TitleAbstractYear(sorted ascending)
alphavirus budding is dependent on the interaction between the nucleocapsid and hydrophobic amino acids on the cytoplasmic domain of the e2 envelope glycoprotein.the interaction between the nucleocapsid core and the glycoprotein spikes is a critical component in the budding process of alphaviruses. a molecular model was previously proposed which suggested that this interaction was mediated by the binding of the cytoplasmic domain of glycoprotein e2 into a hydrophobic pocket found on the surface of the nucleocapsid protein [s. lee, k. e. owen, h.-k. choi, h. lee, g. lu, g. wengler, d. t. brown, m. g. rossmann, and r. j. kuhn (1996) structure 4, 531-541; u ...19979143274
rotavirus contains integrin ligand sequences and a disintegrin-like domain that are implicated in virus entry into cells.rotavirus contains two outer capsid viral proteins, the spike protein vp4 and major capsid component vp7, both of which are implicated in cell entry. we show that vp4 and vp7 contain tripeptide sequences previously shown to act as recognition sites for integrins in extracellular matrix proteins. vp4 contains the alpha2beta1 integrin ligand site dge. in vp7, the alphaxbeta2 integrin ligand site gpr and the alpha4beta1 integrin ligand site ldv are embedded in a novel disintegrin-like domain that a ...19979144247
rapid diagnosis of dengue viremia by reverse transcriptase-polymerase chain reaction using 3'-noncoding region universal primers.a reverse transcriptase-polymerase chain reaction (rt-pcr) method was developed as a rapid diagnostic test of dengue viremia. to detect dengue viruses in serum or plasma specimens, a pair of universal primers was designed for use in the rt-pcr. using these primers, the 3'-noncoding region of dengue virus types 1, 2, 3, and 4 could be amplified, but not those of other flaviviruses, such as west nile virus, japanese encephalitis virus, and yellow fever virus, or the alphavirus sindbis virus. the s ...19979158052
construction of hepatitis c-sin virus recombinants with replicative dependency on hepatitis c virus serine protease in vivo assay system was developed for the serine protease of hepatitis c virus (hcv) using the sindbis (sin) viral replication system in which hcv serine protease activity is essential for the replication of the hcv-sin chimeric virus. two chimeric viral cdna clones were constructed by inserting the ns3/4a region and ns3/4a region with the putative helicase deleted, into the n-terminal region of sin core protein. the constructs were named tpro ct and tpro t, respectively. bhk-21 cells transf ...19979186943
construction and characterization of a reovirus double temperature-sensitive mutant.the infectious reovirus rna system was used to construct a mutant with two temperature-sensitive (ts) lesions in genome segments m2 and s2, respectively. the double mutant is about 300 times more ts than either of its parents, which are about 1,500 and 170 times more ts than their wild-type parent reovirus st3 strain dearing. at 39 degrees c the double mutant is essentially unable to multiply. in spite of its striking temperature sensitivity, the double mutant elicits the formation of significan ...19979192650
detection of expressed chloramphenicol acetyltransferase in the saliva of culex pipiens mosquitoes.mosquito salivary glands play an important role in the transmission of arthropod-borne pathogens. the ability to express genes in mosquitoes would be a powerful approach to characterize salivary gland genes, and to reveal important vector determinants of pathogen transmission. here we report the use of a double subgenomic sindbis (dssin) virus, designated te/3'2j/cat, and a packaged sindbis replicon virus, designated rep5/cat/26s, to express chloramphenicol acetyltransferase (cat) protein in the ...19979219368
effect of enforced expression of human bcl-2 on japanese encephalitis virus-induced apoptosis in cultured cells.infection by japanese encephalitis virus (jev), a mosquito-borne flavivirus, causes acute encephalitis in humans and induces severe cytopathic effects in different types of cultured cells. this study attempted to determine whether apoptosis contributes to virus-induced cell death in a culture system by characterizing jev lytic infection in baby hamster kidney bhk-21 cells, murine neuroblastoma n18 cells, and human neuronal progenitor nt2 cells. according to our results, the replication of jev, a ...19979223486
a single amino acid change in the e2 glycoprotein of sindbis virus confers neurovirulence by altering an early step of virus replication.amino acid changes in the envelope glycoproteins of sindbis virus have been linked to neurovirulence; however, the molecular mechanisms by which these amino acid changes alter neurovirulence are not known. recombinant-virus studies have mapped an important determinant of neurovirulence in adult mice to a single amino acid change, glutamine to histidine, at position 55 of the e2 glycoprotein (p. c. tucker, e. g. strauss, r. j. kuhn, j. h. strauss, and d. e. griffin, j. virol. 67:4605-4610, 1993). ...19979223504
amino acid changes in the sindbis virus e2 glycoprotein that increase neurovirulence improve entry into neuroblastoma cells.sindbis virus (sv) is an alphavirus that causes encephalitis in mice and results in age-dependent mortality. the outcome is dependent on the virus strain. residues at 55 and 172 in the e2 glycoprotein determine the neurovirulence for mice of different ages and the efficiency of replication in the nervous system and neuronal cells. to determine the effects of these two residues on the initial steps in replication, we studied viruses with a histidine or glutamine at e2 position 55 and a glycine or ...19979223505
transcriptional strategy of closteroviruses: mapping the 5' termini of the citrus tristeza virus subgenomic rnas.citrus tristeza virus (ctv) induces formation of a nested set of at least nine 3' coterminal subgenomic rnas (sgrnas) in infected tissue. the organization and expression of the 19,296-nucleotide (nt) ctv genome resembles that of coronaviruses, with polyprotein processing, translational frameshifting, and multiple sgrna formation, but phylogenetically the ctv polymerase, like polymerases of other closteroviruses, belongs to the sindbis virus-like lineage of rna virus polymerases. both positive-st ...19979223524
incorporation of beta-globin untranslated regions into a sindbis virus vector for augmentation of heterologous mrna expression.polynucleotide immunization has been employed as a means of inducing immune responses through the introduction of antigen-encoding dna. while immunization against specific tumor antigens may be achieved through this strategy, various candidate tumor antigens may not be approached via dna-based vaccines as they represent transforming oncogenes. as an alternative approach, we have explored the utility of mrna vectors for polynucleotide immunization. the transient expression achieved by mrna may pr ...19979231080
short-order sindbis vector targeting. 19979255777
cell-specific targeting of sindbis virus vectors displaying igg-binding domains of protein a.sindbis virus can infect a broad range of insect and vertebrate cell types due to the widespread distribution of the cellular receptor for the virus. the development of sindbis virus vectors that target specific cell types could have important implications for the design of gene therapy strategies. to achieve this goal we have designed and constructed sindbis virus particles displaying the igg-binding domain of protein a. the protein a-envelope chimeric sindbis virus vector has minimal infectivi ...19979255791
characterization of the infection of aedes albopictus cell clones by sindbis virus.we have investigated the infection of aedes albopictus (mosquito) cell clones by sindbis virus. variation in the multiplicity of infection (moi) from ranges of 50-0.00005 pfu/cell was determined to have no effect on the progression of the infection to high acute phase titer, suggesting that intracellular factors alone are responsible for the restriction of virus production seen as the infection enters the persistent phase: while persistently infected (over 1 year post infection) cell clones are ...19979255930
superinfection exclusion of alphaviruses in three mosquito cell lines persistently infected with sindbis virus.three aedes albopictus (mosquito) cell lines persistently infected with sindbis virus excluded the replication of both homologous (various strains of sindbis) and heterologous (aura, semliki forest, and ross river) alphaviruses. in contrast, an unrelated flavivirus, yellow fever virus, replicated equally well in uninfected and persistently infected cells of each line. sindbis virus and semliki forest virus are among the most distantly related alphaviruses, and our results thus indicate that mosq ...19979261447
heterogeneous nuclear ribonucleoprotein a1 binds to the transcription-regulatory region of mouse hepatitis virus rna.a cellular protein, previously described as p35/38, binds to the complementary (-)-strand of the leader rna and intergenic (ig) sequence of mouse hepatitis virus (mhv) rna. the extent of the binding of this protein to ig sites correlates with the efficiency of the subgenomic mrna transcription from that ig site, suggesting that it is a requisite transcription factor. we have purified this protein and determined by partial peptide sequencing that it is heterogeneous nuclear ribonucleoprotein (hnr ...19979275159
structure of l-a virus: a specialized compartment for the transcription and replication of double-stranded rna.the genomes of double-stranded (ds)rna viruses are never exposed to the cytoplasm but are confined to and replicated from a specialized protein-bound compartment-the viral capsid. we have used cryoelectron microscopy and three-dimensional image reconstruction to study this compartment in the case of l-a, a yeast virus whose capsid consists of 60 asymmetric dimers of gag protein (76 kd). at 16-a resolution, we distinguish multiple domains in the elongated gag subunits, whose nonequivalent packing ...19979281577
characterization of truncated forms of hepatitis c virus glycoproteins.hepatitis c virus (hcv) glycoproteins (e1 and e2) both contain a carboxy-terminal hydrophobic region, which presumably serves as a membrane anchor. when they are expressed in animal cell cultures, these glycoproteins, in both mature complexes and misfolded aggregates, are retained in the endoplasmic reticulum. the effect of carboxy-terminal deletions on hcv glycoprotein secretion and folding was examined in this study. sindbis and/or vaccinia virus recombinants expressing truncated forms of thes ...19979292018
[comparative analysis of expression of genes for 2',5'-oligoadenylate synthetase and mrna for dsrna-protein kinase in human fibroblasts infected with the sindbis alphavirus and induced by alpha-interferon].expression of 2,5-oas and ds-protein kinase (ds-pk) in human fibroblast culture following treatment with alpha-if in a dose of 1000 u or challenge with karelian fever virus (kfv) (5 pfu/cell, 4 h.p.i.) was compared. a highly sensitive and rapid method, coupled rt-pcr, was used to detect mrna transcription levels. alpha-if had an expressed stimulating effect on 2,5-oas mrna level, whereas the virus markedly inhibited the synthesis of ds-pk mrna.19979297349
the formation of intramolecular disulfide bridges is required for induction of the sindbis virus mutant ts23 phenotype.the sindbis virus envelope protein spike is a hetero-oligomeric complex composed of a trimer of glycoprotein e1-e2 heterodimers. spike assembly is a multistep process which occurs in the endoplasmic reticulum (er) and is required for the export of e1 from the er. pe2 (precursor to e2), however, can transit through the secretory pathway and be expressed at the cell surface in the absence of e1. although oligomer formation does not appear to be required for the export of pe2, there is evidence tha ...19979311853
sequence-specific recognition of a subgenomic rna promoter by a viral rna polymerase.rna templates of 33 nucleotides containing the brome mosaic virus (bmv) core subgenomic promoter were used to determine the promoter elements recognized by the bmv rna-dependent rna polymerase (rdrp) to initiate rna synthesis. nucleotides at positions -17, -14, -13, and -11 relative to the subgenomic initiation site must be maintained for interaction with the rdrp. changes to every other nucleotide at these four positions allow predictions for the base-specific functional groups required for rdr ...19979326593
[effect of the amide of 1-adamantanecarboxylic acid (aaca) and its combination with ribavirin on the course of experimental infection, caused by the sindbis virus in tissue culture and in mouse brain. possible isolation of the virus mutant resistant to ribavirin and to a combination of the inhibitors].it was shown advisable to use ribavirin (a weak inhibitor of sindbis virus reproduction) in combination with acaa. the effect observed was of marked synergistic nature. subcultures of the susceptible strain in the presence of ribavirin/ acaa did not lead to the development of resistance to acaa, ribavirin or their combination. the acaa resistant strain preserved its susceptibility to ribavirin after serial subcultures in the presence of both the inhibitors. however, no synergistic effect of the ...19979334146
expression of beta-galactosidase in mouse brain: utilization of a novel nonreplicative sindbis virus vector as a neuronal gene delivery system.sindbis virus expression has been used for in vitro investigations of antigen processing, presentation and epitope mapping. the recent development of a replication-deficient recombinant sindbis virus expression vector has made in vivo expression possible with minimal pathogenic risk. advantages of sindbis virus over other available viral systems include a comparatively smaller genome size making it possible to clone larger inserts, the ability to infect a wide range of host cell types with reduc ...19979338010
comparison of various expression plasmids for the induction of immune response by dna immunization.intramuscular injection of plasmid dna is an efficient method to introduce a foreign gene into a live animal. we investigated several factors affecting the gene transfer efficiency and the following immune response by intramuscular injection of plasmid dna. when the strength of several highly efficient viral promoters was compared in muscle by using the chloramphenicol acetyltransferase (cat) gene as an indicator, cytomegalovirus (cmv) immediate early promoter was found to be stronger than any o ...19979339893
regulators of apoptosis on the road to persistent alphavirus infection.alphavirus infection can trigger the host cell to activate its genetically programmed cell death pathway, leading to the morphological features of apoptosis. the ability to activate this death pathway is dependent on both viral and cellular determinants. the more virulent strains of alphavirus induce apoptosis with increased efficiency both in animal models and in some cultured cells. although the immune system clearly plays a central role in clearing virus, the importance of other cellular fact ...19979343360
cyclin dependent kinase inhibitors and dominant negative cyclin dependent kinase 4 and 6 promote survival of ngf-deprived sympathetic neurons.neuronal apoptosis plays a critical role in both normal development and disease. however, the precise molecular events controlling neuronal apoptosis are not well understood. previously, we hypothesized that cell cycle regulatory molecules function in controlling the apoptotic pathways of trophic factor-deprived neurons. to test this hypothesis, we used the rna alphavirus sindbis to express three known cyclin dependent kinase inhibitors (ckis), p16(ink4), p21(waf/cip), and p27(kip1), and dominan ...19979364045
a novel viral rna species in sindbis virus-infected cells.sindbis virus (sin), the type alphavirus, has been studied extensively to identify the viral cis-acting sequences and proteins involved in rna transcription and replication. however, very little is known about how these processes are coordinated. for example, synthesis of the genomic rna and the subgenomic mrna depends on the minus strand. do these activities occur independently on different templates, or can replication and transcription take place simultaneously on the same template? we descri ...19979371567
trans-complementation of yellow fever virus ns1 reveals a role in early rna replication.mutational analysis of the nonstructural protein 1 (ns1) of yellow fever virus (yf) has implicated it in viral rna replication. to further explore this observation, we sought a method for uncoupling ns1 function from ns1 expression and processing as part of the large yf polyprotein. here we describe a strategy for providing ns1 in trans, utilizing a noncytopathic sindbis virus vector. replication of a defective yf genome containing a large in-frame deletion of ns1 was dependent on functional exp ...19979371625
yeast mutations in multiple complementation groups inhibit brome mosaic virus rna replication and transcription and perturb regulated expression of the viral polymerase-like gene.brome mosaic virus (bmv), a member of the alphavirus-like superfamily of positive-strand rna viruses, encodes two proteins, 1a and 2a, that interact with each other, with unidentified host proteins, and with host membranes to form the viral rna replication complex. yeast expressing 1a and 2a support replication and subgenomic mrna synthesis by bmv rna3 derivatives. using a multistep selection and screening process, we have isolated yeast mutants in multiple complementation groups that inhibit bm ...19979391109
inactivation of the small gtpase rho disrupts cellular attachment and induces adhesion-dependent and adhesion-independent apoptosis.rho small gtpases regulate a variety of cellular signaling pathways involved in cell growth and transformation. in this study, we examined potential roles for rho in adhesion-dependent and -independent pathways regulating apoptosis. rho gtpases are specifically inactivated by exoenzyme c3 (c3) of clostridium botulinum. using a novel sindbis virus-based gene expression system, we created a double subgenomic recombinant (dssin:c3) capable of expressing active c3 in intact cells. infection of l929 ...19979393976
conversion of bcl-2 to a bax-like death effector by caspases.caspases are a family of cysteine proteases implicated in the biochemical and morphological changes that occur during apoptosis (programmed cell death). the loop domain of bcl-2 is cleaved at asp34 by caspase-3 (cpp32) in vitro, in cells overexpressing caspase-3, and after induction of apoptosis by fas ligation and interleukin-3 withdrawal. the carboxyl-terminal bcl-2 cleavage product triggered cell death and accelerated sindbis virus-induced apoptosis, which was dependent on the bh3 homology an ...19979395403
eps15 and eps15r are essential components of the endocytic pathway.eps15 and eps1sr are substrates of the epidermal growth factor (egf) receptor kinase that are characterized by the presence of a protein:protein interaction domain, the eh domain, and by their ability to bind to the clathrin adaptor protein complex adaptor protein 2. indirect evidence suggests that eps15 and eps15r are involved in endocytosis. here we show that microinjection of antibodies against eps15 and eps15r inhibits internalization of egf and transferrin. in addition, fragments of eps15 ( ...19979407958
the role of antibody in recovery from alphavirus encephalitis.alphaviruses infect neurons in the brain and spinal cord and cause acute encephalomyelitis in a variety of mammals. the outcome of infection is determined by whether the neurons survive infection and this, in turn, is determined by the virulence of the virus and the age of the host at the time of infection. we have been studying sindbis virus (sv) infection of mice as a model system for alphavirus-induced encephalomyelitis. investigation of intracerebral infection of weanling mice with two diffe ...19979416509
packaging signals in alphaviruses.alphaviruses synthesize large amounts of both genomic and subgenomic rna in infected cells, but usually only the genomic rna is packaged. this implies the existence of an encapsidation or packaging signal which would be responsible for selectivity. previously, we had identified a region of the sindbis virus genome that interacts specifically with the viral capsid protein. this 132-nucleotide (nt) fragment lies within the coding region of the nsp1 gene (nt 945 to 1076). we proposed that the 132-m ...19978985344
efficient multiplication of a semliki forest virus chimera containing sindbis virus spikes.using the semliki forest virus (sfv) and sindbis virus (sin) cdnas we have constructed recombinants in which the spike genes were exchanged. analyses of expression showed that the sfv/sin(spike) rna directed efficient assembly of infectious virus, whereas the reciprocal sin/sfv(spike) rna was completely unable to assemble virus. this was apparently due to a defective capsid-spike interaction.19978985423
chimeric sindbis viruses dependent on the ns3 protease of hepatitis c virus.the hepatitis c virus (hcv) ns3 protease cleaves the viral polyprotein at specific sites to release the putative components of the hcv replication machinery. selective inhibition of this enzyme is predicted to block virus replication, and ns3 is thus considered an attractive candidate for development of anti-hcv therapeutics. to set up a system for analysis of ns3 protease activity in cultured cells, we constructed a family of chimeric sindbis viruses which carry sequences coding for ns3 and its ...19978995667
role of glycoprotein pe2 in formation and maturation of the sindbis virus spike.sindbis virus envelope assembly is a multistep process resulting in the maturation of a rigid, highly ordered t=4 icosahedral protein lattice containing 80 spikes composed of trimers of e1-e2 heterodimers. intramolecular disulfide bonds within e1 stabilize e1-e1 associations required for envelope formation and maintenance of the envelope's structural integrity. the structural integrity of the envelope protein lattice is resistant to reduction by dithiothreitol (dtt), indicating that e1 disulfide ...19978995682
expression of a biologically active antiviral antibody using a sindbis virus vector system.monoclonal antibodies to the sindbis virus e2 envelope glycoprotein protect mice against lethal encephalitis and mediate viral clearance from neurons. to facilitate structure-function analyses of anti-e2 mabs, we developed an expression system that can be used for the construction of genetically engineered anti-e2 mabs. we constructed recombinant sindbis/immunoglobulin gene chimeric viruses that express heavy and light chains of an anti-e2 monoclonal antibody, r6. we used a pcr-based strategy to ...19979464526
infectious bursal disease virus polyprotein processing does not involve cellular proteases.the larger genome segment, segment a, of infectious bursal disease virus (ibdv) encodes vp2, vp3 and vp4 as a precursor polyprotein. the viral protease, vp4, is responsible for self-processing of the polyprotein, however, there are additional secondary precursor products such as vpx whose further processing has not been defined. expression of ibdv cdnas in vitro with rabbit reticulocyte lysates in a coupled transcription-translation system and in the sindbis virus expression system (with bhk-21 ...19979672603
sindbis virus infection of neonatal mice results in a severe stress response.neonatal mice were infected with virus derived from a molecular clone of a laboratory strain of sindbis virus, trsb. the resulting acute fatal infection was typified by few if any of the classic hallmarks of encephalitis, very high levels of interferon-alpha/beta (ifnalphabeta), and lesions in the thymus and hematopoietic tissues usually associated with a severe stress response. infection with an attenuated mutant of trsb, which harbors a single amino acid change in the e2 surface glycoprotein ( ...19979007079
a bcl-2 homolog encoded by kaposi sarcoma-associated virus, human herpesvirus 8, inhibits apoptosis but does not heterodimerize with bax or bak.the bcl-2 protein family is characterized by the ability to modulate cell death, and members of this family share two highly conserved domains called bcl-2 homology 1 (bh1) and 2 (bh2) which have been shown to be critical for the death-repressor activity of bcl-2 and bcl-xl. through sequence analysis we identified a novel viral bcl-2 homolog, designated ksbcl-2, from human herpesvirus 8 (hhv8) or kaposi sarcoma-associated herpesvirus. the overall amino acid sequence identity between ksbcl-2 and ...19979012846
monoclonal antibodies specific for semliki forest virus replicase protein nsp2.a panel of monoclonal antibodies (mabs) was raised against semliki forest virus (sfv) nonstructural protein nsp2, which is a protease, an ntpase, a putative rna helicase, and a regulator of the synthesis of the subgenomic 26s mrna encoding the structural proteins. nsp2, used for immunization, was expressed as a histidine fusion protein in escherichia coli and purified by metal affinity chromatography. dot-blot assay, using a membrane fraction from sfv-infected cells as antigen, gave 33 positive ...19979018056
complementation of and interference with sindbis virus replication by full-length and deleted forms of the nonstructural protein, nsp1, expressed in stable transfectants of hela cells.stable transfectants of hela cells were isolated which expressed either the full-length 540-amino-acid sindbis virus (sv) nonstructural protein, nsp1 (the form encoded by the mutant, sv(lm21)), or one of four forms with a carboxyl-terminal deletion. sv(lm21), in contrast to standard sv (sv(std)), can replicate in hela cells maintained in low-methionine (lm) medium. expression of full-length nsp1(1-540), nsp1(1-492), or nsp1(1-448) resulted in complementation of sv(std) when infected hela cells w ...19979018135
identification of mutations in a sindbis virus variant able to establish persistent infection in bhk cells: the importance of a mutation in the nsp2 gene.sindbis virus is a positive strand rna virus that has provided a valuable model for studying virus structure and replication. it is also being developed as a vector for the expression of heterologous proteins. many studies with this virus are carried out in cultured bhk cells where infection is usually highly cytopathic and within 1 or 2 days after infection all of the cells are dead. weiss et al. had established a persistently infected culture of bhk cells by infecting the cells with a virus pr ...19979024811
genus-specific detection of alphaviruses by a semi-nested reverse transcription-polymerase chain reaction.a reverse transcription-polymerase chain reaction (rt-pcr) was developed for the genus-specific detection of alphaviruses. based on the available published sequences, degenerate primers were designed to ensure hybridization to a conserved region within the nonstructural protein 1 gene of all alphavirus species. the expected 434-basepair (bp) cdna fragment was amplified from all 27 alphavirus species by using rna extracted from 200 microl of infected cell culture supernatant. in addition, eight s ...19979430533
self-amplifying vectors for gene delivery.current methods of gene transfer have a rather low efficiency, especially in vivo. therefore, one tries to achieve the highest possible levels of expression in the few cells that do take up foreign dna. one approach is to use self-amplifying expression vectors. these vectors are based on the (+)-strand rna viruses (alphaviruses) sindbis virus and semliki forest virus. in these vectors, the viral capsid protein coding sequences are replaced with the gene of interest. after introduction into the t ...199710837547
the evolution of virus-induced apoptosis.viruses from several different families are able to exploit their host's cell death programmes so as to maximize viral fitness. consideration of the evolution of such strategies has lead to the suggestion that the virus should inhibit apoptosis, in order to prolong the life of the cell and thereby maximize the number of progeny virions. the host, on the other hand, should stimulate apoptosis thereby inhibiting viral growth and blocking viral spread. for example, the function of the latent membra ...19979447732
[the mutiplication of sindbis virus and host bhk-21 cell apoptosis].the process of apoptosis of bhk-21 cells induced by sindbis virus (sbv) infection is reported here in details. the nuclear dna cleavage can be first detected at 6 h after sbv infection, followed by the chromatin margination and condensation at 12 h and the dna ladder can be detected at 24 h after infection. the details of apoptosis body's formation can be revealed by electron microscopy: first, the outer nuclear membrane protrudes where the condensed chromatin accumulates, then the chromatin get ...19979863210
pogosta disease: clinical observations during an outbreak in the province of north karelia, characterize the clinical picture of pogosta disease.19989851265
the alphavirus 3'-nontranslated region: size heterogeneity and arrangement of repeated sequence elements.the 3'-nontranslated region (ntr) of representative strains of all known alphavirus species was amplified by reverse transcription-polymerase chain reaction. for 23 of them, the 3'-ntr sequence was determined. together with previously published data, this allowed an analysis of the 3'-ntr of the viruses in the genus alphavirus. the length of the 3'-ntrs varied from 77 nt for pixuna virus to 609 nt for bebaru virus. the 19-nt conserved sequence element directly adjacent to the poly(a) tract was f ...19989448694
identification and genetic analysis of panama-genotype venezuelan equine encephalitis virus subtype id in peru.venezuelan equine encephalitis (vee) virus was isolated in 1993, 1994, and 1995 from human cases of acute, undifferentiated, febrile illness in the peruvian amazon basin. two virus isolates were recovered in 1994 from peruvian soldiers at a jungle outpost near pantoja in northern peru, and 10 isolates were obtained from military personnel and civilians in 1993-1995 in iquitos, an urban center in northeastern peru. the genetic relationship of these isolates to other vee virus strains was determin ...19989452290
comparison of sindbis virus-induced pathology in mosquito and vertebrate cell cultures.we have compared sindbis virus-induced cytopathology in vertebrate and mosquito (aedes albopictus) cell cultures. it has been shown that vertebrate cells undergo apoptosis when infected by sindbis virus and this was confirmed here using hamster cells (bhk). the occurrence of cell death in sindbis virus-infected a. albopictus cells is a cell clone-specific phenomenon and, unlike in bhk cell cultures, mosquito cell death does not correlate with a large induction of apoptosis, as determined by assa ...19989454692
modulation of cell death by bcl-xl through caspase interaction.the caspases are cysteine proteases that have been implicated in the execution of programmed cell death in organisms ranging from nematodes to humans. many members of the bcl-2 family, including bcl-xl, are potent inhibitors of programmed cell death and inhibit activation of caspases in cells. here, we report a direct interaction between caspases and bcl-xl. the loop domain of bcl-xl is cleaved by caspases in vitro and in cells induced to undergo apoptotic death after sindbis virus infection or ...19989435230
dna immunization against herpes simplex virus: enhanced efficacy using a sindbis virus-based vector.previously we reported the development of a plasmid dna expression vector system derived from sindbis virus (t. w. dubensky, jr., et al., j. virol. 70:508-519, 1996). in vitro, such vectors exhibit high-level heterologous gene expression via self-amplifying cytoplasmic rna replication. in the present study, we demonstrated the in vivo efficacy of the sindbis virus-based psin vectors as dna vaccines. a single intramuscular immunization of balb/c mice with psin vectors expressing the glycoprotein ...19989444987
molecular genetic study of the interaction of sindbis virus e2 with ross river virus e1 for virus budding.glycoprotein pe2 of sindbis virus will form a heterodimer with glycoprotein e1 of ross river virus that is cleaved to an e2/e1 heterodimer and transported to the cell plasma membrane, but this chimeric heterodimer fails to interact with sindbis virus nucleocapsids, and very little budding to produce mature virus occurs upon infection with chimeric viruses. we have isolated in both sindbis virus e2 and in ross river virus e1 a series of suppressing mutations that adapt these two proteins to one a ...19989445043
structural localization of the e3 glycoprotein in attenuated sindbis virus mutants.we have determined the three-dimensional structures of the wild-type sindbis virus and two of its mutants that retain the e3 sequence within pe2. using difference imaging between these mutants and the wild-type virus, we have assigned a location for the 64-amino-acid sequence corresponding to e3 in the mutant spike complex. in the wild-type virus, the spike is composed of an e1-e2 heterotrimer. the e3 protein was found to protrude midway between the center of the spike complex and the tips. base ...19989445057
removal of viruses from human intravenous immune globulin by 35 nm nanofiltration.viral safety is an important prerequisite for clinical immunoglobulin preparations. a common manufacturing practice is to utilize several virus removal/inactivation process steps to ensure the safety of human intravenous immunoglobulin (ivig). in this regard, we examined the use of planova 35 nm filters to reduce potential loads of both non-enveloped and enveloped viruses prior to end-stage solvent detergent treatment. the nanofiltration process was validated for removal of a variety of envelope ...199810403036
cell-specific transfection of choriocarcinoma cells by using sindbis virus hcg expressing chimeric vector.the development of sindbis virus vectors that can target specific cell types would provide an important gene therapy strategy. we explored the possibility of designing a sindbis virus vector that can target human choriocarcinoma cells via ligand-receptor interaction. the sindbis virus envelope gene was modified by insertion of the alpha- and beta-hcg genes. the chimeric helper rna was then transfected into bhk cells along with a virus-based expression vector, allowing the production of virus par ...19989675133
a novel method of cell-specific mrna this study, we developed a cell-specific mrna transfection system using streptavidin-protein a (st-pa) fusion protein and monoclonal antibodies (mabs). we previously reported that st-pa fusion protein and mab complexes can transfer certain biotinylated proteins into specific cell types. at this time, we combined an in vitro transcribed biotinylated and self-replicating sindbis virus genomic rna with st-pa fusion protein and mabs. in the presence of cationic liposomes, to prevent rna degradati ...19989682217
viral inactivation of human bone tissue using supercritical fluid extraction.a new bone tissue process using supercritical carbon dioxide fluid extraction (sfe) has been evaluated for its ability to inactivate or eliminate viruses. four viruses, human immunodeficiency virus type 1 (hiv-1), sindbis virus, polio sabin type i virus, and pseudorabies virus (prv), were exposed to four different processing steps. in addition to supercritical co2, hydrogen peroxide, sodium hydroxide, and ethanol treatments were evaluated. the mean cumulated reduction factors (log10) for the fou ...19989682954
characterization of a baculovirus-encoded rna 5'-triphosphatase.autographa californica nuclear polyhedrosis virus (acnpv) encodes a 168-amino-acid polypeptide that contains the signature motif of the superfamily of protein phosphatases that act via a covalent cysteinyl phosphate intermediate. the sequence of the acnpv phosphatase is similar to that of the rna triphosphatase domain of the metazoan cellular mrna capping enzyme. here, we show that the purified recombinant acnpv protein is an rna 5'-triphosphatase that hydrolyzes the gamma-phosphate of triphosph ...19989696798
interactions between the structural domains of the rna replication proteins of plant-infecting rna viruses.brome mosaic virus (bmv), a positive-strand rna virus, encodes two replication proteins: the 2a protein, which contains polymerase-like sequences, and the 1a protein, with n-terminal putative capping and c-terminal helicase-like sequences. these two proteins are part of a multisubunit complex which is necessary for viral rna replication. we have previously shown that the yeast two-hybrid assay consistently duplicated results obtained from in vivo rna replication assays and biochemical assays of ...19989696810
rescue of defective poliovirus rna replication by 3ab-containing precursor polyproteins.this study demonstrates the in vitro complementation of an rna replication-defective lesion in poliovirus rna by providing a replicase/polymerase precursor polypeptide [p3(wt) (wild type)] in trans. the replication-defective mutation was a phenylalanine-to-histidine change (f69h) in the hydrophobic domain of the membrane-associated viral protein 3ab. rnas encoding wild-type forms of protein 3ab or the p3 precursor polypeptide were cotranslated with full-length poliovirus rnas containing the f69h ...19989696813
trans-complementation of flavivirus rna polymerase gene ns5 by using kunjin virus replicon-expressing bhk cells.a bhk cell line persistently expressing a kunjin (kun) virus replicon rna (repbhk, similar to our recently described me/76neo bhk cell line [a. a. khromykh and e. g. westaway, j. virol. 71:1497-1505, 1997]) was used for rescue and propagation of kun viruses defective in the rna polymerase gene (ns5). a new infectious full-length kun virus cdna clone, flsdx, prepared from our previously described cdna clone pakun (a. a. khromykh and e. g. westaway, j. virol. 68:4580-4588, 1994) and possessing app ...19989696822
binding of sindbis virus to cell surface heparan sulfate.alphaviruses are arthropod-borne viruses with wide species ranges and diverse tissue tropisms. the cell surface receptors which allow infection of so many different species and cell types are still incompletely characterized. we show here that the widely expressed glycosaminoglycan heparan sulfate can participate in the binding of sindbis virus to cells. enzymatic removal of heparan sulfate or the use of heparan sulfate-deficient cells led to a large reduction in virus binding. sindbis virus bou ...19989696831
adaptation of sindbis virus to bhk cells selects for use of heparan sulfate as an attachment receptor.attachment of sindbis virus to the cell surface glycosaminoglycan heparan sulfate (hs) and the selection of this phenotype by cell culture adaptation were investigated. virus (tr339) was derived from a cdna clone representing the consensus sequence of strain ar339 (k. l. mcknight, d. a. simpson, s. c. lin, t. a. knott, j. m. polo, d. f. pence, d. b. johannsen, h. w. heidner, n. l. davis, and r. e. johnston, j. virol. 70:1981-1989, 1996) and from mutant clones containing either one or two dominan ...19989696832
identification of specific nucleotide sequences within the conserved 3'-sl in the dengue type 2 virus genome required for replication.the flavivirus genome is a positive-stranded approximately 11-kb rna including 5' and 3' noncoding regions (ncr) of approximately 100 and 400 to 600 nucleotides (nt), respectively. the 3' ncr contains adjacent, thermodynamically stable, conserved short and long stem-and-loop structures (the 3'-sl), formed by the 3'-terminal approximately 100 nt. the nucleotide sequences within the 3'-sl are not well conserved among species. we examined the requirement for the 3'-sl in the context of dengue virus ...19989696848
classical swine fever virus leader proteinase npro is not required for viral replication in cell culture.the sequence encoding the viral leader proteinase npro was replaced by the murine ubiquitin gene in a full-length cdna clone of the classical swine fever virus (csfv) strain alfort/187. the recombinant virus va187-ubi showed growth characteristics similar to those of the parent va187-1 virus. at two occasions cells infected with va187-ubi exhibited a cytopathic effect and were found to contain a subgenomic viral rna. this rna lacked the same viral genes as the subgenomic rna which has been found ...19989696875
the clathrin endocytic pathway in viral important is the clathrin-dependent endocytic pathway for entry of viruses into host cells? while it is widely accepted that semliki forest virus (sfv), an enveloped virus, requires this pathway there are conflicting data concerning the closely related sindbis virus, as well as varying results with picornaviruses such as human rhinovirus 14 (hrv 14) and poliovirus. we have examined the entry mode of sfv, sindbis virus, hrv 14 and poliovirus using a method that identifies single infected cell ...19989707418
elevated extracellular calcium can prevent apoptosis via the calcium-sensing receptor.the calcium-sensing receptor (car) is a membrane-bound, g-protein-coupled receptor present on parathyroid cells which monitors the level of extracellular calcium (ca2+o) and transduces signals involved in serum calcium regulation. expression of car protein in tissues with functions unrelated to systemic calcium homeostasis, including the brain, suggests that extracellular calcium (ca2+o) may act as a first messenger to regulate diverse cellular functions. to test this hypothesis, we examined the ...19989712695
the role of low ph and disulfide shuffling in the entry and fusion of semliki forest virus and sindbis virus.semliki forest virus (sfv), an enveloped alphavirus, infects cells via a membrane fusion reaction that is induced by the low ph in endocytic vesicles. the role of low ph in the entry of the alphavirus sindbis virus (sin) is unclear, and an alternative fusion mechanism involving receptor-induced disulfide bond rearrangements at neutral ph has been proposed. the entry properties of sfv and sin were here compared in parallel using treatment with the weak base nh4cl or the vacuolar atpase inhibitors ...19989721245
cleavage of highly structured viral rna molecules by combinatorial libraries of hairpin ribozymes. the most effective ribozymes are not predicted by substrate selection rules.combinatorial libraries of hairpin ribozymes representing all possible cleavage specificities (>10(5)) were used to evaluate all ribozyme cleavage sites within a large (4.2-kilobase) and highly structured viral mrna, the 26 s subgenomic rna of sindbis virus. the combinatorial approach simultaneously accounts for target site structure and dynamics, together with ribozyme folding, and the sequences that result in a ribozyme-substrate complex with maximal activity. primer extension was used to map ...19989722591
use of the sindbis replicon system for expression of lacrosse virus envelope proteins in mosquito cells.the sindbis replicon expression system was used to express la crosse (lac) virus envelope glycoprotein genes in both mammalian and mosquito cell culture. replicon expressed lac proteins had correct molecular mass (mr) and were antigenically similar to wild type lac envelope proteins. in addition, lac g1 and g2 proteins colocalized when expressed from separate constructs in both mammalian and mosquito cells suggesting that they were trafficked through the cell similarly to wild type lac proteins. ...19989722880
analysis of constructed e gene mutants of mouse hepatitis virus confirms a pivotal role for e protein in coronavirus assembly.expression studies have shown that the coronavirus small envelope protein e and the much more abundant membrane glycoprotein m are both necessary and sufficient for the assembly of virus-like particles in cells. as a step toward understanding the function of the mouse hepatitis virus (mhv) e protein, we carried out clustered charged-to-alanine mutagenesis on the e gene and incorporated the resulting mutations into the mhv genome by targeted recombination. of the four possible clustered charged-t ...19989733825
comparison of the neurovirulence of a vaccine and a wild-type mumps virus strain in the developing rat brain.prior to the adoption of widespread vaccination programs, mumps virus was the leading cause of virus-induced central nervous system (cns) disease. mumps virus-associated cns complications in vaccinees continue to be reported; outside the united states, some of these complications have been attributed to vaccination with insufficiently attenuated neurovirulent vaccine strains. the development of potentially neurovirulent, live, attenuated mumps virus vaccines stems largely from the lack of an ani ...19989733843
measles virus fusion protein is palmitoylated on transmembrane-intracytoplasmic cysteine residues which participate in cell fusion.[3h]palmitic acid was metabolically incorporated into the viral fusion protein (f) of edmonston or freshly isolated measles virus (mv) during infection of human lymphoid or vero cells. the uncleaved precursor f0 and the f1 subunit from infected cells and extracellular virus were both labeled, indicating that palmitoylation can take place prior to f0 cleavage and that palmitoylated f protein was incorporated into virus particles. [3h]palmitic acid was released from f protein upon hydroxylamine or ...19989733862
effects of site-directed mutations of transmembrane cysteines in sindbis virus e1 and e2 glycoproteins on palmitylation and virus replication.the two glycoproteins that form the external spikes of the alphaviruses are type 1 membrane proteins whose transmembrane domains of hydrophobic amino acids are close to the carboxyl termini of the polypeptides and anchor the proteins in the lipid bilayer. most of the members of the alphavirus genus contain within this transmembrane sequence one or more highly conserved cysteines, which are positioned close to the cytoplasmic face of the lipid bilayer. cysteines in the cytoplasmic domains of the ...19989740777
the susceptibility of mice to immune-mediated neurologic disease correlates with the degree to which their lymphocytes resist the effects of brain-derived gangliosides.sjl mice develop immune-mediated disorders of the central nervous system (cns) when infected with certain neurotropic viruses or when immunized with myelin ags. other strains including balb/c are more resistant to these diseases. during sindbis virus-induced encephalitis, both mice are easily infected and elicit rapid mononuclear cell inflammation in the brain. however, only sjl mice develop immune-mediated paralysis; balb/c mice remain asymptomatic. to understand how the same stimulus produces ...19989743332
differential downstream functions of protein kinase ceta and -theta in el4 mouse thymoma cells.sensitive el4 mouse thymoma cells (s-el4) respond to phorbol esters with growth inhibition, adherence to substrate, and production of cytokines including interleukin 2. since these cells express several of the phorbol ester-sensitive protein kinase c (pkc) isozymes, the function of each isozyme remains unclear. previous studies demonstrated that s-el4 cells expressed substantially more pkceta and pkctheta than did el4 cells resistant to phorbol esters (r-el4). to examine potential roles for pkce ...19989765301
protection against fatal sindbis virus encephalitis by beclin, a novel bcl-2-interacting protein.bcl-2, the prototypic cellular antiapoptotic gene, decreases sindbis virus replication and sindbis virus-induced apoptosis in mouse brains, resulting in protection against lethal encephalitis. to investigate potential mechanisms by which bcl-2 protects against central nervous system sindbis virus infection, we performed a yeast two-hybrid screen to identify bcl-2-interacting gene products in an adult mouse brain library. we identified a novel 60-kda coiled-coil protein, beclin, which we confirme ...19989765397
ribosomal s27a coding sequences upstream of ubiquitin coding sequences in the genome of a pestivirus.molecular characterization of cytopathogenic (cp) bovine viral diarrhea virus (bvdv) strain cp rit, a temperature-sensitive strain widely used for vaccination, revealed that the viral genomic rna is about 15.2 kb long, which is about 2.9 kb longer than the one of noncytopathogenic (noncp) bvdv strains. molecular cloning and nucleotide sequencing of parts of the genome resulted in the identification of a duplication of the genomic region encoding nonstructural proteins ns3, ns4a, and part of ns4b ...19989765411
isolation of an arabidopsis thaliana mutant in which the multiplication of both cucumber mosaic virus and turnip crinkle virus is affected.during the systemic infection of plants by viruses, host factors play an important role in supporting virus multiplication. to identify and characterize the host factors involved in this process, we isolated an arabidopsis thaliana mutant named rb663, in which accumulation of the coat protein (cp) of cucumber mosaic virus (cmv) in upper uninoculated leaves was delayed. genetic analyses suggested that the phenotype of delayed accumulation of cmv cp in rb663 plants was controlled by a monogenic, r ...19989765416
neuronal death induced by brain-derived human immunodeficiency virus type 1 envelope genes differs between demented and nondemented aids patients.human immunodeficiency virus type 1 (hiv-1) infection of the brain results in viral replication primarily in macrophages and microglia. despite frequent detection of viral genome and proteins in the brains of aids patients with and without hiv dementia, only 20% of aids patients become demented. to investigate the role of viral envelope gene variation in the occurrence of dementia, we examined regions of variability in the viral envelope gene isolated from brains of aids patients. brain-derived ...19989765449
inhibition of nf-kappab activation in combination with bcl-2 expression allows for persistence of first-generation adenovirus vectors in the mouse is a key regulator of the innate antiviral immune response, due in part to its transcriptional activation of cytokines and adhesion molecules, which, in turn, function in chemotaxis and activation of inflammatory cells. we reported earlier that viral gene expression in hepatocytes transduced with first-generation (e1-deleted) adenoviruses induced nf-kappab activation, elevation of serum cytokines, and hepatocellular apoptosis during the first days postinfusion. these events did not occ ...19989765474
protease inhibitors as antiviral agents.currently, there are a number of approved antiviral agents for use in the treatment of viral infections. however, many instances exist in which the use of a second antiviral agent would be beneficial because it would allow the option of either an alternative or a combination therapeutic approach. accordingly, virus-encoded proteases have emerged as new targets for antiviral intervention. molecular studies have indicated that viral proteases play a critical role in the life cycle of many viruses ...19989767059
characterization of la crosse virus rna in autopsied central nervous system tissues.a reverse transcription-pcr (rt-pcr) technique was used to detect la crosse (lac) virus rna in the central nervous system (cns) tissues of two patients who died of lac encephalitis in 1960 and 1978. viral rna was readily detected by rt-pcr although the tissues had been stored frozen for up to 37 years. lac virus was detected in the cerebral cortex but not in other cns tissues. rt-pcr allowed detection of replicative forms of the virus, indicating that the virus was actively replicating in the sp ...19989774588
probing the potential glycoprotein binding site of sindbis virus capsid protein with dioxane and model building.alphavirus budding from the plasma membrane is initiated by the specific interaction of the nucleocapsid with the cytoplasmic domain of the glycoprotein e2. it was proposed (lee et al., structure 4:531-541, 1996) that binding of the capsid protein residues 108 to 110 (the "n-terminal arm" residues) to a hydrophobic pocket on the surface of the neighboring capsid protein in the crystal structure mimics the binding of the e2 c-terminal residues into this pocket. in addition, structural comparisons ...19989779796
fractalkine and cx3cr1 mediate a novel mechanism of leukocyte capture, firm adhesion, and activation under physiologic flow.leukocyte migration into sites of inflammation involves multiple molecular interactions between leukocytes and vascular endothelial cells, mediating sequential leukocyte capture, rolling, and firm adhesion. in this study, we tested the role of molecular interactions between fractalkine (fkn), a transmembrane mucin-chemokine hybrid molecule expressed on activated endothelium, and its receptor (cx3cr1) in leukocyte capture, firm adhesion, and activation under physiologic flow conditions. immobiliz ...19989782118
human biliary glycoproteins function as receptors for interspecies transfer of mouse hepatitis virus.a variant mouse hepatitis virus (mhv), designated mhv-h2, was isolated by serial passage in mixed cultures of permissive dbt cells and nonpermissive syrian hamster kidney (bhk) cells. mhv-h2 replicated efficiently in hamster, mouse, primate kidney (vero, cos 1, cos 7), and human adenocarcinoma (hrt) cell lines but failed to replicate in porcine testicular (st), feline kidney (crfk), and canine kidney (mdck) cells. to understand the molecular basis for coronavirus cross-species transfer into huma ...19989782263
effect of clostridium difficile toxin a on human colonic lamina propria cells: early loss of macrophages followed by t-cell apoptosis.we have previously shown that clostridium difficile toxin a induces detachment of human colonic epithelial cells from the basement membrane and subsequent cell death by apoptosis. because these cells require adhesion-dependent signalling from the extracellular matrix for survival, their detachment from the basement membrane by other means also induces apoptosis. the role of toxin a in the induction of apoptosis therefore remains to be determined. in addition, sensitivities to c. difficile toxin ...19989784558
cyclin-dependent kinases participate in death of neurons evoked by dna-damaging agents.previous reports have indicated that dna-damaging treatments including certain anticancer therapeutics cause death of postmitotic nerve cells both in vitro and in vivo. accordingly, it has become important to understand the signaling events that control this process. we recently hypothesized that certain cell cycle molecules may play an important role in neuronal death signaling evoked by dna damage. consequently, we examined whether cyclin-dependent kinase inhibitors (ckis) and dominant-negativ ...19989786955
rna virus vectors: where are we and where do we need to go? 19989788984
noncytopathic sindbis virus rna vectors for heterologous gene expression.infection of vertebrate cells with alphaviruses normally leads to prodigious expression of virus-encoded genes and a dramatic inhibition of host protein synthesis. recombinant sindbis viruses and replicons have been useful as vectors for high level foreign gene expression, but the cytopathic effects of viral replication have limited their use to transient studies. we recently selected sindbis replicons capable of persistent, noncytopathic growth in bhk cells and describe here a new generation of ...19989789028
a review of alphavirus replication in neurons.alphaviruses are important causes of mosquito-borne viral encephalitis. the prototype alphavirus, sindbis virus, causes encephalomyelitis in mice. the primary target cell for nervous system infection is the neuron. thus, sindbis virus infection of mice provides a model system for studying virus-neuron interactions. the outcome of infection is dependent on the maturity of the targeted neurons and on the strain of sindbis virus used for infection. most sindbis virus strains can induce programmed c ...19989809307
recombinant herpes simplex virus type 1 engineered for targeted binding to erythropoietin receptor-bearing cells.the utility of recombinant herpes simplex virus type 1 (hsv-1) vectors may be expanded by manipulation of the virus envelope to achieve cell-specific gene delivery. to this end, an hsv-1 mutant virus deleted for glycoprotein c (gc) and the heparan sulfate binding domain of gb (kgbpk-gc-) was engineered to encode different chimeric proteins composed of n-terminally truncated forms of gc and the full-length erythropoietin hormone (epo). biochemical analyses demonstrated that one gc-epo chimeric mo ...19989811702
human immunodeficiency virus induces a dual regulation of bcl-2, resulting in persistent infection of cd4(+) t- or monocytic cell lines.this work aims at characterizing the interplay between human immunodeficiency virus type 1 (hiv-1) and the antiapoptotic cellular protein bcl-2 responsible for a persistent infection in lymphoblastoid t (j.jhan) or monocytic (u937) cells. we report that the kinetics of bcl-2 protein level during the establishment of a chronic infection is biphasic, characterized by a transient decrease followed by restoration to the initial level. the extent and duration of this transient decrease were inversely ...19989811703
viral glycoproteins accumulate in newly formed annulate lamellae following infection of lymphoid cells by human herpesvirus 6.ultrastructural analysis of hsb-2 t-lymphoid cells and human cord blood mononuclear cells infected with human herpesvirus 6 revealed the presence, in the cell cytoplasm, of annulate lamellae (al), which were absent in uninfected cells. time course analysis of the appearance of al following viral infection showed that no al were visible within the first 72 h postinfection and that their formation correlated with the expression of the late viral glycoprotein gp116. the requirement of active viral ...19989811708
cytoplasmic domain of sendai virus hn protein contains a specific sequence required for its incorporation into the assembly of paramyxoviruses, interactions between viral proteins are presumed to be specific. the focus of this study is to elucidate the protein-protein interactions during the final stage of viral assembly that result in the incorporation of the viral envelope proteins into virions. to this end, we examined the specificity of hn incorporation into progeny virions by transiently transfecting hn cdna genes into sendai virus (sv)-infected cells. sv hn expressed from cdna was efficiently in ...19989811709
antiapoptotic but not antiviral function of human bcl-2 assists establishment of japanese encephalitis virus persistence in cultured cells.upon infection of japanese encephalitis virus (jev), baby hamster kidney (bhk-21) and chinese hamster ovary (cho) cells were killed by a mechanism involved in apoptosis. while readily established in a variety of cell lines, jev persistence has never been successfully instituted in bhk-21 and cho cells. since stable expression of human bcl-2 in bhk-21 cells has been shown to delay jev-induced apoptosis, in this study we investigated whether jev persistence could be established in such cells. when ...19989811720
formation and amplification of a novel tombusvirus defective rna which lacks the 5' nontranslated region of the viral genome.defective interfering (di) rnas of tomato bushy stunt virus (tbsv) are small, subgenomic, helper-dependent replicons that are believed to be generated primarily by aberrant events during replication of the plus-sense rna genome. prototypical tbsv di rnas contain four noncontiguous segments (regions i through iv) derived from the 5' nontranslated region (ntr) (i), an internal section (ii), and the 3'-terminal portion (iii and iv) of the viral genome. we have studied the formation of these molecul ...19989811726
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