sites, likely contributing to observed

  2. [Small interfering RNA-mediated COX-2 gene silencing enhances chemosensitivity of KB/VCR cells by suppressing MDR-1 gene expression and P-glycoprotein activity].

    Science.gov (United States)

    Mo, Xianchao; Li, Weizhong

    2014-05-01

    To investigate the effect of small interfering RNA (siRNA)-mediated COX-2 gene silencing in enhancing the chemosensitivity of KB/VCR cell lines. KB/VCR cells were trasnfected with COX-2 siRNA were examined for expressions of COX-2 and MDR-1 mRNAs with RT-PCR and for Rho-123 accumulation using flow cytometry. MTT assay was used to analyze the proliferation of the transfected KB/VCR cells. Compared with the negative and blank control groups, COX-2 siRNA transfection resulted in significant growth inhibition of KB/VCR cells exposed to vincristine (PKB/VCR cells. COX-2 gene silencing can enhance the chemosensitivity of KB/VCR cells to vincristine, the mechanism of which may involve down-regulated MDR-1 gene expression and inhibition of P-glycoprotein activity.

  3. Receptor-Targeted Nipah Virus Glycoproteins Improve Cell-Type Selective Gene Delivery and Reveal a Preference for Membrane-Proximal Cell Attachment.

    Directory of Open Access Journals (Sweden)

    Ruben R Bender

    2016-06-01

    Full Text Available Receptor-targeted lentiviral vectors (LVs can be an effective tool for selective transfer of genes into distinct cell types of choice. Moreover, they can be used to determine the molecular properties that cell surface proteins must fulfill to act as receptors for viral glycoproteins. Here we show that LVs pseudotyped with receptor-targeted Nipah virus (NiV glycoproteins effectively enter into cells when they use cell surface proteins as receptors that bring them closely enough to the cell membrane (less than 100 Å distance. Then, they were flexible in receptor usage as demonstrated by successful targeting of EpCAM, CD20, and CD8, and as selective as LVs pseudotyped with receptor-targeted measles virus (MV glycoproteins, the current standard for cell-type specific gene delivery. Remarkably, NiV-LVs could be produced at up to two orders of magnitude higher titers compared to their MV-based counterparts and were at least 10,000-fold less effectively neutralized than MV glycoprotein pseudotyped LVs by pooled human intravenous immunoglobulin. An important finding for NiV-LVs targeted to Her2/neu was an about 100-fold higher gene transfer activity when particles were targeted to membrane-proximal regions as compared to particles binding to a more membrane-distal epitope. Likewise, the low gene transfer activity mediated by NiV-LV particles bound to the membrane distal domains of CD117 or the glutamate receptor subunit 4 (GluA4 was substantially enhanced by reducing receptor size to below 100 Å. Overall, the data suggest that the NiV glycoproteins are optimally suited for cell-type specific gene delivery with LVs and, in addition, for the first time define which parts of a cell surface protein should be targeted to achieve optimal gene transfer rates with receptor-targeted LVs.

  4. P-Glycoprotein/MDR1 regulates pokemon gene transcription through p53 expression in human breast cancer cells.

    Science.gov (United States)

    He, Shengnan; Liu, Feng; Xie, Zhenhua; Zu, Xuyu; Xu, Wei; Jiang, Yuyang

    2010-08-27

    P-glycoprotein (Pgp), encoded by the multidrug resistance 1 (MDR1) gene, is an efflux transporter and plays an important role in pharmacokinetics. In this study, we demonstrated that the pokemon promoter activity, the pokemon mRNA and protein expression can be significantly inhibited by Pgp. Chromatin immunoprecipitation assay showed that Pgp can bind the pokemon prompter to repress pokemon transcription activity. Furthermore, Pgp regulated pokemon transcription activity through expression of p53 as seen by use of p53 siRNA transfected MCF-7 cells or p53 mutated MDA-MB-231 cells. Moreover, p53 was detected to bind with Pgp in vivo using immunoprecipitation assay. Taken together, we conclude that Pgp can regulate the expression of pokemon through the presence of p53, suggesting that Pgp is a potent regulator and may offer an effective novel target for cancer therapy.

  5. P-Glycoprotein/MDR1 Regulates Pokemon Gene Transcription Through p53 Expression in Human Breast Cancer Cells

    Directory of Open Access Journals (Sweden)

    Wei Xu

    2010-08-01

    Full Text Available P-glycoprotein (Pgp, encoded by the multidrug resistance 1 (MDR1 gene, is an efflux transporter and plays an important role in pharmacokinetics. In this study, we demonstrated that the pokemon promoter activity, the pokemon mRNA and protein expression can be significantly inhibited by Pgp. Chromatin immunoprecipitation assay showed that Pgp can bind the pokemon prompter to repress pokemon transcription activity. Furthermore, Pgp regulated pokemon transcription activity through expression of p53 as seen by use of p53 siRNA transfected MCF-7 cells or p53 mutated MDA-MB-231 cells. Moreover, p53 was detected to bind with Pgp in vivo using immunoprecipitation assay. Taken together, we conclude that Pgp can regulate the expression of pokemon through the presence of p53, suggesting that Pgp is a potent regulator and may offer an effective novel target for cancer therapy.

  6. Phylogenetic relationships of Iranian infectious hematopoietic necrosis virus of rainbow trout (Oncorhynchus mykiss) based on the glycoprotein gene

    Science.gov (United States)

    Adel, Milad; Amiri, Alireza Babaalian; Dada, Maryam; Kurath, Gael; Laktarashi, Bahram; Ghajari, Amrolah; Breyta, Rachel

    2016-01-01

    Infectious hematopoietic necrosis virus (IHNV), a member of family Rhabdoviridae and genus Novirhabdoviridae, causes a highly lethal disease of salmon and trout. In Iran IHNV was first detected in 2001 on farms rearing rainbow trout (Oncorhynchus mykiss). To evaluate the genetic relationships of IHNV from northern and western Iran, the sequences of a 651-nt region of the glycoprotein gene were determined for two Iranian isolates. These sequences were analyzed to evaluate their genetic relatedness to worldwide isolates representing the five known genogroups of IHNV. Iranian isolates were most closely related to European isolates within the genogroup E rather than those of North American genogroups U, M and L, or the Asian genogroup J. It appears that Iranian IHNV was most likely introduced to Iran from a source in Europe by the movement of contaminated fish eggs.

  7. MicroRNA expression in rainbow trout (Oncorhynchus mykiss) vaccinated with a DNA vaccine encoding the glycoprotein gene of Viral hemorrhagic septicemia virus

    DEFF Research Database (Denmark)

    Bela-Ong, Dennis; Schyth, Brian Dall; Lorenzen, Niels

    particularly to sea-farmed rainbow trout and thus necessitates strategies to mitigate potential disease outbreaks. A DNA vaccine encoding the glycoprotein gene of VHSV has been developed and shown to elicit protective immune responses in laboratory trials. It is important to identify key factors as biomarkers...

  8. Identification and characterization of polymorphisms at the HSA a1-acid glycoprotein (ORM* gene locus in Caucasians

    Directory of Open Access Journals (Sweden)

    Owczarek Catherine M.

    2002-01-01

    Full Text Available Human alpha1-acid glycoprotein (AGP or orosomucoid (ORM is a major acute phase protein that is thought to play a crucial role in maintaining homeostasis. Human AGP is the product of a cluster of at least two adjacent genes located on HSA chromosome 9. Using a range of restriction endonucleases we have investigated DNA variation at the locus encoding the AGP genes in a panel of healthy Caucasians. Polymorphisms were identified using BamHI, EcoRI, BglII, PvuII, HindIII, TaqI and MspI. Non-random associations were found between the BamHI, EcoRI, BglII RFLPs. The RFLPs detected with PvuII, TaqI and MspI were all located in exon 6 of both AGP genes. The duplication of an AGP gene was observed in 11% of the indiviuals studied and was in linkage disequilibrium with the TaqI RFLP. The identification and characterization of these polymorphisms will prove useful for other population and forensic studies.

  9. The short mRNA isoform of the immunoglobulin superfamily, member 1 gene encodes an intracellular glycoprotein.

    Directory of Open Access Journals (Sweden)

    Ying Wang

    Full Text Available Mutations in the immunoglobulin superfamily, member 1 gene (IGSF1/Igsf1 cause an X-linked form of central hypothyroidism. The canonical form of IGSF1 is a transmembrane glycoprotein with 12 immunoglobulin (Ig loops. The protein is co-translationally cleaved into two sub-domains. The carboxyl-terminal domain (CTD, which contains the last 7 Ig loops, is trafficked to the plasma membrane. Most pathogenic mutations in IGSF1 map to the portion of the gene encoding the CTD. IGSF1/Igsf1 encodes a variety of transcripts. A little studied, but abundant splice variant encodes a truncated form of the protein, predicted to contain the first 2 Ig loops of the full-length IGSF1. The protein (hereafter referred to as IGSF1 isoform 2 or IGSF1-2 is likely retained in most individuals with IGSF1 mutations. Here, we characterized basic biochemical properties of the protein as a foray into understanding its potential function. IGSF1-2, like the IGSF1-CTD, is a glycoprotein. In both mouse and rat, the protein is N-glycosylated at a single asparagine residue in the first Ig loop. Contrary to earlier predictions, neither the murine nor rat IGSF1-2 is secreted from heterologous or homologous cells. In addition, neither protein associates with the plasma membrane. Rather, IGSF1-2 appears to be retained in the endoplasmic reticulum. Whether the protein plays intracellular functions or is trafficked through the secretory pathway under certain physiologic or pathophysiologic conditions has yet to be determined.

  10. CD150 is a member of a family of genes that encode glycoproteins on the surface of hematopoietic cells.

    Science.gov (United States)

    Wang, N; Morra, M; Wu, C; Gullo, C; Howie, D; Coyle, T; Engel, P; Terhorst, C

    2001-07-01

    Human CD150 (SLAM) is a glycoprotein expressed on the surface of T, B, natural killer, and dendritic cells. The extracellular domain of CD150 is the receptor for measles virus and CD150 acts as a co-activator on T and B cells. We characterized the mouse and human CD150 genes, each of which comprises seven exons spanning approximately 32 kb. Mouse CD150 mRNA was detected in T cells and in most thymocyte subsets, except CD4-8- cells. Surprisingly, the CD4-8- thymocytes of CD3gammadeltanull mice, but not of Ragnull or severe combined immunodeficiency mice, expressed CD150. Whereas high levels of CD150 were found in Th1 cells, only small amounts were detectable in Th2 cells. CD150 expression was up-regulated upon in vitro activation of mouse T cells by anti-CD3. The complete mouse CD150 gene is highly homologous to its human orthologue in terms of nucleotide sequences and intron/exon organization. The human genomic sequences indicate that all isoforms detected so far have arisen from alternative splicing events. As judged by fluorescence in situ hybridization, mouse CD150 mapped to Chromosome (Chr) 1, band 1H2.2-2.3, and human CD150 was found on Chr 1q22. Human and mouse CD150 share sequence homologies with six other genes, five of which - CD84, CD229 (Ly-9), CD244 (2B4), CD48, and 19A - are localized in a 250-kb segment in close proximity to the human gene. Their location and their sequence similarities strongly suggest that the CD150 family of cell surface receptors arose via successive duplications of a common ancestral gene.

  11. Cryptic nature of a conserved, CD4-inducible V3 loop neutralization epitope in the native envelope glycoprotein oligomer of CCR5-restricted, but not CXCR4-using, primary human immunodeficiency virus type 1 strains.

    Science.gov (United States)

    Lusso, Paolo; Earl, Patricia L; Sironi, Francesca; Santoro, Fabio; Ripamonti, Chiara; Scarlatti, Gabriella; Longhi, Renato; Berger, Edward A; Burastero, Samuele E

    2005-06-01

    The external subunit of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein (Env), gp120, contains conserved regions that mediate sequential interactions with two cellular receptor molecules, CD4 and a chemokine receptor, most commonly CCR5 or CXCR4. However, antibody accessibility to such regions is hindered by diverse protective mechanisms, including shielding by variable loops, conformational flexibility and extensive glycosylation. For the conserved neutralization epitopes hitherto described, antibody accessibility is reportedly unrelated to the viral coreceptor usage phenotype. Here, we characterize a novel, conserved gp120 neutralization epitope, recognized by a murine monoclonal antibody (MAb), D19, which is differentially accessible in the native HIV-1 Env according to its coreceptor specificity. The D19 epitope is contained within the third variable (V3) domain of gp120 and is distinct from those recognized by other V3-specific MAbs. To study the reactivity of MAb D19 with the native oligomeric Env, we generated a panel of PM1 cells persistently infected with diverse primary HIV-1 strains. The D19 epitope was conserved in the majority (23/29; 79.3%) of the subtype-B strains tested, as well as in selected strains from other genetic subtypes. Strikingly, in CCR5-restricted (R5) isolates, the D19 epitope was invariably cryptic, although it could be exposed by addition of soluble CD4 (sCD4); epitope masking was dependent on the native oligomeric structure of Env, since it was not observed with the corresponding monomeric gp120 molecules. By contrast, in CXCR4-using strains (X4 and R5X4), the epitope was constitutively accessible. In accordance with these results, R5 isolates were resistant to neutralization by MAb D19, becoming sensitive only upon addition of sCD4, whereas CXCR4-using isolates were neutralized regardless of the presence of sCD4. Other V3 epitopes examined did not display a similar divergence in accessibility based on

  12. Differential gene expression profile reveals deregulation of pregnancy specific β1 glycoprotein 9 early during colorectal carcinogenesis

    Directory of Open Access Journals (Sweden)

    Gallinger Steven

    2005-06-01

    Full Text Available Abstract Background APC (Adenomatous polyposis coli plays an important role in the pathogenesis of both familial and sporadic colorectal cancer. Patients carrying germline APC mutations develop multiple colonic adenomas at younger age and higher frequency than non-carrier cases which indicates that silencing of one APC allele may be sufficient to initiate the transformation process. Methods To elucidate the biological dysregulation underlying adenoma formation we examined global gene expression profiles of adenomas and corresponding normal mucosa from an FAP patient. Differential expression of the most significant gene identified in this study was further validated by mRNA in situ hybridization, reverse transcriptase PCR and Northern blotting in different sets of adenomas, tumours and cancer cell lines. Results Eighty four genes were differentially expressed between all adenomas and corresponding normal mucosa, while only seven genes showed differential expression within the adenomas. The first group included pregnancy specific β-1 glycoprotein 9 (PSG9 (p PSG9 is a member of the carcinoembryonic antigen (CEA/PSG family and is produced at high levels during pregnancy, mainly by syncytiotrophoblasts. Further analysis of sporadic and familial colorectal cancer confirmed that PSG9 is ectopically upregulated in vivo by cancer cells. In total, deregulation of PSG9 mRNA was detected in 78% (14/18 of FAP adenomas and 75% (45/60 of sporadic colorectal cancer cases tested. Conclusion Detection of PSG9 expression in adenomas, and at higher levels in FAP cases, indicates that germline APC mutations and defects in Wnt signalling modulate PSG9 expression. Since PSG9 is not found in the non-pregnant adult except in association with cancer, and it appears to be an early molecular event associated with colorectal cancer monitoring of its expression may be useful as a biomarker for the early detection of this disease.

  13. Multi-drug resistance (MDR1 gene and P-glycoprotein influence on pharmacokinetic and pharmacodymanic of therapeutic drugs

    Directory of Open Access Journals (Sweden)

    Linardi Renata Lehn

    2006-01-01

    Full Text Available (MDR1 gene expressed in tumor cells and also in several normal tissues, such as intestine, liver, kidney, blood-brain barrier, spinal cord, and placenta. P-gp has been identified in mice, rat, bovine, monkey, rodents, and human beings and has been receiving a particular clinical relevance because this protein expression limits brain access and intestinal absorption of many drugs. This protein plays a role as a protective barrier against a wide variety of substrates, avoiding drug entry into the central nervous system. P-glycoprotein also interferes with drug bioavailability and disposition, including absorption, distribution, metabolization, and excretion, influencing pharmacokinetic and pharmacodynamic of drugs. Modulation of P-gp may help the efficacy of treatment of several diseases and can explain some adverse central nervous system effects induced by drugs after intravenous administration and the poor response of oral administration in patients. Alteration in P-gp expression or function has been associated with several diseases susceptibility in humans and animals. Furthermore, additional studies relating MDR1 and P-gp expression has an important clinical implication also in terms of treatment efficacy.

  14. Expression of multidrug resistance gene and P-glycoprotein in nasopharyngealcarcinoma cells after irradiation

    International Nuclear Information System (INIS)

    Wang Ruoyu; Wang Hui; Fan Kai; Lv Shen

    2007-01-01

    Objective: To mimick a clinical fractionated protocol of exposure to X-radiation in vitro in order to investigate the changes in the function of MDR1 and P-gp in nasopharyngeal carcinoma (NPC) CNE cell before and after irradiation to determine the sequential order of radiotherapy and chemotherapy or the time of chemotherapy after radiotherapy in the treatment of NPC. Methods: Exponentially growing CNE cells were treated with fractionated X-radiation with total dose of 10 Gy (2 Gy per day for 5 days consecutively) in vitro. The expression of MDR1 gene was examined in CNE cells before irradiation and on days 4,8,13,17 and 21 after irradiation by RT-PCR, and its protein P-gp were detected by immunocytochemistry. The function of multidrug resistance protein P-gp was examined by MTT method. Results: Expression of MDR1 gene was below the level of detection before irradiation. Irradiation induced an overexpression of MDR1 gene on day 4, expression of MDR1 was decreased from day 8 to day 21. The overall expression of MDR1 was significantly more than that before irradiation (P<0.05) Expression of P-gp was below the level of detection before irradiation, which demonstrated that irradiation induced an overexpression of P-gp. This overexpression was increased from day 8 to day 21. The overpression of MDR1 gene was maintained dining a short period, however, the emergence of overpression of protein P-gp was later than that of MDR1 gene. Resistance index was 1 for both pre-irradiation and on day 8, and up to 8,10,11.2 on days 13, 17 and 21, respectively. The change of resistance index was accordant with the condition of overexpression of P-gp . Conclusions: Expression of P-gp in nasopharyngeal carcinoma (NPC) CNE cell was below the level of detection before irradiation. Irradiation can induce an overexpression of MDR1 gene and its protein P-gp in CNE cells. The overexpression of MDR1 gene and its protein P-gp lasted a long term. (authors)

  15. Knockout of a P-glycoprotein gene increases susceptibility to abamectin and emamectin benzoate in Spodoptera exigua.

    Science.gov (United States)

    Zuo, Y-Y; Huang, J-L; Wang, J; Feng, Y; Han, T-T; Wu, Y-D; Yang, Y-H

    2018-02-01

    P-glycoprotein [P-gp or the ATP-binding cassette transporter B1 (ABCB1)] is an important participant in multidrug resistance of cancer cells, yet the precise function of this arthropod transporter is unknown. The aim of this study was to determine the importance of P-gp for susceptibility to insecticides in the beet armyworm (Spodoptera exigua) using clustered regularly interspaced short palindromic repeats/CRISPR-associated 9 (CRISPR/Cas9) gene-editing technology. We cloned an open reading frame (ORF) encoding the S. exigua P-gp protein (SeP-gp) predicted to display structural characteristics common to P-gp and other insect ABCB1 transporters. A knockout line with a frame shift deletion of four nucleotides in the SeP-gp ORF was established using the CRISPR/Cas9 gene-editing system to test its potential role in determining susceptibility to chemical insecticides or insecticidal proteins from the bacterium Bacillus thuringiensis (Bt). Results from comparative bioassays demonstrate that knockout of SeP-gp significantly increases susceptibility of S. exigua by around threefold to abamectin and emamectin benzoate (EB), but not to spinosad, chlorfenapyr, beta-cypermethrin, carbosulfan indoxacarb, chlorpyrifos, phoxim, diafenthiuron, chlorfluazuron, chlorantraniliprole or two Bt toxins (Cry1Ca and Cry1Fa). Our data support an important role for SeP-gp in susceptibility of S. exigua to abamectin and EB and imply that overexpression of SeP-gp may contribute to abamectin and EB resistance in S. exigua. © 2017 The Royal Entomological Society.

  16. Gene structure of the pregnancy-associated glycoprotein-like (PAG-L) in the Eurasian beaver (Castor fiber L.).

    Science.gov (United States)

    Lipka, Aleksandra; Majewska, Marta; Panasiewicz, Grzegorz; Bieniek-Kobuszewska, Martyna; Szafranska, Bozena

    2017-09-01

    The pregnancy-associated glycoprotein-like family (PAG-L) is a large group of chorionic products, expressed in the pre-placental trophoblast and later in the post-implantational chorionic epithelium, and are involved in proper placenta development and embryo-maternal interaction in eutherians. This study describes identification of the PAG-L family in the genome of the Eurasian beaver (Castor fiber L.), named CfPAG-L. We identified 7657 bp of the CfPAG-L gDNA sequence (Acc. No. KX377932), encompassing nine exons (1-9) and eight introns (A-H). The length of the CfPAG-L exons (59-200 bp) was equivalently similar to the only known counterparts of bPAG1, bPAG2, and pPAG2. The length of the CfPAG-L introns ranged 288-1937 bp and was completely different from previously known PAG introns. The exonic CfPAG-L regions revealed 50.3-72.9% homology with equivalent segments of bPAG1 and pPAG2 structure. The intronic CfPAG-L regions alignments revealed a lack of homology. Within the entire CfPAG-L gene, 31 potential single nucleotide variants (SNV: 7 transversions and 24 transitions) were predicted. The identified exonic polymorphic loci did not affect the amino acid sequence of the CfPAG-L polypeptide precursor. This is the first report describing the CfPAG-L gene sequence, structural organization, and SNVs in the Eurasian beaver, one of the largest rodents.

  17. Developmentally-Regulated Excision of the SPβ Prophage Reconstitutes a Gene Required for Spore Envelope Maturation in Bacillus subtilis

    Science.gov (United States)

    Abe, Kimihiro; Kawano, Yuta; Iwamoto, Keito; Arai, Kenji; Maruyama, Yuki; Eichenberger, Patrick; Sato, Tsutomu

    2014-01-01

    Temperate phages infect bacteria by injecting their DNA into bacterial cells, where it becomes incorporated into the host genome as a prophage. In the genome of Bacillus subtilis 168, an active prophage, SPβ, is inserted into a polysaccharide synthesis gene, spsM. Here, we show that a rearrangement occurs during sporulation to reconstitute a functional composite spsM gene by precise excision of SPβ from the chromosome. SPβ excision requires a putative site-specific recombinase, SprA, and an accessory protein, SprB. A minimized SPβ, where all the SPβ genes were deleted, except sprA and sprB, retained the SPβ excision activity during sporulation, demonstrating that sprA and sprB are necessary and sufficient for the excision. While expression of sprA was observed during vegetative growth, sprB was induced during sporulation and upon mitomycin C treatment, which triggers the phage lytic cycle. We also demonstrated that overexpression of sprB (but not of sprA) resulted in SPβ prophage excision without triggering the lytic cycle. These results suggest that sprB is the factor that controls the timing of phage excision. Furthermore, we provide evidence that spsM is essential for the addition of polysaccharides to the spore envelope. The presence of polysaccharides on the spore surface renders the spore hydrophilic in water. This property may be beneficial in allowing spores to disperse in natural environments via water flow. A similar rearrangement occurs in Bacillus amyloliquefaciens FZB42, where a SPβ-like element is excised during sporulation to reconstitute a polysaccharide synthesis gene, suggesting that this type of gene rearrangement is common in spore-forming bacteria because it can be spread by phage infection. PMID:25299644

  18. A Taq 1 polymorphism for the human platelet glycoprotein IIIa gene (GP3A)

    Energy Technology Data Exchange (ETDEWEB)

    Burk, C; Ingram, C; Weiner, M; Rappaport, E F; Schwartz, E; Poncz, M [Univ. of Pennsylvania School of Medicine, Philadelphia (USA)

    1988-07-25

    A cDNA clone containing a 4.0 kb GPIIIa insert was isolated from a human erythroleukemia (HEL) cell cDNA library. A 2.3 kb Eco RI fragment, representing the 5{prime} portion of this insert, was used as a probe for these Southern blot experiments. Taq I (T/CGA) identifies invariant bands of 5.0, 3.5, 1.3, 1.1, and 0.8 kb and a simple polymorphism with a band(s) at 8.0 kb or 4.8 and 3.2 kb. The frequency of the gene was studied in 17 persons (11 Caucasians, 3 Asians, and 3 blacks). The GPIIIa gene has been localized to the region 17q21{r arrow}22 by somatic cell hybrid and in situ hybridization studies. Mendelian inheritance was demonstrated in one family. The father is homozygous for the 8.0 kb band, and the mother is heterozygous for the 8.0/4.8 and 3.2 kb bands.

  19. Human coronavirus 229E encodes a single ORF4 protein between the spike and the envelope genes

    Directory of Open Access Journals (Sweden)

    Berkhout Ben

    2006-12-01

    Full Text Available Abstract Background The genome of coronaviruses contains structural and non-structural genes, including several so-called accessory genes. All group 1b coronaviruses encode a single accessory protein between the spike and envelope genes, except for human coronavirus (HCoV 229E. The prototype virus has a split gene, encoding the putative ORF4a and ORF4b proteins. To determine whether primary HCoV-229E isolates exhibit this unusual genome organization, we analyzed the ORF4a/b region of five current clinical isolates from The Netherlands and three early isolates collected at the Common Cold Unit (CCU in Salisbury, UK. Results All Dutch isolates were identical in the ORF4a/b region at amino acid level. All CCU isolates are only 98% identical to the Dutch isolates at the nucleotide level, but more closely related to the prototype HCoV-229E (>98%. Remarkably, our analyses revealed that the laboratory adapted, prototype HCoV-229E has a 2-nucleotide deletion in the ORF4a/b region, whereas all clinical isolates carry a single ORF, 660 nt in size, encoding a single protein of 219 amino acids, which is a homologue of the ORF3 proteins encoded by HCoV-NL63 and PEDV. Conclusion Thus, the genome organization of the group 1b coronaviruses HCoV-NL63, PEDV and HCoV-229E is identical. It is possible that extensive culturing of the HCoV-229E laboratory strain resulted in truncation of ORF4. This may indicate that the protein is not essential in cell culture, but the highly conserved amino acid sequence of the ORF4 protein among clinical isolates suggests that the protein plays an important role in vivo.

  20. Sequence analysis of the 5′ third of glycoprotein C gene of South American bovine herpesviruses 1 and 5

    Energy Technology Data Exchange (ETDEWEB)

    Traesel, C.K.; Bernardes, L.M. [Setor de Virologia, Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil); Spilki, F.R. [Laboratório de Microbiologia Molecular, Universidade Feevale, Novo Hamburgo, RS (Brazil); Weiblen, R.; Flores, E.F. [Setor de Virologia, Departamento de Medicina Veterinária Preventiva, Universidade Federal de Santa Maria, Santa Maria, RS (Brazil)

    2015-03-06

    Bovine herpesviruses 1 (BoHV-1) and 5 (BoHV-5) share high genetic and antigenic similarities, but exhibit marked differences in tissue tropism and neurovirulence. The amino-terminal region of glycoprotein C (gC), which is markedly different in each of the viruses, is involved in virus binding to cellular receptors and in interactions with the immune system. This study investigated the genetic and antigenic differences of the 5′ region of the gC (5′ gC) gene (amino-terminal) of South American BoHV-1 (n=19) and BoHV-5 (n=25) isolates. Sequence alignments of 374 nucleotides (104 amino acids) revealed mean similarity levels of 97.3 and 94.2% among BoHV-1 gC (gC1), respectively, 96.8 and 95.6% among BoHV-5 gC (gC5), and 62 and 53.3% between gC1 and gC5. Differences included the absence of 40 amino acid residues (27 encompassing predicted linear epitopes) scattered throughout 5′ gC1 compared to 5′ gC5. Virus neutralizing assays testing BoHV-1 and BoHV-5 antisera against each isolate revealed a high degree of cross-neutralization between the viruses, yet some isolates were neutralized at very low titers by heterologous sera, and a few BoHV-5 isolates reacted weakly with either sera. The virus neutralization differences observed within the same viral species, and more pronounced between BoHV-1 and BoHV-5, likely reflect sequence differences in neutralizing epitopes. These results demonstrate that the 5′ gC region is well conserved within each viral species but is divergent between BoHV-1 and BoHV-5, likely contributing to their biological and antigenic differences.

  1. Evidence for changes in the transcription levels of two putative P-glycoprotein genes in sea lice (Lepeophtheirus salmonis) in response to emamectin benzoate exposure.

    Science.gov (United States)

    Tribble, Nicholas D; Burka, John F; Kibenge, Frederick S B

    2007-05-01

    Overexpression of P-glycoproteins (Pgps) is assumed to be a principal mechanism of resistance of nematodes and arthropods to macrocyclic lactones. Quantitative RT-PCR (Q-RT-PCR) was used to demonstrate changes in transcription levels of two putative P-glycoprotein genes, designated here as SL0525 and SL-Pgp1, in sea lice (Lepeophtheirus salmonis) following exposure to emamectin benzoate (EMB). Pre-adult L. salmonis were challenged in an EMB bioassay for 24h and gene expression was studied from lice surviving EMB concentrations of 0, 10, and 30ppb. Gene expression was measured using Q-RT-PCR with elongation factor 1 (eEF1alpha) as an internal reference gene. The results show that both target genes, SL0525 and SL-Pgp1, had significantly increased levels of expression with exposure to 10ppb EMB (p=0.11 and p=0.17, respectively) whereas the group exposed to 30ppb was on the verge of being significant (p=0.053) only in the expression of SL-Pgp1. Gene expression for SL0525 and SL-Pgp1 were increased over five-fold at 10ppb EMB. Therefore, the upregulation of these target genes may offer protection by increasing Pgp expression when lice are exposed to EMB. Our optimized Q-RT-PCR can be used to determine if over-expression of these genes could be the basis for development of resistance in sea lice and thus allow suitable alternative chemotherapeutic options to be assessed.

  2. Building envelope

    CSIR Research Space (South Africa)

    Gibberd, Jeremy T

    2009-01-01

    Full Text Available for use in the building. This is done through photovoltaic and solar water heating panels and wind turbines. Ideally these are integrated in the design of the building envelope to improve the aesthetic quality of the building and minimise material... are naturally ventilated. Renewable energy The building envelope includes renewable energy generation such as photovoltaics, wind turbines and solar water heaters and 10% of the building’s energy requirements are generated from these sources. Views All...

  3. Biomimetic Envelopes

    OpenAIRE

    Ilaria Mazzoleni

    2010-01-01

    How to translate the lessons learned from the analysis and observation of the animal world is the design learning experience presented in this article. Skin is a complex and incredibly sophisticated organ that performs various functions, including protection, sensation and heat and water regulation. In a similar way building envelopes serve multiple roles, as they are the interface between the building inhabitants and environmental elements. The resulting architectural building envelopes prot...

  4. Positive selection of mutants with cell envelope defects of a Salmonella typhimurium strain hypersensitive to the products of genes hisF and hisH

    International Nuclear Information System (INIS)

    Anton, D.N.

    1979-01-01

    Strain SB564 and its derivative DA78 are hypersensitive to the inhibitory action of the proteins coded for by genes hisF and hisH on cell division. Transduction of hisO1242, a regulatory mutation that elicits a very high level of expression of the histidine operon, into these strains resulted in the production of long filamentous cells carrying large balloons and in growth failure. Forty-one hisO1242 derivatives that escaped inhibition were isolated. These strains showed a large variety of alterations, many of which were related to the cell envelope. The more-frequent alterations included: changes in cell shape, increased sensitivity to one or more of several drugs (deoxycholate, cycloserine, penicillin, novobiocin, acridine orange), increased autolytic activity in alkaline buffer, anomalous fermentation of maltose on eosin--methylene blue plates, and temperature-conditional cell division. The alterations are produced, in some of the strains, by pleiotropic mutations in gene envB. Strains affected in divC, divD, and rodA loci have also been identified. Genetic analaysis has shown that several strains carry more than one envelope mutation. It is assumed that envelope mutations are positively selected because they somehow alleviate the particularly severe inhibition of cell division caused, in strains SB564 and DA78, by the excessive synthesis of hisF and hisH gene products

  5. Antibodies specific for hypervariable regions 3 to 5 of the feline immunodeficiency virus envelope glycoprotein are not solely responsible for vaccine-induced acceleration of challenge infection in cats

    NARCIS (Netherlands)

    W. Huisman (Willem); E.J.A. Schrauwen (Eefje); S.D. Pas (Suzan); J.A. Karlas (Jos); G.F. Rimmelzwaan (Guus); A.D.M.E. Osterhaus (Albert)

    2004-01-01

    textabstractIn a previous vaccination study in cats, the authors reported on accelerated feline immunodeficiency virus (FIV) replication upon challenge in animals vaccinated with a candidate envelope subunit vaccine. Plasma transfer studies as well as antibody profiles in vaccinated cats indicated a

  6. Contribution of the Pmra Promoter to Expression of Genes in the Escherichia coli mra Cluster of Cell Envelope Biosynthesis and Cell Division Genes

    Science.gov (United States)

    Mengin-Lecreulx, Dominique; Ayala, Juan; Bouhss, Ahmed; van Heijenoort, Jean; Parquet, Claudine; Hara, Hiroshi

    1998-01-01

    Recently, a promoter for the essential gene ftsI, which encodes penicillin-binding protein 3 of Escherichia coli, was precisely localized 1.9 kb upstream from this gene, at the beginning of the mra cluster of cell division and cell envelope biosynthesis genes (H. Hara, S. Yasuda, K. Horiuchi, and J. T. Park, J. Bacteriol. 179:5802–5811, 1997). Disruption of this promoter (Pmra) on the chromosome and its replacement by the lac promoter (Pmra::Plac) led to isopropyl-β-d-thiogalactopyranoside (IPTG)-dependent cells that lysed in the absence of inducer, a defect which was complemented only when the whole region from Pmra to ftsW, the fifth gene downstream from ftsI, was provided in trans on a plasmid. In the present work, the levels of various proteins involved in peptidoglycan synthesis and cell division were precisely determined in cells in which Pmra::Plac promoter expression was repressed or fully induced. It was confirmed that the Pmra promoter is required for expression of the first nine genes of the mra cluster: mraZ (orfC), mraW (orfB), ftsL (mraR), ftsI, murE, murF, mraY, murD, and ftsW. Interestingly, three- to sixfold-decreased levels of MurG and MurC enzymes were observed in uninduced Pmra::Plac cells. This was correlated with an accumulation of the nucleotide precursors UDP–N-acetylglucosamine and UDP–N-acetylmuramic acid, substrates of these enzymes, and with a depletion of the pool of UDP–N-acetylmuramyl pentapeptide, resulting in decreased cell wall peptidoglycan synthesis. Moreover, the expression of ftsZ, the penultimate gene from this cluster, was significantly reduced when Pmra expression was repressed. It was concluded that the transcription of the genes located downstream from ftsW in the mra cluster, from murG to ftsZ, is also mainly (but not exclusively) dependent on the Pmra promoter. PMID:9721276

  7. Co-Expression and Co-Localization of Cartilage Glycoproteins CHI3L1 and Lubricin in Osteoarthritic Cartilage: Morphological, Immunohistochemical and Gene Expression Profiles

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    Marta Anna Szychlinska

    2016-03-01

    Full Text Available Osteoarthritis is the most common human arthritis characterized by degeneration of articular cartilage. Several studies reported that levels of human cartilage glycoprotein chitinase 3-like-1 (CHI3L1 are known as a potential marker for the activation of chondrocytes and the progression of Osteoarthritis (OA, whereas lubricin appears to be chondroprotective. The aim of this study was to investigate the co-expression and co-localization of CHI3L1 and lubricin in normal and osteoarthritic rat articular cartilage to correlate their modified expression to a specific grade of OA. Samples of normal and osteoarthritic rat articular cartilage were analyzed by the Kellgren–Lawrence OA severity scores, the Kraus’ modified Mankin score and the Histopathology Osteoarthritis Research Society International (OARSI system for histomorphometric evaluations, and through CHI3L1 and lubricin gene expression, immunohistochemistry and double immuno-staining analysis. The immunoexpression and the mRNA levels of lubricin increased in normal cartilage and decreased in OA cartilage (normal vs. OA, p < 0.01. By contrast, the immunoexpression and the mRNA levels of CHI3L1 increased in OA cartilage and decreased in normal cartilage (normal vs. OA, p < 0.01. Our findings are consistent with reports suggesting that these two glycoproteins are functionally associated with the development of OA and in particular with grade 2/3 of OA, suggesting that in the future they could be helpful to stage the severity and progression of the disease.

  8. Phylogenetic relationships of the glycoprotein gene of bovine ephemeral fever virus isolated from mainland China, Taiwan, Japan, Turkey, Israel and Australia

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    Zheng Fuying

    2012-11-01

    Full Text Available Abstract Background The glycoprotein (G gene sequences of bovine ephemeral fever virus (BEFV strains derived from mainland China have not been compared with those of the isolates from other countries or areas. Therefore, the G genes of four BEFV isolates obtained from mainland China were amplified and sequenced. A phylogenetic tree was constructed in order to compare and analyze the genetic relationships of the BEFV isolates derived from mainland China and different countries and areas. Results The complete BEFV G gene was successfully amplified and sequenced from four isolates that originated from mainland China. A total of fifty-one BEFV strains were analyzed based on the G gene sequence and were found to be highly conserved. A phylogenetic tree showed that the isolates were grouped into three distinct lineages depending on their source of origin. The antigenic sites of G1, G2 and G3 are conserved among the isolates, except for several substitutions in a few strains. Conclusions The phylogenetic relationships of the BEFV isolates that originated from mainland China, Taiwan, Japan, Turkey, Israel and Australia were closely related to their source of origin, while the antigenic sites G1, G2 and G3 are conserved among the BEFV isolates used in this work.

  9. Construction and growth properties of bovine herpesvirus type 5 recombinants defective in the glycoprotein E or thymidine kinase gene or both

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    M.C.S. Brum

    2010-02-01

    Full Text Available Bovine herpesvirus type 5 (BoHV-5 is an important pathogen of cattle in South America. We describe here the construction and characterization of deletion mutants defective in the glycoprotein E (gE or thymidine kinase (TK gene or both (gE/TK from a highly neurovirulent and well-characterized Brazilian BoHV-5 strain (SV507/99. A gE-deleted recombinant virus (BoHV-5 gE∆ was first generated in which the entire gE open reading frame was replaced with a chimeric green fluorescent protein gene. A TK-deleted recombinant virus (BoHV-5 TK∆ was then generated in which most of the TK open reading frame sequences were deleted and replaced with a chimeric β-galactosidase gene. Subsequently, using the BoHV-5 gE∆ virus as backbone, a double gene-deleted (TK plus gE BoHV-5 recombinant (BoHV-5 gE/TK∆ was generated. The deletion of the gE and TK genes was confirmed by immunoblotting and PCR, respectively. In Madin Darby bovine kidney (MDBK cells, the mutants lacking gE (BoHV-5 gE∆ and TK + gE (BoHV-5 gE/TK∆ produced small plaques while the TK-deleted BoHV-5 produced wild-type-sized plaques. The growth kinetics and virus yields in MDBK cells for all three recombinants (BoHV-5 gE∆, BoHV-5 TK∆ and BoHV-5 gE/TK∆ were similar to those of the parental virus. It is our belief that the dual gene-deleted recombinant (BoHV-5 gE/TK∆ produced on the background of a highly neurovirulent Brazilian BoHV-5 strain may have potential application in a vaccine against BoHV-5.

  10. Evaluation of envelope glycoprotein E(rns) of an atypical bovine pestivirus as antigen in a microsphere immunoassay for the detection of antibodies against bovine viral diarrhea virus 1 and atypical bovine pestivirus.

    Science.gov (United States)

    Vijayaraghavan, Balaje; Xia, Hongyan; Harimoorthy, Rajiv; Liu, Lihong; Belák, Sándor

    2012-11-01

    Atypical bovine pestiviruses are related antigenically and phylogenetically to bovine viral diarrhea viruses (BVDV-1 and BVDV-2), and may cause the same clinical manifestations in animals. Glycoprotein E(rns) of an atypical bovine pestivirus Th/04_KhonKaen was produced in a baculovirus expression system and was purified by affinity chromatography. The recombinant E(rns) protein was used as an antigen in a microsphere immunoassay for the detection of antibodies against BVDV-1 and atypical bovine pestivirus. The diagnostic performance of the new method was evaluated by testing a total of 596 serum samples, and the assay was compared with enzyme-linked immunosorbent assay (ELISA). Based on the negative/positive cut-off median fluorescence intensity (MFI) value of 2800, the microsphere immunoassay had a sensitivity of 100% and specificity of 100% compared to ELISA. The immunoassay was able to detect antibodies against both BVDV-1 and the atypical pestivirus. This novel microsphere immunoassay has the potential to be multiplexed for simultaneous detection of antibodies against different bovine pathogens in a high-throughput and economical way. Copyright © 2012 Elsevier B.V. All rights reserved.

  11. Species-specific deletion of the viral attachment glycoprotein of avian metapneumovirus.

    Science.gov (United States)

    Kong, Byung-Whi; Foster, Linda K; Foster, Douglas N

    2008-03-01

    The avian metapneumovirus (AMPV) genome encodes the fusion (F), small hydrophobic (SH), and attachment glycoprotein (G) as envelope glycoproteins. The F and G proteins mainly function to allow viral entry into host cells during the early steps of the virus life cycle. The highly variable AMPV G protein is a major determinant for distinguishing virus subtypes. Sequence analysis was used to determine if any differences between avian or mammalian cell propagated subtype C AMPV could be detected for the 1.8kb G gene. As a result, the complete 1.8kb G gene was found to be present when AMPV was propagated in our immortal turkey turbinate (TT-1) cell line regardless of passage number. Surprisingly, AMPV propagated for 15 or more passages in mammalian Vero cells revealed an essentially deleted G gene in the viral genome, resulting in no G gene mRNA expression. Although the Vero cell propagated AMPV genome contained a small 122 nucleotide fragment of the G gene, no other mRNA variants were detected from either mammalian or avian propagated AMPV. The G gene truncation might be caused by cellular molecular mechanisms that are species-specific. The lack of viral gene deletions suggests that avian cell propagated AMPV will provide a better alternative host for live recombinant vaccine development based on a reverse genetics system.

  12. HaCaT Keratinocytes and Primary Epidermal Keratinocytes Have Different Transcriptional Profiles of Cornified Envelope-Associated Genes to T Helper Cell Cytokines

    Science.gov (United States)

    Seo, Min-Duk; Kang, Tae Jin; Lee, Chang Hoon; Lee, Ai-Young; Noh, Minsoo

    2012-01-01

    HaCaT cells are the immortalized human keratinocytes and have been extensively used to study the epidermal homeostasis and its pathophysiology. T helper cells play a role in various chronic dermatological conditions and they can affect skin barrier homeostasis. To evaluate whether HaCaT cells can be used as a model cell system to study abnormal skin barrier development in various dermatologic diseases, we analyzed the gene expression profile of epidermal differentiation markers of HaCaT cells in response to major T helper (Th) cell cytokines, such as IFNγ, IL-4, IL-17A and IL-22. The gene transcriptional profile of cornified envelope-associated proteins, such as filaggrin, loricrin, involucrin and keratin 10 (KRT10), in HaCaT cells was generally different from that in normal human keratinocytes (NHKs). This suggests that HaCaT cells have a limitation as a model system to study the pathophysiological mechanism associated with the Th cell cytokine-dependent changes in cornified envelope-associated proteins which are essential for normal skin barrier development. In contrast, the gene transcription profile change of human β2-defensin (HBD2) in response to IFNγ, IL-4 or IL-17A in HaCaT cells was consistent with the expression pattern of NHKs. IFNγ also up-regulated transglutaminase 2 (TGM2) gene transcription in both HaCaT cells and NHKs. As an alternative cell culture system for NHKs, HaCaT cells can be used to study molecular mechanisms associated with abnormal HBD2 and TGM2 expression in response to IFNγ, IL-4 or IL-17A. PMID:24116291

  13. Prediction of conserved sites and domains in glycoproteins B, C and D of herpes viruses.

    Science.gov (United States)

    Rasheed, Muhammad Asif; Ansari, Abdur Rahman; Ihsan, Awais; Navid, Muhammad Tariq; Ur-Rehman, Shahid; Raza, Sohail

    2018-03-01

    Glycoprotein B (gB), C (gC) and D (gD) of herpes simplex virus are implicated in virus adsorption and penetration. The gB, gC and gD are glycoproteins for different processes of virus binding and attachment to the host cells. Moreover, their expression is necessary and sufficient to induce cell fusion in the absence of other glycoproteins. Egress of herpes simplex virus (HSV) and other herpes viruses from cells involves extensive modification of cellular membranes and sequential envelopment, de-envelopment and re-envelopment steps. Viral glycoproteins are important in these processes, and frequently two or more glycoproteins can largely suffice in any step. Hence, we target the 3 important glycoproteins (B, C and D) of eight different herpes viruses of different species. These species include human (HSV1 and 2), bovine (BHV1), equine (EHV1 and 4), chicken (ILT1 and MDV2) and pig (PRV1). By applying different bioinformatics tools, we highlighted the conserved sites in these glycoproteins which might be most significant regarding attachment and infection of the viruses. Moreover the conserved domains in these glycoproteins are also highlighted. From this study, we will able to analyze the role of different viral glycoproteins of different species during herpes virus adsorption and penetration. Moreover, this study will help to construct the antivirals that target the glycoproteins of different herpes viruses. Copyright © 2018 Elsevier Ltd. All rights reserved.

  14. In vitro Effects of Four Native Brazilian Medicinal Plants in CYP3A4 mRNA Gene Expression, Glutathione Levels, and P-Glycoprotein Activity.

    Science.gov (United States)

    Mazzari, Andre L D A; Milton, Flora; Frangos, Samantha; Carvalho, Ana C B; Silveira, Dâmaris; de Assis Rocha Neves, Francisco; Prieto, Jose M

    2016-01-01

    Erythrina mulungu Benth. (Fabaceae), Cordia verbenacea A. DC. (Boraginaceae), Solanum paniculatum L. (Solanaceae) and Lippia sidoides Cham. (Verbenaceae) are medicinal plant species native to Brazil shortlisted by the Brazilian National Health System for future clinical use. However, nothing is known about their effects in metabolic and transporter proteins, which could potentially lead to herb-drug interactions (HDI). In this work, we assess non-toxic concentrations (100 μg/mL) of the plant infusions for their in vitro ability to modulate CYP3A4 mRNA gene expression and intracellular glutathione levels in HepG2 cells, as well as P-glycoprotein (P-gp) activity in vincristine-resistant Caco-2 cells (Caco-2 VCR). Their mechanisms of action were further studied by measuring the activation of human pregnane X receptor (hPXR) in transiently co-transfected HeLa cells and the inhibition of γ-glutamyl transferase (GGT) in HepG2 cells. Our results show that P-gp activity was not affected in any case and that only Solanum paniculatum was able to significantly change CYP3A4 mRNA gene expression (twofold decrease, p effect upon hPXR (EC50 = 0.38 mg/mL). Total intracellular glutathione levels were significantly depleted by exposure to Solanum paniculatum (-44%, p Cordia verbenacea (-47%, p activity (-48%, p active pharmacovigilance is recommended for the other three species, especially in the case of Solanum paniculatum.

  15. Increasing BMI is associated with reduced expression of P-glycoprotein (ABCB1 gene) in the human brain with a stronger association in African-Americans than Caucasians

    DEFF Research Database (Denmark)

    Nielsen, Julie Vendelbo; Olesen, Rasmus Hansen; Lauridsen, Jesper Krogh

    2016-01-01

    The efflux pump, p-glycoprotein, controls bioavailability and excretion of pharmaceutical compounds. In the blood-brain barrier, p-glycoprotein regulates the delivery of pharmaceutical substances to the brain, influencing efficacy and side effects for some drugs notably antipsychotics. Common sid...... online publication, 29 November 2016; doi:10.1038/tpj.2016.74....

  16. Subtle differences in selective pressures applied on the envelope gene of HIV-1 in pregnant versus non-pregnant women.

    Science.gov (United States)

    Ransy, Doris G; Lord, Etienne; Caty, Martine; Lapointe, Normand; Boucher, Marc; Diallo, Abdoulaye Baniré; Soudeyns, Hugo

    2018-04-17

    Pregnancy is associated with modulations of maternal immunity that contribute to foeto-maternal tolerance. To understand whether and how these alterations impact antiviral immunity, a detailed cross-sectional analysis of selective pressures exerted on HIV-1 envelope amino-acid sequences was performed in a group of pregnant (n = 32) and non-pregnant (n = 44) HIV-infected women in absence of treatment with antiretroviral therapy (ART). Independent of HIV-1 subtype, p-distance, dN and dS were all strongly correlated with one another but were not significantly different in pregnant as compared to non-pregnant patients. Differential levels of selective pressure applied on different Env subdomains displayed similar yet non-identical patterns between the two groups, with pressure applied on C1 being significantly lower in constant regions C1 and C2 than in V1, V2, V3 and C3. To draw a general picture of the selection applied on the envelope and compensate for inter-individual variations, we performed a binomial test on selection frequency data pooled from pregnant and non-pregnant women. This analysis uncovered 42 positions, present in both groups, exhibiting statistically-significant frequency of selection that invariably mapped to the surface of the Env protein, with the great majority located within epitopes recognized by Env-specific antibodies or sites associated with the development of cross-reactive neutralizing activity. The median frequency of occurrence of positive selection per site was significantly lower in pregnant versus non-pregnant women. Furthermore, examination of the distribution of positively selected sites using a hypergeometric test revealed that only 2 positions (D137 and S142) significantly differed between the 2 groups. Taken together, these result indicate that pregnancy is associated with subtle yet distinctive changes in selective pressures exerted on the HIV-1 Env protein that are compatible with transient modulations of maternal

  17. Enhanced Efficacy of a Codon-Optimized DNA Vaccine Encoding the Glycoprotein Precursor Gene of Lassa Virus in a Guinea Pig Disease Model When Delivered by Dermal Electroporation

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    Niranjan Y. Sardesai

    2013-07-01

    Full Text Available Lassa virus (LASV causes a severe, often fatal, hemorrhagic fever endemic to West Africa. Presently, there are no FDA-licensed medical countermeasures for this disease. In a pilot study, we constructed a DNA vaccine (pLASV-GPC that expressed the LASV glycoprotein precursor gene (GPC. This plasmid was used to vaccinate guinea pigs (GPs using intramuscular electroporation as the delivery platform. Vaccinated GPs were protected from lethal infection (5/6 with LASV compared to the controls. However, vaccinated GPs experienced transient viremia after challenge, although lower than the mock-vaccinated controls. In a follow-on study, we developed a new device that allowed for both the vaccine and electroporation pulse to be delivered to the dermis. We also codon-optimized the GPC sequence of the vaccine to enhance expression in GPs. Together, these innovations resulted in enhanced efficacy of the vaccine. Unlike the pilot study where neutralizing titers were not detected until after virus challenge, modest neutralizing titers were detected in guinea pigs before challenge, with escalating titers detected after challenge. The vaccinated GPs were never ill and were not viremic at any timepoint. The combination of the codon-optimized vaccine and dermal electroporation delivery is a worthy candidate for further development.

  18. Sequence variation of the glycoprotein gene identifies three distinct lineages within field isolates of viral hemorrhagic septicemia virus, a fish rhabdovirus

    Science.gov (United States)

    Benmansour, A.; Bascuro, B.; Monnier, A.F.; Vende, P.; Winton, J.R.; de Kinkelin, P.

    1997-01-01

    To evaluate the genetic diversity of viral haemorrhagic septicaemia virus (VHSV), the sequence of the glycoprotein genes (G) of 11 North American and European isolates were determined. Comparison with the G protein of representative members of the family Rhabdoviridae suggested that VHSV was a different virus species from infectious haemorrhagic necrosis virus (IHNV) and Hirame rhabdovirus (HIRRV). At a higher taxonomic level, VHSV, IHNV and HIRRV formed a group which was genetically closest to the genus Lyssavirus. Compared with each other, the G genes of VHSV displayed a dissimilar overall genetic diversity which correlated with differences in geographical origin. The multiple sequence alignment of the complete G protein, showed that the divergent positions were not uniformly distributed along the sequence. A central region (amino acid position 245-300) accumulated substitutions and appeared to be highly variable. The genetic heterogeneity within a single isolate was high, with an apparent internal mutation frequency of 1.2 x 10(-3) per nucleotide site, attesting the quasispecies nature of the viral population. The phylogeny separated VHSV strains according to the major geographical area of isolation: genotype I for continental Europe, genotype II for the British Isles, and genotype III for North America. Isolates from continental Europe exhibited the highest genetic variability, with sub-groups correlated partially with the serological classification. Neither neutralizing polyclonal sera, nor monoclonal antibodies, were able to discriminate between the genotypes. The overall structure of the phylogenetic tree suggests that VHSV genetic diversity and evolution fit within the model of random change and positive selection operating on quasispecies.

  19. In vitro Effects of Four Native Brazilian Medicinal Plants in CYP3A4 mRNA Gene Expression, Glutathione Levels, and P-Glycoprotein Activity

    Science.gov (United States)

    Mazzari, Andre L. D. A.; Milton, Flora; Frangos, Samantha; Carvalho, Ana C. B.; Silveira, Dâmaris; de Assis Rocha Neves, Francisco; Prieto, Jose M.

    2016-01-01

    Erythrina mulungu Benth. (Fabaceae), Cordia verbenacea A. DC. (Boraginaceae), Solanum paniculatum L. (Solanaceae) and Lippia sidoides Cham. (Verbenaceae) are medicinal plant species native to Brazil shortlisted by the Brazilian National Health System for future clinical use. However, nothing is known about their effects in metabolic and transporter proteins, which could potentially lead to herb-drug interactions (HDI). In this work, we assess non-toxic concentrations (100 μg/mL) of the plant infusions for their in vitro ability to modulate CYP3A4 mRNA gene expression and intracellular glutathione levels in HepG2 cells, as well as P-glycoprotein (P-gp) activity in vincristine-resistant Caco-2 cells (Caco-2 VCR). Their mechanisms of action were further studied by measuring the activation of human pregnane X receptor (hPXR) in transiently co-transfected HeLa cells and the inhibition of γ-glutamyl transferase (GGT) in HepG2 cells. Our results show that P-gp activity was not affected in any case and that only Solanum paniculatum was able to significantly change CYP3A4 mRNA gene expression (twofold decrease, p Cordia verbenacea (-47%, p < 0.001). The latter plant extract was able to decrease GGT activity (-48%, p < 0.01). In conclusion, this preclinical study shows that the administration of some of these herbal medicines may be able to cause disturbances to metabolic mechanisms in vitro. Although Erythrina mulungu appears safe in our tests, active pharmacovigilance is recommended for the other three species, especially in the case of Solanum paniculatum. PMID:27594838

  20. In vitro effects of four native Brazilian medicinal plants in CYP3A4 mRNA gene expression, glutathione levels and P-glycoprotein activity.

    Directory of Open Access Journals (Sweden)

    Andre Luis Dias Araujo Mazzari

    2016-08-01

    Full Text Available Erythrina mulungu Benth. (Fabaceae, Cordia verbenacea A. DC. (Boraginaceae, Solanum paniculatum L. (Solanaceae and Lippia sidoides Cham. (Verbenaceae are medicinal plants species native to Brazil shortlisted by the Brazilian National Health System for future clinical use. However, nothing is known about their effects in metabolic and transporter proteins, which could potentially lead to herb-drug interactions (HDI. In this work we assess non-toxic concentrations (100μg/mL of their infusions for their in vitro ability to modulate CYP3A4 mRNA gene expression and intracellular glutathione levels in HepG2 cells, as well as P-glycoprotein (P-gp activity in vincristine-resistant Caco-2 cells (Caco-2 VCR. Their mechanisms of action were further studied by measuring the activation of human pregnane X receptor (hPXR in transiently co-transfected HeLa cells and the inhibition of γ-glutamyl transferase (GGT in HepG2 cells. Our results show that P-gp activity was not affected in any case and that only Solanum paniculatum was able to significantly change CYP3A4 mRNA gene expression (two-fold decrease, p<0.05, this being correlated with an antagonist effect upon hPXR (EC50 = 0.38mg/mL. Total intracellular glutathione levels were significantly depleted by exposure to Solanum paniculatum (-44%, p<0.001, Lippia sidoides (-12%, p<0.05 and Cordia verbenacea (-47%, p<0.001. The later plant extract was able to decrease GGT activity (-48%, p<0.01. In conclusion, this preclinical study shows that the administration of some of these herbal medicines may be able to cause disturbances to metabolic mechanisms in vitro. Although Erythrina mulungu appears safe in our tests, active pharmacovigilance is recommended for the other three species, especially in the case of Solanum paniculatum.

  1. The Arabidopsis SKU5 gene encodes an extracellular glycosyl phosphatidylinositol-anchored glycoprotein involved in directional root growth

    Science.gov (United States)

    Sedbrook, John C.; Carroll, Kathleen L.; Hung, Kai F.; Masson, Patrick H.; Somerville, Chris R.

    2002-01-01

    To investigate how roots respond to directional cues, we characterized a T-DNA-tagged Arabidopsis mutant named sku5 in which the roots skewed and looped away from the normal downward direction of growth on inclined agar surfaces. sku5 roots and etiolated hypocotyls were slightly shorter than normal and exhibited a counterclockwise (left-handed) axial rotation bias. The surface-dependent skewing phenotype disappeared when the roots penetrated the agar surface, but the axial rotation defect persisted, revealing that these two directional growth processes are separable. The SKU5 gene belongs to a 19-member gene family designated SKS (SKU5 Similar) that is related structurally to the multiple-copper oxidases ascorbate oxidase and laccase. However, the SKS proteins lack several of the conserved copper binding motifs characteristic of copper oxidases, and no enzymatic function could be assigned to the SKU5 protein. Analysis of plants expressing SKU5 reporter constructs and protein gel blot analysis showed that SKU5 was expressed most strongly in expanding tissues. SKU5 was glycosylated and modified by glycosyl phosphatidylinositol and localized to both the plasma membrane and the cell wall. Our observations suggest that SKU5 affects two directional growth processes, possibly by participating in cell wall expansion.

  2. Tropism, Cytotoxicity, and Inflammatory Properties of Two Envelope Genes of Murine Leukemia Virus Type-Endogenous Retroviruses of C57BL/6J Mice

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    Young-Kwan Lee

    2011-01-01

    Full Text Available Envelope (env proteins of certain endogenous retroviruses (ERVs participate in various pathophysiological processes. In this study, we characterized pathophysiologic properties of two murine leukemia virus-type ERV (MuLV-ERV env genes cloned from the ovary of C57BL/6J mice. The two env genes (named ENVOV1 and ENVOV2, with 1,926\\,bp coding region, originated from two MuLV-ERV loci on chromosomes 8 and 18, respectively. ENVOV1 and ENVOV2 were ~75 kDa and predominantly expressed on the cell membrane. They were capable of producing pseudotype murine leukemia virus virions. Tropism trait and infectivity of ENVOV2 were similar to the polytropic env; however, ENVOV1 had very low level of infectivity. Overexpression of ENVOV2, but not ENVOV1, exerted cytotoxic effects and induced expression of COX-2, IL-1β, IL-6, and iNOS. These findings suggest that the ENVOV1 and ENVOV2 are capable of serving as an env protein for virion assembly, and they exert differential cytotoxicity and modulation of inflammatory mediators.

  3. Effect of PlA1/A2 glycoprotein IIIa gene polymorphism on the long-term outcome after successful coronary stenting

    Directory of Open Access Journals (Sweden)

    Riddell John

    2007-11-01

    Full Text Available Abstract Aim To prospectively determine the role of platelet glycoprotein IIIa (GP IIIa gene PlA1/PlA2 polymorphism on the long-term clinical outcome in patients with coronary artery disease undergoing coronary stenting. Design and setting Prospective observational study in the University Hospital of Caen (France. Patients and methods 1 111 symptomatic consecutive Caucasian patients treated with percutaneous coronary intervention including stent implantation underwent genotyping for GP IIIa PlA1/A2. Main outcome measures Long-term clinical outcome in terms of the rate of major adverse cardiac events (MACE, ie death from any cause, non-fatal Q wave or non Q wave myocardial infarction, and need for coronary revascularisation was obtained and subsequently stratified according to the GP IIIa PlA1/A2 polymorphism. Results Three groups of patients were determined according to the GP IIIa PlA1/A2 polymorphism (71.6% had the A1/A1, 25.8% had the A1/A2 and 2.6% had the A2/A2 genotype. These three groups were comparable for all clinical characteristics including sex ratio, mean age, vascular risk factors, previous coronary events, baseline angiographic exam, indication for the percutaneous coronary intervention and drug therapy. The incidence of MACE was similar in these 3 groups of patients during a mean follow-up period of 654+/-152 days. Independent risk factors for MACE were a left ventricular ejection fraction Conclusion The GP IIIa PlA1/A2 polymorphism does not influence the clinical long-term outcome in patients with symptomatic coronary disease undergoing percutaneous coronary intervention with stent implantation.

  4. A bovine herpesvirus 5 recombinant defective in the thymidine kinase (TK gene and a double mutant lacking TK and the glycoprotein E gene are fully attenuated for rabbits

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    S.C. Silva

    2010-02-01

    Full Text Available Bovine herpesvirus 5 (BoHV-5, the agent of herpetic meningoencephalitis in cattle, is an important pathogen of cattle in South America and several efforts have been made to produce safer and more effective vaccines. In the present study, we investigated in rabbits the virulence of three recombinant viruses constructed from a neurovirulent Brazilian BoHV-5 strain (SV507/99. The recombinants are defective in glycoprotein E (BoHV-5gEΔ, thymidine kinase (BoHV-5TKΔ and both proteins (BoHV-5gEΔTKΔ. Rabbits inoculated with the parental virus (N = 8 developed neurological disease and died or were euthanized in extremis between days 7 and 13 post-infection (pi. Infectivity was detected in several areas of their brains. Three of 8 rabbits inoculated with the recombinant BoHV-5gEΔ developed neurological signs between days 10 and 15 pi and were also euthanized. A more restricted virus distribution was detected in the brain of these animals. Rabbits inoculated with the recombinants BoHV-5TKΔ (N = 8 or BoHV-5gEΔTKΔ (N = 8 remained healthy throughout the experiment in spite of variable levels of virus replication in the nose. Dexamethasone (Dx administration to rabbits inoculated with the three recombinants at day 42 pi did not result in viral reactivation, as demonstrated by absence of virus shedding and/or increase in virus neutralizing titers. Nevertheless, viral DNA was detected in the trigeminal ganglia or olfactory bulbs of all animals at day 28 post-Dx, demonstrating they were latently infected. These results show that recombinants BoHV-5TKΔ and BoHV-5gEΔTKΔ are attenuated for rabbits and constitute potential vaccine candidates upon the confirmation of this phenotype in cattle.

  5. Ectopic expression of TaOEP16-2-5B, a wheat plastid outer envelope protein gene, enhances heat and drought stress tolerance in transgenic Arabidopsis plants.

    Science.gov (United States)

    Zang, Xinshan; Geng, Xiaoli; Liu, Kelu; Wang, Fei; Liu, Zhenshan; Zhang, Liyuan; Zhao, Yue; Tian, Xuejun; Hu, Zhaorong; Yao, Yingyin; Ni, Zhongfu; Xin, Mingming; Sun, Qixin; Peng, Huiru

    2017-05-01

    Abiotic stresses, such as heat and drought, are major environmental factors restricting crop productivity and quality worldwide. A plastid outer envelope protein gene, TaOEP16-2, was identified from our previous transcriptome analysis [1,2]. In this study, the isolation and functional characterization of the TaOEP16-2 gene was reported. Three homoeologous sequences of TaOEP16-2 were isolated from hexaploid wheat, which were localized on the chromosomes 5A, 5B and 5D, respectively. These three homoeologues exhibited different expression patterns under heat stress conditions, TaOEP16-2-5B was the dominant one, and TaOEP16-2-5B was selected for further analysis. Compared with wild type (WT) plants, transgenic Arabidopsis plants overexpressing the TaOEP16-2-5B gene exhibited enhanced tolerance to heat stress, which was supported by improved survival rate, strengthened cell membrane stability and increased sucrose content. It was also found that TaOEP16-2 was induced by drought stress and involved in drought stress tolerance. TaOEP16-2-5B has the same function in ABA-controlled seed germination as AtOEP16-2. Our results suggest that TaOEP16-2-5B plays an important role in heat and drought stress tolerance, and could be utilized in transgenic breeding of wheat and other crop plants. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Characterization of the Fusion and Attachment Glycoproteins of Human Metapneumovirus and Human Serosurvey to Determine Reinfection Rates

    Science.gov (United States)

    2007-06-27

    Metapneumovirus genus. The Paramyxoviridae are in the taxonomical order Mononegavirales which includes Bornaviridae, Rhabdoviridae and Filoviridae which... Rhabdoviridae plant virus, replicate in the cytoplasm (66). The Paramyxoviridae are enveloped viruses and have been defined by the fusion glycoprotein

  7. Glycoprotein on cell surfaces

    International Nuclear Information System (INIS)

    Muramatsu, T.

    1975-01-01

    There are conjugated polysaccharides in cell membranes and outside of animal cells, and they play important role in the control of cell behavior. In this paper, the studies on the glycoprotein on cell surfaces are reported. It was found that the glycoprotein on cell surfaces have both N-glycoside type and O-glycoside type saccharic chains. Therefore it can be concluded that the basic structure of the saccharic chains in the glycoprotein on cell surfaces is similar to that of blood serum and body fluid. The main glycoprotein in the membranes of red blood corpuscles has been studied most in detail, and it also has both types of saccharic chains. The glycoprotein in liver cell membranes was found to have only the saccharic chains of acid type and to be in different pattern from that in endoplasmic reticula and nuclear membranes, which also has the saccharic chains of neutral type. The structure of the saccharic chains of H-2 antigen, i.e. the peculiar glycoprotein on the surfaces of lymph system cells, has been studied, and it is similar to the saccharic chains of glycoprotein in blood serum. The saccharic chain structures of H-2 antigen and TL antigen are different. TL, H-2 (D), Lna and H-2 (K) are the glycoprotein on cell surfaces, and are independent molecules. The analysis of the saccharic chain patterns on cell surfaces was carried out, and it was shown that the acid type saccharic chains were similar to those of ordinary glycoprotein, because the enzyme of pneumococci hydrolyzed most of the acid type saccharic chains. The change of the saccharic chain patterns of glycoprotein on cell surfaces owing to canceration and multiplication is complex matter. (Kako, I.)

  8. Genetic variation of the human α-2-Heremans-Schmid glycoprotein (AHSG gene associated with the risk of SARS-CoV infection.

    Directory of Open Access Journals (Sweden)

    Xiaohui Zhu

    Full Text Available Genetic background may play an important role in the process of SARS-CoV infection and SARS development. We found several proteins that could interact with the nucleocapsid protein of the SARS coronavirus (SARS-CoV. α-2-Heremans-Schmid Glycoprotein (AHSG, which is required for macrophage deactivation by endogenous cations, is associated with inflammatory regulation. Cytochrome P450 Family 3A (CYP4F3A is an ω-oxidase that inactivates Leukotriene B4 (LTB4 in human neutrophils and the liver. We investigated the association between the polymorphisms of these two inflammation-associated genes and SARS development. The linkage disequilibrium (LD maps of these two genes were built with Haploview using data on CHB+JPT (version 2 from the HapMap. A total of ten tag SNPs were selected and genotyped. In the Guangzhou cohort study, after adjusting for age and sex, two AHSG SNPs and one CYP4F3 SNP were found to be associated with SARS susceptibility: rs2248690 (adjusted odds ratio [AOR] 2.42; 95% confidence interval [CI] 1.30-4.51; rs4917 (AOR 1.84; 95% CI 1.02-3.34; and rs3794987 (AOR 2.01; 95% CI 1.10-3.68. To further validate the association, the ten tag SNPs were genotyped in the Beijing cohort. After adjusting for age and sex, only rs2248690 (AOR, 1.63; 95% CI, 1.30-2.04 was found to be associated with SARS susceptibility. The combined analysis of the two studies confirmed tag SNP rs2248690 in AHSG as a susceptibility variant (AOR 1.70; 95% CI 1.37-2.09. The statistical analysis of the rs2248690 genotype data among the patients and healthy controls in the HCW cohort, who were all similarly exposed to the SARS virus, also supported the findings. Further, the SNP rs2248690 affected the transcriptional activity of the AHSG promoter and thus regulated the AHSG serum level. Therefore, our study has demonstrated that the AA genotype of rs2268690, which leads to a higher AHSG serum concentration, was significantly associated with protection against SARS

  9. [Research progress on ebola virus glycoprotein].

    Science.gov (United States)

    Ding, Guo-Yong; Wang, Zhi-Yu; Gao, Lu; Jiang, Bao-Fa

    2013-03-01

    Ebola virus (EBOV) causes outbreaks of a highly lethal hemorrhagic fever in humans and there are no effective therapeutic or prophylactic treatments available. The glycoprotein (GP) of EBOV is a transmembrane envelope protein known to play multiple functions including virus attachment and entry, cell rounding and cytotoxicity, down-regulation of host surface proteins, and enhancement of virus assembly and budding. GP is the primary target of protective immunity and the key target for developing neutralizing antibodies. In this paper, the research progress on genetic structure, pathogenesis and immunogenicity of EBOV GP in the last 5 years is reviewed.

  10. Humanizing recombinant glycoproteins from Chinese hamster ovary cells

    DEFF Research Database (Denmark)

    Hansen, Anders Holmgaard; Amann, Thomas; Kol, Stefan

    With new tools for gene-editing like zinc-fingers, TALENS and CRISPR, it is now feasible totailor-make the N-Glycoforms for therapeutic glycoproteins that have previously been almost impossible. We here demonstrate a case of humanizing a recombinant human glycoprotein that in Wild type (WT) Chinese...

  11. Glycosylation in HIV-1 envelope glycoprotein and its biological implications

    KAUST Repository

    Ho, Yung Shwen; Saksena, Nitin K.

    2013-01-01

    architecture, also controls intra- and inter-clade genetic variations. Discerning intra- and inter-clade glycosylation variations could therefore yield important information for understanding the molecular and biological differences between HIV clades and may

  12. Enveloping Aerodynamic Decelerator

    Science.gov (United States)

    Nock, Kerry T. (Inventor); Aaron, Kim M. (Inventor); McRonald, Angus D. (Inventor); Gates, Kristin L. (Inventor)

    2018-01-01

    An inflatable aerodynamic deceleration method and system is provided for use with an atmospheric entry payload. The inflatable aerodynamic decelerator includes an inflatable envelope and an inflatant, wherein the inflatant is configured to fill the inflatable envelope to an inflated state such that the inflatable envelope surrounds the atmospheric entry payload, causing aerodynamic forces to decelerate the atmospheric entry payload.

  13. Isolation and characterization of broadly neutralizing human monoclonal antibodies to the e1 glycoprotein of hepatitis C virus

    DEFF Research Database (Denmark)

    Meunier, Jean-Christophe; Russell, Rodney S; Goossens, Vera

    2008-01-01

    monoclonal antibodies (MAbs) directed against HCV glycoprotein E1, which may have the potential to control HCV infection. We have identified two MAbs that can strongly neutralize HCV-pseudotyped particles (HCVpp) bearing the envelope glycoproteins of genotypes 1a, 1b, 4a, 5a, and 6a and less strongly...

  14. Monoclonal antibody to an external epitope of the human mdr1 P-glycoprotein

    NARCIS (Netherlands)

    Arceci, R. J.; Stieglitz, K.; Bras, J.; Schinkel, A.; Baas, F.; Croop, J.

    1993-01-01

    A membrane glycoprotein, termed P-glycoprotein, has been shown to be responsible for cross-resistance to a broad range of structurally and functionally distinct cytotoxic agents. P-glycoprotein, encoded in humans by the mdr1 gene, functions as an energy-dependent efflux pump to exclude these

  15. Regulation of pregnane-X-receptor, CYP3A and P-glycoprotein genes in the PCB-resistant killifish (Fundulus heteroclitus) population from New Bedford Harbor

    International Nuclear Information System (INIS)

    Gräns, Johanna; Wassmur, Britt; Fernández-Santoscoy, María; Zanette, Juliano; Woodin, Bruce R.; Karchner, Sibel I.; Nacci, Diane E.; Champlin, Denise; Jayaraman, Saro; Hahn, Mark E.; Stegeman, John J.; Celander, Malin C.

    2015-01-01

    Highlights: • Basal levels of PXR and Pgp mRNA are lower in liver of fish from NBH than from SC. • Hepatic PXR, CYP3A and Pgp mRNA levels are induced by PCB in fish from NBH. • Both non-dioxin-like and dioxin-like PCBs induce PXR, CYP3A and Pgp in NBH fish. • Branchial PXR and CYP3A mRNA levels are induced by PCB 126 in fish from SC. • There is possible cross-talk between AhR and PXR signaling in killifish. - Abstract: Killifish survive and reproduce in the New Bedford Harbor (NBH) in Massachusetts (MA), USA, a site severely contaminated with polychlorinated biphenyls (PCBs) for decades. Levels of 22 different PCB congeners were analyzed in liver from killifish collected in 2008. Concentrations of dioxin-like PCBs in liver of NBH killifish were ∼400 times higher, and the levels of non-dioxin-like PCBs ∼3000 times higher than in killifish from a reference site, Scorton Creek (SC), MA. The NBH killifish are known to be resistant to the toxicity of dioxin-like compounds and to have a reduced aryl hydrocarbon receptor (AhR) signaling response. Little is known about the responses of these fish to non-dioxin-like PCBs, which are at extraordinarily high levels in NBH fish. In mammals, some non-dioxin-like PCB congeners act through nuclear receptor 1I2, the pregnane-X-receptor (PXR). To explore this pathway in killifish, a PXR cDNA was sequenced and its molecular phylogenetic relationship to other vertebrate PXRs was determined. Killifish were also collected in 2009 from NBH and SC, and after four months in the laboratory they were injected with a single dose of either the dioxin-like PCB 126 (an AhR agonist) or the non-dioxin-like PCB 153 (a mammalian PXR agonist). Gills and liver were sampled three days after injection and transcript levels of genes encoding PXR, cytochrome P450 3A (CYP3A), P-glycoprotein (Pgp), AhR2 and cytochrome P450 1A (CYP1A) were measured by quantitative PCR. As expected, there was little effect of PCB exposure on mRNA expression of

  16. Regulation of pregnane-X-receptor, CYP3A and P-glycoprotein genes in the PCB-resistant killifish (Fundulus heteroclitus) population from New Bedford Harbor

    Energy Technology Data Exchange (ETDEWEB)

    Gräns, Johanna; Wassmur, Britt; Fernández-Santoscoy, María [Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, SE 405 30 Gothenburg (Sweden); Zanette, Juliano; Woodin, Bruce R.; Karchner, Sibel I. [Biology Department, MS #32, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States); Nacci, Diane E.; Champlin, Denise; Jayaraman, Saro [Office of Research and Development, National Health and Environmental Effects Research Laboratory, Atlantic Ecology Division, United States Environmental Protection Agency, 27 Tarzwell Drive, Narragansett, RI 02882 (United States); Hahn, Mark E.; Stegeman, John J. [Biology Department, MS #32, Woods Hole Oceanographic Institution, Woods Hole, MA 02543 (United States); Celander, Malin C., E-mail: malin.celander@gu.se [Department of Biological and Environmental Sciences, University of Gothenburg, Box 463, SE 405 30 Gothenburg (Sweden)

    2015-02-15

    Highlights: • Basal levels of PXR and Pgp mRNA are lower in liver of fish from NBH than from SC. • Hepatic PXR, CYP3A and Pgp mRNA levels are induced by PCB in fish from NBH. • Both non-dioxin-like and dioxin-like PCBs induce PXR, CYP3A and Pgp in NBH fish. • Branchial PXR and CYP3A mRNA levels are induced by PCB 126 in fish from SC. • There is possible cross-talk between AhR and PXR signaling in killifish. - Abstract: Killifish survive and reproduce in the New Bedford Harbor (NBH) in Massachusetts (MA), USA, a site severely contaminated with polychlorinated biphenyls (PCBs) for decades. Levels of 22 different PCB congeners were analyzed in liver from killifish collected in 2008. Concentrations of dioxin-like PCBs in liver of NBH killifish were ∼400 times higher, and the levels of non-dioxin-like PCBs ∼3000 times higher than in killifish from a reference site, Scorton Creek (SC), MA. The NBH killifish are known to be resistant to the toxicity of dioxin-like compounds and to have a reduced aryl hydrocarbon receptor (AhR) signaling response. Little is known about the responses of these fish to non-dioxin-like PCBs, which are at extraordinarily high levels in NBH fish. In mammals, some non-dioxin-like PCB congeners act through nuclear receptor 1I2, the pregnane-X-receptor (PXR). To explore this pathway in killifish, a PXR cDNA was sequenced and its molecular phylogenetic relationship to other vertebrate PXRs was determined. Killifish were also collected in 2009 from NBH and SC, and after four months in the laboratory they were injected with a single dose of either the dioxin-like PCB 126 (an AhR agonist) or the non-dioxin-like PCB 153 (a mammalian PXR agonist). Gills and liver were sampled three days after injection and transcript levels of genes encoding PXR, cytochrome P450 3A (CYP3A), P-glycoprotein (Pgp), AhR2 and cytochrome P450 1A (CYP1A) were measured by quantitative PCR. As expected, there was little effect of PCB exposure on mRNA expression of

  17. A Strategy for O-Glycoproteomics of Enveloped Viruses-the O-Glycoproteome of Herpes Simplex Virus Type 1

    DEFF Research Database (Denmark)

    Bagdonaite, Ieva; Nordén, Rickard; Joshi, Hiren J

    2015-01-01

    present a novel proteome-wide discovery strategy for O-glycosylation sites on viral envelope proteins using herpes simplex virus type 1 (HSV-1) as a model. We identified 74 O-linked glycosylation sites on 8 out of the 12 HSV-1 envelope proteins. Two of the identified glycosites found in glycoprotein B...

  18. Envelope proteins of bovine herpesvirus 1: immunological and biochemical studies

    International Nuclear Information System (INIS)

    Rodriguez Roque, L.L.

    1986-01-01

    The authors studied immunological and biochemical properties of the bovid herpesvirus 1 (BHV-1) envelope proteins in order to understand the pathogenesis of BHV-1 infection and to provide basic information for the production of effective subunit vaccines against BHV-1. Ten glycoproteins MW 180, 150, 130, 115, 97, 77, 74, 64, 55, and 45 kilodaltons (K), and a single non-glycosylated 108 K protein were quantitatively removed from purified BHV-1 virions by detergent treatment. These glycoproteins were present on the virion envelope and on the surface of BHV-1 infected cells. The quantitative removal from virions by treatment with nonionic detergents and their presence on the surface of infected cells indicate that 180/97, 150/77, and 130/74/55 K are major components of the BHV-1 envelope and are also the targets of virus neutralizing humoral immune response. Envelope glycoproteins of herpes simplex type 1 (HSV-1) bind immunoglobulin by the Fc end and it is suggested this may increase pathogenicity of this virus. They searched for a similar function in BVH-1 by measuring the ability of BHV-1 infected cells and viral envelope proteins to bind radiolabelled rabbit and bovine IgG. Binding activity for rabbit IgG or bovine IgG-Fc could not be demonstrated by BHV-1 infected MDBK cells, whereas, MDBK cells infected with HSV-1 bound rabbit IgG and bovine IgG-Fc. None of the three major envelope proteins of BHV-1 bound to rabbit or bovine IgG. The results of this study indicate that BHV-1, unlike some other herpesviruses, lack Fc binding activity

  19. Replacement of the cytoplasmic domain alters sorting of a viral glycoprotein in polarized cells.

    OpenAIRE

    Puddington, L; Woodgett, C; Rose, J K

    1987-01-01

    The envelope glycoprotein (G protein) of vesicular stomatitis virus (VSV) is transported to the basolateral plasma membrane of polarized epithelial cells, whereas the hemagglutinin glycoprotein (HA protein) of influenza virus is transported to the apical plasma membrane. To determine if the cytoplasmic domain of VSV G protein might be important in directing G protein to the basolateral membrane, we derived polarized Madin-Darby canine kidney cell lines expressing G protein or G protein with i...

  20. Storage envelopes or sleeves

    International Nuclear Information System (INIS)

    Freshwater, J.R.; Wagman, P.I.

    1980-01-01

    A storage envelope or sleeve particularly for processed X-ray films is described. It consists of front and back panels joined together at a hinge line and connected along the intermediate sides by connecting flaps. An inner pocket is formed from a third flap which is folded to lie against the inner face of the back panel. The panels may have additional score lines parallel to the closed sides of the envelope and the inner pocket so that the envelope and the inner pocket can accommodate bulky contents. The free edge of the pocket is inset from the open side of the envelope, and finger cut-outs may be provided to facilitate access to the contents of the envelope and the pocket. (author)

  1. The pestivirus Erns glycoprotein interacts with E2 in both infected cells and mature virions

    International Nuclear Information System (INIS)

    Lazar, Catalin; Zitzmann, Nicole; Dwek, Raymond A.; Branza-Nichita, Norica

    2003-01-01

    E rns is a pestivirus envelope glycoprotein indispensable for virus attachment and infection of target cells. Unlike the other two envelope proteins E1 and E2, E rns lacks a transmembrane domain and a vast quantity is secreted into the medium of infected cells. The protein is also present in fractions of pure pestivirus virions, raising the important and intriguing question regarding the mechanism of its attachment to the pestivirus envelope. In this study a direct interaction between E rns and E2 glycoproteins was demonstrated in both pestivirus-infected cells and mature virions. By co- and sequential immunoprecipitation we showed that an E rns -E2 heterodimer is assembled very early after translation of the viral polyprotein and before its processing is completed. Our results suggest that E rns is attached to the pestivirus envelope via a direct interaction with E2 and explain the role of E rns in the initial virus-target cell interaction

  2. Pseudotyped Lentiviral Vectors for Retrograde Gene Delivery into Target Brain Regions

    Directory of Open Access Journals (Sweden)

    Kenta Kobayashi

    2017-08-01

    Full Text Available Gene transfer through retrograde axonal transport of viral vectors offers a substantial advantage for analyzing roles of specific neuronal pathways or cell types forming complex neural networks. This genetic approach may also be useful in gene therapy trials by enabling delivery of transgenes into a target brain region distant from the injection site of the vectors. Pseudotyping of a lentiviral vector based on human immunodeficiency virus type 1 (HIV-1 with various fusion envelope glycoproteins composed of different combinations of rabies virus glycoprotein (RV-G and vesicular stomatitis virus glycoprotein (VSV-G enhances the efficiency of retrograde gene transfer in both rodent and nonhuman primate brains. The most recently developed lentiviral vector is a pseudotype with fusion glycoprotein type E (FuG-E, which demonstrates highly efficient retrograde gene transfer in the brain. The FuG-E–pseudotyped vector permits powerful experimental strategies for more precisely investigating the mechanisms underlying various brain functions. It also contributes to the development of new gene therapy approaches for neurodegenerative disorders, such as Parkinson’s disease, by delivering genes required for survival and protection into specific neuronal populations. In this review article, we report the properties of the FuG-E–pseudotyped vector, and we describe the application of the vector to neural circuit analysis and the potential use of the FuG-E vector in gene therapy for Parkinson’s disease.

  3. The VNTR Polymorphism of the DC-SIGNR Gene and Susceptibility to HIV-1 Infection: A Meta-Analysis

    OpenAIRE

    Li, Hui; Yu, Xiao-Min; Wang, Jia-Xin; Hong, Ze-Hui; Tang, Nelson Leung-Sang

    2012-01-01

    BACKGROUND: Dendritic cell-specific intercellular adhesion molecule-3-grabbing nonintegrin related (DC-SIGNR) can bind to the human immunodeficiency virus-1 (HIV-1) gp120 envelope glycoprotein and is thus important for the host-pathogen interaction in HIV-1 infection. Studies of the association between the variable number tandem repeat (VNTR) polymorphism of the DC-SIGNR gene and HIV-1 susceptibility have produced controversial results. METHODS AND FINDINGS: We conducted a meta-analysis of th...

  4. Glycoprotein and proteoglycan techniques

    International Nuclear Information System (INIS)

    Beeley, J.G.

    1985-01-01

    The aim of this book is to describe techniques which can be used to answer some of the basic questions about glycosylated proteins. Methods are discussed for isolation, compositional analysis, and for determination of the primary structure of carbohydrate units and the nature of protein-carbohydrate linkages of glycoproteins and proteoglycans. High resolution NMR is considered, as well as radioactive labelling techniques. (Auth.)

  5. Protective plasma envelope

    International Nuclear Information System (INIS)

    Bocharov, V.N.; Konstantinov, S.G.; Kudryavtsev, A.M.; Myskin, O.K.; Panasyuk, V.M.; Tsel'nik, F.A.

    1984-06-01

    A method of creating an annular plasma envelope used to protect the hot plasma from flows of impurities and gases from the walls of the vacuum chamber is described. The diameter of the envelope is 30 cm, the thickness of the wall is 1.5 cm, the length is 2.5 m, and its density is from 10 13 to 10 14 cm -3 . The envelope attenuates the incident (from outside) flow of helium 10-fold and the low of hydrogen 20-fold

  6. The endogenous retroviral locus ERVWE1 is a bona fide gene involved in hominoid placental physiology

    Science.gov (United States)

    Mallet, François; Bouton, Olivier; Prudhomme, Sarah; Cheynet, Valérie; Oriol, Guy; Bonnaud, Bertrand; Lucotte, Gérard; Duret, Laurent; Mandrand, Bernard

    2004-01-01

    The definitive demonstration of a role for a recently acquired gene is a difficult task, requiring exhaustive genetic investigations and functional analysis. The situation is indeed much more complicated when facing multicopy gene families, because most or portions of the gene are conserved among the hundred copies of the family. This is the case for the ERVWE1 locus of the human endogenous retrovirus W family (HERV-W), which encodes an envelope glycoprotein (syncytin) likely involved in trophoblast differentiation. Here we describe, in 155 individuals, the positional conservation of this locus and the preservation of the envelope ORF. Sequencing of the critical elements of the ERVWE1 provirus showed a striking conservation among the 48 alleles of 24 individuals, including the LTR elements involved in the transcriptional machinery, the splice sites involved in the maturation of subgenomic Env mRNA, and the Env ORF. The functionality and tissue specificity of the 5′ LTR were demonstrated, as well as the fusogenic activity of the envelope polymorphic variants. Such functions were also shown to be preserved in the orthologous loci isolated from chimpanzee, gorilla, orangutan, and gibbon. This functional preservation among humans and during evolution strongly argued for the involvement of this recently acquired retroviral envelope glycoprotein in hominoid placental physiology. PMID:14757826

  7. Structures and Functions of Pestivirus Glycoproteins: Not Simply Surface Matters

    Directory of Open Access Journals (Sweden)

    Fun-In Wang

    2015-06-01

    Full Text Available Pestiviruses, which include economically important animal pathogens such as bovine viral diarrhea virus and classical swine fever virus, possess three envelope glycoproteins, namely Erns, E1, and E2. This article discusses the structures and functions of these glycoproteins and their effects on viral pathogenicity in cells in culture and in animal hosts. E2 is the most important structural protein as it interacts with cell surface receptors that determine cell tropism and induces neutralizing antibody and cytotoxic T-lymphocyte responses. All three glycoproteins are involved in virus attachment and entry into target cells. E1-E2 heterodimers are essential for viral entry and infectivity. Erns is unique because it possesses intrinsic ribonuclease (RNase activity that can inhibit the production of type I interferons and assist in the development of persistent infections. These glycoproteins are localized to the virion surface; however, variations in amino acids and antigenic structures, disulfide bond formation, glycosylation, and RNase activity can ultimately affect the virulence of pestiviruses in animals. Along with mutations that are driven by selection pressure, antigenic differences in glycoproteins influence the efficacy of vaccines and determine the appropriateness of the vaccines that are currently being used in the field.

  8. Structures and Functions of Pestivirus Glycoproteins: Not Simply Surface Matters.

    Science.gov (United States)

    Wang, Fun-In; Deng, Ming-Chung; Huang, Yu-Liang; Chang, Chia-Yi

    2015-06-29

    Pestiviruses, which include economically important animal pathogens such as bovine viral diarrhea virus and classical swine fever virus, possess three envelope glycoproteins, namely Erns, E1, and E2. This article discusses the structures and functions of these glycoproteins and their effects on viral pathogenicity in cells in culture and in animal hosts. E2 is the most important structural protein as it interacts with cell surface receptors that determine cell tropism and induces neutralizing antibody and cytotoxic T-lymphocyte responses. All three glycoproteins are involved in virus attachment and entry into target cells. E1-E2 heterodimers are essential for viral entry and infectivity. Erns is unique because it possesses intrinsic ribonuclease (RNase) activity that can inhibit the production of type I interferons and assist in the development of persistent infections. These glycoproteins are localized to the virion surface; however, variations in amino acids and antigenic structures, disulfide bond formation, glycosylation, and RNase activity can ultimately affect the virulence of pestiviruses in animals. Along with mutations that are driven by selection pressure, antigenic differences in glycoproteins influence the efficacy of vaccines and determine the appropriateness of the vaccines that are currently being used in the field.

  9. Safe operating envelope

    Energy Technology Data Exchange (ETDEWEB)

    Oliva, N [Ontario Hydro, Toronto, ON (Canada)

    1997-12-01

    Safe Operating Envelope is described representing: The outer bound of plant conditions within which day-to-day plant operation must be maintained in order to comply with regulatory requirements, associated safety design criteria and corporate nuclear safety goals. Figs.

  10. Safe operating envelope

    International Nuclear Information System (INIS)

    Oliva, N.

    1997-01-01

    Safe Operating Envelope is described representing: The outer bound of plant conditions within which day-to-day plant operation must be maintained in order to comply with regulatory requirements, associated safety design criteria and corporate nuclear safety goals. Figs

  11. Gypsy transposition correlates with the production of a retroviral envelope-like protein under the tissue-specific control of the Drosophila flamenco gene.

    OpenAIRE

    Pélisson, A; Song, S U; Prud'homme, N; Smith, P A; Bucheton, A; Corces, V G

    1994-01-01

    Gypsy displays striking similarities to vertebrate retroviruses, including the presence of a yet uncharacterized additional open reading frame (ORF3) and the recent evidence for infectivity. It is mobilized with high frequency in the germline of the progeny of females homozygous for the flamenco permissive mutation. We report the characterization of a gypsy subgenomic ORF3 RNA encoding typical retroviral envelope proteins. In females, env expression is strongly repressed by one copy of the no...

  12. Genetic Diversity of Koala Retroviral Envelopes

    Directory of Open Access Journals (Sweden)

    Wenqin Xu

    2015-03-01

    Full Text Available Genetic diversity, attributable to the low fidelity of reverse transcription, recombination and mutation, is an important feature of infectious retroviruses. Under selective pressure, such as that imposed by superinfection interference, gammaretroviruses commonly adapt their envelope proteins to use alternative receptors to overcome this entry block. The first characterized koala retroviruses KoRV subgroup A (KoRV-A were remarkable in their absence of envelope genetic variability. Once it was determined that KoRV-A was present in all koalas in US zoos, regardless of their disease status, we sought to isolate a KoRV variant whose presence correlated with neoplastic malignancies. More than a decade after the identification of KoRV-A, we isolated a second subgroup of KoRV, KoRV-B from koalas with lymphomas. The envelope proteins of KoRV-A and KoRV-B are sufficiently divergent to confer the ability to bind and employ distinct receptors for infection. We have now obtained a number of additional KoRV envelope variants. In the present studies we report these variants, and show that they differ from KoRV-A and KoRV-B envelopes in their host range and superinfection interference properties. Thus, there appears to be considerable variation among KoRVs envelope genes suggesting genetic diversity is a factor following the KoRV-A infection process.

  13. Glycan shield and fusion activation of a deltacoronavirus spike glycoprotein fine-tuned for enteric infections

    NARCIS (Netherlands)

    Xiong, Xiaoli; Tortorici, M Alejandra; Snijder, Joost|info:eu-repo/dai/nl/338018328; Yoshioka, Craig; Walls, Alexandra C; Li, Wentao|info:eu-repo/dai/nl/411296272; McGuire, Andrew T; Rey, Félix A; Bosch, Berend-Jan|info:eu-repo/dai/nl/273306049; Veesler, David

    2017-01-01

    Coronaviruses recently emerged as major human pathogens causing outbreaks of severe acute respiratory syndrome and Middle-East respiratory syndrome. They utilize the spike (S) glycoprotein anchored in the viral envelope to mediate host attachment and fusion of the viral and cellular membranes to

  14. Mechanism of protein import across the chloroplast envelope.

    Science.gov (United States)

    Chen, K; Chen, X; Schnell, D J

    2000-01-01

    The development and maintenance of chloroplasts relies on the contribution of protein subunits from both plastid and nuclear genomes. Most chloroplast proteins are encoded by nuclear genes and are post-translationally imported into the organelle across the double membrane of the chloroplast envelope. Protein import into the chloroplast consists of two essential elements: the specific recognition of the targeting signals (transit sequences) of cytoplasmic preproteins by receptors at the outer envelope membrane and the subsequent translocation of preproteins simultaneously across the double membrane of the envelope. These processes are mediated via the co-ordinate action of protein translocon complexes in the outer (Toc apparatus) and inner (Tic apparatus) envelope membranes.

  15. Association between platelet glycoprotein Ia C807T gene polymorphism and ischemic stroke: a meta-analysis in a separate ethnic group.

    Science.gov (United States)

    Huang, Xiao-Yun; Fu, Wen-Jin; Mei, Zhi-Zhong; Yu, Ying-Li; Huang, Yi-Hong; Lin, Han; Chen, Jian-Jun; Wang, Ming-Xia; Guan, Shao-Bing; Fang, Hao-Wei

    2017-11-30

    Many studies have been examined the association of platelet glycoprotein (GP) Ia C807T polymorphism with ischemic stroke (IS) susceptibility. However, the results of these studies are inconsistent. To further assess the effects of GP Ia C807T polymorphism on the risk of IS, a meta-analysis was performed in a separate ethnic group. Relevant studies were identified using PubMed and Chinese databases through January 2017. Pooled odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations. Finally, 13 studies contained 2438 IS cases and 2308 controls included. In the total analyses, a significantly elevated risk of IS was associated with all variants of GP Ia C807T in the Chinese population (T vs C: OR = 1.24, 95% CI = 1.09-1.40; TT vs CC: OR = 1.59, 95% CI = 1.17-2.15; TT and CT combined vs CC: OR = 1.32, 95% CI = 1.09-1.59; TT vs CC and CT: OR = 1.35, 95% CI = 1.04-1.76). In the subgroup analyses stratified by ethnicity and geographic areas, it revealed the significant results in Chinese Han and in South China. This meta-analysis provides the evidence that GP Ia C807T polymorphism may contribute to the IS development in the Chinese population, especially in South China, and further studies in other ethic groups are required for definite conclusions.

  16. B cell clonal lineage alterations upon recombinant HIV-1 envelope immunization of Rhesus macaques

    Science.gov (United States)

    Broadly neutralizing HIV-1 antibodies (bNAbs) isolated from infected subjects display protective potential in animal models. Their elicitation by immunization is thus highly desirable. The HIV-1 envelope glycoprotein (Env) is the sole viral target of bnAbs, but is also targeted by binding, non-neutr...

  17. Presenting native-like HIV-1 envelope trimers on ferritin nanoparticles improves their immunogenicity

    NARCIS (Netherlands)

    Sliepen, Kwinten; Ozorowski, Gabriel; Burger, Judith A.; van Montfort, Thijs; Stunnenberg, Melissa; Labranche, Celia; Montefiori, David C.; Moore, John P.; Ward, Andrew B.; Sanders, Rogier W.

    2015-01-01

    Background: Presenting vaccine antigens in particulate form can improve their immunogenicity by enhancing B cell activation. Findings: We describe ferritin-based protein nanoparticles that display multiple copies of native-like HIV-1 envelope glycoprotein trimers (BG505 SOSIP.664). Trimer-bearing

  18. HIV-1 neutralizing antibodies induced by native-like envelope trimers

    NARCIS (Netherlands)

    Sanders, Rogier W.; van Gils, Marit J.; Derking, Ronald; Sok, Devin; Ketas, Thomas J.; Burger, Judith A.; Ozorowski, Gabriel; Cupo, Albert; Simonich, Cassandra; Goo, Leslie; Arendt, Heather; Kim, Helen J.; Lee, Jeong Hyun; Pugach, Pavel; Williams, Melissa; Debnath, Gargi; Moldt, Brian; van Breemen, Mariëlle J.; Isik, Gözde; Medina-Ramírez, Max; Back, Jaap Willem; Koff, Wayne C.; Julien, Jean-Philippe; Rakasz, Eva G.; Seaman, Michael S.; Guttman, Miklos; Lee, Kelly K.; Klasse, Per Johan; Labranche, Celia; Schief, William R.; Wilson, Ian A.; Overbaugh, Julie; Burton, Dennis R.; Ward, Andrew B.; Montefiori, David C.; Dean, Hansi; Moore, John P.

    2015-01-01

    A challenge for HIV-1 immunogen design is the difficulty of inducing neutralizing antibodies (NAbs) against neutralization-resistant (tier 2) viruses that dominate human transmissions. We show that a soluble recombinant HIV-1 envelope glycoprotein trimer that adopts a native conformation, BG505

  19. Development of a recombinant poxvirus expressing bovine herpesvirus-1 glycoprotein D

    International Nuclear Information System (INIS)

    Ruiz Saenz, Julian; Osorio, Jorge E; Vera, Victor J.

    2012-01-01

    Bovine herpesvirus-1 is a DNA virus belonging to the family herpesviridae, which affects cattle, causing a wide spectrum of clinical manifestations and economic losses. The main immunogenic component is its envelope glycoprotein d (GD), which has been characterized and used as immunogen in different expression systems. The aim of this work was to generate a recombinant poxvirus (raccoonpox [RCN]) expressing a truncated version of BHV-1 GD to be used as a vaccine. to do this, it was amplified the gene for a truncated version of GD which subsequently was cloned in transfer plasmid PTK/IRES/TPA which has homology to sites of poxvirus thymidine kinase, an internal site of ribosome entry (IRES) and a secretory signal (TPA), generating the construct PTK/GD/IRES/TPA. to generate the recombinant RCN, we took BSC-1 cells and we infected with a wild type RCN (CDC/v71-i-85a) at a multiplicity of infection of 0.05, then cells were transfected with the construct PTK/GD/IRES/TPA, generating different viral populations with and without the gene of interest. To select recombinant viruses expressing the gene of interest, we performed a selection of recombinant thymidine kinase negative and positive for GD by three rounds of plaque purification on rat-2 cells monolayers which are thymidine kinase null and using bromodeoxyuridine. Recombinant viruses were recovered and confirmed by PCR and nucleotide sequencing and so called RCN-GD.

  20. Glycoprotein-G-gene-based molecular and phylogenetic analysis of rabies viruses associated with a large outbreak of bovine rabies in southern Brazil.

    Science.gov (United States)

    Cargnelutti, Juliana F; de Quadros, João M; Martins, Mathias; Batista, Helena B C R; Weiblen, Rudi; Flores, Eduardo F

    2017-12-01

    A large outbreak of hematophagous-bat-associated bovine rabies has been occurring in Rio Grande do Sul (RS), the southernmost Brazilian state, since 2011, with official estimates exceeding 50,000 cattle deaths. The present article describes a genetic characterization of rabies virus (RABV) recovered from 59 affected cattle and two sheep, from 56 herds in 16 municipalities (2012-2016). Molecular analysis was performed using the nucleotide (nt) and predicted amino acid (aa) sequences of RABV glycoprotein G (G). A high level of nt and aa sequence identity was observed among the examined G sequences, ranging from 98.4 to 100%, and from 97.3 to 100%, respectively. Likewise, high levels of nt and aa sequence identity were observed with bovine (nt, 99.8%; aa, 99.8%) and hematophagous bat (nt, 99.5%; aa, 99.4%) RABV sequences from GenBank, and lower levels were observed with carnivore RABV sequences (nt, 92.8%; aa, 88.1%). Some random mutations were observed in the analyzed sequences, and a few consistent mutations were observed in some sequences belonging to cluster 2, subcluster 2b. The clustering of the sequences was observed in a phylogenetic tree, where two distinct clusters were evident. Cluster 1 comprised RABV sequences covering the entire study period (2012 to 2016), but subclusters corresponding to different years could be identified, indicating virus evolution and/or introduction of new viruses into the population. In some cases, viruses from the same location obtained within a short period grouped into different subclusters, suggesting co-circulation of viruses of different origins. Subcluster segregation was also observed in sequences obtained in the same region during different periods, indicating the involvement of different viruses in the cases at different times. In summary, our results indicate that the outbreaks occurring in RS (2012 to 2016) probably involved RABV of different origins, in addition to a possible evolution of RABV isolates within this

  1. Common envelope evolution

    NARCIS (Netherlands)

    Taam, Ronald E.; Ricker, Paul M.

    2010-01-01

    The common envelope phase of binary star evolution plays a central role in many evolutionary pathways leading to the formation of compact objects in short period systems. Using three dimensional hydrodynamical computations, we review the major features of this evolutionary phase, focusing on the

  2. A sensitive HIV-1 envelope induced fusion assay identifies fusion enhancement of thrombin

    International Nuclear Information System (INIS)

    Cheng, De-Chun; Zhong, Guo-Cai; Su, Ju-Xiang; Liu, Yan-Hong; Li, Yan; Wang, Jia-Ye; Hattori, Toshio; Ling, Hong; Zhang, Feng-Min

    2010-01-01

    To evaluate the interaction between HIV-1 envelope glycoprotein (Env) and target cell receptors, various cell-cell-fusion assays have been developed. In the present study, we established a novel fusion system. In this system, the expression of the sensitive reporter gene, firefly luciferase (FL) gene, in the target cells was used to evaluate cell fusion event. Simultaneously, constitutively expressed Renilla luciferase (RL) gene was used to monitor effector cell number and viability. FL gave a wider dynamic range than other known reporters and the introduction of RL made the assay accurate and reproducible. This system is especially beneficial for investigation of potential entry-influencing agents, for its power of ruling out the false inhibition or enhancement caused by the artificial cell-number variation. As a case study, we applied this fusion system to observe the effect of a serine protease, thrombin, on HIV Env-mediated cell-cell fusion and have found the fusion enhancement activity of thrombin over two R5-tropic HIV strains.

  3. Widely Used Herpes Simplex Virus 1 ICP0 Deletion Mutant Strain dl1403 and Its Derivative Viruses Do Not Express Glycoprotein C Due to a Secondary Mutation in the gC Gene.

    Directory of Open Access Journals (Sweden)

    Cristina W Cunha

    Full Text Available Herpes simplex virus 1 (HSV-1 ICP0 is a multi-functional phosphoprotein expressed with immediate early kinetics. An ICP0 deletion mutant, HSV-1 dl1403, has been widely used to study the roles of ICP0 in the HSV-1 replication cycle including gene expression, latency, entry and assembly. We show that HSV-1 dl1403 virions lack detectable levels of envelope protein gC, and that gC is not synthesized in infected cells. Sequencing of the gC gene from HSV-1 dl1403 revealed a single amino acid deletion that results in a frameshift mutation. The HSV-1 dl1403 gC gene is predicted to encode a polypeptide consisting of the original 62 N-terminal amino acids of the gC protein followed by 112 irrelevant, non-gC residues. The mutation was also present in a rescuant virus and in two dl1403-derived viruses, D8 and FXE, but absent from the parental 17+, suggesting that the mutation was introduced during the construction of the dl1403 virus, and not as a result of passage in culture.

  4. Replacement of the V3 domain in the surface subunit of the feline immunodeficiency virus envelope glycoprotein with the equivalent region of a T cell-tropic human immunodeficiency virus type 1 results in a chimeric surface protein that efficiently binds to CXCR4.

    Science.gov (United States)

    González, Silvia A; Falcón, Juan I; Affranchino, José L

    2014-03-01

    Feline immunodeficiency virus (FIV) and the T cell-tropic strains of human immunodeficiency virus type 1 (HIV-1) share the use of the chemokine receptor CXCR4 for cell entry. To study this process further we developed a cell surface binding assay based on the expression of a soluble version of the FIV SU C-terminally tagged with the influenza virus hemagglutinin epitope (HA). The specificity of the assay was demonstrated by the following evidence: (1) the SU-HA protein bound to HeLa cells that express CXCR4 but not to MDCK cells that lack this chemokine receptor; and (2) binding of the SU-HA to HeLa cells was blocked by incubation with the CXCR4 antagonist AMD3100 as well as with the anti-CXCR4 monoclonal antibody (MAb) 12G5. Deletion of the V3 region from the FIV SU glycoprotein abolished its ability to bind CXCR4-expressing cells. Remarkably, substitution of the V3 domain of the FIV SU by the equivalent region of the HIV-1 NL4-3 isolate resulted in efficient cell surface binding of the chimeric SU protein to CXCR4. Moreover, transfection of MDCK cells with a plasmid encoding human CXCR4 allowed the association of the chimeric SU-HA glycoprotein to the transfected cells. Interestingly, while cell binding of the chimeric FIV-HIV SU was inhibited by an anti-HIV-1 V3 MAb, its association with CXCR4 was found to be resistant to AMD3100. Of note, the chimeric FIV-HIV Env glycoprotein was capable of promoting CXCR4-dependent cell-to-cell fusion.

  5. (Quasi-)Poisson enveloping algebras

    OpenAIRE

    Yang, Yan-Hong; Yao, Yuan; Ye, Yu

    2010-01-01

    We introduce the quasi-Poisson enveloping algebra and Poisson enveloping algebra for a non-commutative Poisson algebra. We prove that for a non-commutative Poisson algebra, the category of quasi-Poisson modules is equivalent to the category of left modules over its quasi-Poisson enveloping algebra, and the category of Poisson modules is equivalent to the category of left modules over its Poisson enveloping algebra.

  6. Cyclic AMP regulation of the human glycoprotein hormone α-subunit gene is mediated by an 18-base-pair element

    International Nuclear Information System (INIS)

    Silver, B.J.; Bokar, J.A.; Virgin, J.B.; Vallen, E.A.; Milsted, A.; Nilson, J.H.

    1987-01-01

    cAMP regulates transcription of the gene encoding the α-subunit of human chorionic gonadotropin (hCG) in the choriocarcinoma cells (BeWo). To define the sequences required for regulation by cAMP, the authors inserted fragments from the 5' flanking region of the α-subunit gene into a test vector containing the simian virus 40 early promoter (devoid of its enhancer) linked to the bacterial chloramphenicol acetyltransferase (CAT) gene. Results from transient expression assays in BeWo cells indicated that a 1500-base-pair (bp) fragment conferred cAMP responsiveness on the CAT gene regardless of position or orientation of the insert relative to the viral promoter. A subfragment extending from position -169 to position -100 had the same effect on cAMP-induced expression. Furthermore, the entire stimulatory effect could be achieved with an 18-bp synthetic oligodeoxynucleotide corresponding to a direct repeat between position -146 and -111. In the absence of cAMP, the α-subunit 5' flanking sequence also enhanced transcription from the simian virus 40 early promoter. They localized this enhancer activity to the same -169/-100 fragment containing the cAMP response element. The 18-bp element alone, however, had no effect on basal expression. Thus, this short DNA sequence serves as a cAMP response element and also functions independently of other promoter-regulatory elements located in the 5' flanking sequence of the α-subunit gene

  7. Thermal Activated Envelope

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Pasold, Anke

    2015-01-01

    The research studies the making of a responsive architectural envelope based on bi-materials. The bi-materials are organized according to a method that combines different isotropic metals and plastic into an active composite structure that reacts to temperature variations. Through an evolutionary......, environmental dynamics and occupancy dynamics. Lastly, a physical prototype is created, which illustrates the physical expression of the bi-materials and the problems related to manufacturing of these composite structures.......The research studies the making of a responsive architectural envelope based on bi-materials. The bi-materials are organized according to a method that combines different isotropic metals and plastic into an active composite structure that reacts to temperature variations. Through an evolutionary...

  8. A new strategy for full-length Ebola virus glycoprotein expression in E.coli.

    Science.gov (United States)

    Zai, Junjie; Yi, Yinhua; Xia, Han; Zhang, Bo; Yuan, Zhiming

    2016-12-01

    Ebola virus (EBOV) causes severe hemorrhagic fever in humans and non-human primates with high rates of fatality. Glycoprotein (GP) is the only envelope protein of EBOV, which may play a critical role in virus attachment and entry as well as stimulating host protective immune responses. However, the lack of expression of full-length GP in Escherichia coli hinders the further study of its function in viral pathogenesis. In this study, the vp40 gene was fused to the full-length gp gene and cloned into a prokaryotic expression vector. We showed that the VP40-GP and GP-VP40 fusion proteins could be expressed in E.coli at 16 °C. In addition, it was shown that the position of vp40 in the fusion proteins affected the yields of the fusion proteins, with a higher level of production of the fusion protein when vp40 was upstream of gp compared to when it was downstream. The results provide a strategy for the expression of a large quantity of EBOV full-length GP, which is of importance for further analyzing the relationship between the structure and function of GP and developing an antibody for the treatment of EBOV infection.

  9. Detection of Multiple Budding Yeast Cells and a Partial Sequence of 43-kDa Glycoprotein Coding Gene of Paracoccidioides brasiliensis from a Case of Lacaziosis in a Female Pacific White-Sided Dolphin (Lagenorhynchus obliquidens).

    Science.gov (United States)

    Minakawa, Tomoko; Ueda, Keiichi; Tanaka, Miyuu; Tanaka, Natsuki; Kuwamura, Mitsuru; Izawa, Takeshi; Konno, Toshihiro; Yamate, Jyoji; Itano, Eiko Nakagawa; Sano, Ayako; Wada, Shinpei

    2016-08-01

    Lacaziosis, formerly called as lobomycosis, is a zoonotic mycosis, caused by Lacazia loboi, found in humans and dolphins, and is endemic in the countries on the Atlantic Ocean, Indian Ocean and Pacific Ocean of Japanese coast. Susceptible Cetacean species include the bottlenose dolphin (Tursiops truncatus), the Indian Ocean bottlenose dolphin (T. aduncus), and the estuarine dolphin (Sotalia guianensis); however, no cases have been recorded in other Cetacean species. We diagnosed a case of Lacaziosis in a Pacific white-sided dolphin (Lagenorhynchus obliquidens) nursing in an aquarium in Japan. The dolphin was a female estimated to be more than 14 years old at the end of June 2015 and was captured in a coast of Japan Sea in 2001. Multiple, lobose, and solid granulomatous lesions with or without ulcers appeared on her jaw, back, flipper and fluke skin, in July 2014. The granulomatous skin lesions from the present case were similar to those of our previous cases. Multiple budding and chains of round yeast cells were detected in the biopsied samples. The partial sequence of 43-kDa glycoprotein coding gene confirmed by a nested PCR and sequencing, which revealed a different genotype from both Amazonian and Japanese lacaziosis in bottlenose dolphins, and was 99 % identical to those derived from Paracoccidioides brasiliensis; a sister fungal species to L. loboi. This is the first case of lacaziosis in Pacific white-sided dolphin.

  10. Inactivation of the β(1,2)-xylosyltransferase and the α(1,3)-fucosyltransferase genes in Nicotiana tabacum BY-2 Cells by a Multiplex CRISPR/Cas9 Strategy Results in Glycoproteins without Plant-Specific Glycans.

    Science.gov (United States)

    Mercx, Sébastien; Smargiasso, Nicolas; Chaumont, François; De Pauw, Edwin; Boutry, Marc; Navarre, Catherine

    2017-01-01

    Plants or plant cells can be used to produce pharmacological glycoproteins such as antibodies or vaccines. However these proteins carry N -glycans with plant-typical residues [β(1,2)-xylose and core α(1,3)-fucose], which can greatly impact the immunogenicity, allergenicity, or activity of the protein. Two enzymes are responsible for the addition of plant-specific glycans: β(1,2)-xylosyltransferase (XylT) and α(1,3)-fucosyltransferase (FucT). Our aim consisted of knocking-out two XylT genes and four FucT genes (12 alleles altogether) in Nicotiana tabacum BY-2 suspension cells using CRISPR/Cas9. Three XylT and six FucT sgRNAs were designed to target conserved regions. After transformation of N. tabacum BY-2 cells with genes coding for sgRNAs, Cas9, and a selectable marker ( bar ), transgenic lines were obtained and their extracellular as well as intracellular protein complements were analyzed by Western blotting using antibodies recognizing β(1,2)-xylose and α(1,3)-fucose. Three lines showed a strong reduction of β(1,2)-xylose and α(1,3)-fucose, while two lines were completely devoid of them, indicating complete gene inactivation. The absence of these carbohydrates was confirmed by mass spectrometry analysis of the extracellular proteins. PCR amplification and sequencing of the targeted region indicated small INDEL and/or deletions between the target sites. The KO lines did not show any particular morphology and grew as the wild-type. One KO line was transformed with genes encoding a human IgG2 antibody. The IgG2 expression level was as high as in a control transformant which had not been glycoengineered. The IgG glycosylation profile determined by mass spectrometry confirmed that no β(1,2)-xylose or α(1,3)-fucose were present on the glycosylation moiety and that the dominant glycoform was the GnGn structure. These data represent an important step toward humanizing the glycosylation of pharmacological proteins expressed in N. tabacum BY-2 cells.

  11. Three monoclonal antibodies to the VHS virus glycoprotein: comparison of reactivity in relation to differences in immunoglobulin variable domain gene sequences

    DEFF Research Database (Denmark)

    Lorenzen, Niels; Cupit, P.M.; Secombes, C.J.

    2000-01-01

    and their neutralising activity was evident. Binding kinetic analyses by plasmon resonance identified differences in the dissociation rate constant (kd) as a possible explanation for the different reactivity levels of the MAbs. The Ig variable heavy (VH) and light (V kappa) domain gene sequences of the three hybridomas...... were compared. The inferred amino acid sequence of the two neutralising antibody VH domains differed by three amino acid residues (97% identity) and only one residue difference was evident in the Vk. domains. In contrast, IP1H3 shared only 38 and 39% identity with the 3F1A2 and 3F1H10 VH domains...... respectively and 49 and 50% identity with the 3F1A2 and 3F1H10 VK domains respectively. The neutralising antibodies were produced by hybridomas originating from the same fusion and the high nucleotide sequence homology of the variable Ig gene regions indicated that the plasma cell partners of the hybridomas...

  12. Nucleotide and Predicted Amino Acid Sequence-Based Analysis of the Avian Metapneumovirus Type C Cell Attachment Glycoprotein Gene: Phylogenetic Analysis and Molecular Epidemiology of U.S. Pneumoviruses

    Science.gov (United States)

    Alvarez, Rene; Lwamba, Humphrey M.; Kapczynski, Darrell R.; Njenga, M. Kariuki; Seal, Bruce S.

    2003-01-01

    A serologically distinct avian metapneumovirus (aMPV) was isolated in the United States after an outbreak of turkey rhinotracheitis (TRT) in February 1997. The newly recognized U.S. virus was subsequently demonstrated to be genetically distinct from European subtypes and was designated aMPV serotype C (aMPV/C). We have determined the nucleotide sequence of the gene encoding the cell attachment glycoprotein (G) of aMPV/C (Colorado strain and three Minnesota isolates) and predicted amino acid sequence by sequencing cloned cDNAs synthesized from intracellular RNA of aMPV/C-infected cells. The nucleotide sequence comprised 1,321 nucleotides with only one predicted open reading frame encoding a protein of 435 amino acids, with a predicted Mr of 48,840. The structural characteristics of the predicted G protein of aMPV/C were similar to those of the human respiratory syncytial virus (hRSV) attachment G protein, including two mucin-like regions (heparin-binding domains) flanking both sides of a CX3C chemokine motif present in a conserved hydrophobic pocket. Comparison of the deduced G-protein amino acid sequence of aMPV/C with those of aMPV serotypes A, B, and D, as well as hRSV revealed overall predicted amino acid sequence identities ranging from 4 to 16.5%, suggesting a distant relationship. However, G-protein sequence identities ranged from 72 to 97% when aMPV/C was compared to other members within the aMPV/C subtype or 21% for the recently identified human MPV (hMPV) G protein. Ratios of nonsynonymous to synonymous nucleotide changes were greater than one in the G gene when comparing the more recent Minnesota isolates to the original Colorado isolate. Epidemiologically, this indicates positive selection among U.S. isolates since the first outbreak of TRT in the United States. PMID:12682171

  13. Substantial excretion of digoxin via the intestinal mucosa and prevention of long-term digoxin accumulation in the brain by the mdr1a P-glycoprotein

    NARCIS (Netherlands)

    Mayer, U; Wagenaar, E; Beijnen, J.H; Smit, J.W; Meijer, D.K F; van Asperen, J.; Borst, P; Schinkel, A.H

    1 We have used mice with a disrupted mdrla P-glycoprotein gene (mdrIa (-/-) mice) to study the role of P-glycoprotein in the pharmacokinetics of digoxin, a model P-glycoprotein substrate. 2 [K-3]-digoxin at a dose of 0.2 mg kg(-1) was administered as a single i.v. or oral bolus injection. We

  14. Human immunodeficiency virus type 1 subtype B ancestral envelope protein is functional and elicits neutralizing antibodies in rabbits similar to those elicited by a circulating subtype B envelope.

    Science.gov (United States)

    Doria-Rose, N A; Learn, G H; Rodrigo, A G; Nickle, D C; Li, F; Mahalanabis, M; Hensel, M T; McLaughlin, S; Edmonson, P F; Montefiori, D; Barnett, S W; Haigwood, N L; Mullins, J I

    2005-09-01

    Human immunodeficiency virus type 1 (HIV-1) is a difficult target for vaccine development, in part because of its ever-expanding genetic diversity and attendant capacity to escape immunologic recognition. Vaccine efficacy might be improved by maximizing immunogen antigenic similarity to viruses likely to be encountered by vaccinees. To this end, we designed a prototype HIV-1 envelope vaccine using a deduced ancestral state for the env gene. The ancestral state reconstruction method was shown to be >95% accurate by computer simulation and 99.8% accurate when estimating the known inoculum used in an experimental infection study in rhesus macaques. Furthermore, the deduced ancestor gene differed from the set of sequences used to derive the ancestor by an average of 12.3%, while these latter sequences were an average of 17.3% different from each other. A full-length ancestral subtype B HIV-1 env gene was constructed and shown to produce a glycoprotein of 160 kDa that bound and fused with cells expressing the HIV-1 coreceptor CCR5. This Env was also functional in a virus pseudotype assay. When either gp160- or gp140-expressing plasmids and recombinant gp120 were used to immunize rabbits in a DNA prime-protein boost regimen, the artificial gene induced immunoglobulin G antibodies capable of weakly neutralizing heterologous primary HIV-1 strains. The results were similar for rabbits immunized in parallel with a natural isolate, HIV-1 SF162. Further design efforts to better present conserved neutralization determinants are warranted.

  15. Nuclear envelope alterations in fibroblasts from LGMD1B patients carrying nonsense Y259X heterozygous or homozygous mutation in lamin A/C gene.

    NARCIS (Netherlands)

    Muchir, A.; Engelen, B.G.M. van; Lammens, M.M.Y.; Mislow, J.M.; McNally, E.; Schwartz, K.; Bonne, G.

    2003-01-01

    Mutations in the LMNA gene encoding nuclear lamins A and C are responsible for seven inherited disorders affecting specific tissues. We have analyzed skin fibroblasts from a patient with type 1B limb-girdle muscular dystrophy and from her deceased newborn grandchild carrying, respectively, a

  16. Uncertain data envelopment analysis

    CERN Document Server

    Wen, Meilin

    2014-01-01

    This book is intended to present the milestones in the progression of uncertain Data envelopment analysis (DEA). Chapter 1 gives some basic introduction to uncertain theories, including probability theory, credibility theory, uncertainty theory and chance theory. Chapter 2 presents a comprehensive review and discussion of basic DEA models. The stochastic DEA is introduced in Chapter 3, in which the inputs and outputs are assumed to be random variables. To obtain the probability distribution of a random variable, a lot of samples are needed to apply the statistics inference approach. Chapter 4

  17. Isolation and characterization of broadly neutralizing human monoclonal antibodies to the e1 glycoprotein of hepatitis C virus

    DEFF Research Database (Denmark)

    Meunier, Jean-Christophe; Russell, Rodney S.; Goossens, Vera

    2008-01-01

    The relative importance of humoral and cellular immunity in the prevention or clearance of hepatitis C virus (HCV) infection is poorly understood. However, there is considerable evidence that neutralizing antibodies are involved in disease control. Here we describe the detailed analysis of human...... monoclonal antibodies (MAbs) directed against HCV glycoprotein E1, which may have the potential to control HCV infection. We have identified two MAbs that can strongly neutralize HCV-pseudotyped particles (HCVpp) bearing the envelope glycoproteins of genotypes 1a, 1b, 4a, 5a, and 6a and less strongly...... neutralize HCVpp bearing the envelope glycoproteins of genotype 2a. Genotype 3a was not neutralized. The epitopes for both MAbs were mapped to the region encompassing amino acids 313 to 327. In addition, robust neutralization was also observed against cell culture-adapted viruses of genotypes 1a and 2a...

  18. Enhanced anti-tumor effect of a gene gun-delivered DNA vaccine encoding the human papillomavirus type 16 oncoproteins genetically fused to the herpes simplex virus glycoprotein D

    Directory of Open Access Journals (Sweden)

    M.O. Diniz

    2011-05-01

    Full Text Available Anti-cancer DNA vaccines have attracted growing interest as a simple and non-invasive method for both the treatment and prevention of tumors induced by human papillomaviruses. Nonetheless, the low immunogenicity of parenterally administered vaccines, particularly regarding the activation of cytotoxic CD8+ T cell responses, suggests that further improvements in both vaccine composition and administration routes are still required. In the present study, we report the immune responses and anti-tumor effects of a DNA vaccine (pgD-E7E6E5 expressing three proteins (E7, E6, and E5 of the human papillomavirus type 16 genetically fused to the glycoprotein D of the human herpes simplex virus type 1, which was administered to mice by the intradermal (id route using a gene gun. A single id dose of pgD-E7E6E5 (2 µg/dose induced a strong activation of E7-specific interferon-γ (INF-γ-producing CD8+ T cells and full prophylactic anti-tumor effects in the vaccinated mice. Three vaccine doses inhibited tumor growth in 70% of the mice with established tumors. In addition, a single vaccine dose consisting of the co-administration of pgD-E7E6E5 and the vector encoding interleukin-12 or granulocyte-macrophage colony-stimulating factor further enhanced the therapeutic anti-tumor effects and conferred protection to 60 and 50% of the vaccinated mice, respectively. In conclusion, id administration of pgD-E7E6E5 significantly enhanced the immunogenicity and anti-tumor effects of the DNA vaccine, representing a promising administration route for future clinical trials.

  19. Salivary Mucin 19 Glycoproteins

    Science.gov (United States)

    Culp, David J.; Robinson, Bently; Cash, Melanie N.; Bhattacharyya, Indraneel; Stewart, Carol; Cuadra-Saenz, Giancarlo

    2015-01-01

    Saliva functions in innate immunity of the oral cavity, protecting against demineralization of teeth (i.e. dental caries), a highly prevalent infectious disease associated with Streptococcus mutans, a pathogen also linked to endocarditis and atheromatous plaques. Gel-forming mucins are a major constituent of saliva. Because Muc19 is the dominant salivary gel-forming mucin in mice, we studied Muc19−/− mice for changes in innate immune functions of saliva in interactions with S. mutans. When challenged with S. mutans and a cariogenic diet, total smooth and sulcal surface lesions are more than 2- and 1.6-fold higher in Muc19−/− mice compared with wild type, whereas the severity of lesions are up to 6- and 10-fold higher, respectively. Furthermore, the oral microbiota of Muc19−/− mice display higher levels of indigenous streptococci. Results emphasize the importance of a single salivary constituent in the innate immune functions of saliva. In vitro studies of S. mutans and Muc19 interactions (i.e. adherence, aggregation, and biofilm formation) demonstrate Muc19 poorly aggregates S. mutans. Nonetheless, aggregation is enhanced upon adding Muc19 to saliva from Muc19−/− mice, indicating Muc19 assists in bacterial clearance through formation of heterotypic complexes with salivary constituents that bind S. mutans, thus representing a novel innate immune function for salivary gel-forming mucins. In humans, expression of salivary MUC19 is unclear. We find MUC19 transcripts in salivary glands of seven subjects and demonstrate MUC19 glycoproteins in glandular mucous cells and saliva. Similarities and differences between mice and humans in the expression and functions of salivary gel-forming mucins are discussed. PMID:25512380

  20. Hantavirus Gn and Gc glycoproteins self-assemble into virus-like particles.

    Science.gov (United States)

    Acuña, Rodrigo; Cifuentes-Muñoz, Nicolás; Márquez, Chantal L; Bulling, Manuela; Klingström, Jonas; Mancini, Roberta; Lozach, Pierre-Yves; Tischler, Nicole D

    2014-02-01

    How hantaviruses assemble and exit infected cells remains largely unknown. Here, we show that the expression of Andes (ANDV) and Puumala (PUUV) hantavirus Gn and Gc envelope glycoproteins lead to their self-assembly into virus-like particles (VLPs) which were released to cell supernatants. The viral nucleoprotein was not required for particle formation. Further, a Gc endodomain deletion mutant did not abrogate VLP formation. The VLPs were pleomorphic, exposed protrusions and reacted with patient sera.

  1. The neurovirulence and neuroinvasiveness of chimeric tick-borne encephalitis/dengue virus can be attenuated by introducing defined mutations into the envelope and NS5 protein genes and the 3' non-coding region of the genome

    International Nuclear Information System (INIS)

    Engel, Amber R.; Rumyantsev, Alexander A.; Maximova, Olga A.; Speicher, James M.; Heiss, Brian; Murphy, Brian R.; Pletnev, Alexander G.

    2010-01-01

    Tick-borne encephalitis (TBE) is a severe disease affecting thousands of people throughout Eurasia. Despite the use of formalin-inactivated vaccines in endemic areas, an increasing incidence of TBE emphasizes the need for an alternative vaccine that will induce a more durable immunity against TBE virus (TBEV). The chimeric attenuated virus vaccine candidate containing the structural protein genes of TBEV on a dengue virus genetic background (TBEV/DEN4) retains a high level of neurovirulence in both mice and monkeys. Therefore, attenuating mutations were introduced into the envelope (E 315 ) and NS5 (NS5 654,655 ) proteins, and into the 3' non-coding region (Δ30) of TBEV/DEN4. The variant that contained all three mutations (vΔ30/E 315 /NS5 654,655 ) was significantly attenuated for neuroinvasiveness and neurovirulence and displayed a reduced level of replication and virus-induced histopathology in the brains of mice. The high level of safety in the central nervous system indicates that vΔ30/E 315 /NS5 654,655 should be further evaluated as a TBEV vaccine.

  2. Functional Role of N-Linked Glycosylation in Pseudorabies Virus Glycoprotein gH.

    Science.gov (United States)

    Vallbracht, Melina; Rehwaldt, Sascha; Klupp, Barbara G; Mettenleiter, Thomas C; Fuchs, Walter

    2018-05-01

    Many viral envelope proteins are modified by asparagine (N)-linked glycosylation, which can influence their structure, physicochemical properties, intracellular transport, and function. Here, we systematically analyzed the functional relevance of N-linked glycans in the alphaherpesvirus pseudorabies virus (PrV) glycoprotein H (gH), which is an essential component of the conserved core herpesvirus fusion machinery. Upon gD-mediated receptor binding, the heterodimeric complex of gH and gL activates gB to mediate fusion of the viral envelope with the host cell membrane for viral entry. gH contains five potential N-linked glycosylation sites at positions 77, 162, 542, 604, and 627, which were inactivated by conservative mutations (asparagine to glutamine) singly or in combination. The mutated proteins were tested for correct expression and fusion activity. Additionally, the mutated gH genes were inserted into the PrV genome for analysis of function during virus infection. Our results demonstrate that all five sites are glycosylated. Inactivation of the PrV-specific N77 or the conserved N627 resulted in significantly reduced in vitro fusion activity, delayed penetration kinetics, and smaller virus plaques. Moreover, substitution of N627 greatly affected transport of gH in transfected cells, resulting in endoplasmic reticulum (ER) retention and reduced surface expression. In contrast, mutation of N604, which is conserved in the Varicellovirus genus, resulted in enhanced in vitro fusion activity and viral cell-to-cell spread. These results demonstrate a role of the N-glycans in proper localization and function of PrV gH. However, even simultaneous inactivation of all five N-glycosylation sites of gH did not severely inhibit formation of infectious virus particles. IMPORTANCE Herpesvirus infection requires fusion of the viral envelope with cellular membranes, which involves the conserved fusion machinery consisting of gB and the heterodimeric gH/gL complex. The bona fide

  3. The glycoprotein of measles virus

    International Nuclear Information System (INIS)

    Anttonen, O.; Jokinen, M.; Salmi, A.; Vainionpaeae, R.; Gahmberg, C.G.

    1980-01-01

    Measles virus was propagated in VERO cells and purified from the culture supernatants by two successive tartrate-density-gradient centrifugations. Surface carbohydrates were labelled both in vitro and in vivo with 3 H after treatment with galactose oxidase/NaB 3 H 4 or with [ 3 H]glucosamine. The major labelled glycoprotein in measles virions had a mol.wt. of 79000. After labelling with periodate/NaB 3 H 4 , which would result in specific labelling of sialic acid residues, the 79000-mol.wt. glycoprotein was very weakly labelled. This suggested that there is no or a very low amount of sialic acid in the virions. Further analysis of the glycoprotein showed that galactose is the terminal carbohydrate unit in the oligosaccharide, and the molecular weight of the glycopeptide obtained after Pronase digestion is about 3000. The oligosaccharide is attached to the polypeptide through an alkali-stable bond, indicating a N-glycosidic asparagine linkage. (author)

  4. A chimeric measles virus with a lentiviral envelope replicates exclusively in CD4+/CCR5+ cells

    International Nuclear Information System (INIS)

    Mourez, Thomas; Mesel-Lemoine, Mariana; Combredet, Chantal; Najburg, Valerie; Cayet, Nadege; Tangy, Frederic

    2011-01-01

    We generated a replicating chimeric measles virus in which the hemagglutinin and fusion surface glycoproteins were replaced with the gp160 envelope glycoprotein of simian immunodeficiency virus (SIVmac239). Based on a previously cloned live-attenuated Schwarz vaccine strain of measles virus (MV), this chimera was rescued at high titers using reverse genetics in CD4+ target cells. Cytopathic effect consisted in the presence of large cell aggregates evolving to form syncytia, as observed during SIV infection. The morphology of the chimeric virus was identical to that of the parent MV particles. The presence of SIV gp160 as the only envelope protein on chimeric particles surface altered the cell tropism of the new virus from CD46+ to CD4+ cells. Used as an HIV candidate vaccine, this MV/SIVenv chimeric virus would mimic transient HIV-like infection, benefiting both from HIV-like tropism and the capacity of MV to replicate in dendritic cells, macrophages and lymphocytes.

  5. Structure of a trimeric variant of the Epstein-Barr virus glycoprotein B

    Energy Technology Data Exchange (ETDEWEB)

    Backovic, Marija [Northwestern Univ., Evanston, IL (United States); Longnecker, Richard [Northwestern Univ., Chicago, IL (United States); Jardetzky, Theodore S [Northwestern Univ., Evanston, IL (United States)

    2009-03-16

    Epstein-Barr virus (EBV) is a herpesvirus that is associated with development of malignancies of lymphoid tissue. EBV infections are life-long and occur in >90% of the population. Herpesviruses enter host cells in a process that involves fusion of viral and cellular membranes. The fusion apparatus is comprised of envelope glycoprotein B (gB) and a heterodimeric complex made of glycoproteins H and L. Glycoprotein B is the most conserved envelope glycoprotein in human herpesviruses, and the structure of gB from Herpes simplex virus 1 (HSV-1) is available. Here, we report the crystal structure of the secreted EBV gB ectodomain, which forms 16-nm long spike-like trimers, structurally homologous to the postfusion trimers of the fusion protein G of vesicular stomatitis virus (VSV). Comparative structural analyses of EBV gB and VSV G, which has been solved in its pre and postfusion states, shed light on gB residues that may be involved in conformational changes and membrane fusion. Also, the EBV gB structure reveals that, despite the high sequence conservation of gB in herpesviruses, the relative orientations of individual domains, the surface charge distributions, and the structural details of EBV gB differ from the HSV-1 protein, indicating regions and residues that may have important roles in virus-specific entry.

  6. Replacement of glycoprotein B gene in the Herpes simplex virus type 1 strain ANGpath DNA that originating from non-pathogenic strain KOS reduces the pathogenicity of recombinant virus

    International Nuclear Information System (INIS)

    Kostal, M.; Bacik, I.; Rajcani, J.; Kaerner, H.C.

    1994-01-01

    Herpes simplex virus type-1 (HSV-1) strain ANGpath and its recombinants, in which the 8.1 kbp BamHI G restriction fragment (0.345-0.399) containing the glycoprotein B (gB path ) gene (UL27) or its sub-fragments-coding either for cytoplasmic or surface domain of gB-had been replaced with the corresponding fragments from non-pathogenic KOS virus DNA (gB KOS ), were tested for their pathogenicity for DBA/2 mice and rabbits. The recombinant ANGpath/B6 KOS prepared by transferring the 2.7 kbp SstI-SstI sub-fragment (0.351-0.368) of the BamHI G KOS fragment still had the original sequence of ANGpath DNA coding for the syn 3 marker in the cytoplasmic domain of gB and was pathogenic for mice as well as for rabbits. Virological and immuno-histological studies in DBA/2 mice infected with the latter pathogenic recombinant and with ANGpath showed the presence of infectious virus and viral antigen at inoculation site (epidermis, subcutaneous connective tissue and striated muscle in the area of right lip), in homo-lateral trigeminal nerve and ganglion, brain stem, midbrain, thalamic and hypothalamic nuclei. In contrast, non-pathogenic recombinants ANGpath/syn + B6 KOS (prepared by transferring the whole BamHI G KOS fragment) and ANGpath/syn +KOS (prepared by transferring the 0.8 kbp BamHI-SstI sub-fragment of the BamHI G KOS fragment) showed limited hematogenous and neural spread, but no evidence of replication in CNS; thus, their behaviour resembled that of the wild type strain KOS. The recombinant ANGpath/syn +KOS , which was not pathogenic for mice, still remained pathogenic for rabbits, a phenomenon indicating the presence of an additional locus in the gB molecule participating on virulence. Sequencing the 1478 bp SstI-SstI sub-fragment of the BamHI G path fragment (nt 53,348 - 54,826 of UL segment) showed the presence of at least 3 mutations as compared to the KOS sequence, from which the change of cytosine at nt 54,2251 altered the codon for arginine to that histidine

  7. The NS1 glycoprotein can generate dramatic antibody-enhanced dengue viral replication in normal out-bred mice resulting in lethal multi-organ disease.

    Directory of Open Access Journals (Sweden)

    Andrew K I Falconar

    Full Text Available Antibody-enhanced replication (AER of dengue type-2 virus (DENV-2 strains and production of antibody-enhanced disease (AED was tested in out-bred mice. Polyclonal antibodies (PAbs generated against the nonstructural-1 (NS1 glycoprotein candidate vaccine of the New Guinea-C (NG-C or NSx strains reacted strongly and weakly with these antigens, respectively. These PAbs contained the IgG2a subclass, which cross-reacted with the virion-associated envelope (E glycoprotein of the DENV-2 NSx strain, suggesting that they could generate its AER via all mouse Fcγ-receptor classes. Indeed, when these mice were challenged with a low dose (<0.5 LD₅₀ of the DENV-2 NSx strain, but not the NG-C strain, they all generated dramatic and lethal DENV-2 AER/AED. These AER/AED mice developed life-threatening acute respiratory distress syndrome (ARDS, displayed by diffuse alveolar damage (DAD resulting from i dramatic interstitial alveolar septa-thickening with mononuclear cells, ii some hyperplasia of alveolar type-II pneumocytes, iii copious intra-alveolar protein secretion, iv some hyaline membrane-covered alveolar walls, and v DENV-2 antigen-positive alveolar macrophages. These mice also developed meningo-encephalitis, with greater than 90,000-fold DENV-2 AER titers in microglial cells located throughout their brain parenchyma, some of which formed nodules around dead neurons. Their spleens contained infiltrated megakaryocytes with DENV-2 antigen-positive red-pulp macrophages, while their livers displayed extensive necrosis, apoptosis and macro- and micro-steatosis, with DENV-2 antigen-positive Kuppfer cells and hepatocytes. Their infections were confirmed by DENV-2 isolations from their lungs, spleens and livers. These findings accord with those reported in fatal human "severe dengue" cases. This DENV-2 AER/AED was blocked by high concentrations of only the NG-C NS1 glycoprotein. These results imply a potential hazard of DENV NS1 glycoprotein-based vaccines

  8. Effects of Vector Backbone and Pseudotype on Lentiviral Vector-mediated Gene Transfer: Studies in Infant ADA-Deficient Mice and Rhesus Monkeys

    Science.gov (United States)

    Carbonaro Sarracino, Denise; Tarantal, Alice F; Lee, C Chang I.; Martinez, Michele; Jin, Xiangyang; Wang, Xiaoyan; Hardee, Cinnamon L; Geiger, Sabine; Kahl, Christoph A; Kohn, Donald B

    2014-01-01

    Systemic delivery of a lentiviral vector carrying a therapeutic gene represents a new treatment for monogenic disease. Previously, we have shown that transfer of the adenosine deaminase (ADA) cDNA in vivo rescues the lethal phenotype and reconstitutes immune function in ADA-deficient mice. In order to translate this approach to ADA-deficient severe combined immune deficiency patients, neonatal ADA-deficient mice and newborn rhesus monkeys were treated with species-matched and mismatched vectors and pseudotypes. We compared gene delivery by the HIV-1-based vector to murine γ-retroviral vectors pseudotyped with vesicular stomatitis virus-glycoprotein or murine retroviral envelopes in ADA-deficient mice. The vesicular stomatitis virus-glycoprotein pseudotyped lentiviral vectors had the highest titer and resulted in the highest vector copy number in multiple tissues, particularly liver and lung. In monkeys, HIV-1 or simian immunodeficiency virus vectors resulted in similar biodistribution in most tissues including bone marrow, spleen, liver, and lung. Simian immunodeficiency virus pseudotyped with the gibbon ape leukemia virus envelope produced 10- to 30-fold lower titers than the vesicular stomatitis virus-glycoprotein pseudotype, but had a similar tissue biodistribution and similar copy number in blood cells. The relative copy numbers achieved in mice and monkeys were similar when adjusted to the administered dose per kg. These results suggest that this approach can be scaled-up to clinical levels for treatment of ADA-deficient severe combined immune deficiency subjects with suboptimal hematopoietic stem cell transplantation options. PMID:24925206

  9. Effects of vector backbone and pseudotype on lentiviral vector-mediated gene transfer: studies in infant ADA-deficient mice and rhesus monkeys.

    Science.gov (United States)

    Carbonaro Sarracino, Denise; Tarantal, Alice F; Lee, C Chang I; Martinez, Michele; Jin, Xiangyang; Wang, Xiaoyan; Hardee, Cinnamon L; Geiger, Sabine; Kahl, Christoph A; Kohn, Donald B

    2014-10-01

    Systemic delivery of a lentiviral vector carrying a therapeutic gene represents a new treatment for monogenic disease. Previously, we have shown that transfer of the adenosine deaminase (ADA) cDNA in vivo rescues the lethal phenotype and reconstitutes immune function in ADA-deficient mice. In order to translate this approach to ADA-deficient severe combined immune deficiency patients, neonatal ADA-deficient mice and newborn rhesus monkeys were treated with species-matched and mismatched vectors and pseudotypes. We compared gene delivery by the HIV-1-based vector to murine γ-retroviral vectors pseudotyped with vesicular stomatitis virus-glycoprotein or murine retroviral envelopes in ADA-deficient mice. The vesicular stomatitis virus-glycoprotein pseudotyped lentiviral vectors had the highest titer and resulted in the highest vector copy number in multiple tissues, particularly liver and lung. In monkeys, HIV-1 or simian immunodeficiency virus vectors resulted in similar biodistribution in most tissues including bone marrow, spleen, liver, and lung. Simian immunodeficiency virus pseudotyped with the gibbon ape leukemia virus envelope produced 10- to 30-fold lower titers than the vesicular stomatitis virus-glycoprotein pseudotype, but had a similar tissue biodistribution and similar copy number in blood cells. The relative copy numbers achieved in mice and monkeys were similar when adjusted to the administered dose per kg. These results suggest that this approach can be scaled-up to clinical levels for treatment of ADA-deficient severe combined immune deficiency subjects with suboptimal hematopoietic stem cell transplantation options.

  10. Canine Distemper Virus Matrix Protein Influences Particle Infectivity, Particle Composition, and Envelope Distribution in Polarized Epithelial Cells and Modulates Virulence ▿

    OpenAIRE

    Dietzel, Erik; Anderson, Danielle E.; Castan, Alexandre; von Messling, Veronika; Maisner, Andrea

    2011-01-01

    In paramyxoviruses, the matrix (M) protein mediates the interaction between the envelope and internal proteins during particle assembly and egress. In measles virus (MeV), M mutations, such as those found in subacute sclerosing panencephalitis (SSPE) strains, and differences in vaccine and wild-type M proteins can affect the strength of interaction with the envelope glycoproteins, assembly efficiency, and spread. However, the contribution of the M protein to the replication and pathogenesis o...

  11. THE ROLE OF P-GLYCOPROTEIN IN RATIONAL PHARMACOTHERAPY IN CARDIOLOGY

    Directory of Open Access Journals (Sweden)

    A. V. Shulkin

    2015-09-01

    Full Text Available On the basis of the analysis of published data the role of P-glycoprotein, carrier protein, in rational pharmacotherapy in cardiology was shown on the example of its substrates – digoxin, antiplatelet agents and anticoagulants. Determination of C3435T polymorphism of multidrug resistance gene (MDR1, encoding P-glycoprotein, in pharmacotherapy with digoxin, antiplatelet drugs (clopidogrel tikagrelol, prasugrel and anticoagulants (dabigatran etexilate, rivaroxaban, edoxaban is not feasible in routine practice. Drug in- teractions have clinical implications for the efficacy and safety of pharmacotherapy in coadministration of these drugs with P-glycoprotein substrates, inducers and inhibitors.

  12. Surfing the wave, cycle, life history, and genes/proteins expressed by testicular germ cells. Part 4: intercellular bridges, mitochondria, nuclear envelope, apoptosis, ubiquitination, membrane/voltage-gated channels, methylation/acetylation, and transcription factors.

    Science.gov (United States)

    Hermo, Louis; Pelletier, R-Marc; Cyr, Daniel G; Smith, Charles E

    2010-04-01

    As germ cells divide and differentiate from spermatogonia to spermatozoa, they share a number of structural and functional features that are common to all generations of germ cells and these features are discussed herein. Germ cells are linked to one another by large intercellular bridges which serve to move molecules and even large organelles from the cytoplasm of one cell to another. Mitochondria take on different shapes and features and topographical arrangements to accommodate their specific needs during spermatogenesis. The nuclear envelope and pore complex also undergo extensive modifications concomitant with the development of germ cell generations. Apoptosis is an event that is normally triggered by germ cells and involves many proteins. It occurs to limit the germ cell pool and acts as a quality control mechanism. The ubiquitin pathway comprises enzymes that ubiquitinate as well as deubiquitinate target proteins and this pathway is present and functional in germ cells. Germ cells express many proteins involved in water balance and pH control as well as voltage-gated ion channel movement. In the nucleus, proteins undergo epigenetic modifications which include methylation, acetylation, and phosphorylation, with each of these modifications signaling changes in chromatin structure. Germ cells contain specialized transcription complexes that coordinate the differentiation program of spermatogenesis, and there are many male germ cell-specific differences in the components of this machinery. All of the above features of germ cells will be discussed along with the specific proteins/genes and abnormalities to fertility related to each topic. Copyright 2009 Wiley-Liss, Inc.

  13. Recent Progress in Electrochemical Biosensors for Glycoproteins

    Directory of Open Access Journals (Sweden)

    Uichi Akiba

    2016-12-01

    Full Text Available This review provides an overview of recent progress in the development of electrochemical biosensors for glycoproteins. Electrochemical glycoprotein sensors are constructed by combining metal and carbon electrodes with glycoprotein-selective binding elements including antibodies, lectin, phenylboronic acid and molecularly imprinted polymers. A recent trend in the preparation of glycoprotein sensors is the successful use of nanomaterials such as graphene, carbon nanotube, and metal nanoparticles. These nanomaterials are extremely useful for improving the sensitivity of glycoprotein sensors. This review focuses mainly on the protocols for the preparation of glycoprotein sensors and the materials used. Recent improvements in glycoprotein sensors are discussed by grouping the sensors into several categories based on the materials used as recognition elements.

  14. P-glycoprotein in autoimmune rheumatic diseases.

    Science.gov (United States)

    García-Carrasco, M; Mendoza-Pinto, C; Macias Díaz, S; Vera-Recabarren, M; Vázquez de Lara, L; Méndez Martínez, S; Soto-Santillán, P; González-Ramírez, R; Ruiz-Arguelles, A

    2015-07-01

    P-glycoprotein (Pgp) is a transmembrane protein of 170 kD encoded by the multidrug resistance 1 (MDR-1) gene, localized on chromosome 7. More than 50 polymorphisms of the MDR-1 gene have been described; a subset of these has been shown to play a pathophysiological role in the development of inflammatory bowel disease, femoral head osteonecrosis induced by steroids, lung cancer and renal epithelial tumors. Polymorphisms that have a protective effect on the development of conditions such as Parkinson disease have also been identified. P-glycoprotein belongs to the adenosine triphosphate binding cassette transporter superfamily and its structure comprises a chain of approximately 1280 aminoacid residues with an N-C terminal structure, arranged as 2 homologous halves, each of which has 6 transmembrane segments, with a total of 12 segments with 2 cytoplasmic nucleotide binding domains. Many cytokines like interleukin 2 and tumor necrosis factor alpha increase Pgp expression and activity. Pgp functions as an efflux pump for a variety of toxins in order to protect particular organs and tissues as the central nervous system. Pgp transports a variety of substrates including glucocorticoids while other drugs such as tacrolimus and cyclosporine A act as modulators of this protein. The most widely used method to measure Pgp activity is flow cytometry using naturally fluorescent substrates such as anthracyclines or rhodamine 123. The study of drug resistance and its association to Pgp began with the study of resistance to chemotherapy in the treatment of cancer and antiretroviral therapy for human immunodeficiency virus; however, the role of Pgp in the treatment of systemic lupus erythematosus, rheumatoid arthritis and psoriatic arthritis has been a focus of study lately and has emerged as an important mechanism by which treatment failure occurs. The present review analyzes the role of Pgp in these autoimmune diseases. Copyright © 2015 Elsevier B.V. All rights reserved.

  15. The LHC on an envelope

    CERN Multimedia

    2007-01-01

    The series of envelopes featuring CERN issued this summer was a huge success. The French postal services of the Pays de Gex will shortly be launching the second set of pre-paid envelopes issued in collaboration with the Laboratory this year, this time highlighting the LHC. Five thousand envelopes describing the accelerator’s capabilities will go on sale on 12 November, and some of the packs will even contain a small sample of the cables from the heart of the LHC magnets. The sets of ten pre-paid envelopes will tell you everything about CERN’s flagship accelerator, from its astounding technical capabilities to its spin-offs in the fields of technology and human resources. Each envelope will feature a different attribute or spin-off of the LHC. People will be invited to consult CERN’s public website for more detailed explanations if they want to know more. The new envelopes will be available from five post offices in the Pays ...

  16. The LHC in an envelope

    CERN Multimedia

    2007-01-01

    The series of envelopes featuring CERN issued this summer was a huge success. The French postal services of the Pays de Gex will shortly be launching the second set of pre-paid envelopes issued in collaboration with the Laboratory this year, this time highlighting the LHC. Five thousand envelopes describing the accelerator’s capabilities will go on sale on 12 November, and some of the packs will even contain a small sample of the cables from the heart of the LHC magnets. The sets of ten pre-paid envelopes will tell you everything about CERN’s flagship accelerator, from its astounding technical capabilities to its spin-offs in the fields of technology and human resources. Each envelope will feature a different attribute or spin-off of the LHC. People will be invited to consult CERN’s public website for more detailed explanations if they want to know more. The new envelopes will be available from five post offices in the Pays de Gex (Ferney-Voltaire, Prévessin...

  17. Determination of P-Glycoprotein Expression by Flow Cytometry in Hematological Malignancies

    Directory of Open Access Journals (Sweden)

    Berkay Saraymen

    2016-03-01

    Full Text Available Objective: Determination the expression of P-glycoprotein is especially problematic for normal tissues because immuno­logical methods are limited in terms of sensitivity. We aimed to determine the expression of P-glycoprotein and CD34 by flow cytometry, and to evaluate the level of expression of P-glycoprotein and CD34 with unresponsive to treatment in pa­tients diagnosed with hematologic malignancy. Methods: Our study included fifty patients diagnosed with acute myeloblastic leukemia and acute lymphoblastic leuke­mia, and twenty healthy controls who were admitted to Erci­yes University Hematology-Oncology Hospital. The suspend­ed cells from bone marrow samples of patients and the pe­ripheral blood samples of healthy people were marked with P-glycoprotein phycoerythrin and CD34 FITC or PerCP Cy 5.5; and then surface expression was measured by means of flow cytometry. Results: In 6 of 30 acute myeloblastic leukemia patients P-glycoprotein and CD34 expression, in 6 of 20 acute lympho­blastic leukemia patients P-glycoprotein, in 5 of them CD34 expression were determined. A significant relation between P-glycoprotein and CD34 expressions in acute myeloblas­tic leukemia and acute lymphoblastic leukemia bone marrow samples was reported. Conclusion: Our data indicate that flow cytometry is more reliable, precise and faster than molecular methods for mea­suring P-glycoprotein expression and suggests the pos­sibility of a significant relationship between P-glycoprotein and CD34 expressions in acute myeloblastic leukemia and acute lymphoblastic leukemia bone marrow samples. The blast cells expressing CD34 on their surface along with P-glycoprotein simultaneously show that multi drug resistance 1 gene is mostly active in immature cells.

  18. Role of the Phosphatidylserine Receptor TIM-1 in Enveloped-Virus Entry

    Science.gov (United States)

    Moller-Tank, Sven; Kondratowicz, Andrew S.; Davey, Robert A.; Rennert, Paul D.

    2013-01-01

    The cell surface receptor T cell immunoglobulin mucin domain 1 (TIM-1) dramatically enhances filovirus infection of epithelial cells. Here, we showed that key phosphatidylserine (PtdSer) binding residues of the TIM-1 IgV domain are critical for Ebola virus (EBOV) entry through direct interaction with PtdSer on the viral envelope. PtdSer liposomes but not phosphatidylcholine liposomes competed with TIM-1 for EBOV pseudovirion binding and transduction. Further, annexin V (AnxV) substituted for the TIM-1 IgV domain, supporting a PtdSer-dependent mechanism. Our findings suggest that TIM-1-dependent uptake of EBOV occurs by apoptotic mimicry. Additionally, TIM-1 enhanced infection of a wide range of enveloped viruses, including alphaviruses and a baculovirus. As further evidence of the critical role of enveloped-virion-associated PtdSer in TIM-1-mediated uptake, TIM-1 enhanced internalization of pseudovirions and virus-like proteins (VLPs) lacking a glycoprotein, providing evidence that TIM-1 and PtdSer-binding receptors can mediate virus uptake independent of a glycoprotein. These results provide evidence for a broad role of TIM-1 as a PtdSer-binding receptor that mediates enveloped-virus uptake. Utilization of PtdSer-binding receptors may explain the wide tropism of many of these viruses and provide new avenues for controlling their virulence. PMID:23698310

  19. RD-MolPack technology for the constitutive production of self-inactivating lentiviral vectors pseudotyped with the nontoxic RD114-TR envelope.

    Science.gov (United States)

    Marin, Virna; Stornaiuolo, Anna; Piovan, Claudia; Corna, Stefano; Bossi, Sergio; Pema, Monika; Giuliani, Erica; Scavullo, Cinzia; Zucchelli, Eleonora; Bordignon, Claudio; Rizzardi, Gian Paolo; Bovolenta, Chiara

    2016-01-01

    To date, gene therapy with transiently derived lentivectors has been very successful to cure rare infant genetic diseases. However, transient manufacturing is unfeasible to treat adult malignancies because large vector lots are required. By contrast, stable manufacturing is the best option for high-incidence diseases since it reduces the production cost, which is the major current limitation to scale up the transient methods. We have previously developed the proprietary RD2-MolPack technology for the stable production of second-generation lentivectors, based on the RD114-TR envelope. Of note, opposite to vesicular stomatitis virus glycoprotein (VSV-G) envelope, RD114-TR does not need inducible expression thanks to lack of toxicity. Here, we present the construction of RD2- and RD3-MolPack cells for the production of self-inactivating lentivectors expressing green fluorescent protein (GFP) as a proof-of-concept of the feasibility and safety of this technology before its later therapeutic exploitation. We report that human T lymphocytes transduced with self-inactivating lentivectors derived from RD3-MolPack cells or with self-inactivating VSV-G pseudotyped lentivectors derived from transient transfection show identical T-cell memory differentiation phenotype and comparable transduction efficiency in all T-cell subsets. RD-MolPack technology represents, therefore, a straightforward tool to simplify and standardize lentivector manufacturing to engineer T-cells for frontline immunotherapy applications.

  20. Roll of hemagglutinin gene in the biology of avian inflenza virus

    Directory of Open Access Journals (Sweden)

    Masoud Soltanialvar

    2016-06-01

    Full Text Available The hemagglutinin (HA, the major envelope glycoprotein of influenza, plays an important role during the early stage of infection, and changes in the HA gene prior to the emergence of pathogenic avian influenza viruses. The HA protein controls viral entry through membrane fusion of the viral envelope with the host cell membrane and allows the genetic information released to initiate new virus synthesis. Sharp antigenic variation of HA remains the critical challenge to the development of effective vaccines. Therefore, we highlight the role of HA in need of review: structure of HA, the fusion process and the HA receptor binding specificity in interspecies transmission and the impact of multiple mutations at antigenic sites and host antibodies to the parental virus, and the host susceptibility to productive infection by the drift strains.

  1. Mutational analysis of the hepatitis C virus E1 glycoprotein in retroviral pseudoparticles and cell-culture-derived H77/JFH1 chimeric infectious virus particles

    DEFF Research Database (Denmark)

    Russell, R S; Kawaguchi, K; Meunier, J-C

    2009-01-01

    Cell entry by enveloped viruses is mediated by viral glycoproteins, and generally involves a short hydrophobic peptide (fusion peptide) that inserts into the cellular membrane. An internal hydrophobic domain within E1 (aa262-290) of hepatitis C virus (HCV) may function as a fusion peptide. Retrov...

  2. Alteration of a second putative fusion peptide of structural glycoprotein E2 of Classical Swine Fever Virus alters virus replication and virulence in swine

    Science.gov (United States)

    E2, the major envelope glycoprotein of Classical Swine Fever Virus (CSFV), is involved in several critical virus functions including cell attachment, host range susceptibility, and virulence in natural hosts. Functional structural analysis of E2 based on Wimley-White interfacial hydrophobicity dis...

  3. A prime-boost approach to HIV preventive vaccine using a recombinant canarypox virus expressing glycoprotein 160 (MN) followed by a recombinant glycoprotein 160 (MN/LAI). The AGIS Group, and l'Agence Nationale de Recherche sur le SIDA.

    Science.gov (United States)

    Pialoux, G; Excler, J L; Rivière, Y; Gonzalez-Canali, G; Feuillie, V; Coulaud, P; Gluckman, J C; Matthews, T J; Meignier, B; Kieny, M P

    1995-03-01

    The safety and the immunogenicity of a recombinant canarypox live vector expressing the human immunodeficiency virus type 1 (HIV-1) gp160 gene from the MN isolate, ALVAC-HIV (vCP125), followed by booster injections of a soluble recombinant hybrid envelope glycoprotein MN/LAI (rgp160), were evaluated in vaccinia-immune, healthy adults at low risk for acquiring HIV-1 infection. Volunteers (n = 20) received vCP125 (10(6) TCID50) at 0 and 1 month, followed randomly by rgp160 formulated in alum or in Freund's incomplete adjuvant (FIA) at 3 and 6 months. Local and systemic reactions were mild or moderate and resolved within the first 72 hr after immunization. No significant biological changes in routine tests were observed in any volunteer. Two injections of vCP125 did not elicit antibodies. Neutralizing antibodies (NA) against the HIV-1 MN isolate were detected in 65 and 90% of the subjects after the first and the second rgp 160 booster injections, respectively. Six months after the last boost, only 55% were still positive. Seven of 14 sera with the highest NA titers against MN weakly cross-neutralized the HIV-1 SF2 isolate; none had NA against the HIV-1 LAI or against a North American primary isolate. Specific lymphocyte T cell proliferation to rgp 160 was detected in 25% of the subjects after vCP125 and in all subjects after the first booster injection and 12 months after the first injection. An envelope-specific cytotoxic lymphocyte activity was found in 39% of the volunteers and characterized for some of them as CD3+, CD8+, MHC class I restricted. The adjuvant formulation did not influence significantly the immune responses.(ABSTRACT TRUNCATED AT 250 WORDS)

  4. Characterization of monomeric intermediates during VSV glycoprotein structural transition.

    Directory of Open Access Journals (Sweden)

    Aurélie A Albertini

    2012-02-01

    Full Text Available Entry of enveloped viruses requires fusion of viral and cellular membranes, driven by conformational changes of viral glycoproteins. Crystal structures provide static pictures of pre- and post-fusion conformations of these proteins but the transition pathway remains elusive. Here, using several biophysical techniques, including analytical ultracentrifugation, circular dichroïsm, electron microscopy and small angle X-ray scattering, we have characterized the low-pH-induced fusogenic structural transition of a soluble form of vesicular stomatitis virus (VSV glycoprotein G ectodomain (G(th, aa residues 1-422, the fragment that was previously crystallized. While the post-fusion trimer is the major species detected at low pH, the pre-fusion trimer is not detected in solution. Rather, at high pH, G(th is a flexible monomer that explores a large conformational space. The monomeric population exhibits a marked pH-dependence and adopts more elongated conformations when pH decreases. Furthermore, large relative movements of domains are detected in absence of significant secondary structure modification. Solution studies are complemented by electron micrographs of negatively stained viral particles in which monomeric ectodomains of G are observed at the viral surface at both pH 7.5 and pH 6.7. We propose that the monomers are intermediates during the conformational change and thus that VSV G trimers dissociate at the viral surface during the structural transition.

  5. Safeguards Envelope Progress FY08

    International Nuclear Information System (INIS)

    Bean, Robert; Metcalf, Richard; Bevill, Aaron

    2008-01-01

    The Safeguards Envelope Project met its milestones by creating a rudimentary safeguards envelope, proving the value of the approach on a small scale, and determining the most appropriate path forward. The Idaho Chemical Processing Plant's large cache of reprocessing process monitoring data, dubbed UBER Data, was recovered and used in the analysis. A probabilistic Z test was used on a Markov Monte Carlo simulation of expected diversion data when compared with normal operating data. The data regarding a fully transient event in a tank was used to create a simple requirement, representative of a safeguards envelope, whose impact was a decrease in operating efficiency by 1.3% but an increase in material balance period of 26%. This approach is operator, state, and international safeguards friendly and should be applied to future reprocessing plants. Future requirements include tank-to-tank correlations in reprocessing facilities, detailed operations impact studies, simulation inclusion, automated optimization, advanced statistics analysis, and multi-attribute utility analysis

  6. Characterization of Vesicular Stomatitis Virus Recombinants That Express and Incorporate High Levels of Hepatitis C Virus Glycoproteins

    OpenAIRE

    Buonocore, Linda; Blight, Keril J.; Rice, Charles M.; Rose, John K.

    2002-01-01

    We generated recombinant vesicular stomatitis viruses (VSV) expressing genes encoding hybrid proteins consisting of the extracellular domains of hepatitis C virus (HCV) glycoproteins fused at different positions to the transmembrane and cytoplasmic domains of the VSV G glycoprotein (E1G and E2G). We show that these chimeric proteins are transported to the cell surface and incorporated into VSV virions efficiently. We also generated VSV recombinants in which the gene encoding the VSV G protein...

  7. Moisture dynamics in building envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Peuhkuri, R.

    2003-07-01

    The overall scope of this Thesis 'Moisture dynamics in building envelopes' has been to characterise how the various porous insulation materials investigated performed hygro thermally under conditions similar to those in a typical building envelope. As a result of the changing temperature and moisture conditions in the exterior weather and indoor climate the materials dynamically absorb and release moisture. The complexity of the impact of these conditions on the resulting moisture transport and content of the materials has been studied in this Thesis with controlled laboratory tests. (au)

  8. Moisture Dynamics in Building Envelopes

    DEFF Research Database (Denmark)

    Peuhkuri, Ruut Hannele

    2003-01-01

    The overall scope of this Thesis "Moisture dynamics in building envelopes" has been to characterise how the various porous insulation materials investigated performed hygrothermally under conditions similar to those in a typical building envelope. As a result of the changing temperature...... part of the Thesis consists of a theory and literature review on the moisture storage and transport processes (Chapter 2), on the non-Fickian moisture transport (Chapter 3)and on the methods for determining the moisture properties (Chapter 4). In the second part, the conducted experimental work...

  9. Rabies virus glycoprotein as a carrier for anthrax protective antigen

    International Nuclear Information System (INIS)

    Smith, Mary Ellen; Koser, Martin; Xiao Sa; Siler, Catherine; McGettigan, James P.; Calkins, Catherine; Pomerantz, Roger J.; Dietzschold, Bernhard; Schnell, Matthias J.

    2006-01-01

    Live viral vectors expressing foreign antigens have shown great promise as vaccines against viral diseases. However, safety concerns remain a major problem regarding the use of even highly attenuated viral vectors. Using the rabies virus (RV) envelope protein as a carrier molecule, we show here that inactivated RV particles can be utilized to present Bacillus anthracis protective antigen (PA) domain-4 in the viral membrane. In addition to the RV glycoprotein (G) transmembrane and cytoplasmic domains, a portion of the RV G ectodomain was required to express the chimeric RV G anthrax PA on the cell surface. The novel antigen was also efficiently incorporated into RV virions. Mice immunized with the inactivated recombinant RV virions exhibited seroconversion against both RV G and anthrax PA, and a second inoculation greatly increased these responses. These data demonstrate that a viral envelope protein can carry a bacterial protein and that a viral carrier can display whole polypeptides compared to the limited epitope presentation of previous viral systems

  10. Nature of 'unseen' galactic envelopes

    International Nuclear Information System (INIS)

    McCrea, W.H.

    1983-01-01

    In this paper, it is suggested that unseen matter in a galactic envelope or in a group of galaxies may consist of substellar bodies originating as the first permanent 'stars' in the formation of a very massive galaxy according to a model for galaxy-formation on the basis of simple big-bang cosmology. (Auth.)

  11. Handbook on data envelopment analysis

    CERN Document Server

    Cooper, William W; Zhu, Joe

    2011-01-01

    Focusing on extensively used Data Envelopment Analysis topics, this volume aims to both describe the state of the field and extend the frontier of DEA research. New chapters include DEA models for DMUs, network DEA, models for supply chain operations and applications, and new developments.

  12. Membrane-bound SIV envelope trimers are immunogenic in ferrets after intranasal vaccination with a replication-competent canine distemper virus vector.

    Science.gov (United States)

    Zhang, Xinsheng; Wallace, Olivia; Wright, Kevin J; Backer, Martin; Coleman, John W; Koehnke, Rebecca; Frenk, Esther; Domi, Arban; Chiuchiolo, Maria J; DeStefano, Joanne; Narpala, Sandeep; Powell, Rebecca; Morrow, Gavin; Boggiano, Cesar; Zamb, Timothy J; Richter King, C; Parks, Christopher L

    2013-11-01

    We are investigating canine distemper virus (CDV) as a vaccine vector for the delivery of HIV envelope (Env) that closely resembles the native trimeric spike. We selected CDV because it will promote vaccine delivery to lymphoid tissues, and because human exposure is infrequent, reducing potential effects of pre-existing immunity. Using SIV Env as a model, we tested a number of vector and gene insert designs. Vectors containing a gene inserted between the CDV H and L genes, which encoded Env lacking most of its cytoplasmic tail, propagated efficiently in Vero cells, expressed the immunogen on the cell surface, and incorporated the SIV glycoprotein into progeny virus particles. When ferrets were vaccinated intranasally, there were no signs of distress, vector replication was observed in the gut-associated lymphoid tissues, and the animals produced anti-SIV Env antibodies. These data show that live CDV-SIV Env vectors can safely induce anti-Env immune responses following intranasal vaccination. © 2013 Elsevier Inc. All rights reserved.

  13. Virion Glycoprotein-Mediated Immune Evasion by Human Cytomegalovirus: a Sticky Virus Makes a Slick Getaway

    Science.gov (United States)

    Gardner, Thomas J.

    2016-01-01

    SUMMARY The prototypic herpesvirus human cytomegalovirus (CMV) exhibits the extraordinary ability to establish latency and maintain a chronic infection throughout the life of its human host. This is even more remarkable considering the robust adaptive immune response elicited by infection and reactivation from latency. In addition to the ability of CMV to exist in a quiescent latent state, its persistence is enabled by a large repertoire of viral proteins that subvert immune defense mechanisms, such as NK cell activation and major histocompatibility complex antigen presentation, within the cell. However, dissemination outside the cell presents a unique existential challenge to the CMV virion, which is studded with antigenic glycoprotein complexes targeted by a potent neutralizing antibody response. The CMV virion envelope proteins, which are critical mediators of cell attachment and entry, possess various characteristics that can mitigate the humoral immune response and prevent viral clearance. Here we review the CMV glycoprotein complexes crucial for cell attachment and entry and propose inherent properties of these proteins involved in evading the CMV humoral immune response. These include viral glycoprotein polymorphism, epitope competition, Fc receptor-mediated endocytosis, glycan shielding, and cell-to-cell spread. The consequences of CMV virion glycoprotein-mediated immune evasion have a major impact on persistence of the virus in the population, and a comprehensive understanding of these evasion strategies will assist in designing effective CMV biologics and vaccines to limit CMV-associated disease. PMID:27307580

  14. The nuclear envelope from basic biology to therapy.

    Science.gov (United States)

    Worman, Howard J; Foisner, Roland

    2010-02-01

    The nuclear envelope has long been a focus of basic research for a highly specialized group of cell biologists. More recently, an expanding group of scientists and physicians have developed a keen interest in the nuclear envelope since mutations in the genes encoding lamins and associated proteins have been shown to cause a diverse range of human diseases often called laminopathies or nuclear envelopathies. Most of these diseases have tissue-selective phenotypes, suggesting that the nuclear envelope must function in cell-type- and developmental-stage-specific processes such as chromatin organization, regulation of gene expression, controlled nucleocytoplasmic transport and response to stress in metazoans. On 22-23 April 2009, Professor Christopher Hutchison organized the 4th British Nuclear Envelope Disease and Chromatin Organization meeting at the College of St Hild and St Bede at Durham University, sponsored by the Biochemical Society. In attendance were investigators with one common interest, the nuclear envelope, but with diverse expertise and training in animal and plant cell biology, genetics, developmental biology and medicine. We were each honoured to be keynote speakers. This issue of Biochemical Society Transactions contains papers written by some of the presenters at this scientifically exciting meeting, held in a bucolic setting where the food was tasty and the wine flowed freely. Perhaps at the end of this excellent meeting more questions were raised than answered, which will stimulate future research. However, what became clear is that the nuclear envelope is a cellular structure with critical functions in addition to its traditional role as a barrier separating the nuclear and cytoplasmic compartments in interphase eukaryotic cells.

  15. Cell-type-specific gene delivery into neuronal cells in vitro and in vivo

    International Nuclear Information System (INIS)

    Parveen, Zahida; Mukhtar, Muhammad; Rafi, Mohammed; Wenger, David A.; Siddiqui, Khwaja M.; Siler, Catherine A.; Dietzschold, Bernhard; Pomerantz, Roger J.; Schnell, Matthias J.; Dornburg, Ralph

    2003-01-01

    The avian retroviruses reticuloendotheliosis virus strain A (REV-A) and spleen necrosis virus (SNV) are not naturally infectious in human cells. However, REV-A-derived viral vectors efficiently infect human cells when they are pseudotyped with envelope proteins displaying targeting ligands specific for human cell-surface receptors. Here we report that vectors containing the gag region of REV-A and pol of SNV can be pseudotyped with the envelope protein of vesicular stomatitis virus (VSV) and the glycoproteins of different rabies virus (RV) strains. Vectors pseudotyped with the envelope protein of the highly neurotropic RV strain CVS-N2c facilitated cell type-specific gene delivery into mouse and human neurons, but did not infect other human cell types. Moreover, when such vector particles were injected into the brain of newborn mice, only neuronal cells were infected in vivo. Cell-type-specific gene delivery into neurons may present quite specific gene therapy approaches for many degenerative diseases of the brain

  16. Viral membrane fusion: is glycoprotein G of rhabdoviruses a representative of a new class of viral fusion proteins?

    Directory of Open Access Journals (Sweden)

    A.T. Da Poian

    2005-06-01

    Full Text Available Enveloped viruses always gain entry into the cytoplasm by fusion of their lipid envelope with a cell membrane. Some enveloped viruses fuse directly with the host cell plasma membrane after virus binding to the cell receptor. Other enveloped viruses enter the cells by the endocytic pathway, and fusion depends on the acidification of the endosomal compartment. In both cases, virus-induced membrane fusion is triggered by conformational changes in viral envelope glycoproteins. Two different classes of viral fusion proteins have been described on the basis of their molecular architecture. Several structural data permitted the elucidation of the mechanisms of membrane fusion mediated by class I and class II fusion proteins. In this article, we review a number of results obtained by our laboratory and by others that suggest that the mechanisms involved in rhabdovirus fusion are different from those used by the two well-studied classes of viral glycoproteins. We focus our discussion on the electrostatic nature of virus binding and interaction with membranes, especially through phosphatidylserine, and on the reversibility of the conformational changes of the rhabdovirus glycoprotein involved in fusion. Taken together, these data suggest the existence of a third class of fusion proteins and support the idea that new insights should emerge from studies of membrane fusion mediated by the G protein of rhabdoviruses. In particular, the elucidation of the three-dimensional structure of the G protein or even of the fusion peptide at different pH's might provide valuable information for understanding the fusion mechanism of this new class of fusion proteins.

  17. Inhibition of the Hantavirus Fusion Process by Predicted Domain III and Stem Peptides from Glycoprotein Gc.

    Science.gov (United States)

    Barriga, Gonzalo P; Villalón-Letelier, Fernando; Márquez, Chantal L; Bignon, Eduardo A; Acuña, Rodrigo; Ross, Breyan H; Monasterio, Octavio; Mardones, Gonzalo A; Vidal, Simon E; Tischler, Nicole D

    2016-07-01

    Hantaviruses can cause hantavirus pulmonary syndrome or hemorrhagic fever with renal syndrome in humans. To enter cells, hantaviruses fuse their envelope membrane with host cell membranes. Previously, we have shown that the Gc envelope glycoprotein is the viral fusion protein sharing characteristics with class II fusion proteins. The ectodomain of class II fusion proteins is composed of three domains connected by a stem region to a transmembrane anchor in the viral envelope. These fusion proteins can be inhibited through exogenous fusion protein fragments spanning domain III (DIII) and the stem region. Such fragments are thought to interact with the core of the fusion protein trimer during the transition from its pre-fusion to its post-fusion conformation. Based on our previous homology model structure for Gc from Andes hantavirus (ANDV), here we predicted and generated recombinant DIII and stem peptides to test whether these fragments inhibit hantavirus membrane fusion and cell entry. Recombinant ANDV DIII was soluble, presented disulfide bridges and beta-sheet secondary structure, supporting the in silico model. Using DIII and the C-terminal part of the stem region, the infection of cells by ANDV was blocked up to 60% when fusion of ANDV occurred within the endosomal route, and up to 95% when fusion occurred with the plasma membrane. Furthermore, the fragments impaired ANDV glycoprotein-mediated cell-cell fusion, and cross-inhibited the fusion mediated by the glycoproteins from Puumala virus (PUUV). The Gc fragments interfered in ANDV cell entry by preventing membrane hemifusion and pore formation, retaining Gc in a non-resistant homotrimer stage, as described for DIII and stem peptide inhibitors of class II fusion proteins. Collectively, our results demonstrate that hantavirus Gc shares not only structural, but also mechanistic similarity with class II viral fusion proteins, and will hopefully help in developing novel therapeutic strategies against hantaviruses.

  18. Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

    Directory of Open Access Journals (Sweden)

    Rafael Simó

    Full Text Available Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes and in vivo (C57BL6/mice experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not

  19. Thyroid hormone upregulates zinc-α2-glycoprotein production in the liver but not in adipose tissue.

    Science.gov (United States)

    Simó, Rafael; Hernández, Cristina; Sáez-López, Cristina; Soldevila, Berta; Puig-Domingo, Manel; Selva, David M

    2014-01-01

    Overproduction of zinc-α2-glycoprotein by adipose tissue is crucial in accounting for the lipolysis occurring in cancer cachexia of certain malignant tumors. The main aim of this study was to explore whether thyroid hormone could enhance zinc-α2-glycoprotein production in adipose tissue. In addition, the regulation of zinc-α2-glycoprotein by thyroid hormone in the liver was investigated. We performed in vitro (HepG2 cells and primary human adipocytes) and in vivo (C57BL6/mice) experiments addressed to examine the effect of thyroid hormone on zinc-α2-glycoprotein production (mRNA and protein levels) in liver and visceral adipose tissue. We also measured the zinc-α2-glycoprotein serum levels in a cohort of patients before and after controlling their hyperthyroidism. Our results showed that thyroid hormone up-regulates zinc-α2-glycoprotein production in HepG2 cells in a dose-dependent manner. In addition, the zinc-α2-glycoprotein proximal promoter contains functional thyroid hormone receptor binding sites that respond to thyroid hormone treatment in luciferase reporter gene assays in HepG2 cells. Furthermore, zinc-α2-glycoprotein induced lipolysis in HepG2 in a dose-dependent manner. Our in vivo experiments in mice confirmed the up-regulation of zinc-α2-glycoprotein induced by thyroid hormone in the liver, thus leading to a significant increase in zinc-α2-glycoprotein circulating levels. However, thyroid hormone did not regulate zinc-α2-glycoprotein production in either human or mouse adipocytes. Finally, in patients with hyperthyroidism a significant reduction of zinc-α2-glycoprotein serum levels was detected after treatment but was unrelated to body weight changes. We conclude that thyroid hormone up-regulates the production of zinc-α2-glycoprotein in the liver but not in the adipose tissue. The neutral effect of thyroid hormones on zinc-α2-glycoprotein expression in adipose tissue could be the reason why zinc-α2-glycoprotein is not related to weight

  20. Host Cell Virus Entry Mediated by Australian Bat Lyssavirus Envelope G glycoprotein

    Science.gov (United States)

    2013-10-24

    Richard M. (US), Dzimian, Joyce L. (US), Godwin, Glenn P. (US), Price, Paul J. (US), Epstein, David A. (US), Gruber, Dale (US), Mcclure, Don (US). 2004...of the shedding. Microbiol Immunol 49:733-43 258. Thoulouze MI, Lafage M, Schachner M, Hartmann U, Cremer H, Lafon M. 1998. The neural cell adhesion

  1. Human Immunodeficiency Virus type 1 group M consensus and mosaic envelope glycoproteins

    Science.gov (United States)

    Korber, Bette T.; Fischer, William; Liao, Hua-Xin; Haynes, Barton F.; Letvin, Norman; Hahn, Beatrice H.

    2017-11-21

    The disclosure relates to nucleic acids mosaic clade M HIV-1 Env polypeptides and to compositions and vectors comprising same. The nucleic acids are suitable for use in inducing an immune response to HIV-1 in a human.

  2. Neutralizing activities of caprine antibodies towards conserved regions of the HCV envelope glycoprotein E2

    Directory of Open Access Journals (Sweden)

    El-Shenawy Reem

    2011-08-01

    Full Text Available Abstract Anti HCV vaccine is not currently available and the present antiviral therapies fail to cure approximately half of the treated HCV patients. This study was designed to assess the immunogenic properties of genetically conserved peptides derived from the C-terminal region of HVR-1 and test their neutralizing activities in a step towards developing therapeutic and/or prophylactic immunogens against HCV infection. Antibodies were generated by vaccination of goats with synthetic peptides derived from HCV E2. Viral neutralizing capacity of the generated anti E2 antibodies was tested using in vitro assays. Goats immunized with E2 synthetic peptides termed p412 [a.a 412-419], p430 [a.a 430-447] and p517 [a.a 517-531] generated high titers of antibody responses 2 to 4.5 fold higher than comparable titers of antibodies to the same epitopes in chronic HCV patients. In post infection experiments of native HCV into cultured Huh7.5 cells anti p412 and anti p 517 were proven to be neutralizing to HCV genotype 4a from patients' sera (87.5% and 75% respectively. On the contrary anti p430 exhibited weak viral neutralization capacity on the same samples (31.25%. Furthermore Ab mixes containing anti p430 exhibited reduced viral neutralization properties. From these experiments one could predict that neutralization by Abs towards different E2-epitopes varies considerably and success in the enrichment of neutralization epitope-specific antibodies may be accompanied by favorable results in combating HCV infection. Also, E2 conserved peptides p517 and p412 represent potential components of a candidate peptide vaccine against HCV infection.

  3. Nucleic acids encoding modified human immunodeficiency virus type 1 (HIV-1) group M consensus envelope glycoproteins

    Science.gov (United States)

    Haynes, Barton F [Durham, NC; Gao, Feng [Durham, NC; Korber, Bette T [Los Alamos, NM; Hahn, Beatrice H [Birmingham, AL; Shaw, George M [Birmingham, AL; Kothe, Denise [Birmingham, AL; Li, Ying Ying [Hoover, AL; Decker, Julie [Alabaster, AL; Liao, Hua-Xin [Chapel Hill, NC

    2011-12-06

    The present invention relates, in general, to an immunogen and, in particular, to an immunogen for inducing antibodies that neutralizes a wide spectrum of HIV primary isolates and/or to an immunogen that induces a T cell immune response. The invention also relates to a method of inducing anti-HIV antibodies, and/or to a method of inducing a T cell immune response, using such an immunogen. The invention further relates to nucleic acid sequences encoding the present immunogens.

  4. Safeguards Envelope Progress FY08

    Energy Technology Data Exchange (ETDEWEB)

    Robert Bean; Richard Metcalf; Aaron Bevill

    2008-09-01

    The Safeguards Envelope Project met its milestones by creating a rudimentary safeguards envelope, proving the value of the approach on a small scale, and determining the most appropriate path forward. The Idaho Chemical Processing Plant’s large cache of reprocessing process monitoring data, dubbed UBER Data, was recovered and used in the analysis. A probabilistic Z test was used on a Markov Monte Carlo simulation of expected diversion data when compared with normal operating data. The data regarding a fully transient event in a tank was used to create a simple requirement, representative of a safeguards envelope, whose impact was a decrease in operating efficiency by 1.3% but an increase in material balance period of 26%. This approach is operator, state, and international safeguards friendly and should be applied to future reprocessing plants. Future requirements include tank-to-tank correlations in reprocessing facilities, detailed operations impact studies, simulation inclusion, automated optimization, advanced statistics analysis, and multi-attribute utility analysis.

  5. Transparent ceramic lamp envelope materials

    Energy Technology Data Exchange (ETDEWEB)

    Wei, G C [OSRAM SYLVANIA, 71 Cherry Hill Drive, Beverly, MA 01915 (United States)

    2005-09-07

    Transparent ceramic materials with optical qualities comparable to single crystals of similar compositions have been developed in recent years, as a result of the improved understanding of powder-processing-fabrication- sintering-property inter-relationships. These high-temperature materials with a range of thermal and mechanical properties are candidate envelopes for focused-beam, short-arc lamps containing various fills operating at temperatures higher than quartz. This paper reviews the composition, structure and properties of transparent ceramic lamp envelope materials including sapphire, small-grained polycrystalline alumina, aluminium oxynitride, yttrium aluminate garnet, magnesium aluminate spinel and yttria-lanthana. A satisfactory thermal shock resistance is required for the ceramic tube to withstand the rapid heating and cooling cycles encountered in lamps. Thermophysical properties, along with the geometry, size and thickness of a transparent ceramic tube, are important parameters in the assessment of its resistance to fracture arising from thermal stresses in lamps during service. The corrosive nature of lamp-fill liquid and vapour at high temperatures requires that all lamp components be carefully chosen to meet the target life. The wide range of new transparent ceramics represents flexibility in pushing the limit of envelope materials for improved beamer lamps.

  6. P-glycoprotein activity and biological response

    International Nuclear Information System (INIS)

    Vaalburg, W.; Hendrikse, N.H.; Elsinga, P.H.; Bart, J.; Waarde, A. van

    2005-01-01

    P-glycoprotein (P-gp) is a transmembrane drug efflux pump encoded by the MDR-1 gene in humans. Most likely P-gp protects organs against endogenous and exogenous toxins by extruding toxic compounds such as chemotherapeutics and other drugs. Many drugs are substrates for P-gp. Since P-gp is also expressed in the blood-brain barrier, P-gp substrates reach lower concentrations in the brain than in P-gp-negative tissues. Failure of response to chemotherapy of malignancies can be due to intrinsic or acquired drug resistance. Many tumors are multidrug resistant (MDR); resistant to several structurally unrelated chemotherapeutic agents. Several mechanisms are involved in MDR of which P-gp is studied most extensively. P-gp extrudes drugs out of tumor cells resulting in decreased intracellular drug concentrations, leading to the MDR phenotype. Furthermore, the MDR-1 gene exhibits several single nucleotide polymorphisms, some of which result in different transport capabilities. P-gp functionality and the effect of P-gp modulation on the pharmacokinetics of novel and established drugs can be studied in vivo by positron emission tomography (PET) using carbon-11 and fluorine-18-labeled P-gp substrates and modulators. PET may demonstrate the consequences of genetic differences on tissue pharmacokinetics. Inhibitors such as calcium-channel blockers (verapamil), cyclosporin A, ONT-093, and XR9576 can modulate the P-gp functionality. With PET the effect of P-gp modulation on the bioavailability of drugs can be investigated in humans in vivo. PET also allows the measurement of the efficacy of newly developed P-gp modulators

  7. Chimeric Lyssavirus Glycoproteins with Increased Immunological Potential

    Science.gov (United States)

    Jallet, Corinne; Jacob, Yves; Bahloul, Chokri; Drings, Astrid; Desmezieres, Emmanuel; Tordo, Noël; Perrin, Pierre

    1999-01-01

    The rabies virus glycoprotein molecule (G) can be divided into two parts separated by a flexible hinge: the NH2 half (site II part) containing antigenic site II up to the linear region (amino acids [aa] 253 to 275 encompassing epitope VI [aa 264]) and the COOH half (site III part) containing antigenic site III and the transmembrane and cytoplasmic domains. The structural and immunological roles of each part were investigated by cell transfection and mouse DNA-based immunization with homogeneous and chimeric G genes formed by fusion of the site II part of one genotype (GT) with the site III part of the same or another GT. Various site II-site III combinations between G genes of PV (Pasteur virus strain) rabies (GT1), Mokola (GT3), and EBL1 (European bat lyssavirus 1 [GT5]) viruses were tested. Plasmids pGPV-PV, pGMok-Mok, pGMok-PV, and pGEBL1-PV induced transient expression of correctly transported and folded antigens in neuroblastoma cells and virus-neutralizing antibodies against parental viruses in mice, whereas, pG-PVIII (site III part only) and pGPV-Mok did not. The site III part of PV (GT1) was a strong inducer of T helper cells and was very effective at presenting the site II part of various GTs. Both parts are required for correct folding and transport of chimeric G proteins which have a strong potential value for immunological studies and development of multivalent vaccines. Chimeric plasmid pGEBL1-PV broadens the spectrum of protection against European lyssavirus genotypes (GT1, GT5, and GT6). PMID:9847325

  8. Bovine herpesvirus type-1 glycoprotein K (gK) interacts with UL20 and is required for infectious virus production

    Energy Technology Data Exchange (ETDEWEB)

    Haque, Muzammel; Stanfield, Brent; Kousoulas, Konstantin G.

    2016-12-15

    We have previously shown that the HSV-1 gK and UL20 proteins interact and function in virion envelopment, membrane fusion, and neuronal entry. Alignment of the predicted secondary structures of gKs encoded by BoHV-1, HSV-1, HSV-2, EHV-1 and VZV indicated a high degree of domain conservation. Two BoHV-1 gK-null mutant viruses were created by either gK gene deletion or stop codon insertion. In addition, a V5 epitope-tag was inserted at the carboxyl terminus of gK gene to detect gK. The engineered gK-null mutant viruses failed to replicate and produce viral plaques. Co-immunoprecipitation of gK and UL20 expressed via different methods revealed that gK and UL20 physically interacted in the presence or absence of other viral proteins. Confocal microscopy showed that gK and UL20 colocalized in infected cells. These results indicate that BoHV-1 gK and UL20 may function in a similar manner to other alphaherpesvirus orthologues specified by HSV-1, PRV and EHV-1. -- Highlights: •Glycoprotein K(gK) is conserved among alphaherpesviruses and serves similar functions. •The bovine herpesvirus-1 gK and UL20 proteins physically interact in a similar manner to herpes simplex virus type 1 and equine herpesvirus-1. •The bovine herpesvirus-1 (BoHV-1) gK interacts with UL20 and is essential for virus replication and spread.

  9. Bovine herpesvirus type-1 glycoprotein K (gK) interacts with UL20 and is required for infectious virus production

    International Nuclear Information System (INIS)

    Haque, Muzammel; Stanfield, Brent; Kousoulas, Konstantin G.

    2016-01-01

    We have previously shown that the HSV-1 gK and UL20 proteins interact and function in virion envelopment, membrane fusion, and neuronal entry. Alignment of the predicted secondary structures of gKs encoded by BoHV-1, HSV-1, HSV-2, EHV-1 and VZV indicated a high degree of domain conservation. Two BoHV-1 gK-null mutant viruses were created by either gK gene deletion or stop codon insertion. In addition, a V5 epitope-tag was inserted at the carboxyl terminus of gK gene to detect gK. The engineered gK-null mutant viruses failed to replicate and produce viral plaques. Co-immunoprecipitation of gK and UL20 expressed via different methods revealed that gK and UL20 physically interacted in the presence or absence of other viral proteins. Confocal microscopy showed that gK and UL20 colocalized in infected cells. These results indicate that BoHV-1 gK and UL20 may function in a similar manner to other alphaherpesvirus orthologues specified by HSV-1, PRV and EHV-1. -- Highlights: •Glycoprotein K(gK) is conserved among alphaherpesviruses and serves similar functions. •The bovine herpesvirus-1 gK and UL20 proteins physically interact in a similar manner to herpes simplex virus type 1 and equine herpesvirus-1. •The bovine herpesvirus-1 (BoHV-1) gK interacts with UL20 and is essential for virus replication and spread.

  10. Cortical processing of dynamic sound envelope transitions.

    Science.gov (United States)

    Zhou, Yi; Wang, Xiaoqin

    2010-12-08

    Slow envelope fluctuations in the range of 2-20 Hz provide important segmental cues for processing communication sounds. For a successful segmentation, a neural processor must capture envelope features associated with the rise and fall of signal energy, a process that is often challenged by the interference of background noise. This study investigated the neural representations of slowly varying envelopes in quiet and in background noise in the primary auditory cortex (A1) of awake marmoset monkeys. We characterized envelope features based on the local average and rate of change of sound level in envelope waveforms and identified envelope features to which neurons were selective by reverse correlation. Our results showed that envelope feature selectivity of A1 neurons was correlated with the degree of nonmonotonicity in their static rate-level functions. Nonmonotonic neurons exhibited greater feature selectivity than monotonic neurons in quiet and in background noise. The diverse envelope feature selectivity decreased spike-timing correlation among A1 neurons in response to the same envelope waveforms. As a result, the variability, but not the average, of the ensemble responses of A1 neurons represented more faithfully the dynamic transitions in low-frequency sound envelopes both in quiet and in background noise.

  11. P-glycoprotein-deficient mice have proximal tubule dysfunction but are protected against ischemic renal injury

    NARCIS (Netherlands)

    Huls, M.; Kramers, C.; Levtchenko, E.N.; Wilmer, M.J.G.; Dijkman, H.B.P.M.; Kluijtmans, L.A.J.; Hoorn, J.W.A. van der; Russel, F.G.M.; Masereeuw, R.

    2007-01-01

    The multidrug resistance gene 1 product, P-glycoprotein (P-gp), is expressed in several excretory organs, including the apical membrane of proximal tubules. After inducing acute renal failure, P-gp expression is upregulated and this might be a protective function by pumping out toxicants and harmful

  12. The bacteria binding glycoprotein salivary agglutinin (SAG/gp340) activates complement via the lectin pathway

    NARCIS (Netherlands)

    Leito, Jelani T. D.; Ligtenberg, Antoon J. M.; van Houdt, Michel; van den Berg, Timo K.; Wouters, Diana

    2011-01-01

    Salivary agglutinin (SAG), also known as gp-340 and Deleted in Malignant Brain Tumours 1, is a glycoprotein that is present in tears, lung fluid and mucosal surfaces along the gastrointestinal tract. It is encoded by the Deleted in Malignant Brain Tumours 1 gene, a member of the Scavenger Receptor

  13. Characterization of glycoprotein C of HSZP strain of herpes simplex virus 1

    NARCIS (Netherlands)

    Oravcova, [No Value; Kudelova, M; Mlcuchova, J; Matis, J; Bystricka, M; Westra, DF; Welling-Wester, S; Rajcani, J

    Sequences of UL44 genes of strains HSZP, KOS and 17 of herpes simplex virus 1 (HSV-1) were determined and the amino acid sequences of corresponding glycoproteins (gC) were deduced. In comparison with the 17 strain, the HSZP strain showed specific changes in 3 nucleotides and in 2 amino acids (aa 139

  14. Nuclear envelope breakdown induced by herpes simplex virus type 1 involves the activity of viral fusion proteins

    Energy Technology Data Exchange (ETDEWEB)

    Maric, Martina; Haugo, Alison C. [Department of Microbiology, University of Iowa, Iowa City, IA 52242 (United States); Dauer, William [Department of Neurology, University of Michigan, Ann Arbor, MI 48109 (United States); Johnson, David [Department of Microbiology and Immunology, Oregon Health Sciences University, Portland, OR 97201 (United States); Roller, Richard J., E-mail: richard-roller@uiowa.edu [Department of Microbiology, University of Iowa, Iowa City, IA 52242 (United States)

    2014-07-15

    Herpesvirus infection reorganizes components of the nuclear lamina usually without loss of integrity of the nuclear membranes. We report that wild-type HSV infection can cause dissolution of the nuclear envelope in transformed mouse embryonic fibroblasts that do not express torsinA. Nuclear envelope breakdown is accompanied by an eight-fold inhibition of virus replication. Breakdown of the membrane is much more limited during infection with viruses that lack the gB and gH genes, suggesting that breakdown involves factors that promote fusion at the nuclear membrane. Nuclear envelope breakdown is also inhibited during infection with virus that does not express UL34, but is enhanced when the US3 gene is deleted, suggesting that envelope breakdown may be enhanced by nuclear lamina disruption. Nuclear envelope breakdown cannot compensate for deletion of the UL34 gene suggesting that mixing of nuclear and cytoplasmic contents is insufficient to bypass loss of the normal nuclear egress pathway. - Highlights: • We show that wild-type HSV can induce breakdown of the nuclear envelope in a specific cell system. • The viral fusion proteins gB and gH are required for induction of nuclear envelope breakdown. • Nuclear envelope breakdown cannot compensate for deletion of the HSV UL34 gene.

  15. Safeguards Envelope Progress FY10

    International Nuclear Information System (INIS)

    Metcalf, Richard

    2010-01-01

    The Safeguards Envelope is a strategy to determine a set of specific operating parameters within which nuclear facilities may operate to maximize safeguards effectiveness without sacrificing safety or plant efficiency. This paper details the additions to the advanced operating techniques that will be applied to real plant process monitoring (PM) data from the Idaho Chemical Processing Plant (ICPP). Research this year focused on combining disparate pieces of data together to maximize operating time with minimal downtime due to safeguards. A Chi-Square and Croiser's cumulative sum were both included as part of the new analysis. Because of a major issue with the original data, the implementation of the two new tests did not add to the existing set of tests, though limited one-variable optimization made a small increase in detection probability. Additional analysis was performed to determine if prior analysis would have caused a major security or safety operating envelope issue. It was determined that a safety issue would have resulted from the prior research, but that the security may have been increased under certain conditions.

  16. Identification, isolation, and N-terminal sequencing of style glycoproteins associated with self-incompatibility in Nicotiana alata.

    Science.gov (United States)

    Jahnen, W; Batterham, M P; Clarke, A E; Moritz, R L; Simpson, R J

    1989-05-01

    S-Gene-associated glycoproteins (S-glycoproteins) from styles of Nicotiana alata, identified by non-equilibrium two-dimensional electrophoresis, were purified by cation exchange fast protein liquid chromatography with yields of 0.5 to 8 micrograms of protein per style, depending on the S-genotype of the plant. The method relies on the highly basic nature of the S-glycoproteins. The elution profiles of the different S-glycoproteins from the fast protein liquid chromatography column were characteristic of each S-glycoprotein, and could be used to establish the S-genotype of plants in outbreeding populations. In all cases, the S-genotype predicted from the style protein profile corresponded to that predicted from DNA gel blot analysis using S-allele-specific DNA probes and to that established by conventional breeding tests. Amino-terminal sequences of five purified S-glycoproteins showed a high degree of homology with the previously published sequences of N. alata and Lycopersicon esculentum S-glycoproteins.

  17. Evolution of envelope solitons of ionization waves

    International Nuclear Information System (INIS)

    Ohe, K.; Hashimoto, M.

    1985-01-01

    The time evolution of a particle-like envelope soliton of ionization waves in plasma was investigated theoretically. The hydrodynamic equations of one spatial dimension were solved and the nonlinear dispersion relation was derived. For the amplitude of the wave the nonlinear Schroedinger equation was derived. Its soliton solution was interpreted as the envelope soliton which was experimentally found. The damping rate of the envelope soliton was estimated. (D.Gy.)

  18. Glycosylation of dengue virus glycoproteins and their interactions with carbohydrate receptors: possible targets for antiviral therapy.

    Science.gov (United States)

    Idris, Fakhriedzwan; Muharram, Siti Hanna; Diah, Suwarni

    2016-07-01

    Dengue virus, an RNA virus belonging to the genus Flavivirus, affects 50 million individuals annually, and approximately 500,000-1,000,000 of these infections lead to dengue hemorrhagic fever or dengue shock syndrome. With no licensed vaccine or specific antiviral treatments available to prevent dengue infection, dengue is considered a major public health problem in subtropical and tropical regions. The virus, like other enveloped viruses, uses the host's cellular enzymes to synthesize its structural (C, E, and prM/M) and nonstructural proteins (NS1-5) and, subsequently, to glycosylate these proteins to produce complete and functional glycoproteins. The structural glycoproteins, specifically the E protein, are known to interact with the host's carbohydrate receptors through the viral proteins' N-glycosylation sites and thus mediate the viral invasion of cells. This review focuses on the involvement of dengue glycoproteins in the course of infection and the virus' exploitation of the host's glycans, especially the interactions between host receptors and carbohydrate moieties. We also discuss the recent developments in antiviral therapies that target these processes and interactions, focusing specifically on the use of carbohydrate-binding agents derived from plants, commonly known as lectins, to inhibit the progression of infection.

  19. Defining glycoprotein cancer biomarkers by MS in conjunction with glycoprotein enrichment.

    Science.gov (United States)

    Song, Ehwang; Mechref, Yehia

    2015-01-01

    Protein glycosylation is an important and common post-translational modification. More than 50% of human proteins are believed to be glycosylated to modulate the functionality of proteins. Aberrant glycosylation has been correlated to several diseases, such as inflammatory skin diseases, diabetes mellitus, cardiovascular disorders, rheumatoid arthritis, Alzheimer's and prion diseases, and cancer. Many approved cancer biomarkers are glycoproteins which are not highly abundant proteins. Therefore, effective qualitative and quantitative assessment of glycoproteins entails enrichment methods. This chapter summarizes glycoprotein enrichment methods, including lectin affinity, immunoaffinity, hydrazide chemistry, hydrophilic interaction liquid chromatography, and click chemistry. The use of these enrichment approaches in assessing the qualitative and quantitative changes of glycoproteins in different types of cancers are presented and discussed. This chapter highlights the importance of glycoprotein enrichment techniques for the identification and characterization of new reliable cancer biomarkers.

  20. Comparative Analysis of Whey N-Glycoproteins in Human Colostrum and Mature Milk Using Quantitative Glycoproteomics.

    Science.gov (United States)

    Cao, Xueyan; Song, Dahe; Yang, Mei; Yang, Ning; Ye, Qing; Tao, Dongbing; Liu, Biao; Wu, Rina; Yue, Xiqing

    2017-11-29

    Glycosylation is a ubiquitous post-translational protein modification that plays a substantial role in various processes. However, whey glycoproteins in human milk have not been completely profiled. Herein, we used quantitative glycoproteomics to quantify whey N-glycosylation sites and their alteration in human milk during lactation; 110 N-glycosylation sites on 63 proteins and 91 N-glycosylation sites on 53 proteins were quantified in colostrum and mature milk whey, respectively. Among these, 68 glycosylation sites on 38 proteins were differentially expressed in human colostrum and mature milk whey. These differentially expressed N-glycoproteins were highly enriched in "localization", "extracellular region part", and "modified amino acid binding" according to gene ontology annotation and mainly involved in complement and coagulation cascades pathway. These results shed light on the glycosylation sites, composition and biological functions of whey N-glycoproteins in human colostrum and mature milk, and provide substantial insight into the role of protein glycosylation during infant development.

  1. Contribution of the attachment G glycoprotein to pathogenicity and immunogenicity of avian metapneumovirus subgroup C.

    Science.gov (United States)

    Govindarajan, Dhanasekaran; Kim, Shin-Hee; Samal, Siba K

    2010-03-01

    Avian metapneumovirus (AMPV) causes an upper respiratory tract infection in turkeys leading to serious economic losses to the turkey industry. The G glycoprotein of AMPV is known to be associated with viral attachment and pathogenesis. In this study, we determined the role of the G glycoprotein in the pathogenicity and immunogenicity of AMPV strain Colorado (AMPV/CO). Recombinant AMPV/CO lacking the G protein (rAMPV/CO-deltaG) was generated using a reverse-genetics system. The recovered rAMPV/CO-deltaG replicated slightly better than did wild-type AMPV in Vero cells. However, deletion of the G gene in AMPV resulted in attenuation of the virus in turkeys. The mutant virus induced less-severe clinical signs and a weaker immune response in turkeys than did the wild-type AMPV. Our results suggest that the G glycoprotein is an important determinant for the pathogenicity and immunogenicity of AMPV.

  2. Normal viability and altered pharmacokinetics in mice lacking mdr1-type (drug-transporting) P-glycoproteins

    NARCIS (Netherlands)

    Schinkel, A. H.; Mayer, U.; Wagenaar, E.; Mol, C. A.; van Deemter, L.; Smit, J. J.; van der Valk, M. A.; Voordouw, A. C.; Spits, H.; van Tellingen, O.; Zijlmans, J. M.; Fibbe, W. E.; Borst, P.

    1997-01-01

    The mdr1-type P-glycoproteins (P-gps) confer multidrug resistance to cancer cells by active extrusion of a wide range of drugs from the cell. To study their physiological roles, we have generated mice genetically deficient in the mdr1b gene [mdr1b (-/-) mice] and in both the mdr1a and mdr1b genes

  3. The expression and serological reactivity of recombinant canine herpesvirus 1 glycoprotein D

    Directory of Open Access Journals (Sweden)

    MarkéŽta Vaňkov‡á

    2016-01-01

    Full Text Available The aim of this work was to express recombinant glycoprotein D of canine herpesvirus 1 in bacterial cells and to evaluate its diagnostic sensitivity and specificity when compared to traditional serological methods. The gene fragment coding glycoprotein D of canine herpesvirus 1 was amplified by polymerase chain reaction, cloned into plasmid vector and expressed in Escherichia coli cells. Recombinant protein was then purified and used as an antigen in immunoblot for a detection of canine herpesvirus 1 specific antibodies. Antibody testing was performed on the panel of 100 canine sera by immunoblot with recombinant glycoprotein D as antigen and compared with indirect immunofluorescence assay. Serum samples were collected from 83 dogs with no history of canine herpesvirus 1 or reproductive disorders, and from 17 dogs from breeding kennels with a history of canine herpesvirus 1 related reproductive disorders. Sensitivity of glycoprotein D based immunoblot was 89.2% and specificity was 93%. Kappa value was calculated to be 0.8 between immunoblot and indirect immunofluorescence assay. Antibodies against canine herpesvirus 1 infection were detected in 33% of samples by immunoblot assay. Our study confirms that recombinant glycoprotein D expressed in bacterial cells could be used as a suitable and sensitive antigen for immunological tests and that herpesvirus infection seems to be common among the canine population in the Czech Republic.

  4. Analysis of Determinants in Filovirus Glycoproteins Required for Tetherin Antagonism

    Directory of Open Access Journals (Sweden)

    Kerstin Gnirß

    2014-04-01

    Full Text Available The host cell protein tetherin can restrict the release of enveloped viruses from infected cells. The HIV-1 protein Vpu counteracts tetherin by removing it from the site of viral budding, the plasma membrane, and this process depends on specific interactions between the transmembrane domains of Vpu and tetherin. In contrast, the glycoproteins (GPs of two filoviruses, Ebola and Marburg virus, antagonize tetherin without reducing surface expression, and the domains in GP required for tetherin counteraction are unknown. Here, we show that filovirus GPs depend on the presence of their authentic transmembrane domains for virus-cell fusion and tetherin antagonism. However, conserved residues within the transmembrane domain were dispensable for membrane fusion and tetherin counteraction. Moreover, the insertion of the transmembrane domain into a heterologous viral GP, Lassa virus GPC, was not sufficient to confer tetherin antagonism to the recipient. Finally, mutation of conserved residues within the fusion peptide of Ebola virus GP inhibited virus-cell fusion but did not ablate tetherin counteraction, indicating that the fusion peptide and the ability of GP to drive host cell entry are not required for tetherin counteraction. These results suggest that the transmembrane domains of filoviral GPs contribute to tetherin antagonism but are not the sole determinants.

  5. The epigenetics of nuclear envelope organization and disease

    International Nuclear Information System (INIS)

    Schirmer, Eric C.

    2008-01-01

    Mammalian chromosomes and some specific genes have non-random positions within the nucleus that are tissue-specific and heritable. Work in many organisms has shown that genes at the nuclear periphery tend to be inactive and altering their partitioning to the interior results in their activation. Proteins of the nuclear envelope can recruit chromatin with specific epigenetic marks and can also recruit silencing factors that add new epigenetic modifications to chromatin sequestered at the periphery. Together these findings indicate that the nuclear envelope is a significant epigenetic regulator. The importance of this function is emphasized by observations of aberrant distribution of peripheral heterochromatin in several human diseases linked to mutations in NE proteins. These debilitating inherited diseases range from muscular dystrophies to the premature aging progeroid syndromes and the heterochromatin changes are just one early clue for understanding the molecular details of how they work. The architecture of the nuclear envelope provides a unique environment for epigenetic regulation and as such a great deal of research will be required before we can ascertain the full range of its contributions to epigenetics

  6. Mosaic HIV envelope immunogenic polypeptides

    Science.gov (United States)

    Korber, Bette T. M.; Gnanakaran, S.; Perkins, Simon; Sodroski, Joseph; Haynes, Barton

    2018-01-02

    Disclosed herein are mosaic HIV envelope (Env) polypeptides that can elicit an immune response to HIV (such as cytotoxic T cell (CTL), helper T cell, and/or humoral responses). Also disclosed are sets of the disclosed mosaic Env polypeptides, which include two or more (for example, three) of the polypeptides. Also disclosed herein are methods for treating or inhibiting HIV in a subject including administering one or more of the disclosed immunogenic polypeptides or compositions to a subject infected with HIV or at risk of HIV infection. In some embodiments, the methods include inducing an immune response to HIV in a subject comprising administering to the subject at least one (such as two, three, or more) of the immunogenic polypeptides or at least one (such as two, three, or more) nucleic acids encoding at least one of the immunogenic polypeptides disclosed herein.

  7. Glycoprotein biosynthesis by human normal platelets

    International Nuclear Information System (INIS)

    Rodriguez, P.; Bello, O.; Apitz-Castro, R.

    1987-01-01

    Incorporation of radioactive Man, Gal, Fuc, Glc-N, and NANA into washed human normal platelets and endogenous glycoproteins has been found. Both parameters were time dependent. Analysis of hydrolyzed labeled glycoproteins by paper chromatography revealed that the radioactive monosaccharide incubated with the platelets had not been converted into other sugars. Acid hydrolysis demonstrates the presence of a glycosidic linkage. All the effort directed to the demonstration of the existence of a lipid-sugar intermediate in intact human platelets yielded negative results for Man and Glc-N used as precursors. The incorporation of these sugars into glycoproteins is insensitive to bacitracin, suggesting no involvement of lipid-linked saccharides in the synthesis of glycoproteins in human blood platelets. The absence of inhibition of the glycosylation process in the presence of cycloheximide suggests that the sugars are added to proteins present in the intact platelets. These results support the contention that glycoprotein biosynthesis in human blood platelets observed under our experimental conditions is effected through direct sugar nucleotide glycosylation

  8. Amino acid differences in glycoproteins B (gB, C (gC, H (gH and L(gL are associated with enhanced herpes simplex virus type-1 (McKrae entry via the paired immunoglobulin-like type-2 receptor α

    Directory of Open Access Journals (Sweden)

    Chowdhury Sona

    2012-06-01

    Full Text Available Abstract Background Herpes simplex virus type-1 (HSV-1 enters into cells via membrane fusion of the viral envelope with plasma or endosomal membranes mediated by viral glycoproteins. HSV-1 virions attach to cell surfaces by binding of viral glycoproteins gC, gD and gB to specific cellular receptors. Here we show that the human ocular and highly neurovirulent HSV-1 strain McKrae enters substantially more efficiently into cells via the gB-specific human paired immunoglobulin-like type-2 receptor-α (hPILR-α. Comparison of the predicted amino acid sequences between HSV-1(F and McKrae strains indicates that amino acid changes within gB, gC, gH and gL may cause increased entry via the hPILR- α receptor. Results HSV-1 (McKrae entered substantially more efficiently than viral strain F in Chinese hamster ovary (CHO cells expressing hPIRL-α but not within CHO-human nectin-1, -(CHO-hNectin-1, CHO-human HVEM (CHO-hHVEM or Vero cells. The McKrae genes encoding viral glycoproteins gB, gC, gD, gH, gL, gK and the membrane protein UL20 were sequenced and their predicted amino acid (aa sequences were compared with virulent strains F, H129, and the attenuated laboratory strain KOS. Most aa differences between McKrae and F were located at their gB amino termini known to bind with the PILRα receptor. These aa changes included a C10R change, also seen in the neurovirulent strain ANG, as well as redistribution and increase of proline residues. Comparison of gC aa sequences revealed multiple aa changes including an L132P change within the 129-247 aa region known to bind to heparan sulfate (HS receptors. Two aa changes were located within the H1 domain of gH that binds gL. Multiple aa changes were located within the McKrae gL sequence, which were preserved in the H129 isolate, but differed for the F strain. Viral glycoproteins gD and gK and the membrane protein UL20 were conserved between McKrae and F strains. Conclusions The results indicate that the observed

  9. Implementation of an Improved Safe Operating Envelope

    International Nuclear Information System (INIS)

    Prime, Robyn; McIntyre, Mark; Reeves, David

    2008-01-01

    This paper is a continuation of the paper presented at IYNC 2004 on 'The Definition of a Safe Operating Envelope'. The current paper concentrates on the implementation process of the Safe Operating Envelope employed at the Point Lepreau Generating Station. (authors)

  10. Physical properties of the red giant envelopes

    Energy Technology Data Exchange (ETDEWEB)

    Maciel, W J [Instituto de Astronomia e Geofisico da Universidade de Sao Paulo (Brazil)

    1978-12-01

    In this work, several model envelopes are calculated for cool giant stars with mass loss due to the action of stellar radiation pressure on molecules and grains. Molecular profiles as well as average values of some physical parameters of the envelopes are obtained.

  11. Physical properties of the red giant envelopes

    International Nuclear Information System (INIS)

    Maciel, W.J.

    1978-01-01

    In this work, several model envelopes are calculated for cool giant stars with mass loss due to the action of stellar radiation pressure on molecules and grains. Molecular profiles as well as average values of some physical parameters of the envelopes are obtained [pt

  12. Implementation of an Improved Safe Operating Envelope

    Energy Technology Data Exchange (ETDEWEB)

    Prime, Robyn; McIntyre, Mark [NB Power Nuclear, P.O. Box 600, Lepreau, NB (Canada); Reeves, David [Atlantic Nuclear Services Ltd., PO Box 1268 Fredericton, NB (Canada)

    2008-07-01

    This paper is a continuation of the paper presented at IYNC 2004 on 'The Definition of a Safe Operating Envelope'. The current paper concentrates on the implementation process of the Safe Operating Envelope employed at the Point Lepreau Generating Station. (authors)

  13. Glycoprotein Enrichment Analytical Techniques: Advantages and Disadvantages.

    Science.gov (United States)

    Zhu, R; Zacharias, L; Wooding, K M; Peng, W; Mechref, Y

    2017-01-01

    Protein glycosylation is one of the most important posttranslational modifications. Numerous biological functions are related to protein glycosylation. However, analytical challenges remain in the glycoprotein analysis. To overcome the challenges associated with glycoprotein analysis, many analytical techniques were developed in recent years. Enrichment methods were used to improve the sensitivity of detection, while HPLC and mass spectrometry methods were developed to facilitate the separation of glycopeptides/proteins and enhance detection, respectively. Fragmentation techniques applied in modern mass spectrometers allow the structural interpretation of glycopeptides/proteins, while automated software tools started replacing manual processing to improve the reliability and throughput of the analysis. In this chapter, the current methodologies of glycoprotein analysis were discussed. Multiple analytical techniques are compared, and advantages and disadvantages of each technique are highlighted. © 2017 Elsevier Inc. All rights reserved.

  14. Induction of antigen-specific immune responses in mice by recombinant baculovirus expressing premembrane and envelope proteins of West Nile virus

    Directory of Open Access Journals (Sweden)

    Zhu Bibo

    2012-07-01

    Full Text Available Abstract Background West Nile Virus (WNV is an emerging arthropod-born flavivirus with increasing distribution worldwide that is responsible for a large proportion of viral encephalitis in humans and horses. Given that there are no effective antiviral drugs available for treatment of the disease, efforts have been directed to develop vaccines to prevent WNV infection. Recently baculovirus has emerged as a novel and attractive gene delivery vehicle for mammalian cells. Results In the present study, recombinant baculoviruses expressing WNV premembrane (prM and envelope (E proteins under the cytomegalovirus (CMV promoter with or without vesicular stomatitis virus glycoprotein (VSV/G were constructed. The recombinant baculoviruses designated Bac-G-prM/E and Bac-prM/E, efficiently express E protein in mammalian cells. Intramuscular injection of the two recombinant baculoviruses (at doses of 108 or 109 PFU/mouse induced the production of WNV-specific antibodies, neutralizing antibodies as well as gamma interferon (IFN-γ in a dose-dependent pattern. Interestingly, the recombinant baculovirus Bac-G-prM/E was found to be a more efficient immunogen than Bac-prM/E to elicit a robust immune response upon intramuscular injection. In addition, inoculation of baculovirus resulted in the secretion of inflammatory cytokines, such as TNF-α, IL-2 and IL-6. Conclusions These recombinant baculoviruses are capable of eliciting robust humoral and cellular immune responses in mice, and may be considered as novel vaccine candidates for West Nile Virus.

  15. Inhibition of Lassa virus glycoprotein cleavage and multicycle replication by site 1 protease-adapted alpha(1-antitrypsin variants.

    Directory of Open Access Journals (Sweden)

    Anna Maisa

    2009-06-01

    Full Text Available Proteolytic processing of the Lassa virus envelope glycoprotein precursor GP-C by the host proprotein convertase site 1 protease (S1P is a prerequisite for the incorporation of the subunits GP-1 and GP-2 into viral particles and, hence, essential for infectivity and virus spread. Therefore, we tested in this study the concept of using S1P as a target to block efficient virus replication.We demonstrate that stable cell lines inducibly expressing S1P-adapted alpha(1-antitrypsin variants inhibit the proteolytic maturation of GP-C. Introduction of the S1P recognition motifs RRIL and RRLL into the reactive center loop of alpha(1-antitrypsin resulted in abrogation of GP-C processing by endogenous S1P to a similar level observed in S1P-deficient cells. Moreover, S1P-specific alpha(1-antitrypsins significantly inhibited replication and spread of a replication-competent recombinant vesicular stomatitis virus expressing the Lassa virus glycoprotein GP as well as authentic Lassa virus. Inhibition of viral replication correlated with the ability of the different alpha(1-antitrypsin variants to inhibit the processing of the Lassa virus glycoprotein precursor.Our data suggest that glycoprotein cleavage by S1P is a promising target for the development of novel anti-arenaviral strategies.

  16. Engineered CHO cells for production of diverse, homogeneous glycoproteins

    DEFF Research Database (Denmark)

    Yang, Zhang; Wang, Shengjun; Halim, Adnan

    2015-01-01

    Production of glycoprotein therapeutics in Chinese hamster ovary (CHO) cells is limited by the cells' generic capacity for N-glycosylation, and production of glycoproteins with desirable homogeneous glycoforms remains a challenge. We conducted a comprehensive knockout screen of glycosyltransferas...

  17. Genetic Interaction Maps in Escherichia coli Reveal Functional Crosstalk among Cell Envelope Biogenesis Pathways

    Science.gov (United States)

    Vlasblom, James; Gagarinova, Alla; Phanse, Sadhna; Graham, Chris; Yousif, Fouad; Ding, Huiming; Xiong, Xuejian; Nazarians-Armavil, Anaies; Alamgir, Md; Ali, Mehrab; Pogoutse, Oxana; Pe'er, Asaf; Arnold, Roland; Michaut, Magali; Parkinson, John; Golshani, Ashkan; Whitfield, Chris; Wodak, Shoshana J.; Moreno-Hagelsieb, Gabriel; Greenblatt, Jack F.; Emili, Andrew

    2011-01-01

    As the interface between a microbe and its environment, the bacterial cell envelope has broad biological and clinical significance. While numerous biosynthesis genes and pathways have been identified and studied in isolation, how these intersect functionally to ensure envelope integrity during adaptive responses to environmental challenge remains unclear. To this end, we performed high-density synthetic genetic screens to generate quantitative functional association maps encompassing virtually the entire cell envelope biosynthetic machinery of Escherichia coli under both auxotrophic (rich medium) and prototrophic (minimal medium) culture conditions. The differential patterns of genetic interactions detected among >235,000 digenic mutant combinations tested reveal unexpected condition-specific functional crosstalk and genetic backup mechanisms that ensure stress-resistant envelope assembly and maintenance. These networks also provide insights into the global systems connectivity and dynamic functional reorganization of a universal bacterial structure that is both broadly conserved among eubacteria (including pathogens) and an important target. PMID:22125496

  18. Genetic interaction maps in Escherichia coli reveal functional crosstalk among cell envelope biogenesis pathways.

    Directory of Open Access Journals (Sweden)

    Mohan Babu

    2011-11-01

    Full Text Available As the interface between a microbe and its environment, the bacterial cell envelope has broad biological and clinical significance. While numerous biosynthesis genes and pathways have been identified and studied in isolation, how these intersect functionally to ensure envelope integrity during adaptive responses to environmental challenge remains unclear. To this end, we performed high-density synthetic genetic screens to generate quantitative functional association maps encompassing virtually the entire cell envelope biosynthetic machinery of Escherichia coli under both auxotrophic (rich medium and prototrophic (minimal medium culture conditions. The differential patterns of genetic interactions detected among > 235,000 digenic mutant combinations tested reveal unexpected condition-specific functional crosstalk and genetic backup mechanisms that ensure stress-resistant envelope assembly and maintenance. These networks also provide insights into the global systems connectivity and dynamic functional reorganization of a universal bacterial structure that is both broadly conserved among eubacteria (including pathogens and an important target.

  19. Bacillus subtilis extracytoplasmic function (ECF) sigma factors and defense of the cell envelope.

    Science.gov (United States)

    Helmann, John D

    2016-04-01

    Bacillus subtilis provides a model for investigation of the bacterial cell envelope, the first line of defense against environmental threats. Extracytoplasmic function (ECF) sigma factors activate genes that confer resistance to agents that threaten the integrity of the envelope. Although their individual regulons overlap, σ(W) is most closely associated with membrane-active agents, σ(X) with cationic antimicrobial peptide resistance, and σ(V) with resistance to lysozyme. Here, I highlight the role of the σ(M) regulon, which is strongly induced by conditions that impair peptidoglycan synthesis and includes the core pathways of envelope synthesis and cell division, as well as stress-inducible alternative enzymes. Studies of these cell envelope stress responses provide insights into how bacteria acclimate to the presence of antibiotics. Copyright © 2016 Elsevier Ltd. All rights reserved.

  20. Influenza A virus targets a cGAS-independent STING pathway that controls enveloped RNA viruses.

    Science.gov (United States)

    Holm, Christian K; Rahbek, Stine H; Gad, Hans Henrik; Bak, Rasmus O; Jakobsen, Martin R; Jiang, Zhaozaho; Hansen, Anne Louise; Jensen, Simon K; Sun, Chenglong; Thomsen, Martin K; Laustsen, Anders; Nielsen, Camilla G; Severinsen, Kasper; Xiong, Yingluo; Burdette, Dara L; Hornung, Veit; Lebbink, Robert Jan; Duch, Mogens; Fitzgerald, Katherine A; Bahrami, Shervin; Mikkelsen, Jakob Giehm; Hartmann, Rune; Paludan, Søren R

    2016-02-19

    Stimulator of interferon genes (STING) is known be involved in control of DNA viruses but has an unexplored role in control of RNA viruses. During infection with DNA viruses STING is activated downstream of cGAMP synthase (cGAS) to induce type I interferon. Here we identify a STING-dependent, cGAS-independent pathway important for full interferon production and antiviral control of enveloped RNA viruses, including influenza A virus (IAV). Further, IAV interacts with STING through its conserved hemagglutinin fusion peptide (FP). Interestingly, FP antagonizes interferon production induced by membrane fusion or IAV but not by cGAMP or DNA. Similar to the enveloped RNA viruses, membrane fusion stimulates interferon production in a STING-dependent but cGAS-independent manner. Abolishment of this pathway led to reduced interferon production and impaired control of enveloped RNA viruses. Thus, enveloped RNA viruses stimulate a cGAS-independent STING pathway, which is targeted by IAV.

  1. Vaccination directed against the human endogenous retrovirus-K envelope protein inhibits tumor growth in a murine model system.

    Science.gov (United States)

    Kraus, Benjamin; Fischer, Katrin; Büchner, Sarah M; Wels, Winfried S; Löwer, Roswitha; Sliva, Katja; Schnierle, Barbara S

    2013-01-01

    Human endogenous retrovirus (HERV) genomes are chromosomally integrated in all cells of an individual. They are normally transcriptionally silenced and transmitted only vertically. Enhanced expression of HERV-K accompanied by the emergence of anti-HERV-K-directed immune responses has been observed in tumor patients and HIV-infected individuals. As HERV-K is usually not expressed and immunological tolerance development is unlikely, it is an appropriate target for the development of immunotherapies. We generated a recombinant vaccinia virus (MVA-HKenv) expressing the HERV-K envelope glycoprotein (ENV), based on the modified vaccinia virus Ankara (MVA), and established an animal model to test its vaccination efficacy. Murine renal carcinoma cells (Renca) were genetically altered to express E. coli beta-galactosidase (RLZ cells) or the HERV-K ENV gene (RLZ-HKenv cells). Intravenous injection of RLZ-HKenv cells into syngenic BALB/c mice led to the formation of pulmonary metastases, which were detectable by X-gal staining. A single vaccination of tumor-bearing mice with MVA-HKenv drastically reduced the number of pulmonary RLZ-HKenv tumor nodules compared to vaccination with wild-type MVA. Prophylactic vaccination of mice with MVA-HKenv precluded the formation of RLZ-HKenv tumor nodules, whereas wild-type MVA-vaccinated animals succumbed to metastasis. Protection from tumor formation correlated with enhanced HERV-K ENV-specific killing activity of splenocytes. These data demonstrate for the first time that HERV-K ENV is a useful target for vaccine development and might offer new treatment opportunities for diverse types of cancer.

  2. Injection envelope matching in storage rings

    International Nuclear Information System (INIS)

    Minty, M.G.; Spence, W.L.

    1995-05-01

    The shape and size of the transverse phase space injected into a storage ring can be deduced from turn-by-turn measurements of the transient behavior of the beam envelope in the ring. Envelope oscillations at 2 x the β-tron frequency indicate the presence of a β-mismatch, while envelope oscillations at the β-tron frequency are the signature of a dispersion function mismatch. Experiments in injection optimization using synchrotron radiation imaging of the beam and a fast-gated camera at the SLC damping rings are reported

  3. MHTGR thermal performance envelopes: Reliability by design

    International Nuclear Information System (INIS)

    Etzel, K.T.; Howard, W.W.; Zgliczynski, J.B.

    1992-05-01

    This document discusses thermal performance envelopes which are used to specify steady-state design requirements for the systems of the Modular High Temperature Gas-Cooled Reactor to maximize plant performance reliability with optimized design. The thermal performance envelopes are constructed around the expected operating point accounting for uncertainties in actual plant as-built parameters and plant operation. The components are then designed to perform successfully at all points within the envelope. As a result, plant reliability is maximized by accounting for component thermal performance variation in the design. The design is optimized by providing a means to determine required margins in a disciplined and visible fashion

  4. Isolation of glycoproteins from brown algae

    DEFF Research Database (Denmark)

    2015-01-01

    The present invention relates to a novel process for the isolation of unique anti-oxidative glycoproteins from the pH precipitated fractions of enzymatic extracts of brown algae. Two brown seaweeds viz, Fucus serratus and Fucus vesiculosus were hydrolysed by using 3 enzymes viz, Alcalase, Viscozyme...

  5. P-glycoprotein targeted nanoscale drug carriers

    KAUST Repository

    Li, Wengang; Abu Samra, Dina Bashir Kamil; Merzaban, Jasmeen; Khashab, Niveen M.

    2013-01-01

    Multi-drug resistance (MDR) is a trend whereby tumor cells exposed to one cytotoxic agent develop cross-resistance to a range of structurally and functionally unrelated compounds. P -glycoprotein (P -gp) efflux pump is one of the mostly studied drug

  6. Platelet Glycoprotein Ib-IX and Malignancy

    Science.gov (United States)

    2010-09-01

    provide a unique microenvironment supporting the accumulation of more platelets and the elaboration of a fibrin - rich network produced by coagulation...process and can initiate the formation of a platelet - rich thrombus by tethering the platelet to a thrombogenic surface. Several ligands binding to GP Ib... Platelet Glycoprotein Ib-IX and Malignancy PRINCIPAL INVESTIGATOR: Jerry Ware, Ph.D

  7. Involvement of Leishmania donovani major surface glycoprotein ...

    Indian Academy of Sciences (India)

    The major surface glycoprotein gp63 of the kinetoplastid protozoal parasite Leishmania is implicated as a ligand mediating uptake of the parasite into, and survival within, the host macrophage. By expressing gp63 antisense RNA from an episomal vector in L. donovani promastigotes, gp63-deficient transfectants were ...

  8. eEF-2 Phosphorylation Down-Regulates P-Glycoprotein Over-Expression in Rat Brain Microvessel Endothelial Cells.

    Directory of Open Access Journals (Sweden)

    Xing Hua Tang

    Full Text Available We investigated whether glutamate, NMDA receptors, and eukaryote elongation factor-2 kinase (eEF-2K/eEF-2 regulate P-glycoprotein expression, and the effects of the eEF-2K inhibitor NH125 on the expression of P-glycoprotein in rat brain microvessel endothelial cells (RBMECs.Cortex was obtained from newborn Wistar rat brains. After surface vessels and meninges were removed, the pellet containing microvessels was resuspended and incubated at 37°C in culture medium. Cell viability was assessed by the MTT assay. RBMECs were identified by immunohistochemistry with anti-vWF. P-glycoprotein, phospho-eEF-2, and eEF-2 expression were determined by western blot analysis. Mdr1a gene expression was analyzed by RT-PCR.Mdr1a mRNA, P-glycoprotein and phospho-eEF-2 expression increased in L-glutamate stimulated RBMECs. P-glycoprotein and phospho-eEF-2 expression were down-regulated after NH125 treatment in L-glutamate stimulated RBMECs.eEF-2K/eEF-2 should have played an important role in the regulation of P-glycoprotein expression in RBMECs. eEF-2K inhibitor NH125 could serve as an efficacious anti-multidrug resistant agent.

  9. Comparative Studies of Vertebrate Platelet Glycoprotein 4 (CD36

    Directory of Open Access Journals (Sweden)

    Roger S. Holmes

    2012-09-01

    Full Text Available Platelet glycoprotein 4 (CD36 (or fatty acyl translocase [FAT], or scavenger receptor class B, member 3 [SCARB3] is an essential cell surface and skeletal muscle outer mitochondrial membrane glycoprotein involved in multiple functions in the body. CD36 serves as a ligand receptor of thrombospondin, long chain fatty acids, oxidized low density lipoproteins (LDLs and malaria-infected erythrocytes. CD36 also influences various diseases, including angiogenesis, thrombosis, atherosclerosis, malaria, diabetes, steatosis, dementia and obesity. Genetic deficiency of this protein results in significant changes in fatty acid and oxidized lipid uptake. Comparative CD36 amino acid sequences and structures and CD36 gene locations were examined using data from several vertebrate genome projects. Vertebrate CD36 sequences shared 53–100% identity as compared with 29–32% sequence identities with other CD36-like superfamily members, SCARB1 and SCARB2. At least eight vertebrate CD36 N-glycosylation sites were conserved which are required for membrane integration. Sequence alignments, key amino acid residues and predicted secondary structures were also studied. Three CD36 domains were identified including cytoplasmic, transmembrane and exoplasmic sequences. Conserved sequences included N- and C-terminal transmembrane glycines; and exoplasmic cysteine disulphide residues; TSP-1 and PE binding sites, Thr92 and His242, respectively; 17 conserved proline and 14 glycine residues, which may participate in forming CD36 ‘short loops’; and basic amino acid residues, and may contribute to fatty acid and thrombospondin binding. Vertebrate CD36 genes usually contained 12 coding exons. The human CD36 gene contained transcription factor binding sites (including PPARG and PPARA contributing to a high gene expression level (6.6 times average. Phylogenetic analyses examined the relationships and potential evolutionary origins of the vertebrate CD36 gene with vertebrate

  10. Acid-induced movements in the glycoprotein shell of an alphavirus turn the spikes into membrane fusion mode

    OpenAIRE

    Haag, Lars; Garoff, Henrik; Xing, Li; Hammar, Lena; Kan, Sin-Tau; Cheng, R.Holland

    2002-01-01

    In the icosahedral (T = 4) Semliki Forest virus, the envelope protomers, i.e. E1–E2 heterodimers, make one-to-one interactions with capsid proteins below the viral lipid bilayer, transverse the membrane and form an external glycoprotein shell with projections. The shell is organized by protomer domains interacting as hexamers and pentamers around shell openings at icosahedral 2- and 5-fold axes, respectively, and the projections by other domains associating as trimers at 3- and quasi 3-fold a...

  11. Nuclear envelopathies: a complex LINC between nuclear envelope and pathology.

    Science.gov (United States)

    Janin, Alexandre; Bauer, Delphine; Ratti, Francesca; Millat, Gilles; Méjat, Alexandre

    2017-08-30

    Since the identification of the first disease causing mutation in the gene coding for emerin, a transmembrane protein of the inner nuclear membrane, hundreds of mutations and variants have been found in genes encoding for nuclear envelope components. These proteins can be part of the inner nuclear membrane (INM), such as emerin or SUN proteins, outer nuclear membrane (ONM), such as Nesprins, or the nuclear lamina, such as lamins A and C. However, they physically interact with each other to insure the nuclear envelope integrity and mediate the interactions of the nuclear envelope with both the genome, on the inner side, and the cytoskeleton, on the outer side. The core of this complex, called LINC (LInker of Nucleoskeleton to Cytoskeleton) is composed of KASH and SUN homology domain proteins. SUN proteins are INM proteins which interact with lamins by their N-terminal domain and with the KASH domain of nesprins located in the ONM by their C-terminal domain.Although most of these proteins are ubiquitously expressed, their mutations have been associated with a large number of clinically unrelated pathologies affecting specific tissues. Moreover, variants in SUN proteins have been found to modulate the severity of diseases induced by mutations in other LINC components or interactors. For these reasons, the diagnosis and the identification of the molecular explanation of "nuclear envelopathies" is currently challenging.The aim of this review is to summarize the human diseases caused by mutations in genes coding for INM proteins, nuclear lamina, and ONM proteins, and to discuss their potential physiopathological mechanisms that could explain the large spectrum of observed symptoms.

  12. Nuclear envelope and genome interactions in cell fate

    Science.gov (United States)

    Talamas, Jessica A.; Capelson, Maya

    2015-01-01

    The eukaryotic cell nucleus houses an organism’s genome and is the location within the cell where all signaling induced and development-driven gene expression programs are ultimately specified. The genome is enclosed and separated from the cytoplasm by the nuclear envelope (NE), a double-lipid membrane bilayer, which contains a large variety of trans-membrane and associated protein complexes. In recent years, research regarding multiple aspects of the cell nucleus points to a highly dynamic and coordinated concert of efforts between chromatin and the NE in regulation of gene expression. Details of how this concert is orchestrated and how it directs cell differentiation and disease are coming to light at a rapid pace. Here we review existing and emerging concepts of how interactions between the genome and the NE may contribute to tissue specific gene expression programs to determine cell fate. PMID:25852741

  13. Alternative promoter usage of the membrane glycoprotein CD36

    Directory of Open Access Journals (Sweden)

    Whatling Carl

    2006-03-01

    Full Text Available Abstract Background CD36 is a membrane glycoprotein involved in a variety of cellular processes such as lipid transport, immune regulation, hemostasis, adhesion, angiogenesis and atherosclerosis. It is expressed in many tissues and cell types, with a tissue specific expression pattern that is a result of a complex regulation for which the molecular mechanisms are not yet fully understood. There are several alternative mRNA isoforms described for the gene. We have investigated the expression patterns of five alternative first exons of the CD36 gene in several human tissues and cell types, to better understand the molecular details behind its regulation. Results We have identified one novel alternative first exon of the CD36 gene, and confirmed the expression of four previously known alternative first exons of the gene. The alternative transcripts are all expressed in more than one human tissue and their expression patterns vary highly in skeletal muscle, heart, liver, adipose tissue, placenta, spinal cord, cerebrum and monocytes. All alternative first exons are upregulated in THP-1 macrophages in response to oxidized low density lipoproteins. The alternative promoters lack TATA-boxes and CpG islands. The upstream region of exon 1b contains several features common for house keeping gene and monocyte specific gene promoters. Conclusion Tissue-specific expression patterns of the alternative first exons of CD36 suggest that the alternative first exons of the gene are regulated individually and tissue specifically. At the same time, the fact that all first exons are upregulated in THP-1 macrophages in response to oxidized low density lipoproteins may suggest that the alternative first exons are coregulated in this cell type and environmental condition. The molecular mechanisms regulating CD36 thus appear to be unusually complex, which might reflect the multifunctional role of the gene in different tissues and cellular conditions.

  14. Constructing canonical bases of quantized enveloping algebras

    OpenAIRE

    Graaf, W.A. de

    2001-01-01

    An algorithm for computing the elements of a given weight of the canonical basis of a quantized enveloping algebra is described. Subsequently, a similar algorithm is presented for computing the canonical basis of a finite-dimensional module.

  15. The Role of the MHV Receptor and Related Glycoproteins in Murine Hepatitis Virus Infection of Murine Cell Lines

    Science.gov (United States)

    1995-04-13

    vaccinia virus-T7 RNA polymerase s y stem for e xpression of target genes . Mol . Cell . BioI . 7 : 2538-2544 . Gagneten , S ., Gout , 0 ., Dubois-Dalcq...glycoprotein. These results showed f or the first time that two murine CEA- related genes can be co-expressed in some cell lines from inbred mice...49 Southern Hybridization ................ . ............ 50 Subcloning of PCR Products and Gene Cloning ........ 51 Growth

  16. Creating a Lunar EVA Work Envelope

    Science.gov (United States)

    Griffin, Brand N.; Howard, Robert; Rajulu, Sudhakar; Smitherman, David

    2009-01-01

    A work envelope has been defined for weightless Extravehicular Activity (EVA) based on the Space Shuttle Extravehicular Mobility Unit (EMU), but there is no equivalent for planetary operations. The weightless work envelope is essential for planning all EVA tasks because it determines the location of removable parts, making sure they are within reach and visibility of the suited crew member. In addition, using the envelope positions the structural hard points for foot restraints that allow placing both hands on the job and provides a load path for reacting forces. EVA operations are always constrained by time. Tasks are carefully planned to ensure the crew has enough breathing oxygen, cooling water, and battery power. Planning first involves computers using a virtual work envelope to model tasks, next suited crew members in a simulated environment refine the tasks. For weightless operations, this process is well developed, but planetary EVA is different and no work envelope has been defined. The primary difference between weightless and planetary work envelopes is gravity. It influences anthropometry, horizontal and vertical mobility, and reaction load paths and introduces effort into doing "overhead" work. Additionally, the use of spacesuits other than the EMU, and their impacts on range of motion, must be taken into account. This paper presents the analysis leading to a concept for a planetary EVA work envelope with emphasis on lunar operations. There is some urgency in creating this concept because NASA has begun building and testing development hardware for the lunar surface, including rovers, habitats and cargo off-loading equipment. Just as with microgravity operations, a lunar EVA work envelope is needed to guide designers in the formative stages of the program with the objective of avoiding difficult and costly rework.

  17. The Arabidopsis Nuclear Pore and Nuclear Envelope

    OpenAIRE

    Meier, Iris; Brkljacic, Jelena

    2010-01-01

    The nuclear envelope is a double membrane structure that separates the eukaryotic cytoplasm from the nucleoplasm. The nuclear pores embedded in the nuclear envelope are the sole gateways for macromolecular trafficking in and out of the nucleus. The nuclear pore complexes assembled at the nuclear pores are large protein conglomerates composed of multiple units of about 30 different nucleoporins. Proteins and RNAs traffic through the nuclear pore complexes, enabled by the interacting activities...

  18. All the Universe in an envelope

    CERN Multimedia

    2007-01-01

    Do you know which force is hidden in an envelope or how many billions of years old are the atoms it contains? You will find the answers to these (curious) questions in a post office in the Pays de Gex. The French postal services of the Pays de Gex are again issuing pre-paid envelopes in collaboration with CERN (see Bulletin No. 24/2006). The new series presents some of the concepts of modern physics in an amazing way by showing what you can learn about the Universe with a single envelope. Packets of ten pre-stamped envelopes, each carrying a statement on fundamental physics, will be on sale from 7 July onwards. To learn more about the physics issues presented on the envelopes, people are invited to go to the CERN Web site where they will find the explanations. Five thousand envelopes will be put on sale in July and five thousand more during the French "Fête de la science" in October. They will be available from five post offices in the Pays de Gex (F...

  19. Removal of envelope protein-free retroviral vectors by anion-exchange chromatography to improve product quality.

    Science.gov (United States)

    Rodrigues, Teresa; Alves, Ana; Lopes, António; Carrondo, Manuel J T; Alves, Paula M; Cruz, Pedro E

    2008-10-01

    We have investigated the role of the retroviral lipid bilayer and envelope proteins in the adsorption of retroviral vectors (RVs) to a Fractogel DEAE matrix. Intact RVs and their degradation components (envelope protein-free vectors and solubilized vector components) were adsorbed to this matrix and eluted using a linear gradient. Envelope protein-free RVs (Env(-)) and soluble envelope proteins (gp70) eluted in a significantly lower range of conductivities than intact RVs (Env(+)) (13.7-30 mS/cm for Env(-) and gp70 proteins vs. 47-80 mS/cm for Env(+)). The zeta (zeta)-potential of Env(+) and Env(-) vectors was evaluated showing that envelope proteins define the pI of the viral particles (pI (Env(+)) improvement to the quality of retroviral preparations for gene therapy applications.

  20. Full-length Ebola glycoprotein accumulates in the endoplasmic reticulum

    Directory of Open Access Journals (Sweden)

    Bhattacharyya Suchita

    2011-01-01

    Full Text Available Abstract The Filoviridae family comprises of Ebola and Marburg viruses, which are known to cause lethal hemorrhagic fever. However, there is no effective anti-viral therapy or licensed vaccines currently available for these human pathogens. The envelope glycoprotein (GP of Ebola virus, which mediates entry into target cells, is cytotoxic and this effect maps to a highly glycosylated mucin-like region in the surface subunit of GP (GP1. However, the mechanism underlying this cytotoxic property of GP is unknown. To gain insight into the basis of this GP-induced cytotoxicity, HEK293T cells were transiently transfected with full-length and mucin-deleted (Δmucin Ebola GP plasmids and GP localization was examined relative to the nucleus, endoplasmic reticulum (ER, Golgi, early and late endosomes using deconvolution fluorescent microscopy. Full-length Ebola GP was observed to accumulate in the ER. In contrast, GPΔmucin was uniformly expressed throughout the cell and did not localize in the ER. The Ebola major matrix protein VP40 was also co-expressed with GP to investigate its influence on GP localization. GP and VP40 co-expression did not alter GP localization to the ER. Also, when VP40 was co-expressed with the nucleoprotein (NP, it localized to the plasma membrane while NP accumulated in distinct cytoplasmic structures lined with vimentin. These latter structures are consistent with aggresomes and may serve as assembly sites for filoviral nucleocapsids. Collectively, these data suggest that full-length GP, but not GPΔmucin, accumulates in the ER in close proximity to the nuclear membrane, which may underscore its cytotoxic property.

  1. Solitary Alfven wave envelopes and the modulational instability

    International Nuclear Information System (INIS)

    Kennel, C.F.

    1987-06-01

    The derivative nonlinear Schroedinger equation describes the modulational instability of circularly polarized dispersive Alfven wave envelopes. It also may be used to determine the properties of finite amplitude localized stationary wave envelopes. Such envelope solitons exist only in conditions of modulational stability. This leaves open the question of whether, and if so, how, the modulational instability produces envelope solitons. 12 refs

  2. Leucine-rich repeat-containing G protein-coupled receptor 4 facilitates vesicular stomatitis virus infection by binding vesicular stomatitis virus glycoprotein.

    Science.gov (United States)

    Zhang, Na; Huang, Hongjun; Tan, Binghe; Wei, Yinglei; Xiong, Qingqing; Yan, Yan; Hou, Lili; Wu, Nannan; Siwko, Stefan; Cimarelli, Andrea; Xu, Jianrong; Han, Honghui; Qian, Min; Liu, Mingyao; Du, Bing

    2017-10-06

    Vesicular stomatitis virus (VSV) and rabies and Chandipura viruses belong to the Rhabdovirus family. VSV is a common laboratory virus to study viral evolution and host immune responses to viral infection, and recombinant VSV-based vectors have been widely used for viral oncolysis, vaccination, and gene therapy. Although the tropism of VSV is broad, and its envelope glycoprotein G is often used for pseudotyping other viruses, the host cellular components involved in VSV infection remain unclear. Here, we demonstrate that the host protein leucine-rich repeat-containing G protein-coupled receptor 4 (Lgr4) is essential for VSV and VSV-G pseudotyped lentivirus (VSVG-LV) to infect susceptible cells. Accordingly, Lgr4-deficient mice had dramatically decreased VSV levels in the olfactory bulb. Furthermore, Lgr4 knockdown in RAW 264.7 cells also significantly suppressed VSV infection, and Lgr4 overexpression in RAW 264.7 cells enhanced VSV infection. Interestingly, only VSV infection relied on Lgr4, whereas infections with Newcastle disease virus, influenza A virus (A/WSN/33), and herpes simplex virus were unaffected by Lgr4 status. Of note, assays of virus entry, cell ELISA, immunoprecipitation, and surface plasmon resonance indicated that VSV bound susceptible cells via the Lgr4 extracellular domain. Pretreating cells with an Lgr4 antibody, soluble LGR4 extracellular domain, or R-spondin 1 blocked VSV infection by competitively inhibiting VSV binding to Lgr4. Taken together, the identification of Lgr4 as a VSV-specific host factor provides important insights into understanding VSV entry and its pathogenesis and lays the foundation for VSV-based gene therapy and viral oncolytic therapeutics. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  3. Characterization of soluble glycoprotein D-mediated herpes simplex virus type 1 infection

    International Nuclear Information System (INIS)

    Tsvitov, Marianna; Frampton, Arthur R.; Shah, Waris A.; Wendell, Steven K.; Ozuer, Ali; Kapacee, Zoher; Goins, William F.; Cohen, Justus B.; Glorioso, Joseph C.

    2007-01-01

    Herpes simplex virus type 1 (HSV-1) entry into permissive cells involves attachment to cell-surface glycosaminoglycans (GAGs) and fusion of the virus envelope with the cell membrane triggered by the binding of glycoprotein D (gD) to cognate receptors. In this study, we characterized the observation that soluble forms of the gD ectodomain (sgD) can mediate entry of gD-deficient HSV-1. We examined the efficiency and receptor specificity of this activity and used sequential incubation protocols to determine the order and stability of the initial interactions required for entry. Surprisingly, virus binding to GAGs did not increase the efficiency of sgD-mediated entry and gD-deficient virus was capable of attaching to GAG-deficient cells in the absence of sgD. These observations suggested a novel binding interaction that may play a role in normal HSV infection

  4. Characterization of canine herpesvirus glycoprotein C expressed by a recombinant baculovirus in insect cells.

    Science.gov (United States)

    Xuan, X; Maeda, K; Mikami, T; Otsuka, H

    1996-12-01

    The gene encoding the canine herpesvirus (CHV) glycoprotein C (gC) homologue has been identified by sequence homology analyses with other well studied herpesviruses. Previously, we have identified three CHV glycoproteins, gp145/112, gp80 and gp47 using a panel of monoclonal antibodies (MAbs). To determine which CHV glycoprotein corresponds to gC, a recombinant baculovirus which contains the putative CHV gC structural gene under the baculovirus polyhedrin promoter was constructed. The recombinant baculovirus expressed gC-related polypeptides (44-62 kDa), which reacted only with MAbs against CHV gp80, indicating that the previously identified CHV gp80 is the translation product of the gC gene. The baculovirus expressed gC was glycosylated and transported to the surface of infected cells. At least seven neutralizing epitopes were conserved on the gC produced in insect cells. It was found that the recombinant baculovirus infected cells adsorbed murine erythrocytes as is the case for CHV-infected cells. The hemadsorption activity was inhibited by heparin, indicating that the CHV gC binds to heparan sulfate on the surface of murine erythrocytes. Mice immunized with the recombinant gC produced strong neutralizing antibodies. Our results suggest that CHV gC produced in insect cells may be useful as a subunit vaccine to control CHV infections.

  5. Role of HIV-2 envelope in Lv2-mediated restriction

    International Nuclear Information System (INIS)

    Reuter, Sandra; Kaumanns, Patrick; Buschhorn, Sabine B.; Dittmar, Matthias T.

    2005-01-01

    We have characterized envelope protein pseudotyped HIV-2 particles derived from two HIV-2 isolates termed prCBL23 and CBL23 in order to define the role of the envelope protein for the Lv2-mediated restriction to infection. Previously, it has been described that the primary isolate prCBL23 is restricted to infection of several human cell types, whereas the T cell line adapted isolate CBL23 is not restricted in these cell types. Molecular cloning of the two isolates revealed that the env and the gag gene are responsible for the observed phenotype and that this restriction is mediated by Lv2, which is distinct from Ref1/Lv1 (Schmitz, C., Marchant, D., Neil, S.J., Aubin, K., Reuter, S., Dittmar, M.T., McKnight, A., Kizhatil, K., Albritton, L.M., 2004. Lv2, a novel postentry restriction, is mediated by both capsid and envelope. J. Virol. 78 (4), 2006-2016). We generated pseudotyped viruses consisting of HIV-2 (ROD-AΔenv-GFP, ROD-AΔenv-RFP, or ROD-AΔenv-REN) and the prCBL23 or CBL23 envelope proteins as well as chimeric proteins between these envelopes. We demonstrate that a single amino acid exchange at position 74 in the surface unit of CBL23-Env confers restriction to infection. This single point mutation causes tighter CD4 binding, resulting in a less efficient fusion into the cytosol of the restricted cell line. Prevention of endosome formation and prevention of endosome acidification enhance infectivity of the restricted particles for GHOST/X4 cells indicating a degradative lysosomal pathway as a cause for the reduced cytosolic entry. The described restriction to infection of the primary isolate prCBL23 is therefore largely caused by an entry defect. A remaining restriction to infection (19-fold) is preserved when endosomal acidification is prevented. This restriction to infection is also dependent on the presence of the point mutation at position 74 (G74E)

  6. Construction and characterization of a glycoprotein E deletion mutant of bovine herpesvirus type 1.2 strain isolated in Brazil

    NARCIS (Netherlands)

    Franco, A.C.; Rijsewijk, F.A.M.; Flores, E.F.; Weiblen, R.; Roehe, P.M.

    2002-01-01

    This paper describes the construction and characterization of a Brazilian strain of bovine herpesvirus type 1.2a (BoHV-1.2a) with a deletion of the glycoprotein E (gE) gene. The deletion was introduced by co-transfection of a deletion fragment containing the 5´and 3´gE flanking regions and genomic

  7. Labelled antibody techniques in glycoprotein estimation

    International Nuclear Information System (INIS)

    Hazra, D.K.; Ekins, R.P.; Edwards, R.; Williams, E.S.

    1977-01-01

    The problems in the radioimmunoassay of the glycoprotein hormones (pituitary LH, FSH and TSH and human chlorionic gonadotrophin HGG) are reviewed viz: limited specificity and sensitivity in the clinical context, interpretation of disparity between bioassay and radioimmunoassay, and interlaboratory variability. The advantages and limitations of the labelled antibody techniques - classical immonoradiometric methods and 2-site or 125 I-anti-IgG indirect labelling modifications are reviewed in general, and their theoretical potential in glycoprotein assays examined in the light of previous work. Preliminary experiments in the development of coated tube 2-site assay for glycoproteins using 125 I anti-IgG labelling are described, including conditions for maximizing solid phase extraction of the antigen, iodination of anti-IgG, and assay conditions such as effects of temperature of incubation with antigen 'hormonefree serum', heterologous serum and detergent washing. Experiments with extraction and antigen-specific antisera raised in the same or different species are described as exemplified by LH and TSH assay systems, the latter apparently promising greater sensitivity than radioimmunoassay. Proposed experimental and mathematical optimisation and validation of the method as an assay system is outlined, and the areas for further work delineated. (orig.) [de

  8. Functional processing and secretion of Chikungunya virus E1 and E2 glycoproteins in insect cells

    Directory of Open Access Journals (Sweden)

    Goldbach Rob W

    2011-07-01

    Full Text Available Abstract Background Chikungunya virus (CHIKV is a mosquito-borne, arthrogenic Alphavirus that causes large epidemics in Africa, South-East Asia and India. Recently, CHIKV has been transmitted to humans in Southern Europe by invading and now established Asian tiger mosquitoes. To study the processing of envelope proteins E1 and E2 and to develop a CHIKV subunit vaccine, C-terminally his-tagged E1 and E2 envelope glycoproteins were produced at high levels in insect cells with baculovirus vectors using their native signal peptides located in CHIKV 6K and E3, respectively. Results Expression in the presence of either tunicamycin or furin inhibitor showed that a substantial portion of recombinant intracellular E1 and precursor E3E2 was glycosylated, but that a smaller fraction of E3E2 was processed by furin into mature E3 and E2. Deletion of the C-terminal transmembrane domains of E1 and E2 enabled secretion of furin-cleaved, fully processed E1 and E2 subunits, which could then be efficiently purified from cell culture fluid via metal affinity chromatography. Confocal laser scanning microscopy on living baculovirus-infected Sf21 cells revealed that full-length E1 and E2 translocated to the plasma membrane, suggesting similar posttranslational processing of E1 and E2, as in a natural CHIKV infection. Baculovirus-directed expression of E1 displayed fusogenic activity as concluded from syncytia formation. CHIKV-E2 was able to induce neutralizing antibodies in rabbits. Conclusions Chikungunya virus glycoproteins could be functionally expressed at high levels in insect cells and are properly glycosylated and cleaved by furin. The ability of purified, secreted CHIKV-E2 to induce neutralizing antibodies in rabbits underscores the potential use of E2 in a subunit vaccine to prevent CHIKV infections.

  9. Canine distemper virus matrix protein influences particle infectivity, particle composition, and envelope distribution in polarized epithelial cells and modulates virulence.

    Science.gov (United States)

    Dietzel, Erik; Anderson, Danielle E; Castan, Alexandre; von Messling, Veronika; Maisner, Andrea

    2011-07-01

    In paramyxoviruses, the matrix (M) protein mediates the interaction between the envelope and internal proteins during particle assembly and egress. In measles virus (MeV), M mutations, such as those found in subacute sclerosing panencephalitis (SSPE) strains, and differences in vaccine and wild-type M proteins can affect the strength of interaction with the envelope glycoproteins, assembly efficiency, and spread. However, the contribution of the M protein to the replication and pathogenesis of the closely related canine distemper virus (CDV) has not been characterized. To this end this, we generated a recombinant wild-type CDV carrying a vaccine strain M protein. The recombinant virus retained the parental growth phenotype in VerodogSLAMtag cells, but displayed an increased particle-to-infectivity ratio very similar to that of the vaccine strain, likely due to inefficient H protein incorporation. Even though infectious virus was released only from the apical surface, consistent with the release polarity of the wild-type CDV strain, envelope protein distribution in polarized epithelial cells reproduced the bipolar pattern seen in vaccine strain-infected cells. Most notably, the chimeric virus was completely attenuated in ferrets and caused only a mild and transient leukopenia, indicating that the differences in particle infectivity and envelope protein sorting mediated by the vaccine M protein contribute importantly to vaccine strain attenuation.

  10. Characterizing Functional Domains for TIM-Mediated Enveloped Virus Entry

    Science.gov (United States)

    Moller-Tank, Sven; Albritton, Lorraine M.; Rennert, Paul D.

    2014-01-01

    ABSTRACT T-cell immunoglobulin and mucin domain 1 (TIM-1) and other TIM family members were recently identified as phosphatidylserine (PtdSer)-mediated virus entry-enhancing receptors (PVEERs). These proteins enhance entry of Ebola virus (EBOV) and other viruses by binding PtdSer on the viral envelope, concentrating virus on the cell surface, and promoting subsequent internalization. The PtdSer-binding activity of the immunoglobulin-like variable (IgV) domain is essential for both virus binding and internalization by TIM-1. However, TIM-3, whose IgV domain also binds PtdSer, does not effectively enhance virus entry, indicating that other domains of TIM proteins are functionally important. Here, we investigate the domains supporting enhancement of enveloped virus entry, thereby defining the features necessary for a functional PVEER. Using a variety of chimeras and deletion mutants, we found that in addition to a functional PtdSer-binding domain PVEERs require a stalk domain of sufficient length, containing sequences that promote an extended structure. Neither the cytoplasmic nor the transmembrane domain of TIM-1 is essential for enhancing virus entry, provided the protein is still plasma membrane bound. Based on these defined characteristics, we generated a mimic lacking TIM sequences and composed of annexin V, the mucin-like domain of α-dystroglycan, and a glycophosphatidylinositol anchor that functioned as a PVEER to enhance transduction of virions displaying Ebola, Chikungunya, Ross River, or Sindbis virus glycoproteins. This identification of the key features necessary for PtdSer-mediated enhancement of virus entry provides a basis for more effective recognition of unknown PVEERs. IMPORTANCE T-cell immunoglobulin and mucin domain 1 (TIM-1) and other TIM family members are recently identified phosphatidylserine (PtdSer)-mediated virus entry-enhancing receptors (PVEERs). These proteins enhance virus entry by binding the phospholipid, PtdSer, present on the viral

  11. Inhibition of enveloped viruses infectivity by curcumin.

    Directory of Open Access Journals (Sweden)

    Tzu-Yen Chen

    Full Text Available Curcumin, a natural compound and ingredient in curry, has antiinflammatory, antioxidant, and anticarcinogenic properties. Previously, we reported that curcumin abrogated influenza virus infectivity by inhibiting hemagglutination (HA activity. This study demonstrates a novel mechanism by which curcumin inhibits the infectivity of enveloped viruses. In all analyzed enveloped viruses, including the influenza virus, curcumin inhibited plaque formation. In contrast, the nonenveloped enterovirus 71 remained unaffected by curcumin treatment. We evaluated the effects of curcumin on the membrane structure using fluorescent dye (sulforhodamine B; SRB-containing liposomes that mimic the viral envelope. Curcumin treatment induced the leakage of SRB from these liposomes and the addition of the influenza virus reduced the leakage, indicating that curcumin disrupts the integrity of the membranes of viral envelopes and of liposomes. When testing liposomes of various diameters, we detected higher levels of SRB leakage from the smaller-sized liposomes than from the larger liposomes. Interestingly, the curcumin concentration required to reduce plaque formation was lower for the influenza virus (approximately 100 nm in diameter than for the pseudorabies virus (approximately 180 nm and the vaccinia virus (roughly 335 × 200 × 200 nm. These data provide insights on the molecular antiviral mechanisms of curcumin and its potential use as an antiviral agent for enveloped viruses.

  12. Featured Image: Orbiting Stars Share an Envelope

    Science.gov (United States)

    Kohler, Susanna

    2016-03-01

    This beautiful series of snapshots from a simulation (click for a better look!) shows what happens when two stars in a binary system become enclosed in the same stellar envelope. In this binary system, one of the stars has exhausted its hydrogen fuel and become a red giant, complete with an expanding stellar envelope composed of hydrogen and helium. Eventually, the envelope expands so much that the companion star falls into it, where it releases gravitational potential energy into the common envelope. A team led by Sebastian Ohlmann (Heidelberg Institute for Theoretical Studies and University of Wrzburg) recently performed hydrodynamic simulations of this process. Ohlmann and collaborators discovered that the energy release eventually triggers large-scale flow instabilities, which leads to turbulence within the envelope. This process has important consequences for how these systems next evolve (for instance, determining whether or not a supernova occurs!). You can check out the authors video of their simulated stellar inspiral below, or see their paper for more images and results from their study.CitationSebastian T. Ohlmann et al 2016 ApJ 816 L9. doi:10.3847/2041-8205/816/1/L9

  13. Inhibition of Enveloped Viruses Infectivity by Curcumin

    Science.gov (United States)

    Wen, Hsiao-Wei; Ou, Jun-Lin; Chiou, Shyan-Song; Chen, Jo-Mei; Wong, Min-Liang; Hsu, Wei-Li

    2013-01-01

    Curcumin, a natural compound and ingredient in curry, has antiinflammatory, antioxidant, and anticarcinogenic properties. Previously, we reported that curcumin abrogated influenza virus infectivity by inhibiting hemagglutination (HA) activity. This study demonstrates a novel mechanism by which curcumin inhibits the infectivity of enveloped viruses. In all analyzed enveloped viruses, including the influenza virus, curcumin inhibited plaque formation. In contrast, the nonenveloped enterovirus 71 remained unaffected by curcumin treatment. We evaluated the effects of curcumin on the membrane structure using fluorescent dye (sulforhodamine B; SRB)-containing liposomes that mimic the viral envelope. Curcumin treatment induced the leakage of SRB from these liposomes and the addition of the influenza virus reduced the leakage, indicating that curcumin disrupts the integrity of the membranes of viral envelopes and of liposomes. When testing liposomes of various diameters, we detected higher levels of SRB leakage from the smaller-sized liposomes than from the larger liposomes. Interestingly, the curcumin concentration required to reduce plaque formation was lower for the influenza virus (approximately 100 nm in diameter) than for the pseudorabies virus (approximately 180 nm) and the vaccinia virus (roughly 335 × 200 × 200 nm). These data provide insights on the molecular antiviral mechanisms of curcumin and its potential use as an antiviral agent for enveloped viruses. PMID:23658730

  14. Dimers of beta 2-glycoprotein I mimic the in vitro effects of beta 2-glycoprotein I-anti-beta 2-glycoprotein I antibody complexes

    NARCIS (Netherlands)

    Lutters, B. C.; Meijers, J. C.; Derksen, R. H.; Arnout, J.; de Groot, P. G.

    2001-01-01

    Anti-beta(2)-glycoprotein I antibodies are thought to cause lupus anticoagulant activity by forming bivalent complexes with beta(2)-glycoprotein I (beta(2)GPI). To test this hypothesis, chimeric fusion proteins were constructed of the dimerization domain (apple 4) of factor XI and beta(2)GPI. Both a

  15. Mechanisms for lymphocytic choriomeningitis virus glycoprotein cleavage, transport, and incorporation into virions

    International Nuclear Information System (INIS)

    Kunz, Stefan; Edelmann, Kurt H.; Torre, Juan-Carlos de la; Gorney, Robert; Oldstone, Michael B.A.

    2003-01-01

    The glycoprotein (GP) of lymphocytic choriomeningitis virus (LCMV) serves as virus attachment protein to its receptor on host cells and is a key determinant for cell tropism, pathogenesis, and epidemiology of the virus. The GP of LCMV is posttranslationally cleaved by the subtilase SKI-1/S1P into two subunits, the peripheral GP1, which is implicated in receptor binding, and the transmembrane GP2 that is structurally similar to the fusion active membrane proximal portions of the glycoproteins of other enveloped viruses. The present study shows that cleavage by SKI-1/S1P is not required for cell surface expression of LCMVGP on infected cells but is essential for its incorporation into virions and for the production of infectious virus particles. In absence of SKI-1/S1P cleavage, cell-to-cell propagation of the virus was markedly reduced. Further, proteolytic processing of LCMVGP depends on the presence of a cluster of basic amino acids at the C-terminus of the cytoplasmic domain of GP2, a structural motif that is conserved in Old World arenaviruses. The effect of the truncation of the cytoplasmic tail on cleavage suggests a structural interdependence between the cytoplasmic domain and the ectodomains of LCMVGP

  16. Serological responses in chimpanzees inoculated with human immunodeficiency virus glycoprotein (gp120) subunit vaccine

    International Nuclear Information System (INIS)

    Arthur, L.O.; Pyle, S.W.; Nara, P.L.

    1987-01-01

    The major envelope glycoprotein of a human immunodeficiency virus (HIV) has been purified and was utilized as a prototype vaccine in chimpanzees. The 120,000-dalton glycoprotein (gp120) was purified from membranes of human T-lymphotropic virus (HTLV)-IIIB-infected cells and the final preparation contained low levels to no detectable HTLV-IIIB core antigen (p24) and low levels of endotoxin. Chimpanzees inoculated with gp120 responded by developing antibodies that precipitated radiolabeled gp120 and neutralized in vitro infection of HTLV-IIIB. Antibodies to HTLV-IIIB p24 were not detected in the gp120-immunized chimpanzees. Peripheral blood leukocytes from the vaccinated animals were examined for T4 + and T8 + cells, and no decrease in the T4/T8 ratio was found, indicating that immunization with a ligand (gp120) that binds to T4 has not detectable adverse effect on the population of T4 + cells. The only current animal model that can be reproducibly infected with HIV is the chimpanzee. Immunization of chimpanzees with HIV proteins will provide an experimental system for testing the effectiveness of prototype vaccines for preventing HIV infection in vivo

  17. Structural and Antigenic Definition of Hepatitis C Virus E2 Glycoprotein Epitopes Targeted by Monoclonal Antibodies

    Directory of Open Access Journals (Sweden)

    Giuseppe Sautto

    2013-01-01

    Full Text Available Hepatitis C virus (HCV is the major cause of chronic liver disease as well as the major indication for liver transplantation worldwide. Current standard of care is not completely effective, not administrable in grafted patients, and burdened by several side effects. This incomplete effectiveness is mainly due to the high propensity of the virus to continually mutate under the selective pressure exerted by the host immune response as well as currently administered antiviral drugs. The E2 envelope surface glycoprotein of HCV (HCV/E2 is the main target of the host humoral immune response and for this reason one of the major variable viral proteins. However, broadly cross-neutralizing monoclonal antibodies (mAbs directed against HCV/E2 represent a promising tool for the study of virus-host interplay as well as for the development of effective prophylactic and therapeutic approaches. In the last few years many anti-HCV/E2 mAbs have been evaluated in preclinical and clinical trials as possible candidate antivirals, particularly for administration in pre- and post-transplant settings. In this review we summarize the antigenic and structural characteristics of HCV/E2 determined through the use of anti-HCV/E2 mAbs, which, given the absence of a crystal structure of this glycoprotein, represent currently the best tool available.

  18. Cell wall O-glycoproteins and N-glycoproteins: biosynthesis and some functional aspects.

    Directory of Open Access Journals (Sweden)

    Eric eNguema-Ona

    2014-10-01

    Full Text Available Cell wall O-glycoproteins and N-glycoproteins are two types of glycomolecules whose glycans are structurally complex. They are both assembled and modified within the endomembrane system, i.e., the endoplasmic reticulum (ER and the Golgi apparatus, before their transport to their final locations within or outside the cell. In contrast to extensin, the O-glycan chains of arabinogalactan proteins are highly heterogeneous consisting mostly of (i a short oligo-arabinoside chain of three to four residues, and (ii a larger -1,3-linked galactan backbone with -1,6-linked side chains containing galactose, arabinose and, often, fucose, rhamnose or glucuronic acid. The fine structure of arabinogalactan chains varies between, and within plant species, and is important for the functional activities of the glycoproteins. With regards to N-glycans, ER-synthesizing events are highly conserved in all eukaryotes studied so far since they are essential for efficient protein folding. In contrast, evolutionary adaptation of N-glycan processing in the Golgi apparatus has given rise to a variety of organism-specific complex structures. Therefore, plant complex-type N-glycans contain specific glyco-epitopes such as core 1,2-xylose, core 1,3-fucose residues and Lewisa substitutions on the terminal position of the antenna. Like O-glycans, N-glycans of proteins are essential for their stability and function. Mutants affected in the glycan metabolic pathways have provided valuable information on the role of N-/O-glycoproteins in the control of growth, morphogenesis and adaptation to biotic and abiotic stresses. With regards to O-glycoproteins only extensin and arabinogalactan proteins are considered herein. The biosynthesis of these glycoproteins and functional aspects are presented and discussed in this review.

  19. Genetic Signatures of HIV-1 Envelope-mediated Bystander Apoptosis

    Science.gov (United States)

    Joshi, Anjali; Lee, Raphael T. C.; Mohl, Jonathan; Sedano, Melina; Khong, Wei Xin; Ng, Oon Tek; Maurer-Stroh, Sebastian; Garg, Himanshu

    2014-01-01

    The envelope (Env) glycoprotein of HIV is an important determinant of viral pathogenesis. Several lines of evidence support the role of HIV-1 Env in inducing bystander apoptosis that may be a contributing factor in CD4+ T cell loss. However, most of the studies testing this phenomenon have been conducted with laboratory-adapted HIV-1 isolates. This raises the question of whether primary Envs derived from HIV-infected patients are capable of inducing bystander apoptosis and whether specific Env signatures are associated with this phenomenon. We developed a high throughput assay to determine the bystander apoptosis inducing activity of a panel of primary Envs. We tested 38 different Envs for bystander apoptosis, virion infectivity, neutralizing antibody sensitivity, and putative N-linked glycosylation sites along with a comprehensive sequence analysis to determine if specific sequence signatures within the viral Env are associated with bystander apoptosis. Our studies show that primary Envs vary considerably in their bystander apoptosis-inducing potential, a phenomenon that correlates inversely with putative N-linked glycosylation sites and positively with virion infectivity. By use of a novel phylogenetic analysis that avoids subtype bias coupled with structural considerations, we found specific residues like Arg-476 and Asn-425 that were associated with differences in bystander apoptosis induction. A specific role of these residues was also confirmed experimentally. These data demonstrate for the first time the potential of primary R5 Envs to mediate bystander apoptosis in CD4+ T cells. Furthermore, we identify specific genetic signatures within the Env that may be associated with the bystander apoptosis-inducing phenotype. PMID:24265318

  20. Reduction of a 4q35-encoded nuclear envelope protein in muscle differentiation

    International Nuclear Information System (INIS)

    Ostlund, Cecilia; Guan, Tinglu; Figlewicz, Denise A.; Hays, Arthur P.; Worman, Howard J.; Gerace, Larry; Schirmer, Eric C.

    2009-01-01

    Muscular dystrophy and peripheral neuropathy have been linked to mutations in genes encoding nuclear envelope proteins; however, the molecular mechanisms underlying these disorders remain unresolved. Nuclear envelope protein p19A is a protein of unknown function encoded by a gene at chromosome 4q35. p19A levels are significantly reduced in human muscle as cells differentiate from myoblasts to myotubes; however, its levels are not similarly reduced in all differentiation systems tested. Because 4q35 has been linked to facioscapulohumeral muscular dystrophy (FSHD) and some adjacent genes are reportedly misregulated in the disorder, levels of p19A were analyzed in muscle samples from patients with FSHD. Although p19A was increased in most cases, an absolute correlation was not observed. Nonetheless, p19A downregulation in normal muscle differentiation suggests that in the cases where its gene is inappropriately re-activated it could affect muscle differentiation and contribute to disease pathology.

  1. Reduction of a 4q35-encoded nuclear envelope protein in muscle differentiation

    Energy Technology Data Exchange (ETDEWEB)

    Ostlund, Cecilia [Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Guan, Tinglu [Department of Cell Biology, Scripps Research Institute, La Jolla, CA 92037 (United States); Figlewicz, Denise A. [Department of Neurology, University of Michigan, Ann Arbor, MI 48109 (United States); Hays, Arthur P. [Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Worman, Howard J. [Department of Medicine, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Department of Pathology and Cell Biology, College of Physicians and Surgeons, Columbia University, New York, NY 10032 (United States); Gerace, Larry [Department of Cell Biology, Scripps Research Institute, La Jolla, CA 92037 (United States); Schirmer, Eric C., E-mail: e.schirmer@ed.ac.uk [Department of Cell Biology, Scripps Research Institute, La Jolla, CA 92037 (United States); Wellcome Trust Centre for Cell Biology, University of Edinburgh, Edinburgh EH9 3JR (United Kingdom)

    2009-11-13

    Muscular dystrophy and peripheral neuropathy have been linked to mutations in genes encoding nuclear envelope proteins; however, the molecular mechanisms underlying these disorders remain unresolved. Nuclear envelope protein p19A is a protein of unknown function encoded by a gene at chromosome 4q35. p19A levels are significantly reduced in human muscle as cells differentiate from myoblasts to myotubes; however, its levels are not similarly reduced in all differentiation systems tested. Because 4q35 has been linked to facioscapulohumeral muscular dystrophy (FSHD) and some adjacent genes are reportedly misregulated in the disorder, levels of p19A were analyzed in muscle samples from patients with FSHD. Although p19A was increased in most cases, an absolute correlation was not observed. Nonetheless, p19A downregulation in normal muscle differentiation suggests that in the cases where its gene is inappropriately re-activated it could affect muscle differentiation and contribute to disease pathology.

  2. Computation of Phase Equilibrium and Phase Envelopes

    DEFF Research Database (Denmark)

    Ritschel, Tobias Kasper Skovborg; Jørgensen, John Bagterp

    formulate the involved equations in terms of the fugacity coefficients. We present expressions for the first-order derivatives. Such derivatives are necessary in computationally efficient gradient-based methods for solving the vapor-liquid equilibrium equations and for computing phase envelopes. Finally, we......In this technical report, we describe the computation of phase equilibrium and phase envelopes based on expressions for the fugacity coefficients. We derive those expressions from the residual Gibbs energy. We consider 1) ideal gases and liquids modeled with correlations from the DIPPR database...... and 2) nonideal gases and liquids modeled with cubic equations of state. Next, we derive the equilibrium conditions for an isothermal-isobaric (constant temperature, constant pressure) vapor-liquid equilibrium process (PT flash), and we present a method for the computation of phase envelopes. We...

  3. Boundaries, injective envelopes, and reduced crossed products

    DEFF Research Database (Denmark)

    Bryder, Rasmus Sylvester

    In this dissertation, we study boundary actions, equivariant injective envelopes, as well as theideal structure of reduced crossed products. These topics have recently been linked to thestudy of C-simple groups, that is, groups with simple reduced group C-algebras.In joint work with Matthew Kennedy......, we consider reduced twisted crossed products overC-simple groups. For any twisted C-dynamical system over a C-simple group, we provethat there is a one-to-one correspondence between maximal invariant ideals in the underlyingC-algebra and maximal ideals in the reduced crossed product. When......*-algebras, and relate the intersection property for group actions on unital C*-algebras to the intersection property for theequivariant injective envelope. Moreover, we also prove that the equivariant injective envelopeof the centre of the injective envelope of a unital C*-algebra can be regarded as a C...

  4. Expression of variable viruses as herpes simplex glycoprotein D and varicella zoster gE glycoprotein using a novel plasmid based expression system in insect cell

    Directory of Open Access Journals (Sweden)

    A.M. Al-Sulaiman

    2017-11-01

    Full Text Available Several prokaryotic and eukaryotic expression systems have been used for in vitro production of viruses’ proteins. However eukaryotic expression system was always the first choice for production of proteins that undergo post-translational modification such as glycosylation. Recombinant baculoviruses have been widely used as safe vectors to express heterologous genes in the culture of insect cells, but the manipulation involved in creating, titrating, and amplifying viral stocks make it time consuming and laborious. Therefore, to facilitate rapid expression in insect cell, a plasmid based expression system was used to express herpes simplex type 1 glycoprotein D (HSV-1 gD and varicella zoster glycoprotein E (VZV gE. Recombinant plasmids were generated, transfected into insect cells (SF9, and both glycoproteins were expressed 48 h post-infection. A protein with approximately molecular weight of 64-kDa and 98-kDa for HSV-1 gD and VZV gE respectively was expressed and confirmed by SDS. Proteins were detected in insect cells cytoplasm and outer membrane by immunofluorescence. The antigenicity and immunoreactivity of each protein were confirmed by immunoblot and ELISA. Results suggest that this system can be an alternative to the traditional baculovirus expression for small scale expression system in insect cells.

  5. Isolation of allergenically active glycoprotein from Prosopis juliflora pollen.

    Science.gov (United States)

    Thakur, I S

    1989-03-01

    An allergenically active glycoprotein was homogeneously isolated from the aqueous extract of Prosopis juliflora pollen by ConA-Sepharose affinity chromatography. The molecular weight of this glycoprotein was 20,000 dalton, determined by gel filtration and SDS-PAGE. This fraction showed a total carbohydrate concentration of 25%. The purified glycoprotein revealed immunochemically most antigenic or allergenic and demonstrated homogeneous after reaction with P. juliflora pollen antiserum, characterized by gel diffusion, Immunoelectrophoresis and Radioallergosorbent test.

  6. A study of some Be star envelopes

    International Nuclear Information System (INIS)

    Kitchen, C.R.

    1976-01-01

    The envelope model and emission region radius of six Be stars have been determined from 36 lines on 15 spectra taken with the Isaac Newton telescope. The results have been compared with earlier determinations to search for changes with the time. No definite evidence for such changes has been found, although there may be an indication of a change in phi Per. A re-determination of the errors involved in the method of analysis shows that these are smaller than previously estimated and range from about 9% to 35% for both envelope model and emission region radius. (Auth.)

  7. Asymmetry of the SN 1987A envelope

    International Nuclear Information System (INIS)

    Chugaj, N.N.

    1991-01-01

    The origin of the peculiar structure in the profiles of the emission lines observed in the spectrum of SN 1987A, namely, (1) redshift of maxima, and (2) fine structure of hydrogen lines, is considered. Among the three proposed hypothesis for the redshift, at least two (electron scattering in the spherically-symmetric envelope, and geometrical effects in the fragmented envelope) have serious drawbacks. More favorable is the third hypothesis which invokes asymmetric distribution of 56 Ni and of the iron-peak elements

  8. Radio Imaging of Envelopes of Evolved Stars

    Science.gov (United States)

    Cotton, Bill

    2018-04-01

    This talk will cover imaging of stellar envelopes using radio VLBI techniques; special attention will be paid to the technical differences between radio and optical/IR interferomery. Radio heterodyne receivers allow a straightforward way to derive spectral cubes and full polarization observations. Milliarcsecond resolution of very bright, i.e. non thermal, emission of molecular masers in the envelopes of evolved stars can be achieved using VLBI techniques with baselines of thousands of km. Emission from SiO, H2O and OH masers are commonly seen at increasing distance from the photosphere. The very narrow maser lines allow accurate measurements of the velocity field within the emitting region.

  9. Global Envelope Tests for Spatial Processes

    DEFF Research Database (Denmark)

    Myllymäki, Mari; Mrkvička, Tomáš; Grabarnik, Pavel

    2017-01-01

    Envelope tests are a popular tool in spatial statistics, where they are used in goodness-of-fit testing. These tests graphically compare an empirical function T(r) with its simulated counterparts from the null model. However, the type I error probability α is conventionally controlled for a fixed d......) the construction of envelopes for a deviation test. These new tests allow the a priori selection of the global α and they yield p-values. We illustrate these tests using simulated and real point pattern data....

  10. Global envelope tests for spatial processes

    DEFF Research Database (Denmark)

    Myllymäki, Mari; Mrkvička, Tomáš; Grabarnik, Pavel

    Envelope tests are a popular tool in spatial statistics, where they are used in goodness-of-fit testing. These tests graphically compare an empirical function T(r) with its simulated counterparts from the null model. However, the type I error probability α is conventionally controlled for a fixed......) the construction of envelopes for a deviation test. These new tests allow the a priori selection of the global α and they yield p-values. We illustrate these tests using simulated and real point pattern data....

  11. Retention and topology of the bovine viral diarrhea virus glycoprotein E2.

    Science.gov (United States)

    Radtke, Christina; Tews, Birke Andrea

    2017-10-01

    Pestiviruses are enveloped viruses that bud intracellularly. They have three envelope glycoproteins, E rns , E1, and E2. E2 is the receptor binding protein and the main target for neutralizing antibodies. Both E rns and E2 are retained intracellularly. Here, E2 of the bovine viral diarrhea virus (BVDV) strain CP7 was used to study the membrane topology and intracellular localization of the protein. E2 is localized in the ER and there was no difference between E2 expressed alone or in the context of the viral polyprotein. The mature E2 protein was found to possess a single span transmembrane anchor. For the mapping of a retention signal CD72-E2 fusion proteins, as well as E2 alone were analysed. This confirmed the importance of the transmembrane domain and arginine 355 for intracellular retention, but also revealed a modulating effect on retention through the cytoplasmic tail of the E2 protein, especially through glutamine 370. Mutants with a strong impact on retention were tested in the viral context and we were able to rescue BVDV with certain mutations that in E2 alone impaired intracellular retention and lead to export of E2 to the cells surface.

  12. Isolation of antigenic substances from HIV-1 envelope gp160 gene transfectants by mild acid elution and X-irradiation treatment. For the development of CTL-based immunotherapy

    International Nuclear Information System (INIS)

    Fujimoto, Chiaki; Nakagawa, Yohko; Shimizu, Masumi; Ohara, Kunitoshi; Takahashi, Hidemi

    2003-01-01

    Cytotoxic T lymphocytes (CTLs) play a central role in a broad spectrum of tumor immunity. Such CTLs generally recognize processed antigenic fragments in association with class I major histocompatibility complex (MHC) molecules. Thus, it is important to identify naturally processed antigens associated with class I MHC molecules to generate and activate antigen-specific CTLs. Those processed antigens fitted in the groove of class I MHC molecules are fixed by the β2-microglobulin. Mild acid elution is one method used to isolate antigenic fragments from class I MHC molecules on tumor cells by unfastening a clasp of β2-microglobulin, a critical component for stabilizing class I MHC molecules on the cell surface. Indeed, after the mild acid treatment, the expression of class I MHC molecules was temporarily down-modulated and a strong antigenic fraction for CTL recognition was obtained. To our surprise, such down-modulation of class I MHC molecule expression was also observed when the tumor cells were irradiated. Therefore, using human immunodeficiency virus type I (HIV-1) gp160 env gene transfectants, we examined the effect of X-irradiation on releasing the loaded antigenic fragments. Functional extracts were obtained from X-irradiated cell supernatants that sensitized syngeneic fibroblasts for specific CTL recognition, suggesting that X-irradiation extracts would also contain known antigenic epitopes. These results indicate that, in addition to the conventional mild acid elution treatment, X-irradiation method shown in this paper may provide a new approach for CTL-based vaccine development via isolating antigenic molecules from various tumors or virally infected cells. (author)

  13. Resting lymphocyte transduction with measles virus glycoprotein pseudotyped lentiviral vectors relies on CD46 and SLAM

    International Nuclear Information System (INIS)

    Zhou Qi; Schneider, Irene C.; Gallet, Manuela; Kneissl, Sabrina; Buchholz, Christian J.

    2011-01-01

    The measles virus (MV) glycoproteins hemagglutinin (H) and fusion (F) were recently shown to mediate transduction of resting lymphocytes by lentiviral vectors. MV vaccine strains use CD46 or signaling lymphocyte activation molecule (SLAM) as receptor for cell entry. A panel of H protein mutants derived from vaccine strain or wild-type MVs that lost or gained CD46 or SLAM receptor usage were investigated for their ability to mediate gene transfer into unstimulated T lymphocytes. The results demonstrate that CD46 is sufficient for efficient vector particle association with unstimulated lymphocytes. For stable gene transfer into these cells, however, both MV receptors were found to be essential.

  14. Synthesis of Structures Related to Antifreeze Glycoproteins

    OpenAIRE

    Fyrner, Timmy

    2005-01-01

    In this thesis, synthesis of structures related to antifreeze glycoproteins (AFGPs) are presented. Synthetic routes to a protected carbohydrate derivative, 2,3,4,6-tetra-O-benzyl-β-galactopyranosyl-(1→3)-2-deoxy-2-azido-4,6-di-O-benzyl-β-D-thio-1-galactopyranoside, and a tBu-Ala-Thr-Ala-Fmoc tripeptide, are described. These compounds are meant to be used in the assembly of AFGPs and analogues thereof. A Gal-GlcN disaccharide was synthesized via glycosylation between the donor, bromo-2-O-benzo...

  15. Podoplanin - a small glycoprotein with many faces

    OpenAIRE

    Ugorski, Maciej; Dziegiel, Piotr; Suchanski, Jaroslaw

    2016-01-01

    Podoplanin is a small membrane glycoprotein with a large number of O-glycoside chains and therefore it belongs to mucin-type proteins. It can be found on the surface of many types of normal cells originating from various germ layers. It is present primarily on the endothelium of lymphatic vessels, type I pneumocytes and glomerular podocytes. Increased levels of podoplanin or its neo-expression have been found in numerous types of human carcinomas, but it is especially common in squamous cell ...

  16. Glycoprotein component of plant cell walls

    International Nuclear Information System (INIS)

    Cooper, J.B.; Chen, J.A.; Varner, J.E.

    1984-01-01

    The primary wall surrounding most dicotyledonous plant cells contains a hydroxyproline-rich glycoprotein (HRGP) component named extensin. A small group of glycopeptides solubilized from isolated cell walls by proteolysis contained a repeated pentapeptide glycosylated by tri- and tetraarabinosides linked to hydroxyproline and, by galactose, linked to serine. Recently, two complementary approaches to this problem have provided results which greatly increase the understanding of wall extensin. In this paper the authors describe what is known about the structure of soluble extensin secreted into the walls of the carrot root cells

  17. Integrated Energy Design of the Building Envelope

    DEFF Research Database (Denmark)

    Nielsen, Martin Vraa

    This thesis describes the outcome of the PhD project Integrated energy design of the building envelope carried out through a combination of scientific dissemination reported through peer-reviewed journals and a wide range of affiliated projects involved in at an architectural firm. The research...

  18. SAFEGUARDS ENVELOPE: PREVIOUS WORK AND EXAMPLES

    International Nuclear Information System (INIS)

    Metcalf, Richard; Bevill, Aaron; Charlton, William; Bean, Robert

    2008-01-01

    The future expansion of nuclear power will require not just electricity production but fuel cycle facilities such as fuel fabrication and reprocessing plants. As large reprocessing facilities are built in various states, they must be built and operated in a manner to minimize the risk of nuclear proliferation. Process monitoring has returned to the spotlight as an added measure that can increase confidence in the safeguards of special nuclear material (SNM). Process monitoring can be demonstrated to lengthen the allowable inventory period by reducing accountancy requirements, and to reduce the false positive indications. The next logical step is the creation of a Safeguards Envelope, a set of operational parameters and models to maximize anomaly detection and inventory period by process monitoring while minimizing operator impact and false positive rates. A brief example of a rudimentary Safeguards Envelope is presented, and shown to detect synthetic diversions overlaying a measured processing plant data set. This demonstration Safeguards Envelope is shown to increase the confidence that no SNM has been diverted with minimal operator impact, even though it is based on an information sparse environment. While the foundation on which a full Safeguards Envelope can be built has been presented in historical demonstrations of process monitoring, several requirements remain yet unfulfilled. Future work will require reprocessing plant transient models, inclusion of 'non-traditional' operating data, and exploration of new methods of identifying subtle events in transient processes

  19. Multi-layered breathing architectural envelope

    DEFF Research Database (Denmark)

    Lund Larsen, Andreas; Foged, Isak Worre; Jensen, Rasmus Lund

    2014-01-01

    A multi layered breathing envelope is developed as a method of natural ventilation. The two main layers consist of mineral wool and air permeable concrete. The mineral wool works as a dynamic insulation and the permeable concrete as a heat recovery system with a high thermal mass for heat storage...

  20. Cost Allocation and Convex Data Envelopment

    DEFF Research Database (Denmark)

    Hougaard, Jens Leth; Tind, Jørgen

    such as Data Envelopment Analysis (DEA). The convexity constraint of the BCC model introduces a non-zero slack in the objective function of the multiplier problem and we show that the cost allocation rules discussed in this paper can be used as candidates to allocate this slack value on to the input (or output...

  1. The Purification of a Blood Group A Glycoprotein: An Affinity Chromatography Experiment.

    Science.gov (United States)

    Estelrich, J.; Pouplana, R.

    1988-01-01

    Describes a purification process through affinity chromatography necessary to obtain specific blood group glycoproteins from erythrocytic membranes. Discusses the preparation of erythrocytic membranes, extraction of glycoprotein from membranes, affinity chromatography purification, determination of glycoproteins, and results. (CW)

  2. Moisture accumulation in a building envelope

    Energy Technology Data Exchange (ETDEWEB)

    Forest, T.W.; Checkwitch, K.

    1988-09-01

    In a large number of cases, the failure of a building envelope can be traced to the accumulation of moisture. In a cold winter climate, characteristic of the Canadian prairies, moisture is deposited in the structure by the movement of warm, moist air through the envelope. Tests on the moisture accumulation in a building envelope were initiated in a test house at an Alberta research facility during the 1987/88 heating season. The indoor moisture generation rate was measured and compared with the value inferred from the measured air infiltration rate. With the flue open, the moisture generation rate was approximately 5.5 kg/d of which 0.7 kg/d entered the building envelope; the remainder was exhausted through the flue. With the flue blocked, the moisture generation rate decreased to 3.4 kg/d, while the amount of moisture migrating through the envelope increased to 4.0 kg/d. The moisture accumulation in wall panels located on the north and south face of the test house was also monitored. Moisture was allowed to enter the wall cavity via a hole in the drywall. The fiberglass insulation remained dry throughout the test period. The moisture content of the exterior sheathing of the north panel increased to a maximum of 18% wt in the vicinity of the hole, but quickly dried when the ambient temperatures increased towards the end of the season. The south panel showed very little moisture accumlation due to the effects of solar radiation. 14 refs., 9 figs.

  3. Validating predictions from climate envelope models.

    Directory of Open Access Journals (Sweden)

    James I Watling

    Full Text Available Climate envelope models are a potentially important conservation tool, but their ability to accurately forecast species' distributional shifts using independent survey data has not been fully evaluated. We created climate envelope models for 12 species of North American breeding birds previously shown to have experienced poleward range shifts. For each species, we evaluated three different approaches to climate envelope modeling that differed in the way they treated climate-induced range expansion and contraction, using random forests and maximum entropy modeling algorithms. All models were calibrated using occurrence data from 1967-1971 (t1 and evaluated using occurrence data from 1998-2002 (t2. Model sensitivity (the ability to correctly classify species presences was greater using the maximum entropy algorithm than the random forest algorithm. Although sensitivity did not differ significantly among approaches, for many species, sensitivity was maximized using a hybrid approach that assumed range expansion, but not contraction, in t2. Species for which the hybrid approach resulted in the greatest improvement in sensitivity have been reported from more land cover types than species for which there was little difference in sensitivity between hybrid and dynamic approaches, suggesting that habitat generalists may be buffered somewhat against climate-induced range contractions. Specificity (the ability to correctly classify species absences was maximized using the random forest algorithm and was lowest using the hybrid approach. Overall, our results suggest cautious optimism for the use of climate envelope models to forecast range shifts, but also underscore the importance of considering non-climate drivers of species range limits. The use of alternative climate envelope models that make different assumptions about range expansion and contraction is a new and potentially useful way to help inform our understanding of climate change effects on

  4. Validating predictions from climate envelope models

    Science.gov (United States)

    Watling, J.; Bucklin, D.; Speroterra, C.; Brandt, L.; Cabal, C.; Romañach, Stephanie S.; Mazzotti, Frank J.

    2013-01-01

    Climate envelope models are a potentially important conservation tool, but their ability to accurately forecast species’ distributional shifts using independent survey data has not been fully evaluated. We created climate envelope models for 12 species of North American breeding birds previously shown to have experienced poleward range shifts. For each species, we evaluated three different approaches to climate envelope modeling that differed in the way they treated climate-induced range expansion and contraction, using random forests and maximum entropy modeling algorithms. All models were calibrated using occurrence data from 1967–1971 (t1) and evaluated using occurrence data from 1998–2002 (t2). Model sensitivity (the ability to correctly classify species presences) was greater using the maximum entropy algorithm than the random forest algorithm. Although sensitivity did not differ significantly among approaches, for many species, sensitivity was maximized using a hybrid approach that assumed range expansion, but not contraction, in t2. Species for which the hybrid approach resulted in the greatest improvement in sensitivity have been reported from more land cover types than species for which there was little difference in sensitivity between hybrid and dynamic approaches, suggesting that habitat generalists may be buffered somewhat against climate-induced range contractions. Specificity (the ability to correctly classify species absences) was maximized using the random forest algorithm and was lowest using the hybrid approach. Overall, our results suggest cautious optimism for the use of climate envelope models to forecast range shifts, but also underscore the importance of considering non-climate drivers of species range limits. The use of alternative climate envelope models that make different assumptions about range expansion and contraction is a new and potentially useful way to help inform our understanding of climate change effects on species.

  5. A novel family of plant nuclear envelope-associated proteins.

    Science.gov (United States)

    Pawar, Vidya; Poulet, Axel; Détourné, Gwénaëlle; Tatout, Christophe; Vanrobays, Emmanuel; Evans, David E; Graumann, Katja

    2016-10-01

    This paper describes the characterisation of a new family of higher plant nuclear envelope-associated proteins (NEAPs) that interact with other proteins of the nuclear envelope. In the model plant Arabidopsis thaliana, the family consists of three genes expressed ubiquitously (AtNEAP1-3) and a pseudogene (AtNEAP4). NEAPs consist of extensive coiled-coil domains, followed by a nuclear localisation signal and a C-terminal predicted transmembrane domain. Domain deletion mutants confirm the presence of a functional nuclear localisation signal and transmembrane domain. AtNEAP proteins localise to the nuclear periphery as part of stable protein complexes, are able to form homo- and heteromers, and interact with the SUN domain proteins AtSUN1 and AtSUN2, involved in the linker of nucleoskeleton and cytoskeleton (LINC) complex. An A. thaliana cDNA library screen identified a putative transcription factor called AtbZIP18 as a novel interactor of AtNEAP1, which suggest a connection between NEAP and chromatin. An Atneap1 Atneap3 double-knockout mutant showed reduced root growth, and altered nuclear morphology and chromatin structure. Thus AtNEAPs are suggested as inner nuclear membrane-anchored coiled-coil proteins with roles in maintaining nuclear morphology and chromatin structure. © The Author 2016. Published by Oxford University Press on behalf of the Society for Experimental Biology. All rights reserved. For permissions, please email: journals.permissions@oup.com.

  6. Glycan shield and fusion activation of a deltacoronavirus spike glycoprotein fine-tuned for enteric infections.

    Science.gov (United States)

    Xiong, Xiaoli; Tortorici, M Alejandra; Snijder, Joost; Yoshioka, Craig; Walls, Alexandra C; Li, Wentao; McGuire, Andrew T; Rey, Félix A; Bosch, Berend-Jan; Veesler, David

    2017-11-01

    Coronaviruses recently emerged as major human pathogens causing outbreaks of severe acute respiratory syndrome and Middle-East respiratory syndrome. They utilize the spike (S) glycoprotein anchored in the viral envelope to mediate host attachment and fusion of the viral and cellular membranes to initiate infection. The S protein is a major determinant of the zoonotic potential of coronaviruses and is also the main target of the host humoral immune response. We report here the 3.5 Å resolution cryo-electron microscopy structure of the S glycoprotein trimer from the pathogenic porcine deltacoronavirus (PDCoV), which belongs to the recently identified delta genus. Structural and glycoproteomics data indicate that the glycans of PDCoV S are topologically conserved when compared with the human respiratory coronavirus HCoV-NL63 S, resulting in similar surface areas being shielded from neutralizing antibodies and implying that both viruses are under comparable immune pressure in their respective hosts. The structure further reveals a shortened S 2 ' activation loop, containing a reduced number of basic amino acids, which participates to rendering the spike largely protease-resistant. This property distinguishes PDCoV S from recently characterized betacoronavirus S proteins and suggests that the S protein of enterotropic PDCoV has evolved to tolerate the protease-rich environment of the small intestine and to fine-tune its fusion activation to avoid premature triggering and reduction of infectivity. IMPORTANCE Coronaviruses use transmembrane spike (S) glycoprotein trimers to promote host attachment and fusion of the viral and cellular membranes. We determined a near-atomic resolution cryo-electron microscopy structure of the S ectodomain trimer from the pathogenic porcine deltacoronavirus (PDCoV), which is responsible for diarrhea in piglets and has had devastating consequences for the swine industry worldwide. Structural and glycoproteomics data reveal that PDCoV S is

  7. Membrane glycoproteins of differentiating skeletal muscle cells

    International Nuclear Information System (INIS)

    Miller, K.R.; Remy, C.N.; Smith, P.B.

    1987-01-01

    The composition of N-linked glycoprotein oligosaccharides was studied in myoblasts and myotubes of the C2 muscle cell line. Oligosaccharides were radioactively labelled for 15 hr with [ 3 H] mannose and plasma membranes isolated. Ten glycopeptides were detected by SDS-PAGE and fluorography. The extent of labelling was 4-6 fold greater in myoblasts vs myotubes. A glycopeptide of Mr > 100,000 was found exclusively in myoblast membranes. Lectin chromatography revealed that the proportion of tri-, tetranntenary, biantennary and high mannose chains was similar throughout differentiation. The high mannose chain fraction was devoid of hybrid chains. The major high mannose chain contained nine mannose residues. The higher level of glycopeptide labelling in myoblasts vs myotubes corresponded to a 5-fold greater rate of protein synthesis. Pulse-chase experiments were used to follow the synthesis of the Dol-oligosaccharides. Myoblasts and myotubes labelled equivalently the glucosylated tetradecasaccharide but myoblasts labelled the smaller intermediates 3-4 greater than myotubes. Myoblasts also exhibited a 2-3 fold higher Dol-P dependent glycosyl transferase activity for chain elongation and Dol-sugar synthesis. Together these results show that the degree of protein synthesis and level of Dol-P are contributing factors in the higher capacity of myoblasts to produce N-glycoproteins compared to myotubes

  8. Annotating Human P-Glycoprotein Bioassay Data.

    Science.gov (United States)

    Zdrazil, Barbara; Pinto, Marta; Vasanthanathan, Poongavanam; Williams, Antony J; Balderud, Linda Zander; Engkvist, Ola; Chichester, Christine; Hersey, Anne; Overington, John P; Ecker, Gerhard F

    2012-08-01

    Huge amounts of small compound bioactivity data have been entering the public domain as a consequence of open innovation initiatives. It is now the time to carefully analyse existing bioassay data and give it a systematic structure. Our study aims to annotate prominent in vitro assays used for the determination of bioactivities of human P-glycoprotein inhibitors and substrates as they are represented in the ChEMBL and TP-search open source databases. Furthermore, the ability of data, determined in different assays, to be combined with each other is explored. As a result of this study, it is suggested that for inhibitors of human P-glycoprotein it is possible to combine data coming from the same assay type, if the cell lines used are also identical and the fluorescent or radiolabeled substrate have overlapping binding sites. In addition, it demonstrates that there is a need for larger chemical diverse datasets that have been measured in a panel of different assays. This would certainly alleviate the search for other inter-correlations between bioactivity data yielded by different assay setups.

  9. Novel Real-Time Flight Envelope Monitoring System, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — The proposed innovation is an aircraft flight envelope monitoring system that will provide real-time in-cockpit estimations of aircraft flight envelope boundaries....

  10. Ammonia transport in the kidney by Rhesus glycoproteins

    Science.gov (United States)

    Verlander, Jill W.

    2014-01-01

    Renal ammonia metabolism is a fundamental element of acid-base homeostasis, comprising a major component of both basal and physiologically altered renal net acid excretion. Over the past several years, a fundamental change in our understanding of the mechanisms of renal epithelial cell ammonia transport has occurred, replacing the previous model which was based upon diffusion equilibrium for NH3 and trapping of NH4+ with a new model in which specific and regulated transport of both NH3 and NH4+ across renal epithelial cell membranes via specific membrane proteins is required for normal ammonia metabolism. A major advance has been the recognition that members of a recently recognized transporter family, the Rhesus glycoprotein family, mediate critical roles in renal and extrarenal ammonia transport. The erythroid-specific Rhesus glycoprotein, Rh A Glycoprotein (Rhag), was the first Rhesus glycoprotein recognized as an ammonia-specific transporter. Subsequently, the nonerythroid Rh glycoproteins, Rh B Glycoprotein (Rhbg) and Rh C Glycoprotein (Rhcg), were cloned and identified as ammonia transporters. They are expressed in specific cell populations and membrane domains in distal renal epithelial cells, where they facilitate ammonia secretion. In this review, we discuss the distribution of Rhbg and Rhcg in the kidney, the regulation of their expression and activity in physiological disturbances, the effects of genetic deletion on renal ammonia metabolism, and the molecular mechanisms of Rh glycoprotein-mediated ammonia transport. PMID:24647713

  11. Gene

    Data.gov (United States)

    U.S. Department of Health & Human Services — Gene integrates information from a wide range of species. A record may include nomenclature, Reference Sequences (RefSeqs), maps, pathways, variations, phenotypes,...

  12. An improved radioimmunoassay for urinary Tamm-Horsfall glycoprotein

    International Nuclear Information System (INIS)

    Dawnay, A.B. St. J.; Thornley, C.; Cattell, W.R.

    1982-01-01

    A rapid specific radioimmunoassay has been used to measure Tamm-Horsfall glycoprotein (TH glycoprotein) in urine, and the method described. The apparent concentration increased with increasing dilution of urine in water, reaching a plateau at 1 in 20. This increase was greater the higher the osmolality and TH glycoprotein concentration and the lower the pH of the original sample. The apparent concentration of TH glycoprotein in neat or diluted urine was not affected by freezing or by storage at 4 0 C or room temperature for at least 2 days. A physiological range for the urinary excretion rate was established as 22-56 mg/24h, (considerably higher than the amount present in serum) based on samples from 29 individuals with normal renal function, as defined by their creatinine clearance. There was no significant correlation between serum concentrations of TH glycoprotein and its urinary excretion rate, nor between urinary excretion rate and creatinine clearance. (author)

  13. Inversion of Auditory Spectrograms, Traditional Spectrograms, and Other Envelope Representations

    DEFF Research Database (Denmark)

    Decorsière, Remi Julien Blaise; Søndergaard, Peter Lempel; MacDonald, Ewen

    2015-01-01

    Envelope representations such as the auditory or traditional spectrogram can be defined by the set of envelopes from the outputs of a filterbank. Common envelope extraction methods discard information regarding the fast fluctuations, or phase, of the signal. Thus, it is difficult to invert, or re...... to the framework is proposed, which leads to a more accurate inversion of traditional spectrograms...

  14. 200 Area Deactivation Project Facilities Authorization Envelope Document

    International Nuclear Information System (INIS)

    DODD, E.N.

    2000-01-01

    Project facilities as required by HNF-PRO-2701, Authorization Envelope and Authorization Agreement. The Authorization Agreements (AA's) do not identify the specific set of environmental safety and health requirements that are applicable to the facility. Therefore, the facility Authorization Envelopes are defined here to identify the applicable requirements. This document identifies the authorization envelopes for the 200 Area Deactivation

  15. 14 CFR 27.87 - Height-speed envelope.

    Science.gov (United States)

    2010-01-01

    ... applicable power failure condition in paragraph (b) of this section, a limiting height-speed envelope must be... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Height-speed envelope. 27.87 Section 27.87... STANDARDS: NORMAL CATEGORY ROTORCRAFT Flight Performance § 27.87 Height-speed envelope. (a) If there is any...

  16. 14 CFR 29.87 - Height-velocity envelope.

    Science.gov (United States)

    2010-01-01

    ... Category A engine isolation requirements, the height-velocity envelope for complete power failure must be... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Height-velocity envelope. 29.87 Section 29... AIRWORTHINESS STANDARDS: TRANSPORT CATEGORY ROTORCRAFT Flight Performance § 29.87 Height-velocity envelope. (a...

  17. Analysis of Building Envelope Construction in 2003 CBECS

    Energy Technology Data Exchange (ETDEWEB)

    Winiarski, David W.; Halverson, Mark A.; Jiang, Wei

    2007-06-01

    The purpose of this analysis is to determine "typical" building envelope characteristics for buildings built after 1980. We address three envelope components in this paper - roofs, walls, and window area. These typical building envelope characteristics were used in the development of DOE’s Reference Buildings .

  18. Structural and Functional Studies on the Fusion and Attachment Envelope Glycoproteins of Nipah Virus and Hendra Virus

    National Research Council Canada - National Science Library

    Bossart, Katharine

    2003-01-01

    Nipah virus (NiV) and Hendra (HeV) virus are emerging, biosafety level 4 paramyxoviruses responsible for fatal zoonotic infections of humans from pigs and horses, respectively, and are the prototypic members of a new Paramyxovirinae...

  19. Structural and Functional Studies on the Fusion and Attachment Envelope Glycoproteins of Nipah Virus and Hendra Virus

    Science.gov (United States)

    2003-01-01

    including measles virus (MeV), mumps virus, Sendai virus (SeV), Newcastle disease virus (NDV), rinderpest virus, canine distemper virus (CDV), human...Institute of Health, Bethesda, MD. Hut 102, MT2, MT4, and CEM human T cell lines were provided by Chou-Zen Giam, USUHS, Bethesda, MD. The human osteosarcoma

  20. The role of proteolytic processing and the stable signal peptide in expression of the Old World arenavirus envelope glycoprotein ectodomain

    International Nuclear Information System (INIS)

    Burri, Dominique J.; Pasquato, Antonella; Ramos da Palma, Joel; Igonet, Sebastien; Oldstone, Michael B.A.; Kunz, Stefan

    2013-01-01

    Maturation of the arenavirus GP precursor (GPC) involves proteolytic processing by cellular signal peptidase and the proprotein convertase subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P), yielding a tripartite complex comprised of a stable signal peptide (SSP), the receptor-binding GP1, and the fusion-active transmembrane GP2. Here we investigated the roles of SKI-1/S1P processing and SSP in the biosynthesis of the recombinant GP ectodomains of lymphocytic choriomeningitis virus (LCMV) and Lassa virus (LASV). When expressed in mammalian cells, the LCMV and LASV GP ectodomains underwent processing by SKI-1/S1P, followed by dissociation of GP1 from GP2. The GP2 ectodomain spontaneously formed trimers as revealed by chemical cross-linking. The endogenous SSP, known to be crucial for maturation and transport of full-length arenavirus GPC was dispensable for processing and secretion of the soluble GP ectodomain, suggesting a specific role of SSP in the stable prefusion conformation and transport of full-length GPC.

  1. The role of proteolytic processing and the stable signal peptide in expression of the Old World arenavirus envelope glycoprotein ectodomain

    Energy Technology Data Exchange (ETDEWEB)

    Burri, Dominique J.; Pasquato, Antonella; Ramos da Palma, Joel [Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011 (Switzerland); Igonet, Sebastien; Oldstone, Michael B.A. [Department of Immunology and Microbial Science, The Scripps Research Institute, La Jolla, CA 92037 (United States); Kunz, Stefan, E-mail: Stefan.Kunz@chuv.ch [Institute of Microbiology, University Hospital Center and University of Lausanne, Lausanne CH-1011 (Switzerland)

    2013-02-05

    Maturation of the arenavirus GP precursor (GPC) involves proteolytic processing by cellular signal peptidase and the proprotein convertase subtilisin kexin isozyme 1 (SKI-1)/site 1 protease (S1P), yielding a tripartite complex comprised of a stable signal peptide (SSP), the receptor-binding GP1, and the fusion-active transmembrane GP2. Here we investigated the roles of SKI-1/S1P processing and SSP in the biosynthesis of the recombinant GP ectodomains of lymphocytic choriomeningitis virus (LCMV) and Lassa virus (LASV). When expressed in mammalian cells, the LCMV and LASV GP ectodomains underwent processing by SKI-1/S1P, followed by dissociation of GP1 from GP2. The GP2 ectodomain spontaneously formed trimers as revealed by chemical cross-linking. The endogenous SSP, known to be crucial for maturation and transport of full-length arenavirus GPC was dispensable for processing and secretion of the soluble GP ectodomain, suggesting a specific role of SSP in the stable prefusion conformation and transport of full-length GPC.

  2. Essential Bacillus subtilis genes

    DEFF Research Database (Denmark)

    Kobayashi, K.; Ehrlich, S.D.; Albertini, A.

    2003-01-01

    To estimate the minimal gene set required to sustain bacterial life in nutritious conditions, we carried out a systematic inactivation of Bacillus subtilis genes. Among approximate to4,100 genes of the organism, only 192 were shown to be indispensable by this or previous work. Another 79 genes were...... predicted to be essential. The vast majority of essential genes were categorized in relatively few domains of cell metabolism, with about half involved in information processing, one-fifth involved in the synthesis of cell envelope and the determination of cell shape and division, and one-tenth related...... to cell energetics. Only 4% of essential genes encode unknown functions. Most essential genes are present throughout a wide range of Bacteria, and almost 70% can also be found in Archaea and Eucarya. However, essential genes related to cell envelope, shape, division, and respiration tend to be lost from...

  3. Equivariant calculus in the differential envelope

    International Nuclear Information System (INIS)

    Kastler, D.

    1991-01-01

    The author shows how Z/2-graded cyclic cohomology is related to the equivariant calculus of S. Klimek, W. Kondracki, and A. Lesniewski (HUTMP 90/B247 (1990)). He uses the differential envelope of a complex unital differential algebra. After a presentation of fiber-preserved operators on equivariant functions valued in this algebra on a group he considers certain operators on this algebra. Finally he discusses explicitly the case G=Z/2. (HSI)

  4. Equivariant calculus in the differential envelope

    Energy Technology Data Exchange (ETDEWEB)

    Kastler, D. (Centre National de la Recherche Scientifique, 13 - Marseille (France). Centre de Physique Theorique)

    1991-01-01

    The author shows how Z/2-graded cyclic cohomology is related to the equivariant calculus of S. Klimek, W. Kondracki, and A. Lesniewski (HUTMP 90/B247 (1990)). He uses the differential envelope of a complex unital differential algebra. After a presentation of fiber-preserved operators on equivariant functions valued in this algebra on a group he considers certain operators on this algebra. Finally he discusses explicitly the case G=Z/2. (HSI).

  5. Digital image envelope: method and evaluation

    Science.gov (United States)

    Huang, H. K.; Cao, Fei; Zhou, Michael Z.; Mogel, Greg T.; Liu, Brent J.; Zhou, Xiaoqiang

    2003-05-01

    Health data security, characterized in terms of data privacy, authenticity, and integrity, is a vital issue when digital images and other patient information are transmitted through public networks in telehealth applications such as teleradiology. Mandates for ensuring health data security have been extensively discussed (for example The Health Insurance Portability and Accountability Act, HIPAA) and health informatics guidelines (such as the DICOM standard) are beginning to focus on issues of data continue to be published by organizing bodies in healthcare; however, there has not been a systematic method developed to ensure data security in medical imaging Because data privacy and authenticity are often managed primarily with firewall and password protection, we have focused our research and development on data integrity. We have developed a systematic method of ensuring medical image data integrity across public networks using the concept of the digital envelope. When a medical image is generated regardless of the modality, three processes are performed: the image signature is obtained, the DICOM image header is encrypted, and a digital envelope is formed by combining the signature and the encrypted header. The envelope is encrypted and embedded in the original image. This assures the security of both the image and the patient ID. The embedded image is encrypted again and transmitted across the network. The reverse process is performed at the receiving site. The result is two digital signatures, one from the original image before transmission, and second from the image after transmission. If the signatures are identical, there has been no alteration of the image. This paper concentrates in the method and evaluation of the digital image envelope.

  6. The cell envelope glycoconjugates of Mycobacterium tuberculosis

    Science.gov (United States)

    Angala, Shiva Kumar; Belardinelli, Juan Manuel; Huc-Claustre, Emilie; Wheat, William H.; Jackson, Mary

    2015-01-01

    Tuberculosis (TB) remains the second most common cause of death due to a single infectious agent. The cell envelope of Mycobacterium tuberculosis (Mtb), the causative agent of the disease in humans, is a source of unique glycoconjugates and the most distinctive feature of the biology of this organism. It is the basis of much of Mtb pathogenesis and one of the major causes of its intrinsic resistance to chemotherapeutic agents. At the same time, the unique structures of Mtb cell envelope glycoconjugates, their antigenicity and essentiality for mycobacterial growth provide opportunities for drug, vaccine, diagnostic and biomarker development, as clearly illustrated by recent advances in all of these translational aspects. This review focuses on our current understanding of the structure and biogenesis of Mtb glycoconjugates with particular emphasis on one of most intriguing and least understood aspect of the physiology of mycobacteria: the translocation of these complex macromolecules across the different layers of the cell envelope. It further reviews the rather impressive progress made in the last ten years in the discovery and development of novel inhibitors targeting their biogenesis. PMID:24915502

  7. Spectral envelope sensitivity of musical instrument sounds.

    Science.gov (United States)

    Gunawan, David; Sen, D

    2008-01-01

    It is well known that the spectral envelope is a perceptually salient attribute in musical instrument timbre perception. While a number of studies have explored discrimination thresholds for changes to the spectral envelope, the question of how sensitivity varies as a function of center frequency and bandwidth for musical instruments has yet to be addressed. In this paper a two-alternative forced-choice experiment was conducted to observe perceptual sensitivity to modifications made on trumpet, clarinet and viola sounds. The experiment involved attenuating 14 frequency bands for each instrument in order to determine discrimination thresholds as a function of center frequency and bandwidth. The results indicate that perceptual sensitivity is governed by the first few harmonics and sensitivity does not improve when extending the bandwidth any higher. However, sensitivity was found to decrease if changes were made only to the higher frequencies and continued to decrease as the distorted bandwidth was widened. The results are analyzed and discussed with respect to two other spectral envelope discrimination studies in the literature as well as what is predicted from a psychoacoustic model.

  8. Protein and Glycoprotein Patterns Related to Morphogenesis in Mammillaria gracillis Pfeiff. Tissue Culture

    Directory of Open Access Journals (Sweden)

    Biljana Balen

    2002-01-01

    Full Text Available As plants with Crassulacean Acid Metabolism (CAM, cacti are highly affected by artificial environmental conditions in tissue culture. Plants of Mammillaria gracillis Pfeiff. (Cactaceae propagated in vitro produced callus spontaneously. This habituated callus regenerated normal and hyperhydric shoots without the addition of growth regulators. In order to compare habituated callus with the tumorous one, cactus cells were transformed with two strains of Agrobacterium tumefaciens: the wild strain B6S3 (tumour line TW and the rooty mutant GV3101 (tumour line TR. Gene expression in cactus plants, habituated callus, regenerated shoots and two tumour lines was analysed at the level of cellular and extracellular protein and glycoprotein profiles. Proteins were separated by SDS-polyacrylamide gel electrophoresis and 2-D PAGE electrophoresis and silver stained. Concavalin A-peroxidase staining detected glycoproteins with D-manose in their glycan component on protein blots. Developmentally specific protein patterns of Mammillaria gracillis tissue lines were detected. The 2-D PAGE electrophoresis revealed some tissue specific protein groups. The cellular glycoprotein of 42 kDa detected by ConA was highly expressed in undifferentiated tissues (habituated callus, TW and TR tumours and in hyperhydric regenerants. Tumours produced extracellular proteins of 33, 23 and 22 kDa. The N glycosylation of cellular and extracellular proteins was related to specific developmental stage of cactus tissue.

  9. O-linked glycosylation of retroviral envelope gene products

    Energy Technology Data Exchange (ETDEWEB)

    Pinter, A.; Honnen, W.J. (Public Health Research Institute of the City of New York Inc., NY (USA))

    1988-03-01

    Treatment of ({sup 3}H)glucosamine-labeled Friend mink cell focus-forming virus (FrMCF) gp70 with excess peptide:N-glycanase F (PNGase F) resulted in removal of the expected seven N-linked oligosaccharide chains; however, approximately 10% of the glucosamine label was retained in the resulting 49,000-M{sub r} (49K) product. For ({sup 3}H)mannose-labeled gp70, similar treatment led to removal of all the carbohydrate label from the protein. Prior digestion of the PNGase F-treated gp70 with neuraminidase resulted in an addition size shift, and treatment with O-glycanase led to the removal of almost all of the PNGase F-resistant sugars. These results indicate that gp70 possesses sialic acid-containing O-linked oligosaccharides. Analysis of intracellular env precursors demonstrated that O-linked sugars were present in gPr90{sup env}, the polyprotein intermediate which contains complex sugars, but not in the primary translation product, gPr80{sup env}, and proteolytic digestion studies allowed localization of the O-linked carbohydrates to a 10K region near the center of the gp70 molecule. similar substituents were detected on the gp70s of ecotropic and xenotropic murine leukemia viruses and two subgroups of feline leukemia virus, indicting that O-linked glycosylation is a conserved feature of retroviral env proteins.

  10. O-linked glycosylation of retroviral envelope gene products

    International Nuclear Information System (INIS)

    Pinter, A.; Honnen, W.J.

    1988-01-01

    Treatment of [ 3 H]glucosamine-labeled Friend mink cell focus-forming virus (FrMCF) gp70 with excess peptide:N-glycanase F (PNGase F) resulted in removal of the expected seven N-linked oligosaccharide chains; however, approximately 10% of the glucosamine label was retained in the resulting 49,000-M r (49K) product. For [ 3 H]mannose-labeled gp70, similar treatment led to removal of all the carbohydrate label from the protein. Prior digestion of the PNGase F-treated gp70 with neuraminidase resulted in an addition size shift, and treatment with O-glycanase led to the removal of almost all of the PNGase F-resistant sugars. These results indicate that gp70 possesses sialic acid-containing O-linked oligosaccharides. Analysis of intracellular env precursors demonstrated that O-linked sugars were present in gPr90 env , the polyprotein intermediate which contains complex sugars, but not in the primary translation product, gPr80 env , and proteolytic digestion studies allowed localization of the O-linked carbohydrates to a 10K region near the center of the gp70 molecule. similar substituents were detected on the gp70s of ecotropic and xenotropic murine leukemia viruses and two subgroups of feline leukemia virus, indicting that O-linked glycosylation is a conserved feature of retroviral env proteins

  11. Pumping of drugs by P-glycoprotein

    DEFF Research Database (Denmark)

    Litman, Thomas; Skovsgaard, Torben; Stein, Wilfred D

    2003-01-01

    The apparent inhibition constant, Kapp, for the blockade of P-glycoprotein (P-gp) by four drugs, verapamil, cyclosporin A, XR9576 (tariquidar), and vinblastine, was measured by studying their ability to inhibit daunorubicin and calcein-AM efflux from four strains of Ehrlich cells with different...... levels of drug resistance and P-gp content. For daunorubicin as a transport substrate, Kapp was independent of [P-gp] for verapamil but increased strictly linearly with [P-gp] for vinblastine, cyclosporin A, and XR9576. A theoretical analysis of the kinetics of drug pumping and its reversal shows...... but rather, in serial, i.e., a drug that is pumped from the cytoplasmic phase has to pass the preemptive route upon leaving the cell. Our results are consistent with the Sauna-Ambudkar two-step model for pumping by P-gp. We suggest that the vinblastine/cyclosporin A/XR9576-binding site accepts daunorubicin...

  12. Raman optical activity of proteins and glycoproteins

    International Nuclear Information System (INIS)

    Smyth, E.

    2000-03-01

    Raman optical activity (ROA), measured in this project as a small difference in the intensity of Raman scattering from chiral molecules in right- and left-circularly polarised incident laser light, offers the potential to provide more information about the structure of biological molecules in aqueous solution than conventional spectroscopic techniques. Chapter one contains a general discussion of the relative merits of different spectroscopic techniques for structure determination of biomolecules, as well as a brief introduction to ROA. In Chapter two a theoretical analysis of ROA is developed, which extends the discussion in chapter one. The spectrometer setup and sample preparation is then discussed in chapter three. Instrument and sample conditions are monitored to ensure that the best results are obtained. As with any experimental project problems occur, which may result in a degradation of the spectra obtained. The cause of these problems was explored and remedied whenever possible. Chapter four introduces a brief account of protein, glycoprotein and carbohydrate structure and function, with a particular emphasis on the structure of proteins. In the remaining chapters experimental ROA results on proteins and glycoproteins, with some carbohydrate samples, from a wide range of sources are examined. For example, in chapter five some β-sheet proteins are examined. Structural features in these proteins are examined in the extended amide III region of their ROA spectra, revealing that ROA is sensitive to the rigidity or flexibility inherent in proteins. Chapter six concentrates on a group of proteins (usually glycoproteins) known as the serine proteinase inhibitors (serpins). Medically, the serpins are one of the most important groups of proteins of current interest, with wide-ranging implications in conditions such as Down's syndrome, Alzheimer's disease, and emphysema with associated cirrhosis of the liver. With favourable samples and conditions ROA may offer the

  13. Nuclear envelope breakdown induced by herpes simplex virus type 1 involves the activity of viral fusion proteins.

    Science.gov (United States)

    Maric, Martina; Haugo, Alison C; Dauer, William; Johnson, David; Roller, Richard J

    2014-07-01

    Herpesvirus infection reorganizes components of the nuclear lamina usually without loss of integrity of the nuclear membranes. We report that wild-type HSV infection can cause dissolution of the nuclear envelope in transformed mouse embryonic fibroblasts that do not express torsinA. Nuclear envelope breakdown is accompanied by an eight-fold inhibition of virus replication. Breakdown of the membrane is much more limited during infection with viruses that lack the gB and gH genes, suggesting that breakdown involves factors that promote fusion at the nuclear membrane. Nuclear envelope breakdown is also inhibited during infection with virus that does not express UL34, but is enhanced when the US3 gene is deleted, suggesting that envelope breakdown may be enhanced by nuclear lamina disruption. Nuclear envelope breakdown cannot compensate for deletion of the UL34 gene suggesting that mixing of nuclear and cytoplasmic contents is insufficient to bypass loss of the normal nuclear egress pathway. Copyright © 2014 Elsevier Inc. All rights reserved.

  14. Regulation of glycoprotein synthesis in yeast by mating pheromones

    International Nuclear Information System (INIS)

    Tanner, W.

    1984-01-01

    In Saccharomyces cerevisiae, glycosylated proteins amount to less than 2% of the cell protein. Two intensively studied examples of yeast glycoproteins are the external cell wall - associated invertase and the vacuolar carboxypeptidase Y. Recently, it was shown that the mating pheromone, alpha factor, specifically and strongly inhibits the synthesis of N-glycosylated proteins in haploid a cells, whereas O-glycosylated proteins are not affected. In this paper, the pathways of glycoprotein biosynthesis are summarized briefly, and evidence is presented that mating pheomones have a regulatory function in glycoprotein synthesis

  15. NF-κB and p53 Are the Dominant Apoptosis-inducing Transcription Factors Elicited by the HIV-1 Envelope

    OpenAIRE

    Perfettini, Jean-Luc; Roumier, Thomas; Castedo, Maria; Larochette, Nathanael; Boya, Patricia; Raynal, Brigitte; Lazar, Vladimir; Ciccosanti, Fabiola; Nardacci, Roberta; Penninger, Josef; Piacentini, Mauro; Kroemer, Guido

    2004-01-01

    The coculture of cells expressing the HIV-1 envelope glycoprotein complex (Env) with cells expressing CD4 results into cell fusion, deregulated mitosis, and subsequent cell death. Here, we show that NF-κB, p53, and AP1 are activated in Env-elicited apoptosis. The nuclear factor κB (NF-κB) super repressor had an antimitotic and antiapoptotic effect and prevented the Env-elicited phosphorylation of p53 on serine 15 and 46, as well as the activation of AP1. Transfection with dominant-negative p5...

  16. Evaluating the Effects of Cytomegalovirus Glycoprotein B on the Maturation and Function of Monocyte-derived dendritic cells

    Directory of Open Access Journals (Sweden)

    Afsson shariat

    2015-11-01

    Full Text Available Background & Objectives: Interaction of cytomegalovirus glycoprotein B with toll-like receptors of dendritic cells leads to early signaling and innate immune responses. The aim of this study is to evaluate the effects of cytomegalovirus glycoprotein B on the maturation and function of monocyte-derived dendritic cells in treated groups in comparison with control groups. Materials & Methods: Blood samples were taken from 5 healthy volunteers. Following the generation of monocyte-derived dendritic cells on the fifth day of cell culture, half of the immature dendritic cells were treated with cytomegalovirus glycoprotein B, and the rest of them were induced to mature dendritic untreated cells and were used as the control group. The maturation and function of dendritic cells were evaluated in these two groups. Results: The gene expression level of toll-like receptor-4 significantly increased in the group treated with glycoprotein B (p < 0.05, whereas there were no significant differences in the expression rates of CD83, CD86, CD1a, and HLA-DR and the secretion of IL-23 from monocyte-derived dendritic cells between the treated groups and the controls. Conclusion: The increase in the gene expression of toll-like receptor-4 in monocyte-derived dendritic cells treated with cytomegalovirus glycoprotein B showed that cell contact is required to elicit cellular antiviral response and toll-like receptor activation. Thus, it is critical to recognize the viral and cellular determinants of the immune system in order to develop new therapeutic strategies against cytomegalovirus.

  17. Characterization of the fusion core in zebrafish endogenous retroviral envelope protein

    Energy Technology Data Exchange (ETDEWEB)

    Shi, Jian [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072 (China); State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Zhang, Huaidong [CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Gong, Rui, E-mail: gongr@wh.iov.cn [CAS Key Laboratory of Special Pathogens and Biosafety, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China); Xiao, Gengfu, E-mail: xiaogf@wh.iov.cn [State Key Laboratory of Virology, College of Life Sciences, Wuhan University, Wuhan, Hubei 430072 (China); State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, Hubei 430071 (China)

    2015-05-08

    Zebrafish endogenous retrovirus (ZFERV) is the unique endogenous retrovirus in zebrafish, as yet, containing intact open reading frames of its envelope protein gene in zebrafish genome. Similarly, several envelope proteins of endogenous retroviruses in human and other mammalian animal genomes (such as syncytin-1 and 2 in human, syncytin-A and B in mouse) were identified and shown to be functional in induction of cell–cell fusion involved in placental development. ZFERV envelope protein (Env) gene appears to be also functional in vivo because it is expressible. After sequence alignment, we found ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes, especially in the regions of N- and C-terminal heptad repeats (NHR and CHR) which were crucial for membrane fusion. We expressed the regions of N + C protein in the ZFERV Env (residues 459–567, including predicted NHR and CHR) to characterize the fusion core structure. We found N + C protein could form a stable coiled-coil trimer that consists of three helical NHR regions forming a central trimeric core, and three helical CHR regions packing into the grooves on the surface of the central core. The structural characterization of the fusion core revealed the possible mechanism of fusion mediated by ZFERV Env. These results gave comprehensive explanation of how the ancient virus infects the zebrafish and integrates into the genome million years ago, and showed a rational clue for discovery of physiological significance (e.g., medicate cell–cell fusion). - Highlights: • ZFERV Env shares similar structural profiles with syncytin and other type I viral envelopes. • The fusion core of ZFERV Env forms stable coiled-coil trimer including three NHRs and three CHRs. • The structural mechanism of viral entry mediated by ZFERV Env is disclosed. • The results are helpful for further discovery of physiological function of ZFERV Env in zebrafish.

  18. N-glycan maturation mutants in Lotus japonicus for basic and applied glycoprotein research

    DEFF Research Database (Denmark)

    Pedersen, Carina T.; Loke, Ian; Lorentzen, Andrea

    2017-01-01

    Studies of protein N-glycosylation are important for answering fundamental questions on the diverse functions of glycoproteins in plant growth and development. Here we generated and characterised a comprehensive collection of Lotus japonicusLORE1 insertion mutants, each lacking the activity of one...... in the target glyco-genes. For example, both mass spectrometry and immunoblotting experiments suggest that proteins derived from the α1,3-fucosyltransferase (Lj3fuct) mutant completely lacked α1,3-core fucosylation. Mass spectrometry also suggested that the Lotus japonicus convicilin 2 was one of the main...

  19. A Potato cDNA Encoding a Homologue of Mammalian Multidrug Resistant P-Glycoprotein

    Science.gov (United States)

    Wang, W.; Takezawa, D.; Poovaiah, B. W.

    1996-01-01

    A homologue of the multidrug resistance (MDR) gene was obtained while screening a potato stolon tip cDNA expression library with S-15-labeled calmodulin. The mammalian MDR gene codes for a membrane-bound P-glycoprotein (170-180 kDa) which imparts multidrug resistance to cancerous cells. The potato cDNA (PMDR1) codes for a polypeptide of 1313 amino acid residues (ca. 144 kDa) and its structural features are very similar to the MDR P-glycoprotein. The N-terminal half of the PMDR1-encoded protein shares striking homology with its C-terminal half, and each half contains a conserved ATP-binding site and six putative transmembrane domains. Southern blot analysis indicated that potato has one or two MDR-like genes. PMDR1 mRNA is constitutively expressed in all organs studied with higher expression in the stem and stolon tip. The PMDR1 expression was highest during tuber initiation and decreased during tuber development.

  20. P-glycoprotein Inhibition Increases the Brain Distribution and Antidepressant-Like Activity of Escitalopram in Rodents

    OpenAIRE

    O'Brien, Fionn E; O'Connor, Richard M; Clarke, Gerard; Dinan, Timothy G; Griffin, Brendan T; Cryan, John F

    2013-01-01

    Despite the clinical prevalence of the antidepressant escitalopram, over 30% of escitalopram-treated patients fail to respond to treatment. Recent gene association studies have highlighted a potential link between the drug efflux transporter P-glycoprotein (P-gp) and response to escitalopram. The present studies investigated pharmacokinetic and pharmacodynamic interactions between P-gp and escitalopram. In vitro bidirectional transport studies revealed that escitalopram is a transported subst...

  1. Extra-oviductal expression of oviductal glycoprotein 1 in mouse ...

    Indian Academy of Sciences (India)

    2017-01-11

    Jan 11, 2017 ... oestrogen-dependent protein, oviduct-specific glycoprotein. 1 (Ovgp1) also ... the tissues collected were testis, epididymis, prostate gland and seminal vesicle. ... The antigenic sites were unmasked by incuba- tion of sections ...

  2. Herpesvirus glycoproteins undergo multiple antigenic changes before membrane fusion.

    Directory of Open Access Journals (Sweden)

    Daniel L Glauser

    Full Text Available Herpesvirus entry is a complicated process involving multiple virion glycoproteins and culminating in membrane fusion. Glycoprotein conformation changes are likely to play key roles. Studies of recombinant glycoproteins have revealed some structural features of the virion fusion machinery. However, how the virion glycoproteins change during infection remains unclear. Here using conformation-specific monoclonal antibodies we show in situ that each component of the Murid Herpesvirus-4 (MuHV-4 entry machinery--gB, gH/gL and gp150--changes in antigenicity before tegument protein release begins. Further changes then occurred upon actual membrane fusion. Thus virions revealed their final fusogenic form only in late endosomes. The substantial antigenic differences between this form and that of extracellular virions suggested that antibodies have only a limited opportunity to block virion membrane fusion.

  3. Dispersion - does it degrade a pulse envelope

    International Nuclear Information System (INIS)

    Deighton, M.O.

    1985-01-01

    In hostile environments, transmitting information as ultrasonic Lamb wave pulses has advantages, since the stainless steel strip serving as a waveguide is very durable. Besides attenuation, velocity dispersion (inherent in Lamb waves) can be important even in fairly short guides. Theory shows that unlimited propagation of a pulsed r.f. envelope is possible, even with dispersion present. The constant group velocity needed would favour asub(o)-mode pulses over other modes, provided ordinary attenuation is small. An approximate formula indicates the useful range of a pulse, when group velocity does vary. (author)

  4. Shape Control of Responsive Building Envelopes

    DEFF Research Database (Denmark)

    Foged, Isak Worre; Kirkegaard, Poul Henning; Christensen, Jesper Thøger

    2010-01-01

    The present paper considers shape control of adaptive architectural structures for improvement of structural performance by recognizing changes in their environments and loads, adapting to meet goals, and using past events to improve future performance or maintain serviceability. The general scop...... environmental system to a primary structural system joint into a collective behavioral system equipment with an actuator system is presented....... alternatives. The adaptive structure is a proposal for a responsive building envelope which is an idea of a first level operational framework for present and future investigations towards performance based responsive architectures through a set of responsive typologies. A mock-up concept of a secondary...

  5. Snell Envelope with Small Probability Criteria

    Energy Technology Data Exchange (ETDEWEB)

    Del Moral, Pierre, E-mail: Pierre.Del-Moral@inria.fr; Hu, Peng, E-mail: Peng.Hu@inria.fr [Universite de Bordeaux I, Centre INRIA Bordeaux et Sud-Ouest and Institut de Mathematiques de Bordeaux (France); Oudjane, Nadia, E-mail: Nadia.Oudjane@edf.fr [EDF R and D Clamart (France)

    2012-12-15

    We present a new algorithm to compute the Snell envelope in the specific case where the criteria to optimize is associated with a small probability or a rare event. This new approach combines the Stochastic Mesh approach of Broadie and Glasserman with a particle approximation scheme based on a specific change of measure designed to concentrate the computational effort in regions pointed out by the criteria. The theoretical analysis of this new algorithm provides non asymptotic convergence estimates. Finally, the numerical tests confirm the practical interest of this approach.

  6. The RSV F and G glycoproteins interact to form a complex on the surface of infected cells

    International Nuclear Information System (INIS)

    Low, Kit-Wei; Tan, Timothy; Ng, Ken; Tan, Boon-Huan; Sugrue, Richard J.

    2008-01-01

    In this study, the interaction between the respiratory syncytial virus (RSV) fusion (F) protein, attachment (G) protein, and small hydrophobic (SH) proteins was examined. Immunoprecipitation analysis suggested that the F and G proteins exist as a protein complex on the surface of RSV-infected cells, and this conclusion was supported by ultracentrifugation analysis that demonstrated co-migration of surface-expressed F and G proteins. Although our analysis provided evidence for an interaction between the G and SH proteins, no evidence was obtained for a single protein complex involving all three of the virus proteins. These data suggest the existence of multiple virus glycoprotein complexes within the RSV envelope. Although the stimulus that drives RSV-mediated membrane fusion is unknown, the association between the G and F proteins suggest an indirect role for the G protein in this process

  7. Orthobunyavirus ultrastructure and the curious tripodal glycoprotein spike.

    Directory of Open Access Journals (Sweden)

    Thomas A Bowden

    Full Text Available The genus Orthobunyavirus within the family Bunyaviridae constitutes an expanding group of emerging viruses, which threaten human and animal health. Despite the medical importance, little is known about orthobunyavirus structure, a prerequisite for understanding virus assembly and entry. Here, using electron cryo-tomography, we report the ultrastructure of Bunyamwera virus, the prototypic member of this genus. Whilst Bunyamwera virions are pleomorphic in shape, they display a locally ordered lattice of glycoprotein spikes. Each spike protrudes 18 nm from the viral membrane and becomes disordered upon introduction to an acidic environment. Using sub-tomogram averaging, we derived a three-dimensional model of the trimeric pre-fusion glycoprotein spike to 3-nm resolution. The glycoprotein spike consists mainly of the putative class-II fusion glycoprotein and exhibits a unique tripod-like arrangement. Protein-protein contacts between neighbouring spikes occur at membrane-proximal regions and intra-spike contacts at membrane-distal regions. This trimeric assembly deviates from previously observed fusion glycoprotein arrangements, suggesting a greater than anticipated repertoire of viral fusion glycoprotein oligomerization. Our study provides evidence of a pH-dependent conformational change that occurs during orthobunyaviral entry into host cells and a blueprint for the structure of this group of emerging pathogens.

  8. The hydroxyapatite-binding regions of a rat salivary glycoprotein.

    Science.gov (United States)

    Embery, G; Green, D R

    1989-09-01

    The regions of a salivary sulphated glycoprotein which are involved in its attachment to hydroxyapatite (Biogel HTP) have been characterised. The sulphated glycoprotein, a 35S-labelled preparation from mixed palatal and buccal minor gland secretions of the rat was bound onto hydroxyapatite and the resultant glycoprotein-hydroxyapatite complex was sequentially digested with pronase E and alpha-L-fucosidase, a treatment which released 86.8% +/- 1.7% of the radioactivity of the initially bound glycoprotein. The fragments which remained attached to the hydroxyapatite after enzymic digestion were fractionated on Sephadex G-25 and analysed for carbohydrate and amino acid components. A range of amino acids were detected which could reflect both glycosylated and non-glycosylated-binding regions. Sialic acid, although considered to be involved in the attachment process was not detected in any of the fragments remaining after enzymic digestion, a finding which provides indirect evidence that the enzymically liberated products do not subsequently re-attach to the hydroxyapatite surface. The notable feature of the fractions with average Mr estimated at 1000 or less is the high proportion of N-acetylhexosamine and N-acetylgalactosamine. It is apparent that the hexosamine residues, which normally bear the ester sulphate moieties of sulphated glycoproteins, play an important role in the attachment of sulphated glycoproteins to hydroxyapatite.

  9. Envelope as Climate Negotiator: Evaluating adaptive building envelope's capacity to moderate indoor climate and energy

    Science.gov (United States)

    Erickson, James

    Through manipulation of adaptable opportunities available within a given environment, individuals become active participants in managing personal comfort requirements, by exercising control over their comfort without the assistance of mechanical heating and cooling systems. Similarly, continuous manipulation of a building skin's form, insulation, porosity, and transmissivity qualities exerts control over the energy exchanged between indoor and outdoor environments. This research uses four adaptive response variables in a modified software algorithm to explore an adaptive building skin's potential in reacting to environmental stimuli with the purpose of minimizing energy use without sacrificing occupant comfort. Results illustrate that significant energy savings can be realized with adaptive envelopes over static building envelopes even under extreme summer and winter climate conditions; that the magnitude of these savings are dependent on climate and orientation; and that occupant thermal comfort can be improved consistently over comfort levels achieved by optimized static building envelopes. The resulting adaptive envelope's unique climate-specific behavior could inform designers in creating an intelligent kinetic aesthetic that helps facilitate adaptability and resiliency in architecture.

  10. Reconstituted influenza virus envelopes as an efficient carrier system for cellular delivery of small-interfering RNAs

    NARCIS (Netherlands)

    de Jonge, J; Holtrop, M; Wilschut, J; Huckriede, A

    Application of RNA interference for in vivo evaluation of gene function or for therapeutic interventions has been hampered by a lack of suitable delivery methods for small interfering RNA ( siRNA). Here, we present reconstituted viral envelopes (virosomes) derived from influenza virus as suitable

  11. Herpesvirus gB-induced fusion between the virion envelope and outer nuclear membrane during virus egress is regulated by the viral US3 kinase.

    Science.gov (United States)

    Wisner, Todd W; Wright, Catherine C; Kato, Akihisa; Kawaguchi, Yasushi; Mou, Fan; Baines, Joel D; Roller, Richard J; Johnson, David C

    2009-04-01

    Herpesvirus capsids collect along the inner surface of the nuclear envelope and bud into the perinuclear space. Enveloped virions then fuse with the outer nuclear membrane (NM). We previously showed that herpes simplex virus (HSV) glycoproteins gB and gH act in a redundant fashion to promote fusion between the virion envelope and the outer NM. HSV mutants lacking both gB and gH accumulate enveloped virions in herniations, vesicles that bulge into the nucleoplasm. Earlier studies had shown that HSV mutants lacking the viral serine/threonine kinase US3 also accumulate herniations. Here, we demonstrate that HSV gB is phosphorylated in a US3-dependent manner in HSV-infected cells, especially in a crude nuclear fraction. Moreover, US3 directly phosphorylated the gB cytoplasmic (CT) domain in in vitro assays. Deletion of gB in the context of a US3-null virus did not add substantially to defects in nuclear egress. The majority of the US3-dependent phosphorylation of gB involved the CT domain and amino acid T887, a residue present in a motif similar to that recognized by US3 in other proteins. HSV recombinants lacking gH and expressing either gB substitution mutation T887A or a gB truncated at residue 886 displayed substantial defects in nuclear egress. We concluded that phosphorylation of the gB CT domain is important for gB-mediated fusion with the outer NM. This suggested a model in which the US3 kinase is incorporated into the tegument layer (between the capsid and envelope) in HSV virions present in the perinuclear space. By this packaging, US3 might be brought close to the gB CT tail, leading to phosphorylation and triggering fusion between the virion envelope and the outer NM.

  12. The performance of energy efficient residential building envelope systems

    Energy Technology Data Exchange (ETDEWEB)

    Proskiw, G.

    1996-08-01

    The adequacy and durability of residential building envelope systems under actual field conditions were evaluated. A building envelope offers protection from cold, heat, moisture, wind and noise. However, they are exposed to thermal, structural, and moisture stresses and their performance can degrade over time. Envelope performance was evaluated at 20 energy efficient and four conventional, detached modern homes in Winnipeg, Canada. The three complementary measurement tools were wood moisture content (WMC) of framing members, thermographic examinations, and airtightness tests. As expected, energy efficient building envelope systems performed better than the conventional systems. No evidence of envelope degradation was found in any of the energy efficient houses. The building envelopes using polyethylene air barriers performed slightly better than those which used the airtight drywall approach, although both were considered satisfactory. WMC levels were a bit lower in the polyethylene-clad house. 1 ref., 1 tab.

  13. Nucleic acid-binding glycoproteins which solubilize nucleic acids in dilute acid: re-examination of the Ustilago maydis glycoproteins

    Energy Technology Data Exchange (ETDEWEB)

    Unrau, P.; Champ, D.R.; Young, J.L.; Grant, C.E.

    1980-01-01

    Holloman reported the isolation from Ustilago maydis of a glycoprotein which prevented the precipitation of nucleic acids in cold 5% trichloroacetic acid. Two glycoprotein fractions from U. maydis with this nucleic acid-solubilizing activity were isolated in our laboratory using improved purification procedures. The activity was not due to nuclease contamination. The glycoproteins are distinguished by: their ability to bind to concanavalin A-Sepharose; their differential binding to double- and single-stranded deoxyribonucleic acid, and to ribonucleic acid; their molecular weights (46,000 and 69,000); and the relative amounts present in growing versus nongrowing cells. Both fractions required sulfhydryl-reducing conditions for optimal yields, specific activity, and stability. Nucleic acid binding was cooperative, the minimum number of glycoproteins required to make a native T7 DNA molecule soluble in dilute acid being estimated at 2 and 15, respectively.

  14. Grain formation in cool stellar envelopes

    International Nuclear Information System (INIS)

    Deguchi, S.

    1980-01-01

    The nucleation and growth of dust grains in the stellar envelope are investigated for the case of oxygen-rich stars, where the mass loss occurs as a result of the radiation pressure on the dust grains. The number density of grains, the final grain sizes, and the final amount of metals remaining in gaseous states are calculated based on the grain-nucleation theory proposed by Yamamoto and Hasegawa and Draine and Salpeter. It is shown that, even if we base our calculations on the Lothe-Pound nucleation rate equation instead of the classical, homogeneous nucleation rate equation, the proposed theory gives a number density of grains quite similar to that based on the classical rate equation. The approximate solution of the flow, in this paper, brings physical insight to the problem of how the formation of grains couples the flow passing the sonic point. The metals in the outer envelope remain in gaseous state by the amount of 1--10% of the initial content for the mass-loss rate of 10 -5 M/sub sun/ yr -1 and by less than 1% for the massloss are less than 3 x 10 -6 M/sub sun/ yr -1 . Species of metals condensed onto the grains are also discussed

  15. Bellanca building, Yellowknife : building envelope retrofit project

    Energy Technology Data Exchange (ETDEWEB)

    Rajewski, G. [A.D. Williams Engineering Inc., Edmonton, AB (Canada)

    2008-07-01

    The Bellanca building is a ten-story, commercial office building, located in Yellowknife, Northwest Territories. The owner was concerned about annual fuel consumption, relative to other buildings of similar size. Tenants reported cold drafts and some ice build-up had been reported in the past, on the exterior of the cladding. In addition, some water penetration had occurred during rainfall. This presentation provided background information on the Bellanca building and discussed a building envelope retrofit project. A.D. Williams was hired in late 2006 in order to provide an opinion on the present condition of the building envelope. This presentation described the site investigation and presented an interior and exterior review of the building. It also presented a thermographic survey in order to map thermal anomalies and establish trends. Following acceptance of the report on findings, one of five options was selected for further development. This included removal of existing cladding, exterior gypsum wallboard, fiberglass insulation and application of BASF Walltite CT foam, sheathing, rigid insulation, drainage plane and new cladding. The preliminary design was then presented. This paper also described the tender and award of the contract; construction phase; and substantial completion of the project. tabs, figs.

  16. Chemistry of Protostellar Envelopes and Disks

    Science.gov (United States)

    Flores Rivera, Lizxandra; Terebey, Susan; Willacy, Karen

    2018-06-01

    Molecule formation is dynamic during the protostar collapse phase, driven by changes in temperature, density, and UV radiation as gas and dust flows from the envelope onto the forming protoplanetary disk. In this work, we compare physical models based on two different collapse solutions. We modeled the chemistry (created by Karen Willacy) for C18O to see how its abundance changes over time using as primary input parameters the temperature and density profile that were produced by the dust Radiative Transfer (MCRT) model called HOCHUNK3D from Whitney (2003). Given this model, we produce synthetic line emission maps from L1527 IRS to simulate the Class 0/I protostar L1527 IRS using RADMC3D code and compare them with previous observations from ALMA. High concentrations of gas phase molecules of C18O are found within the 20 AU in areas in the envelope that are close to the surface of the disk. In the outermost part of the disk surface, the C18O freezes out beyond 400 AU, showing a much reduced abundance where the temperature profile drops down below 25 K. In cold regions, the radiation field plays an important role in the chemistry.

  17. [An improved algorithm for electrohysterogram envelope extraction].

    Science.gov (United States)

    Lu, Yaosheng; Pan, Jie; Chen, Zhaoxia; Chen, Zhaoxia

    2017-02-01

    Extraction uterine contraction signal from abdominal uterine electromyogram(EMG) signal is considered as the most promising method to replace the traditional tocodynamometer(TOCO) for detecting uterine contractions activity. The traditional root mean square(RMS) algorithm has only some limited values in canceling the impulsive noise. In our study, an improved algorithm for uterine EMG envelope extraction was proposed to overcome the problem. Firstly, in our experiment, zero-crossing detection method was used to separate the burst of uterine electrical activity from the raw uterine EMG signal. After processing the separated signals by employing two filtering windows which have different width, we used the traditional RMS algorithm to extract uterus EMG envelope. To assess the performance of the algorithm, the improved algorithm was compared with two existing intensity of uterine electromyogram(IEMG) extraction algorithms. The results showed that the improved algorithm was better than the traditional ones in eliminating impulsive noise present in the uterine EMG signal. The measurement sensitivity and positive predictive value(PPV) of the improved algorithm were 0.952 and 0.922, respectively, which were not only significantly higher than the corresponding values(0.859 and 0.847) of the first comparison algorithm, but also higher than the values(0.928 and 0.877) of the second comparison algorithm. Thus the new method is reliable and effective.

  18. Solution of K-V envelope equations

    International Nuclear Information System (INIS)

    Anderson, O.A.

    1995-04-01

    The envelope equations for a KV beam with space charge have been analyzed systematically by an e expansion followed by integrations. The focusing profile as a function of axial length is assumed to be symmetric but otherwise arbitrary. Given the bean current, emittance, and peak focusing field, we find the envelopes a(s) and b(s) and obtain , a max , σ, and σ 0 . Explicit results are presented for various truncations of the expansion. The zeroth order results correspond to those from the well-known smooth approximation; the same convenient format is retained for the higher order cases. The first order results, involving single correction terms, give 3--10 times better accuracy and are good to ∼1% at σ 0 = 70 degree. Third order gives a factor of 10--30 improvement over the smooth approximation and derived quantities accurate to ∼1% at σ 0 = 112 degree. The first order expressions are convenient design tools. They lend themselves to variable energy problems and have been applied to the design, construction, and testing of ESQ accelerators at LBL

  19. Solitons, envelope solitons in collisonless plasmas

    International Nuclear Information System (INIS)

    Ichikawa, Y.H.; Watanabe, S.

    1977-08-01

    A review is given to extensive development of theoretical, computational and experimental studies of nonlinear wave propagation in collisionless plasmas. Firstly, the historical experiment of Ikezi et al. is discussed in comparison with theoretical analysis based on the Korteweg-de Vries equation. Systematic discrepancy between the observation and the theoretical prediction suggests that it is necessary to examine such as higher order mode coupling effect and contribution of trapped particles. Secondly, effects of the nonlinear Landau damping on the envelope solution of ion plasma wave is discussed on the basis of theoretical study of Ichikawa-Taniuti, experimental observation of Watanabe and numerical analysis of Yajima et al. Finally, a new type of evolution equation derived for the Alfven wave is examined in some detail. The rigorous solution obtained for this mode represents a new kind of envelope solution, in which both of its phase and amplitude are subject to modulation of comparable spatial extension. In conclusion, the emphasis will be placed on the fact that much more intensive experimental researches are expected to be done, since the powerful methods to disentangle various nonlinear evolution equations are now available for theoretical approach. (auth.)

  20. P-glycoprotein targeted nanoscale drug carriers

    KAUST Repository

    Li, Wengang

    2013-02-01

    Multi-drug resistance (MDR) is a trend whereby tumor cells exposed to one cytotoxic agent develop cross-resistance to a range of structurally and functionally unrelated compounds. P -glycoprotein (P -gp) efflux pump is one of the mostly studied drug carrying processes that shuttle the drugs out of tumor cells. Thus, P -gp inhibitors have attracted a lot of attention as they can stop cancer drugs from being pumped out of target cells with the consumption of ATP. Using quantitive structure activity relationship (QSAR), we have successfully synthesized a series of novel P -gp inhibitors. The obtained dihydropyrroloquinoxalines series were fully characterized and then tested against bacterial and tumor assays with over-expressed P -gps. All compounds were bioactive especially compound 1c that had enhanced antibacterial activity. Furthermore, these compounds were utilized as targeting vectors to direct drug delivery vehicles such as silica nanoparticles (SNPs) to cancerous Hela cells with over expressed P -gps. Cell uptake studies showed a successful accumulation of these decorated SNPs in tumor cells compared to undecorated SNPs. The results obtained show that dihydropyrroloquinoxalines constitute a promising drug candidate for targeting cancers with MDR. Copyright © 2013 American Scientific Publishers All rights reserved.

  1. An Alphavirus E2 Membrane-Proximal Domain Promotes Envelope Protein Lateral Interactions and Virus Budding

    Directory of Open Access Journals (Sweden)

    Emily A. Byrd

    2017-11-01

    Full Text Available Alphaviruses are members of a group of small enveloped RNA viruses that includes important human pathogens such as Chikungunya virus and the equine encephalitis viruses. The virus membrane is covered by a lattice composed of 80 spikes, each a trimer of heterodimers of the E2 and E1 transmembrane proteins. During virus endocytic entry, the E1 glycoprotein mediates the low-pH-dependent fusion of the virus membrane with the endosome membrane, thus initiating virus infection. While much is known about E1 structural rearrangements during membrane fusion, it is unclear how the E1/E2 dimer dissociates, a step required for the fusion reaction. A recent Alphavirus cryo-electron microscopy reconstruction revealed a previously unidentified D subdomain in the E2 ectodomain, close to the virus membrane. A loop within this region, here referred to as the D-loop, contains two highly conserved histidines, H348 and H352, which were hypothesized to play a role in dimer dissociation. We generated Semliki Forest virus mutants containing the single and double alanine substitutions H348A, H352A, and H348/352A. The three D-loop mutations caused a reduction in virus growth ranging from 1.6 to 2 log but did not significantly affect structural protein biosynthesis or transport, dimer stability, virus fusion, or specific infectivity. Instead, growth reduction was due to inhibition of a late stage of virus assembly at the plasma membrane. The virus particles that are produced show reduced thermostability compared to the wild type. We propose the E2 D-loop as a key region in establishing the E1-E2 contacts that drive glycoprotein lattice formation and promote Alphavirus budding from the plasma membrane.

  2. Crystal structure of the Hendra virus attachment G glycoprotein bound to a potent cross-reactive neutralizing human monoclonal antibody.

    Directory of Open Access Journals (Sweden)

    Kai Xu

    Full Text Available The henipaviruses, represented by Hendra (HeV and Nipah (NiV viruses are highly pathogenic zoonotic paramyxoviruses with uniquely broad host tropisms responsible for repeated outbreaks in Australia, Southeast Asia, India and Bangladesh. The high morbidity and mortality rates associated with infection and lack of licensed antiviral therapies make the henipaviruses a potential biological threat to humans and livestock. Henipavirus entry is initiated by the attachment of the G envelope glycoprotein to host cell membrane receptors. Previously, henipavirus-neutralizing human monoclonal antibodies (hmAb have been isolated using the HeV-G glycoprotein and a human naïve antibody library. One cross-reactive and receptor-blocking hmAb (m102.4 was recently demonstrated to be an effective post-exposure therapy in two animal models of NiV and HeV infection, has been used in several people on a compassionate use basis, and is currently in development for use in humans. Here, we report the crystal structure of the complex of HeV-G with m102.3, an m102.4 derivative, and describe NiV and HeV escape mutants. This structure provides detailed insight into the mechanism of HeV and NiV neutralization by m102.4, and serves as a blueprint for further optimization of m102.4 as a therapeutic agent and for the development of entry inhibitors and vaccines.

  3. Analysis of ZP1 gene reveals differences in zona pellucida composition in carnivores.

    Science.gov (United States)

    Moros-Nicolás, C; Leza, A; Chevret, P; Guillén-Martínez, A; González-Brusi, L; Boué, F; Lopez-Bejar, M; Ballesta, J; Avilés, M; Izquierdo-Rico, M J

    2018-01-01

    The zona pellucida (ZP) is an extracellular envelope that surrounds mammalian oocytes. This coat participates in the interaction between gametes, induction of the acrosome reaction, block of polyspermy and protection of the oviductal embryo. Previous studies suggested that carnivore ZP was formed by three glycoproteins (ZP2, ZP3 and ZP4), with ZP1 being a pseudogene. However, a recent study in the cat found that all four proteins were expressed. In the present study, in silico and molecular analyses were performed in several carnivores to clarify the ZP composition in this order of mammals. The in silico analysis demonstrated the presence of the ZP1 gene in five carnivores: cheetah, panda, polar bear, tiger and walrus, whereas in the Antarctic fur seal and the Weddell seal there was evidence of pseudogenisation. Molecular analysis showed the presence of four ZP transcripts in ferret ovaries (ZP1, ZP2, ZP3 and ZP4) and three in fox ovaries (ZP2, ZP3 and ZP4). Analysis of the fox ZP1 gene showed the presence of a stop codon. The results strongly suggest that all four ZP genes are expressed in most carnivores, whereas ZP1 pseudogenisation seems to have independently affected three families (Canidae, Otariidae and Phocidae) of the carnivore tree.

  4. Adaptive Flight Envelope Estimation and Protection, Phase I

    Data.gov (United States)

    National Aeronautics and Space Administration — Impact Technologies, in collaboration with the Georgia Institute of Technology, proposes to develop and demonstrate an innovative flight envelope estimation and...

  5. Study of the role of the covalently linked cell wall protein (Ccw14p) and yeast glycoprotein (Ygp1p) within biofilm formation in a flor yeast strain.

    Science.gov (United States)

    Moreno-García, J; Coi, A L; Zara, G; García-Martínez, T; Mauricio, J C; Budroni, M

    2018-03-01

    Flor yeasts are Saccharomyces cerevisiae strains noted by their ability to create a type of biofilm in the air-liquid interface of some wines, known as 'flor' or 'velum', for which certain proteins play an essential role. Following a proteomic study of a flor yeast strain, we deleted the CCW14 (covalently linked cell wall protein) and YGP1 (yeast glycoprotein) genes-codifying for two cell surface glycoproteins-in a haploid flor yeast strain and we reported that both influence the weight of the biofilm as well as cell adherence (CCW14).

  6. Radiative transfer in spherical circumstellar dust envelopes. III. Dust envelope models of some well known infrared stars

    International Nuclear Information System (INIS)

    Apruzese, J.P.

    1975-01-01

    The radiative transfer techniques described elsewhere by the author have been employed to construct dust envelope models of several well known infrared stars. The resulting calculations indicate that the infrared emissivity of circumstellar grains generally must be higher than that which many calculations of small nonsilicate grains yield. This conclusion is dependent to some degree on the (unknown) size of the stellar envelopes considered, but is quite firm in the case of the spatially resolved envelope of IRC+10216. Further observations of the spatial distribution of the infrared radiation from stellar envelopes will be invaluable in deciphering the properties of the circumstellar grains

  7. Morphology and Molecular Composition of Purified Bovine Viral Diarrhea Virus Envelope.

    Directory of Open Access Journals (Sweden)

    Nathalie Callens

    2016-03-01

    Full Text Available The family Flaviviridae includes viruses that have different virion structures and morphogenesis mechanisms. Most cellular and molecular studies have been so far performed with viruses of the Hepacivirus and Flavivirus genera. Here, we studied bovine viral diarrhea virus (BVDV, a member of the Pestivirus genus. We set up a method to purify BVDV virions and analyzed their morphology by electron microscopy and their protein and lipid composition by mass spectrometry. Cryo-electron microscopy showed near spherical viral particles displaying an electron-dense capsid surrounded by a phospholipid bilayer with no visible spikes. Most particles had a diameter of 50 nm and about 2% were larger with a diameter of up to 65 nm, suggesting some size flexibility during BVDV morphogenesis. Morphological and biochemical data suggested a low envelope glycoprotein content of BVDV particles, E1 and E2 being apparently less abundant than Erns. Lipid content of BVDV particles displayed a ~2.3 to 3.5-fold enrichment in cholesterol, sphingomyelin and hexosyl-ceramide, concomitant with a 1.5 to 5-fold reduction of all glycerophospholipid classes, as compared to lipid content of MDBK cells. Although BVDV buds in the endoplasmic reticulum, its lipid content differs from a typical endoplasmic reticulum membrane composition. This suggests that BVDV morphogenesis includes a mechanism of lipid sorting. Functional analyses confirmed the importance of cholesterol and sphingomyelin for BVDV entry. Surprisingly, despite a high cholesterol and sphingolipid content of BVDV envelope, E2 was not found in detergent-resistant membranes. Our results indicate that there are differences between the structure and molecular composition of viral particles of Flaviviruses, Pestiviruses and Hepaciviruses within the Flaviviridae family.

  8. Polarimetry and physics of Be star envelopes

    International Nuclear Information System (INIS)

    Coyne, G.V.; McLean, I.S.

    1982-01-01

    A review of the most recent developments in polarization studies of Be stars is presented. New polarization techniques for high-resolution spectropolarimetry and for near infrared polarimetry are described and a wide range of new observations are discussed. These include broad-band, intermediate-band and multichannel observations of the continuum polarization of Be stars in the wavelength interval 0.3-2.2 microns, high resolution (0.5 A) line profile polarimetry of a few stars and surveys of many stars for the purposes of statistical analyses. The physical significance of the observational material is discussed in the light of recent theoretical models. Emphasis is placed on the physical and geometrical parameters of Be star envelopes which polarimetry helps to determine. (Auth.)

  9. Enveloping branes and brane-world singularities

    Energy Technology Data Exchange (ETDEWEB)

    Antoniadis, Ignatios; Cotsakis, Spiros [CERN-Theory Division, Department of Physics, Geneva 23 (Switzerland); Klaoudatou, Ifigeneia [University of the Aegean, Research Group of Geometry, Dynamical Systems and Cosmology, Department of Information and Communication Systems Engineering, Samos (Greece)

    2014-12-01

    The existence of envelopes is studied for systems of differential equations in connection with the method of asymptotic splittings which allows one to determine the singularity structure of the solutions. The result is applied to brane-worlds consisting of a 3-brane in a five-dimensional bulk, in the presence of an analog of a bulk perfect fluid parameterizing a generic class of bulk matter. We find that all flat brane solutions suffer from a finite-distance singularity contrary to previous claims. We then study the possibility of avoiding finite-distance singularities by cutting the bulk and gluing regular solutions at the position of the brane. Further imposing physical conditions such as finite Planck mass on the brane and positive energy conditions on the bulk fluid, excludes, however, this possibility as well. (orig.)

  10. Performance measurement with fuzzy data envelopment analysis

    CERN Document Server

    Tavana, Madjid

    2014-01-01

    The intensity of global competition and ever-increasing economic uncertainties has led organizations to search for more efficient and effective ways to manage their business operations.  Data envelopment analysis (DEA) has been widely used as a conceptually simple yet powerful tool for evaluating organizational productivity and performance. Fuzzy DEA (FDEA) is a promising extension of the conventional DEA proposed for dealing with imprecise and ambiguous data in performance measurement problems. This book is the first volume in the literature to present the state-of-the-art developments and applications of FDEA. It is designed for students, educators, researchers, consultants and practicing managers in business, industry, and government with a basic understanding of the DEA and fuzzy logic concepts.

  11. Pushing the Envelope of Extreme Space Weather

    Science.gov (United States)

    Pesnell, W. D.

    2014-12-01

    Extreme Space Weather events are large solar flares or geomagnetic storms, which can cost billions of dollars to recover from. We have few examples of such events; the Carrington Event (the solar superstorm) is one of the few that had superlatives in three categories: size of solar flare, drop in Dst, and amplitude of aa. Kepler observations show that stars similar to the Sun can have flares releasing millions of times more energy than an X-class flare. These flares and the accompanying coronal mass ejections could strongly affect the atmosphere surrounding a planet. What level of solar activity would be necessary to strongly affect the atmosphere of the Earth? Can we map out the envelope of space weather along the evolution of the Sun? What would space weather look like if the Sun stopped producing a magnetic field? To what extreme should Space Weather go? These are the extremes of Space Weather explored in this talk.

  12. Data envelopment analysis of randomized ranks

    Directory of Open Access Journals (Sweden)

    Sant'Anna Annibal P.

    2002-01-01

    Full Text Available Probabilities and odds, derived from vectors of ranks, are here compared as measures of efficiency of decision-making units (DMUs. These measures are computed with the goal of providing preliminary information before starting a Data Envelopment Analysis (DEA or the application of any other evaluation or composition of preferences methodology. Preferences, quality and productivity evaluations are usually measured with errors or subject to influence of other random disturbances. Reducing evaluations to ranks and treating the ranks as estimates of location parameters of random variables, we are able to compute the probability of each DMU being classified as the best according to the consumption of each input and the production of each output. Employing the probabilities of being the best as efficiency measures, we stretch distances between the most efficient units. We combine these partial probabilities in a global efficiency score determined in terms of proximity to the efficiency frontier.

  13. Enhanced conformational sampling using enveloping distribution sampling.

    Science.gov (United States)

    Lin, Zhixiong; van Gunsteren, Wilfred F

    2013-10-14

    To lessen the problem of insufficient conformational sampling in biomolecular simulations is still a major challenge in computational biochemistry. In this article, an application of the method of enveloping distribution sampling (EDS) is proposed that addresses this challenge and its sampling efficiency is demonstrated in simulations of a hexa-β-peptide whose conformational equilibrium encompasses two different helical folds, i.e., a right-handed 2.7(10∕12)-helix and a left-handed 3(14)-helix, separated by a high energy barrier. Standard MD simulations of this peptide using the GROMOS 53A6 force field did not reach convergence of the free enthalpy difference between the two helices even after 500 ns of simulation time. The use of soft-core non-bonded interactions in the centre of the peptide did enhance the number of transitions between the helices, but at the same time led to neglect of relevant helical configurations. In the simulations of a two-state EDS reference Hamiltonian that envelops both the physical peptide and the soft-core peptide, sampling of the conformational space of the physical peptide ensures that physically relevant conformations can be visited, and sampling of the conformational space of the soft-core peptide helps to enhance the transitions between the two helices. The EDS simulations sampled many more transitions between the two helices and showed much faster convergence of the relative free enthalpy of the two helices compared with the standard MD simulations with only a slightly larger computational effort to determine optimized EDS parameters. Combined with various methods to smoothen the potential energy surface, the proposed EDS application will be a powerful technique to enhance the sampling efficiency in biomolecular simulations.

  14. Mechanistic understanding of N-glycosylation in Ebola virus glycoprotein maturation and function.

    Science.gov (United States)

    Wang, Bin; Wang, Yujie; Frabutt, Dylan A; Zhang, Xihe; Yao, Xiaoyu; Hu, Dan; Zhang, Zhuo; Liu, Chaonan; Zheng, Shimin; Xiang, Shi-Hua; Zheng, Yong-Hui

    2017-04-07

    The Ebola virus (EBOV) trimeric envelope glycoprotein (GP) precursors are cleaved into the receptor-binding GP 1 and the fusion-mediating GP 2 subunits and incorporated into virions to initiate infection. GP 1 and GP 2 form heterodimers that have 15 or two N -glycosylation sites (NGSs), respectively. Here we investigated the mechanism of how N -glycosylation contributes to GP expression, maturation, and function. As reported before, we found that, although GP 1 NGSs are not critical, the two GP 2 NGSs, Asn 563 and Asn 618 , are essential for GP function. Further analysis uncovered that Asn 563 and Asn 618 regulate GP processing, demannosylation, oligomerization, and conformation. Consequently, these two NGSs are required for GP incorporation into EBOV-like particles and HIV type 1 (HIV-1) pseudovirions and determine viral transduction efficiency. Using CRISPR/Cas9 technology, we knocked out the two classical endoplasmic reticulum chaperones calnexin (CNX) and/or calreticulin (CRT) and found that both CNX and CRT increase GP expression. Nevertheless, NGSs are not required for the GP interaction with CNX or CRT. Together, we conclude that, although Asn 563 and Asn 618 are not required for EBOV GP expression, they synergistically regulate its maturation, which determines its functionality. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

  15. Structures of phlebovirus glycoprotein Gn and identification of a neutralizing antibody epitope.

    Science.gov (United States)

    Wu, Yan; Zhu, Yaohua; Gao, Feng; Jiao, Yongjun; Oladejo, Babayemi O; Chai, Yan; Bi, Yuhai; Lu, Shan; Dong, Mengqiu; Zhang, Chang; Huang, Guangmei; Wong, Gary; Li, Na; Zhang, Yanfang; Li, Yan; Feng, Wen-Hai; Shi, Yi; Liang, Mifang; Zhang, Rongguang; Qi, Jianxun; Gao, George F

    2017-09-05

    Severe fever with thrombocytopenia syndrome virus (SFTSV) and Rift Valley fever virus (RVFV) are two arthropod-borne phleboviruses in the Bunyaviridae family, which cause severe illness in humans and animals. Glycoprotein N (Gn) is one of the envelope proteins on the virus surface and is a major antigenic component. Despite its importance for virus entry and fusion, the molecular features of the phleboviruse Gn were unknown. Here, we present the crystal structures of the Gn head domain from both SFTSV and RVFV, which display a similar compact triangular shape overall, while the three subdomains (domains I, II, and III) making up the Gn head display different arrangements. Ten cysteines in the Gn stem region are conserved among phleboviruses, four of which are responsible for Gn dimerization, as revealed in this study, and they are highly conserved for all members in Bunyaviridae Therefore, we propose an anchoring mode on the viral surface. The complex structure of the SFTSV Gn head and human neutralizing antibody MAb 4-5 reveals that helices α6 in subdomain III is the key component for neutralization. Importantly, the structure indicates that domain III is an ideal region recognized by specific neutralizing antibodies, while domain II is probably recognized by broadly neutralizing antibodies. Collectively, Gn is a desirable vaccine target, and our data provide a molecular basis for the rational design of vaccines against the diseases caused by phleboviruses and a model for bunyavirus Gn embedding on the viral surface.

  16. Restoration of glycoprotein Erns dimerization via pseudoreversion partially restores virulence of classical swine fever virus.

    Science.gov (United States)

    Tucakov, Anna Katharina; Yavuz, Sabine; Schürmann, Eva-Maria; Mischler, Manjula; Klingebeil, Anne; Meyers, Gregor

    2018-01-01

    The classical swine fever virus (CSFV) represents one of the most important pathogens of swine. The CSFV glycoprotein E rns is an essential structural protein and an important virulence factor. The latter is dependent on the RNase activity of this envelope protein and, most likely, its secretion from the infected cell. A further important feature with regard to its function as a virulence factor is the formation of disulfide-linked E rns homodimers that are found in virus-infected cells and virions. Mutant CSFV lacking cysteine (Cys) 171, the residue responsible for intermolecular disulfide bond formation, were found to be attenuated in pigs (Tews BA, Schürmann EM, Meyers G. J Virol 2009;83:4823-4834). In the course of an animal experiment with such a dimerization-negative CSFV mutant, viruses were reisolated from pigs that contained a mutation of serine (Ser) 209 to Cys. This mutation restored the ability to form disulphide-linked E rns homodimers. In transient expression studies E rns mutants carrying the S209C change were found to form homodimers with about wt efficiency. Also the secretion level of the mutated proteins was equivalent to that of wt E rns . Virus mutants containing the Cys171Ser/Ser209Cys configuration exhibited wt growth rates and increased virulence when compared with the Cys171Ser mutant. These results provide further support for the connection between CSFV virulence and E rns dimerization.

  17. Amino-terminal sequence of glycoprotein D of herpes simplex virus types 1 and 2

    International Nuclear Information System (INIS)

    Eisenberg, R.J.; Long, D.; Hogue-Angeletti, R.; Cohen, G.H.

    1984-01-01

    Glycoprotein D (gD) of herpes simplex virus is a structural component of the virion envelope which stimulates production of high titers of herpes simplex virus type-common neutralizing antibody. The authors caried out automated N-terminal amino acid sequencing studies on radiolabeled preparations of gD-1 (gD of herpes simplex virus type 1) and gD-2 (gD of herpes simplex virus type 2). Although some differences were noted, particularly in the methionine and alanine profiles for gD-1 and gD-2, the amino acid sequence of a number of the first 30 residues of the amino terminus of gD-1 and gD-2 appears to be quite similar. For both proteins, the first residue is a lysine. When we compared out sequence data for gD-1 with those predicted by nucleic acid sequencing, the two sequences could be aligned (with one exception) starting at residue 26 (lysine) of the predicted sequence. Thus, the first 25 amino acids of the predicted sequence are absent from the polypeptides isolated from infected cells

  18. Lipid Binding of the Amphipathic Helix Serving as Membrane Anchor of Pestivirus Glycoprotein Erns.

    Science.gov (United States)

    Aberle, Daniel; Oetter, Kay-Marcus; Meyers, Gregor

    2015-01-01

    Pestiviruses express a peculiar protein named Erns representing envelope glycoprotein and RNase, which is important for control of the innate immune response and persistent infection. The latter functions are connected with secretion of a certain amount of Erns from the infected cell. Retention/secretion of Erns is most likely controlled by its unusual membrane anchor, a long amphipathic helix attached in plane to the membrane. Here we present results of experiments conducted with a lipid vesicle sedimentation assay able to separate lipid-bound from unbound protein dissolved in the water phase. Using this technique we show that a protein composed of tag sequences and the carboxyterminal 65 residues of Erns binds specifically to membrane vesicles with a clear preference for compositions containing negatively charged lipids. Mutations disturbing the helical folding and/or amphipathic character of the anchor as well as diverse truncations and exchange of amino acids important for intracellular retention of Erns had no or only small effects on the proteins membrane binding. This result contrasts the dramatically increased secretion rates observed for Erns proteins with equivalent mutations within cells. Accordingly, the ratio of secreted versus cell retained Erns is not determined by the lipid affinity of the membrane anchor.

  19. Lipid Binding of the Amphipathic Helix Serving as Membrane Anchor of Pestivirus Glycoprotein Erns.

    Directory of Open Access Journals (Sweden)

    Daniel Aberle

    Full Text Available Pestiviruses express a peculiar protein named Erns representing envelope glycoprotein and RNase, which is important for control of the innate immune response and persistent infection. The latter functions are connected with secretion of a certain amount of Erns from the infected cell. Retention/secretion of Erns is most likely controlled by its unusual membrane anchor, a long amphipathic helix attached in plane to the membrane. Here we present results of experiments conducted with a lipid vesicle sedimentation assay able to separate lipid-bound from unbound protein dissolved in the water phase. Using this technique we show that a protein composed of tag sequences and the carboxyterminal 65 residues of Erns binds specifically to membrane vesicles with a clear preference for compositions containing negatively charged lipids. Mutations disturbing the helical folding and/or amphipathic character of the anchor as well as diverse truncations and exchange of amino acids important for intracellular retention of Erns had no or only small effects on the proteins membrane binding. This result contrasts the dramatically increased secretion rates observed for Erns proteins with equivalent mutations within cells. Accordingly, the ratio of secreted versus cell retained Erns is not determined by the lipid affinity of the membrane anchor.

  20. Chimeric rabies viruses for trans-species comparison of lyssavirus glycoprotein ectodomain functions in virus replication and pathogenesis.

    Science.gov (United States)

    Genz, Berit; Nolden, Tobias; Negatsch, Alexandra; Teifke, Jens-Peter; Conzelmann, Karl-Klaus; Finke, Stefan

    2012-01-01

    The glycoprotein G of lyssaviruses is the major determinant of virus pathogenicity and serves as a target for immunological responses to virus infections. However, assessment of the exact contribution of lyssavirus G proteins to observed differences in the pathogenicity of lyssavirus species is challenging, since the direct comparison of natural lyssaviruses does not allow specific ascription to individual virus proteins or domains. Here we describe the generation and characterization of recombinant rabies viruses (RABV) that express chimeric G proteins comprising of a RABV cytoplasma domain fused to transmembrane and ectodomain G sequences of a virulent RABV (challenge virus standard; CVS-11) or two European bat lyssaviruses (EBLV- and EBLV-2). These "envelope-switched" recombinant viruses were recovered from cDNAs. Similar growth kinetics and protein expression in neuroblastoma cell cultures and successful targeting of primary neurons showed that the chimeric G proteins were able to replace the authentic G protein in a RABV based virus vector. Inoculation of six week old CD-1 mice by the intracranial (i. c.) route of infection further demonstrated that all recombinant viruses were able to spread in the brain and to induce disease. The "envelope-switched" RABV therefore represent an important tool to further investigate the influence of lyssavirus ectodomains on virus tropism, and pathogenicity.

  1. Dynamic assembly of brambleberry mediates nuclear envelope fusion during early development.

    Science.gov (United States)

    Abrams, Elliott W; Zhang, Hong; Marlow, Florence L; Kapp, Lee; Lu, Sumei; Mullins, Mary C

    2012-08-03

    To accommodate the large cells following zygote formation, early blastomeres employ modified cell divisions. Karyomeres are one such modification, mitotic intermediates wherein individual chromatin masses are surrounded by nuclear envelope; the karyomeres then fuse to form a single mononucleus. We identified brambleberry, a maternal-effect zebrafish mutant that disrupts karyomere fusion, resulting in formation of multiple micronuclei. As karyomeres form, Brambleberry protein localizes to the nuclear envelope, with prominent puncta evident near karyomere-karyomere interfaces corresponding to membrane fusion sites. brambleberry corresponds to an unannotated gene with similarity to Kar5p, a protein that participates in nuclear fusion in yeast. We also demonstrate that Brambleberry is required for pronuclear fusion following fertilization in zebrafish. Our studies provide insight into the machinery required for karyomere fusion and suggest that specialized proteins are necessary for proper nuclear division in large dividing blastomeres. Copyright © 2012 Elsevier Inc. All rights reserved.

  2. Semiparametric Power Envelopes for Tests of the Unit Root Hypothesis

    DEFF Research Database (Denmark)

    Jansson, Michael

    This paper derives asymptotic power envelopes for tests of the unit root hypothesis in a zero-mean AR(1) model. The power envelopes are derived using the limits of experiments approach and are semiparametric in the sense that the underlying error distribution is treated as an unknown...

  3. Full waveform inversion using envelope-based global correlation norm

    Science.gov (United States)

    Oh, Ju-Won; Alkhalifah, Tariq

    2018-05-01

    To increase the feasibility of full waveform inversion on real data, we suggest a new objective function, which is defined as the global correlation of the envelopes of modelled and observed data. The envelope-based global correlation norm has the advantage of the envelope inversion that generates artificial low-frequency information, which provides the possibility to recover long-wavelength structure in an early stage. In addition, the envelope-based global correlation norm maintains the advantage of the global correlation norm, which reduces the sensitivity of the misfit to amplitude errors so that the performance of inversion on real data can be enhanced when the exact source wavelet is not available and more complex physics are ignored. Through the synthetic example for 2-D SEG/EAGE overthrust model with inaccurate source wavelet, we compare the performance of four different approaches, which are the least-squares waveform inversion, least-squares envelope inversion, global correlation norm and envelope-based global correlation norm. Finally, we apply the envelope-based global correlation norm on the 3-D Ocean Bottom Cable (OBC) data from the North Sea. The envelope-based global correlation norm captures the strong reflections from the high-velocity caprock and generates artificial low-frequency reflection energy that helps us recover long-wavelength structure of the model domain in the early stages. From this long-wavelength model, the conventional global correlation norm is sequentially applied to invert for higher-resolution features of the model.

  4. Calculation of CWKB envelope in boson and fermion productions

    Indian Academy of Sciences (India)

    Abstract. We present the calculation of envelope of boson and of both low- and high- mass fermion production at the end of inflation when the coherently oscillating inflatons decay into bosons and fermions. We consider three different models of inflation and use. CWKB technique to calculate the envelope to understand the ...

  5. 14 CFR 29.1517 - Limiting height-speed envelope.

    Science.gov (United States)

    2010-01-01

    ... 14 Aeronautics and Space 1 2010-01-01 2010-01-01 false Limiting height-speed envelope. 29.1517... Operating Limitations § 29.1517 Limiting height-speed envelope. For Category A rotorcraft, if a range of... following power failure, the range of heights and its variation with forward speed must be established...

  6. Beam envelope profile of non-centrosymmetric polygonal phase space

    International Nuclear Information System (INIS)

    Chen Yinbao; Xie Xi

    1984-01-01

    The general theory of beam envelope profile of non-centrosymmetric polygonal phase space is developed. By means of this theory the beam envelope profile of non-centrosymmetric polygonal phase space can be calculated directly. An example is carried out in detail to show the practical application of the theory

  7. A novel method for analysis of membrane microdomains: vesicular stomatitis virus glycoprotein microdomains change in size during infection, and those outside of budding sites resemble sites of virus budding

    International Nuclear Information System (INIS)

    Brown, Erica L.; Lyles, Douglas S.

    2003-01-01

    Membrane proteins, including viral envelope glycoproteins, may be organized into areas of locally high concentration, commonly referred to as membrane microdomains. Some viruses bud from detergent-resistant microdomains referred to as lipid rafts. However, vesicular stomatitis virus (VSV) serves as a prototype for viruses that bud from areas of plasma membrane that are not detergent resistant. We developed a new analytical method for immunoelectron microscopy data to determine whether the VSV envelope glycoprotein (G protein) is organized into plasma membrane microdomains. This method was used to quantify the distribution of the G protein in microdomains in areas of plasma membrane that did not contain budding sites. These microdomains were compared to budding virus envelopes to address the question of whether G protein-containing microdomains were formed only at the sites of budding. At early times postinfection, most of the G protein was organized into membrane microdomains outside of virus budding sites that were approximately 100-150 nm, with smaller amounts distributed into larger microdomains. In contrast to early times postinfection, the increased level of G protein in the host plasma membrane at later times postinfection led to distribution of G protein among membrane microdomains of a wider variety of sizes, rather than a higher G protein concentration in the 100- to 150-nm microdomains. VSV budding occurred in G protein-containing microdomains with a range of sizes, some of which were smaller than the virus envelope. These microdomains extended in size to a maximum of 300-400 nm from the tip of the budding virion. The data support a model for virus assembly in which G protein organizes into membrane microdomains that resemble virus envelopes prior to formation of budding sites, and these microdomains serve as the sites of assembly of internal virion components

  8. Involvement of viral envelope GP2 in Ebola virus entry into cells expressing the macrophage galactose-type C-type lectin

    International Nuclear Information System (INIS)

    Usami, Katsuaki; Matsuno, Keita; Igarashi, Manabu; Denda-Nagai, Kaori; Takada, Ayato; Irimura, Tatsuro

    2011-01-01

    Highlights: → Ebola virus infection is mediated by binding to and fusion with the target cells. → Structural feature of the viral glycoprotein determines the infectivity. → Surface C-type lectin, MGL, of macrophages and dendritic cells mediate the infection. → GP2, one of glycoprotein subunits, plays an essential role in MGL-mediated infection. → There is a critical amino acid residue involved in high infectivity. -- Abstract: Ebola virus (EBOV) infection is initiated by the interaction of the viral surface envelope glycoprotein (GP) with the binding sites on target cells. Differences in the mortality among different species of the Ebola viruses, i.e., Zaire ebolavirus (ZEBOV) and Reston ebolavirus (REBOV), correspond to the in vitro infectivity of the pseudo-typed virus constructed with the GPs in cells expressing macrophage galactose-type calcium-type lectin (MGL/CD301). Through mutagenesis of GP2, the transmembrane-anchored subunit of GP, we found that residues 502-527 of the GP2 sequence determined the different infectivity between VSV-ZEBOV GP and -REBOV GP in MGL/CD301-expressing cells and a histidine residue at position 516 of ZEBOV GP2 appeared essential in the differential infectivity. These findings may provide a clue to clarify a molecular basis of different pathogenicity among EBOV species.

  9. Involvement of viral envelope GP2 in Ebola virus entry into cells expressing the macrophage galactose-type C-type lectin

    Energy Technology Data Exchange (ETDEWEB)

    Usami, Katsuaki [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan); Matsuno, Keita; Igarashi, Manabu [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo 001-0020 (Japan); Denda-Nagai, Kaori [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan); Takada, Ayato [Department of Global Epidemiology, Hokkaido University Research Center for Zoonosis Control, Sapporo 001-0020 (Japan); Irimura, Tatsuro, E-mail: irimura@mol.f.u-tokyo.ac.jp [Laboratory of Cancer Biology and Molecular Immunology, Graduate School of Pharmaceutical Sciences, University of Tokyo, Tokyo 113-0033 (Japan)

    2011-04-01

    Highlights: {yields} Ebola virus infection is mediated by binding to and fusion with the target cells. {yields} Structural feature of the viral glycoprotein determines the infectivity. {yields} Surface C-type lectin, MGL, of macrophages and dendritic cells mediate the infection. {yields} GP2, one of glycoprotein subunits, plays an essential role in MGL-mediated infection. {yields} There is a critical amino acid residue involved in high infectivity. -- Abstract: Ebola virus (EBOV) infection is initiated by the interaction of the viral surface envelope glycoprotein (GP) with the binding sites on target cells. Differences in the mortality among different species of the Ebola viruses, i.e., Zaire ebolavirus (ZEBOV) and Reston ebolavirus (REBOV), correspond to the in vitro infectivity of the pseudo-typed virus constructed with the GPs in cells expressing macrophage galactose-type calcium-type lectin (MGL/CD301). Through mutagenesis of GP2, the transmembrane-anchored subunit of GP, we found that residues 502-527 of the GP2 sequence determined the different infectivity between VSV-ZEBOV GP and -REBOV GP in MGL/CD301-expressing cells and a histidine residue at position 516 of ZEBOV GP2 appeared essential in the differential infectivity. These findings may provide a clue to clarify a molecular basis of different pathogenicity among EBOV species.

  10. A Spectral Algorithm for Envelope Reduction of Sparse Matrices

    Science.gov (United States)

    Barnard, Stephen T.; Pothen, Alex; Simon, Horst D.

    1993-01-01

    The problem of reordering a sparse symmetric matrix to reduce its envelope size is considered. A new spectral algorithm for computing an envelope-reducing reordering is obtained by associating a Laplacian matrix with the given matrix and then sorting the components of a specified eigenvector of the Laplacian. This Laplacian eigenvector solves a continuous relaxation of a discrete problem related to envelope minimization called the minimum 2-sum problem. The permutation vector computed by the spectral algorithm is a closest permutation vector to the specified Laplacian eigenvector. Numerical results show that the new reordering algorithm usually computes smaller envelope sizes than those obtained from the current standard algorithms such as Gibbs-Poole-Stockmeyer (GPS) or SPARSPAK reverse Cuthill-McKee (RCM), in some cases reducing the envelope by more than a factor of two.

  11. Fusogenic properties of Sendai virosome envelopes in rat brain preparations.

    Science.gov (United States)

    de Fiebre, C M; Bryant, S O; Notabartolo, D; Wu, P; Meyer, E M

    1993-10-01

    Sendai virosomes were characterized with respect to their ability to bind to, fuse with, and introduce substances into several rat brain preparations. Encapsulation efficiency for Sendai virosomes was enhanced but binding to cerebral cortical P2 preparations was attenuated by addition of bovine brain phosphatidylcholine during reconstitution. A higher percentage of Sendai virosomes than phosphatidylcholine liposomes appeared to bind to, fuse with and subsequently deliver [14C]sucrose into osmotically labile pools of the P2 preparation. Fusogenic activity was estimated by measuring dequenching of fluorescently labelled N-NBD-phosphatidylethanolamine. More virosomally encapsulated [14C]sucrose was bound to the P2 fraction than introduced into osmotically labile organelles, and the fraction of vesicles undergoing fusion was intermediate between these two values. Non-encapsulated [14C]sucrose did not bind to and was not taken up by the P2 fraction in a quantifiable manner. Virosomal envelopes also bound to primary cultures of rat brain neurons and glia in an apparently saturable manner. Addition of increasing amounts of the adenoassociated virus-derived vector pJDT95 increased encapsulation efficiency, and virosomes reconstituted in the presence of 60 micrograms DNA retained most of their binding activity (5.4% of total label) compared to those containing [14C]sucrose alone (8.4%). These data indicate that Sendai virosomes may be useful in the delivery of substances into brain-derived tissues, potentially for the modulation of gene expression and neurotransmission.

  12. Overview of P-glycoprotein inhibitors: a rational outlook

    Directory of Open Access Journals (Sweden)

    Kale Mohana Raghava Srivalli

    2012-09-01

    Full Text Available P-glycoprotein (P-gp, a transmembrane permeability glycoprotein, is a member of ATP binding cassette (ABC super family that functions specifically as a carrier mediated primary active efflux transporter. It is widely distributed throughout the body and has a diverse range of substrates. Several vital therapeutic agents are substrates to P-gp and their bioavailability is lowered or a resistance is induced because of the protein efflux. Hence P-gp inhibitors were explored for overcoming multidrug resistance and poor bioavailability problems of the therapeutic P-gp substrates. The sensitivity of drug moieties to P-gp and vice versa can be established by various experimental models in silico, in vitro and in vivo. Ever since the discovery of P-gp, the research plethora identified several chemical structures as P-gp inhibitors. The aim of this review was to emphasize on the discovery and development of newer, inert, non-toxic, and more efficient, specifically targeting P-gp inhibitors, like those among the natural herb extracts, pharmaceutical excipients and formulations, and other rational drug moieties. The applications of cellular and molecular biology knowledge, in silico designed structural databases, molecular modeling studies and quantitative structure-activity relationship (QSAR analyses in the development of novel rational P-gp inhibitors have also been mentioned.Glicoproteína-p (P-gp, uma glicoproteína de transmembrana permeável, é um membro da superfamília (ABC de cassete de gene de ligação de ATP que funciona especificamente como um carreador mediado pelo transportador de efluxo ativo primário. É amplamente distribuído por todo o corpo e apresenta uma gama diversificada de substratos. Diversos agentes terapêuticos vitais são substratos para P-gp e sua biodisponibilidade é reduzida ou a resistência é induzida devido ao efluxo de proteínas. Portanto, os inibidores da P-gp foram explorados para a superação da resistência a

  13. Envelope enhancement increases cortical sensitivity to interaural envelope delays with acoustic and electric hearing.

    Directory of Open Access Journals (Sweden)

    Douglas E H Hartley

    Full Text Available Evidence from human psychophysical and animal electrophysiological studies suggests that sensitivity to interaural time delay (ITD in the modulating envelope of a high-frequency carrier can be enhanced using half-wave rectified stimuli. Recent evidence has shown potential benefits of equivalent electrical stimuli to deaf individuals with bilateral cochlear implants (CIs. In the current study we assessed the effects of envelope shape on ITD sensitivity in the primary auditory cortex of normal-hearing ferrets, and profoundly-deaf animals with bilateral CIs. In normal-hearing animals, cortical sensitivity to ITDs (±1 ms in 0.1-ms steps was assessed in response to dichotically-presented i sinusoidal amplitude-modulated (SAM and ii half-wave rectified (HWR tones (100-ms duration; 70 dB SPL presented at the best-frequency of the unit over a range of modulation frequencies. In separate experiments, adult ferrets were deafened with neomycin administration and bilaterally-implanted with intra-cochlear electrode arrays. Electrically-evoked auditory brainstem responses (EABRs were recorded in response to bipolar electrical stimulation of the apical pair of electrodes with singe biphasic current pulses (40 µs per phase over a range of current levels to measure hearing thresholds. Subsequently, we recorded cortical sensitivity to ITDs (±800 µs in 80-µs steps within the envelope of SAM and HWR biphasic-pulse trains (40 µs per phase; 6000 pulses per second, 100-ms duration over a range of modulation frequencies. In normal-hearing animals, nearly a third of cortical neurons were sensitive to envelope-ITDs in response to SAM tones. In deaf animals with bilateral CI, the proportion of ITD-sensitive cortical neurons was approximately a fifth in response to SAM pulse trains. In normal-hearing and deaf animals with bilateral CI the proportion of ITD sensitive units and neural sensitivity to ITDs increased in response to HWR, compared with SAM stimuli

  14. Synthetic glycopeptides and glycoproteins with applications in biological research

    Directory of Open Access Journals (Sweden)

    Ulrika Westerlind

    2012-05-01

    Full Text Available Over the past few years, synthetic methods for the preparation of complex glycopeptides have been drastically improved. The need for homogenous glycopeptides and glycoproteins with defined chemical structures to study diverse biological phenomena further enhances the development of methodologies. Selected recent advances in synthesis and applications, in which glycopeptides or glycoproteins serve as tools for biological studies, are reviewed. The importance of specific antibodies directed to the glycan part, as well as the peptide backbone has been realized during the development of synthetic glycopeptide-based anti-tumor vaccines. The fine-tuning of native chemical ligation (NCL, expressed protein ligation (EPL, and chemoenzymatic glycosylation techniques have all together enabled the synthesis of functional glycoproteins. The synthesis of structurally defined, complex glycopeptides or glyco-clusters presented on natural peptide backbones, or mimics thereof, offer further possibilities to study protein-binding events.

  15. Intracellular localization of hydroxyproline-rich glycoprotein biosynthesis

    International Nuclear Information System (INIS)

    Robinson, D.G.; Andreae, M.; Glas, A.R.; Sauer, A.

    1984-01-01

    The structural proteins of plant cell walls are glycoproteins characterized by O-glucosidic linkages to hydroxyproline or serine. Proline, not hydroxyproline, is the translatable amino acid in hydroxyproline-rich glycoproteins (HRGP). Hydroxylation and arabinosylation of proline are sequential, post-translational events. Because of this, there is no a priori reason for expecting HRGP synthesis to follow the well-established route for secretory and plasma membrane (PM) glycoproteins, i.e., from endoplasmic reticulum (ER) via the Golgi apparatus (GA) to the PM. In this paper, two plausible alternatives for HRGO secretion are examined. Because a feature of the majority of dicotyledons is overlapping GA and PM regions in sucrose density gradients, the authors have used two monocotyledonous systems to determine the distribution of HRGP and enzyme activity

  16. Australine, a pyrrolizidine alkaloid that inhibits amyloglucosidase and glycoprotein processing

    International Nuclear Information System (INIS)

    Tropea, J.E.; Molyneux, R.J.; Kaushal, G.P.; Pan, Y.T.; Mitchell, M.; Elbein, A.D.

    1989-01-01

    Australine is a polyhydroxylated pyrrolizidine alkaloid that was isolated from the seeds of the Australian tree Castanospermum australe and characterized by NMR and X-ray diffraction analysis. Since swainsonine and catanospermine are polyhydroxylated indolizidine alkaloids that inhibit specific glycosidases, the authors tested australine against a variety of exoglycosidases to determine whether it would inhibit any of these enzymes. This alkaloid proved to be a good inhibitor of the α-glucosidase amyloglucosidase (50% inhibition at 5.8 μM), but it did not inhibit β-glucosidase, α- or β-mannosidase, or α- or β-galactosidase. The inhibition of amyloglucosidase was of a competitive nature. Australine also inhibited the glycoprotein processing enzyme glucosidase I, but had only slight activity toward glucosidase II. When incubated with cultured cells, this alkaloid inhibited glycoprotein processing at the glucosidase I step and caused the accumulation of glycoproteins with Glc 3 Man 7-9 (GlcNAc) 2 -oligosaccharides

  17. Infectious Entry Pathway Mediated by the Human Endogenous Retrovirus K Envelope Protein.

    Science.gov (United States)

    Robinson, Lindsey R; Whelan, Sean P J

    2016-01-20

    Endogenous retroviruses (ERVs), the majority of which exist as degraded remnants of ancient viruses, comprise approximately 8% of the human genome. The youngest human ERVs (HERVs) belong to the HERV-K(HML-2) subgroup and were endogenized within the past 1 million years. The viral envelope protein (ENV) facilitates the earliest events of endogenization (cellular attachment and entry), and here, we characterize the requirements for HERV-K ENV to mediate infectious cell entry. Cell-cell fusion assays indicate that a minimum of two events are required for fusion, proteolytic processing by furin-like proteases and exposure to acidic pH. We generated an infectious autonomously replicating recombinant vesicular stomatitis virus (VSV) in which the glycoprotein was replaced by HERV-K ENV. HERV-K ENV imparts an endocytic entry pathway that requires dynamin-mediated membrane scission and endosomal acidification but is distinct from clathrin-dependent or macropinocytic uptake pathways. The lack of impediments to the replication of the VSV core in eukaryotic cells allowed us to broadly survey the HERV-K ENV-dictated tropism. Unlike extant betaretroviral envelopes, which impart a narrow species tropism, we found that HERV-K ENV mediates broad tropism encompassing cells from multiple mammalian and nonmammalian species. We conclude that HERV-K ENV dictates an evolutionarily conserved entry pathway and that the restriction of HERV-K to primate genomes reflects downstream stages of the viral replication cycle. Approximately 8% of the human genome is of retroviral origin. While many of those viral genomes have become inactivated, some copies of the most recently endogenized human retrovirus, HERV-K, can encode individual functional proteins. Here, we characterize the envelope protein (ENV) of the virus to define how it mediates infection of cells. We demonstrate that HERV-K ENV undergoes a proteolytic processing step and triggers membrane fusion in response to acidic pH--a strategy

  18. Boosting of HIV-1 neutralizing antibody responses by a distally related retroviral envelope protein.

    Science.gov (United States)

    Uchtenhagen, Hannes; Schiffner, Torben; Bowles, Emma; Heyndrickx, Leo; LaBranche, Celia; Applequist, Steven E; Jansson, Marianne; De Silva, Thushan; Back, Jaap Willem; Achour, Adnane; Scarlatti, Gabriella; Fomsgaard, Anders; Montefiori, David; Stewart-Jones, Guillaume; Spetz, Anna-Lena

    2014-06-15

    Our knowledge of the binding sites for neutralizing Abs (NAb) that recognize a broad range of HIV-1 strains (bNAb) has substantially increased in recent years. However, gaps remain in our understanding of how to focus B cell responses to vulnerable conserved sites within the HIV-1 envelope glycoprotein (Env). In this article, we report an immunization strategy composed of a trivalent HIV-1 (clade B envs) DNA prime, followed by a SIVmac239 gp140 Env protein boost that aimed to focus the immune response to structurally conserved parts of the HIV-1 and simian immunodeficiency virus (SIV) Envs. Heterologous NAb titers, primarily to tier 1 HIV-1 isolates, elicited during the trivalent HIV-1 env prime, were significantly increased by the SIVmac239 gp140 protein boost in rabbits. Epitope mapping of Ab-binding reactivity revealed preferential recognition of the C1, C2, V2, V3, and V5 regions. These results provide a proof of concept that a distally related retroviral SIV Env protein boost can increase pre-existing NAb responses against HIV-1. Copyright © 2014 by The American Association of Immunologists, Inc.

  19. Selection of unadapted, pathogenic SHIVs encoding newly transmitted HIV-1 envelope proteins.

    Science.gov (United States)

    Del Prete, Gregory Q; Ailers, Braiden; Moldt, Brian; Keele, Brandon F; Estes, Jacob D; Rodriguez, Anthony; Sampias, Marissa; Oswald, Kelli; Fast, Randy; Trubey, Charles M; Chertova, Elena; Smedley, Jeremy; LaBranche, Celia C; Montefiori, David C; Burton, Dennis R; Shaw, George M; Markowitz, Marty; Piatak, Michael; KewalRamani, Vineet N; Bieniasz, Paul D; Lifson, Jeffrey D; Hatziioannou, Theodora

    2014-09-10

    Infection of macaques with chimeric viruses based on SIVMAC but expressing the HIV-1 envelope (Env) glycoproteins (SHIVs) remains the most powerful model for evaluating prevention and therapeutic strategies against AIDS. Unfortunately, only a few SHIVs are currently available. Furthermore, their generation has required extensive adaptation of the HIV-1 Env sequences in macaques so they may not accurately represent HIV-1 Env proteins circulating in humans, potentially limiting their translational utility. We developed a strategy for generating large numbers of SHIV constructs expressing Env proteins from newly transmitted HIV-1 strains. By inoculating macaques with cocktails of multiple SHIV variants, we selected SHIVs that can replicate and cause AIDS-like disease in immunologically intact rhesus macaques without requiring animal-to-animal passage. One of these SHIVs could be transmitted mucosally. We demonstrate the utility of the SHIVs generated by this method for evaluating neutralizing antibody administration as a protection against mucosal SHIV challenge. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Lentiviral gene transfer into the dorsal root ganglion of adult rats

    Directory of Open Access Journals (Sweden)

    Park Frank

    2011-08-01

    Full Text Available Abstract Background Lentivector-mediated gene delivery into the dorsal root ganglion (DRG is a promising method for exploring pain pathophysiology and for genetic treatment of chronic neuropathic pain. In this study, a series of modified lentivector particles with different cellular promoters, envelope glycoproteins, and viral accessory proteins were generated to evaluate the requirements for efficient transduction into neuronal cells in vitro and adult rat DRG in vivo. Results In vitro, lentivectors expressing enhanced green fluorescent protein (EGFP under control of the human elongation factor 1α (EF1α promoter and pseudotyped with the conventional vesicular stomatitis virus G protein (VSV-G envelope exhibited the best performance in the transfer of EGFP into an immortalized DRG sensory neuron cell line at low multiplicities of infection (MOIs, and into primary cultured DRG neurons at higher MOIs. In vivo, injection of either first or second-generation EF1α-EGFP lentivectors directly into adult rat DRGs led to transduction rates of 19 ± 9% and 20 ± 8% EGFP-positive DRG neurons, respectively, detected at 4 weeks post injection. Transduced cells included a full range of neuronal phenotypes, including myelinated neurons as well as both non-peptidergic and peptidergic nociceptive unmyelinated neurons. Conclusion VSV-G pseudotyped lentivectors containing the human elongation factor 1α (EF1α-EGFP expression cassette demonstrated relatively efficient transduction to sensory neurons following direct injection into the DRG. These results clearly show the potential of lentivectors as a viable system for delivering target genes into DRGs to explore basic mechanisms of neuropathic pain, with the potential for future clinical use in treating chronic pain.

  1. Preparation of 131I-asialo-α1-acid glycoprotein

    International Nuclear Information System (INIS)

    Rijk, P.P. van

    1975-01-01

    α 1 -Acid glycoprotein (orosomucoid) was prepared from a byproduct of the ethanol plasma fractionation by means of ion-exchange procedures. Immunoelectrophoresis suggested a high degree of purity; the purified protein contained 13.5% sialic acid and 17.8% hexose. The α 1 -acid glycoprotein was modified by removal of sialic acid with neurominidase (E.C. 3.2.1.18) followed by iodination with 131 I. The purpose of the preparation, its potential use as a pharmacon for liver-function studies in nuclear medicine, is the subject of further study

  2. Intestinal mucus and juice glycoproteins have a liquid crystalline structure

    International Nuclear Information System (INIS)

    Denisova, E.A.; Lazarev, P.I.; Vazina, A.A.; Zheleznaya, L.A.

    1985-01-01

    X-ray diffraction patterns have been obtained from the following components of canine gastrointestinal tract: (1) native small intestine mucus layer; (2) the precipitate of the flocks formed in the duodenal juice with decreasing pH; (3) concentrated solutions of glycoproteins isolated from the duodenal juice. The X-ray patterns consist of a large number of sharp reflections of spacings between about 100 and 4 A. Some reflections are common for all components studied. All the patterns are interpreted as arising from the glycoprotein molecules ordered into a liquid crystalline structure. (author)

  3. Selecting Energy Efficient Building Envelope Retrofits to Existing Department of Defense Building Using Value Focused Thinking

    National Research Council Canada - National Science Library

    Pratt, David M

    2006-01-01

    ... these facilities that have the greatest potential for energy efficient building envelope retrofits. There are hundreds of various new building envelope technologies available to retrofit an existing building envelope, including window, roof, and wall technologies...

  4. Multidrug resistance gene expression is controlled by steroid hormones in the secretory epithelium of the uterus

    NARCIS (Netherlands)

    Arceci, R. J.; Baas, F.; Raponi, R.; Horwitz, S. B.; Housman, D.; Croop, J. M.

    1990-01-01

    The multidrug resistance (mdr) gene family has been shown to encode a membrane glycoprotein, termed the P-glycoprotein, which functions as a drug efflux pump with broad substrate specificity. This multigene family is expressed in a tissue-specific fashion in a wide variety of normal and neoplastic

  5. Three-Dimensionally Functionalized Reverse Phase Glycoprotein Array for Cancer Biomarker Discovery and Validation.

    Science.gov (United States)

    Pan, Li; Aguilar, Hillary Andaluz; Wang, Linna; Iliuk, Anton; Tao, W Andy

    2016-11-30

    Glycoproteins have vast structural diversity that plays an important role in many biological processes and have great potential as disease biomarkers. Here, we report a novel functionalized reverse phase protein array (RPPA), termed polymer-based reverse phase glycoprotein array (polyGPA), to capture and profile glycoproteomes specifically, and validate glycoproteins. Nitrocellulose membrane functionalized with globular hydroxyaminodendrimers was used to covalently capture preoxidized glycans on glycoproteins from complex protein samples such as biofluids. The captured glycoproteins were subsequently detected using the same validated antibodies as in RPPA. We demonstrated the outstanding specificity, sensitivity, and quantitative capabilities of polyGPA by capturing and detecting purified as well as endogenous α-1-acid glycoprotein (AGP) in human plasma. We further applied quantitative N-glycoproteomics and the strategy to validate a panel of glycoproteins identified as potential biomarkers for bladder cancer by analyzing urine glycoproteins from bladder cancer patients or matched healthy individuals.

  6. The limited role of recombination energy in common envelope removal

    Science.gov (United States)

    Grichener, Aldana; Sabach, Efrat; Soker, Noam

    2018-05-01

    We calculate the outward energy transport time by convection and photon diffusion in an inflated common envelope and find this time to be shorter than the envelope expansion time. We conclude therefore that most of the hydrogen recombination energy ends in radiation rather than in kinetic energy of the outflowing envelope. We use the stellar evolution code MESA and inject energy inside the envelope of an asymptotic giant branch star to mimic energy deposition by a spiraling-in stellar companion. During 1.7 years the envelope expands by a factor of more than 2. Along the entire evolution the convection can carry the energy very efficiently outwards, to the radius where radiative transfer becomes more efficient. The total energy transport time stays within several months, shorter than the dynamical time of the envelope. Had we included rapid mass loss, as is expected in the common envelope evolution, the energy transport time would have been even shorter. It seems that calculations that assume that most of the recombination energy ends in the outflowing gas might be inaccurate.

  7. Critical point analysis of phase envelope diagram

    Energy Technology Data Exchange (ETDEWEB)

    Soetikno, Darmadi; Siagian, Ucok W. R. [Department of Petroleum Engineering, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia); Kusdiantara, Rudy, E-mail: rkusdiantara@s.itb.ac.id; Puspita, Dila, E-mail: rkusdiantara@s.itb.ac.id; Sidarto, Kuntjoro A., E-mail: rkusdiantara@s.itb.ac.id; Soewono, Edy; Gunawan, Agus Y. [Department of Mathematics, Institut Teknologi Bandung, Jl. Ganesha 10, Bandung 40132 (Indonesia)

    2014-03-24

    Phase diagram or phase envelope is a relation between temperature and pressure that shows the condition of equilibria between the different phases of chemical compounds, mixture of compounds, and solutions. Phase diagram is an important issue in chemical thermodynamics and hydrocarbon reservoir. It is very useful for process simulation, hydrocarbon reactor design, and petroleum engineering studies. It is constructed from the bubble line, dew line, and critical point. Bubble line and dew line are composed of bubble points and dew points, respectively. Bubble point is the first point at which the gas is formed when a liquid is heated. Meanwhile, dew point is the first point where the liquid is formed when the gas is cooled. Critical point is the point where all of the properties of gases and liquids are equal, such as temperature, pressure, amount of substance, and others. Critical point is very useful in fuel processing and dissolution of certain chemicals. Here in this paper, we will show the critical point analytically. Then, it will be compared with numerical calculations of Peng-Robinson equation by using Newton-Raphson method. As case studies, several hydrocarbon mixtures are simulated using by Matlab.

  8. Critical point analysis of phase envelope diagram

    International Nuclear Information System (INIS)

    Soetikno, Darmadi; Siagian, Ucok W. R.; Kusdiantara, Rudy; Puspita, Dila; Sidarto, Kuntjoro A.; Soewono, Edy; Gunawan, Agus Y.

    2014-01-01

    Phase diagram or phase envelope is a relation between temperature and pressure that shows the condition of equilibria between the different phases of chemical compounds, mixture of compounds, and solutions. Phase diagram is an important issue in chemical thermodynamics and hydrocarbon reservoir. It is very useful for process simulation, hydrocarbon reactor design, and petroleum engineering studies. It is constructed from the bubble line, dew line, and critical point. Bubble line and dew line are composed of bubble points and dew points, respectively. Bubble point is the first point at which the gas is formed when a liquid is heated. Meanwhile, dew point is the first point where the liquid is formed when the gas is cooled. Critical point is the point where all of the properties of gases and liquids are equal, such as temperature, pressure, amount of substance, and others. Critical point is very useful in fuel processing and dissolution of certain chemicals. Here in this paper, we will show the critical point analytically. Then, it will be compared with numerical calculations of Peng-Robinson equation by using Newton-Raphson method. As case studies, several hydrocarbon mixtures are simulated using by Matlab

  9. The eikonal equation, envelopes and contact transformations

    International Nuclear Information System (INIS)

    Frittelli, Simonetta; Kamran, Niky; Newman, Ezra T

    2003-01-01

    We begin with an arbitrary but given conformal Lorentzian metric on an open neighbourhood, U, of a four-dimensional manifold (spacetime) and study families of solutions of the eikonal equation. In particular, the families that are of interest to us are the complete solutions. Their level surfaces form a two-parameter (points of S 2 ) family of foliations of U. We show that, from such a complete solution, it is possible to derive a pair of second-order PDEs defined solely on the parameter space S 2 , i.e., they have no reference to the spacetime points. We then show that if one uses the classical envelope method for the construction of new complete solutions from any given complete solution, then the new pair of PDEs (found from the new complete solution) is related to the old pair by contact transformations in the second jet bundle over S 2 . Further, we demonstrate that the pair of second-order PDEs obtained in this manner from any complete solution lies in a subclass of all pairs of second-order PDEs defined by the vanishing of a certain function obtained from the pair and is referred to as the generalized-Wuenschmann invariant. For completeness we briefly discuss the analogous issues associated with the eikonal equation in three dimensions. Finally we point out that conformally invariant geometric structures from the Lorentzian manifold have natural counterparts in the second jet bundle over S 2 on which the pair of PDEs lives

  10. Ecosystem functioning is enveloped by hydrometeorological variability.

    Science.gov (United States)

    Pappas, Christoforos; Mahecha, Miguel D; Frank, David C; Babst, Flurin; Koutsoyiannis, Demetris

    2017-09-01

    Terrestrial ecosystem processes, and the associated vegetation carbon dynamics, respond differently to hydrometeorological variability across timescales, and so does our scientific understanding of the underlying mechanisms. Long-term variability of the terrestrial carbon cycle is not yet well constrained and the resulting climate-biosphere feedbacks are highly uncertain. Here we present a comprehensive overview of hydrometeorological and ecosystem variability from hourly to decadal timescales integrating multiple in situ and remote-sensing datasets characterizing extra-tropical forest sites. We find that ecosystem variability at all sites is confined within a hydrometeorological envelope across sites and timescales. Furthermore, ecosystem variability demonstrates long-term persistence, highlighting ecological memory and slow ecosystem recovery rates after disturbances. However, simulation results with state-of-the-art process-based models do not reflect this long-term persistent behaviour in ecosystem functioning. Accordingly, we develop a cross-time-scale stochastic framework that captures hydrometeorological and ecosystem variability. Our analysis offers a perspective for terrestrial ecosystem modelling and paves the way for new model-data integration opportunities in Earth system sciences.

  11. Fullerenes and fulleranes in circumstellar envelopes

    International Nuclear Information System (INIS)

    Zhang, Yong; Kwok, Sun; Sadjadi, SeyedAbdolreza

    2016-01-01

    Three decades of search have recently led to convincing discoveries of cosmic fullerenes. The presence of C_6_0 and C"+ _6_0 in both circumstellar and interstellar environments suggests that these molecules and their derivatives can be efficiently formed in circumstellar envelopes and survive in harsh conditions. Detailed analysis of the infrared bands from fullerenes and their connections with the local properties can provide valuable information on the physical conditions and chemical processes that occurred in the late stages of stellar evolution. The identification of C"+ _6_0 as the carrier of four diffuse interstellar bands (DIBs) suggests that fullerene- related compounds are abundant in interstellar space and are essential for resolving the DIB mystery. Experiments have revealed a high hydrogenation rate when C_6_0 is exposed to atomic hydrogen, motivating the attempt to search for cosmic fulleranes. In this paper, we present a short review of current knowledge of cosmic fullerenes and fulleranes and briefly discuss the implications on circumstellar chemistry. (paper)

  12. Mining the O-mannose glycoproteome reveals cadherins as major O-mannosylated glycoproteins

    DEFF Research Database (Denmark)

    Vester-Christensen, Malene B; Halim, Adnan; Joshi, Hiren Jitendra

    2013-01-01

    The metazoan O-mannose (O-Man) glycoproteome is largely unknown. It has been shown that up to 30% of brain O-glycans are of the O-Man type, but essentially only alpha-dystroglycan (α-DG) of the dystrophin-glycoprotein complex is well characterized as an O-Man glycoprotein. Defects in O-Man...... glycosylation underlie congenital muscular dystrophies and considerable efforts have been devoted to explore this O-glycoproteome without much success. Here, we used our SimpleCell strategy using nuclease-mediated gene editing of a human cell line (MDA-MB-231) to reduce the structural heterogeneity of O-Man...... glycans and to probe the O-Man glycoproteome. In this breast cancer cell line we found that O-Man glycosylation is primarily found on cadherins and plexins on β-strands in extracellular cadherin and Ig-like, plexin and transcription factor domains. The positions and evolutionary conservation of O-Man...

  13. Envelope exchange for the generation of live-attenuated arenavirus vaccines.

    Directory of Open Access Journals (Sweden)

    Andreas Bergthaler

    2006-06-01

    Full Text Available Arenaviruses such as Lassa fever virus cause significant mortality in endemic areas and represent potential bioterrorist weapons. The occurrence of arenaviral hemorrhagic fevers is largely confined to Third World countries with a limited medical infrastructure, and therefore live-attenuated vaccines have long been sought as a method of choice for prevention. Yet their rational design and engineering have been thwarted by technical limitations. In addition, viral genes had not been identified that are needed to cause disease but can be deleted or substituted to generate live-attenuated vaccine strains. Lymphocytic choriomeningitis virus, the prototype arenavirus, induces cell-mediated immunity against Lassa fever virus, but its safety for humans is unclear and untested. Using this virus model, we have developed the necessary methodology to efficiently modify arenavirus genomes and have exploited these techniques to identify an arenaviral Achilles' heel suitable for targeting in vaccine design. Reverse genetic exchange of the viral glycoprotein for foreign glycoproteins created attenuated vaccine strains that remained viable although unable to cause disease in infected mice. This phenotype remained stable even after extensive propagation in immunodeficient hosts. Nevertheless, the engineered viruses induced T cell-mediated immunity protecting against overwhelming systemic infection and severe liver disease upon wild-type virus challenge. Protection was established within 3 to 7 d after immunization and lasted for approximately 300 d. The identification of an arenaviral Achilles' heel demonstrates that the reverse genetic engineering of live-attenuated arenavirus vaccines is feasible. Moreover, our findings offer lymphocytic choriomeningitis virus or other arenaviruses expressing foreign glycoproteins as promising live-attenuated arenavirus vaccine candidates.

  14. Envelope Exchange for the Generation of Live-Attenuated Arenavirus Vaccines.

    Directory of Open Access Journals (Sweden)

    2006-06-01

    Full Text Available Arenaviruses such as Lassa fever virus cause significant mortality in endemic areas and represent potential bioterrorist weapons. The occurrence of arenaviral hemorrhagic fevers is largely confined to Third World countries with a limited medical infrastructure, and therefore live-attenuated vaccines have long been sought as a method of choice for prevention. Yet their rational design and engineering have been thwarted by technical limitations. In addition, viral genes had not been identified that are needed to cause disease but can be deleted or substituted to generate live-attenuated vaccine strains. Lymphocytic choriomeningitis virus, the prototype arenavirus, induces cell-mediated immunity against Lassa fever virus, but its safety for humans is unclear and untested. Using this virus model, we have developed the necessary methodology to efficiently modify arenavirus genomes and have exploited these techniques to identify an arenaviral Achilles' heel suitable for targeting in vaccine design. Reverse genetic exchange of the viral glycoprotein for foreign glycoproteins created attenuated vaccine strains that remained viable although unable to cause disease in infected mice. This phenotype remained stable even after extensive propagation in immunodeficient hosts. Nevertheless, the engineered viruses induced T cell-mediated immunity protecting against overwhelming systemic infection and severe liver disease upon wild-type virus challenge. Protection was established within 3 to 7 d after immunization and lasted for approximately 300 d. The identification of an arenaviral Achilles' heel demonstrates that the reverse genetic engineering of live-attenuated arenavirus vaccines is feasible. Moreover, our findings offer lymphocytic choriomeningitis virus or other arenaviruses expressing foreign glycoproteins as promising live-attenuated arenavirus vaccine candidates.

  15. Shedding of soluble glycoprotein 1 detected during acute Lassa virus infection in human subjects

    Directory of Open Access Journals (Sweden)

    Momoh Mambu

    2010-11-01

    Full Text Available Abstract Background Lassa hemorrhagic fever (LHF is a neglected tropical disease with significant impact on the health care system, society, and economy of Western and Central African nations where it is endemic. With a high rate of infection that may lead to morbidity and mortality, understanding how the virus interacts with the host's immune system is of great importance for generating vaccines and therapeutics. Previous work by our group identified a soluble isoform of the Lassa virus (LASV GP1 (sGP1 in vitro resulting from the expression of the glycoprotein complex (GPC gene 12. Though no work has directly been done to demonstrate the function of this soluble isoform in arenaviral infections, evidence points to immunomodulatory effects against the host's immune system mediated by a secreted glycoprotein component in filoviruses, another class of hemorrhagic fever-causing viruses. A significant fraction of shed glycoprotein isoforms during viral infection and biogenesis may attenuate the host's inflammatory response, thereby enhancing viral replication and tissue damage. Such shed glycoprotein mediated effects were previously reported for Ebola virus (EBOV, a filovirus that also causes hemorrhagic fever with nearly 90% fatality rates 345. The identification of an analogous phenomenon in vivo could establish a new correlate of LHF infection leading to the development of sensitive diagnostics targeting the earliest molecular events of the disease. Additionally, the reversal of potentially untoward immunomodulatory functions mediated by sGP1 could potentiate the development of novel therapeutic intervention. To this end, we investigated the presence of sGP1 in the serum of suspected LASV patients admitted to the Kenema Government Hospital (KGH Lassa Fever Ward (LFW, in Kenema, Sierra Leone that tested positive for viral antigen or displayed classical signs of Lassa fever. Results It is reasonable to expect that a narrow window exists for

  16. Shedding of soluble glycoprotein 1 detected during acute Lassa virus infection in human subjects.

    Science.gov (United States)

    Branco, Luis M; Grove, Jessica N; Moses, Lina M; Goba, Augustine; Fullah, Mohammed; Momoh, Mambu; Schoepp, Randal J; Bausch, Daniel G; Garry, Robert F

    2010-11-09

    Lassa hemorrhagic fever (LHF) is a neglected tropical disease with significant impact on the health care system, society, and economy of Western and Central African nations where it is endemic. With a high rate of infection that may lead to morbidity and mortality, understanding how the virus interacts with the host's immune system is of great importance for generating vaccines and therapeutics. Previous work by our group identified a soluble isoform of the Lassa virus (LASV) GP1 (sGP1) in vitro resulting from the expression of the glycoprotein complex (GPC) gene [1, 2]. Though no work has directly been done to demonstrate the function of this soluble isoform in arenaviral infections, evidence points to immunomodulatory effects against the host's immune system mediated by a secreted glycoprotein component in filoviruses, another class of hemorrhagic fever-causing viruses. A significant fraction of shed glycoprotein isoforms during viral infection and biogenesis may attenuate the host's inflammatory response, thereby enhancing viral replication and tissue damage. Such shed glycoprotein mediated effects were previously reported for Ebola virus (EBOV), a filovirus that also causes hemorrhagic fever with nearly 90 percent fatality rates [3 - 5]. The identification of an analogous phenomenon in vivo could establish a new correlate of LHF infection leading to the development of sensitive diagnostics targeting the earliest molecular events of the disease. Additionally, the reversal of potentially untoward immunomodulatory functions mediated by sGP1 could potentiate the development of novel therapeutic intervention. To this end, we investigated the presence of sGP1 in the serum of suspected LASV patients admitted to the Kenema Government Hospital (KGH) Lassa Fever Ward (LFW), in Kenema, Sierra Leone that tested positive for viral antigen or displayed classical signs of Lassa fever. It is reasonable to expect that a narrow window exists for detection of sGP1 as the sole

  17. DATA ENVELOPMENT ANALYSIS OF BANKING SECTOR IN BANGLADESH

    Directory of Open Access Journals (Sweden)

    Md. Rashedul Hoque

    2012-05-01

    Full Text Available Banking sector of Bangladesh is flourishing and contributing to its economy. In this aspect measuring efficiency is important. Data Envelopment Analysis technique is used for this purpose. The data are collected from the annual reports of twenty four different banks in Bangladesh. Data Envelopment Analysis is mainly of two types - constant returns to scale and variable returns to scale. Since this study attempts to maximize output, so the output oriented Data Envelopment Analysis is used. The most efficient bank is one that obtains the highest efficiency score.

  18. Pre-paid envelopes commemorating the 2013 Open Days

    CERN Multimedia

    2013-01-01

    The post office on CERN's Prévessin site is still selling pre-paid envelopes commemorating the 2013 Open Days. Hurry while stocks last!   The special envelopes, which are valid in France for non-priority letters weighing up to 20 grams, are ideal for your Christmas and New Year correspondence. A set of ten envelopes, each featuring a different image, costs € 8.70 or 10 CHF. The post office is located in Building 866 on the Prévessin site and is open Mondays to Thursdays from 9.30 a.m. to 12.30 p.m.

  19. Characterization and interactome study of white spot syndrome virus envelope protein VP11.

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    Wang-Jing Liu

    Full Text Available White spot syndrome virus (WSSV is a large enveloped virus. The WSSV viral particle consists of three structural layers that surround its core DNA: an outer envelope, a tegument and a nucleocapsid. Here we characterize the WSSV structural protein VP11 (WSSV394, GenBank accession number AF440570, and use an interactome approach to analyze the possible associations between this protein and an array of other WSSV and host proteins. Temporal transcription analysis showed that vp11 is an early gene. Western blot hybridization of the intact viral particles and fractionation of the viral components, and immunoelectron microscopy showed that VP11 is an envelope protein. Membrane topology software predicted VP11 to be a type of transmembrane protein with a highly hydrophobic transmembrane domain at its N-terminal. Based on an immunofluorescence assay performed on VP11-transfected Sf9 cells and a trypsin digestion analysis of the virion, we conclude that, contrary to topology software prediction, the C-terminal of this protein is in fact inside the virion. Yeast two-hybrid screening combined with co-immunoprecipitation assays found that VP11 directly interacted with at least 12 other WSSV structural proteins as well as itself. An oligomerization assay further showed that VP11 could form dimers. VP11 is also the first reported WSSV structural protein to interact with the major nucleocapsid protein VP664.

  20. Interaction of E2 glycoprotein with heparan sulfate is crucial for cellular infection of Sindbis virus.

    Directory of Open Access Journals (Sweden)

    Wuyang Zhu

    Full Text Available Cell culture-adapted strains of Sindbis virus (SINV initially attach to cells by the ability to interact with heparan sulfate (HS through selective mutation for positively charged amino acid (aa scattered in E2 glycoprotein (W. B. Klimstra, K. D. Ryman, and R. E. Johnston, J. Virol. 72: 7357-7366, 1998. Here we have further confirmed that interaction of E2 protein with HS is crucial for cellular infection of SINV based on the reverse genetic system of XJ-160 virus, a Sindbis-like virus (SINLV. Both SINV YN87448 and SINLV XJ-160 displayed similar infectivity on BHK-21, Vero, or C6/36 cells, but XJ-160 failed to infect mouse embryonic fibroblast (MEF cells. The molecular mechanisms underlying the selective infectivity of XJ-160 were approached by substituting the E1, E2, or both genes of XJ-160 with that of YN87448, and the chimeric virus was denominated as XJ-160/E1, XJ-160/E2, or XJ-160/E1E2, respectively. In contrast to the parental XJ-160, all chimeric viruses became infectious to wild-type MEF cells (MEF-wt. While MEF-Ext(-/- cells, producing shortened HS chains, were resistant not only to XJ-160, but also to YN87448 as well as the chimeric viruses, indicating that the inability of XJ-160 to infect MEF-wt cells likely due to its incompetent discrimination of cellular HS. Treatment with heparin or HS-degrading enzyme resulted in a substantial decrease in plaque formation by YN87448, XJ-160/E2, and XJ-160/E1E2, but had marginal effect on XJ-160 and XJ-160/E1, suggesting that E2 glycoprotein from YN87448 plays a more important role than does E1 in mediating cellular HS-related cell infection. In addition, the peptide containing 145-150 aa from E2 gene of YN87448 specifically bound to heparin, while the corresponding peptide from the E2 gene of XJ-160 essentially showed no binding to heparin. As a new dataset, these results clearly confirm an essential role of E2 glycoprotein, especially the domain of 145-150 aa, in SINV cellular infection