Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| an epitope of the semliki forest virus fusion protein exposed during virus-membrane fusion. | semliki forest virus (sfv) is an enveloped alphavirus that infects cells via a membrane fusion reaction triggered by acidic ph in the endocytic pathway. fusion is mediated by the spike protein e1 subunit, an integral membrane protein that contains the viral fusion peptide and forms a stable homotrimer during fusion. we have characterized four monoclonal antibodies (mabs) specific for the acid conformation of e1. these mabs did not inhibit fusion, suggesting that they bind to an e1 region differe ... | 1999 | 10559317 |
| putative rna capping activities encoded by brome mosaic virus: methylation and covalent binding of guanylate by replicase protein 1a. | brome mosaic virus (bmv) rna replication is directed by two virus-encoded proteins, 1a and 2a. the amino-terminal half of 1a is a distant homolog of alphavirus nonstructural protein nsp1, which has been implicated in capping viral rnas. in this study, we examined the enzymatic activities of bmv 1a expressed in yeast, where the protein is fully functional in rna replication. 1a methylated gtp, dgtp, and the cap analogs gpppg and gpppa, using s-adenosylmethionine (adomet) as the methyl donor. prod ... | 1999 | 10559320 |
| efficient trans-complementation of the flavivirus kunjin ns5 protein but not of the ns1 protein requires its coexpression with other components of the viral replicase. | successful trans-complementation of the defective kunjin virus (kun) rna fldgdd with a deletion of the rna polymerase motif gdd in the ns5 gene by using a bhk cell line, repbhk, that continuously produced a functionally active kun replication complex (rc) from replicon rna was recently reported (a. a. khromykh, m. t. kenney, and e. g. westaway, j. virol. 72:7270-7279, 1998). in order to identify whether this complementation of fldgdd rna was provided by the wild-type ns5 protein alone or with th ... | 1999 | 10559344 |
| induction of apoptosis by sindbis virus occurs at cell entry and does not require virus replication. | sindbis virus (sv) is an alphavirus that causes encephalitis in mice and can lead to the apoptotic death of infected cells. to determine the step in virus replication during which apoptosis is triggered, we used uv-inactivated sv, chemicals that block virus fusion or protein synthesis, and cells that do and do not express heparan sulfate, the initial binding molecule for sv infection of many cells. in initial experiments, uv-inactivated neuroadapted sv (nsv) induced apoptosis in chinese hamster ... | 1999 | 10559347 |
| brome mosaic virus rna replication proteins 1a and 2a colocalize and 1a independently localizes on the yeast endoplasmic reticulum. | the universal membrane association of positive-strand rna virus rna replication complexes is implicated in their function, but the intracellular membranes used vary among viruses. brome mosaic virus (bmv) encodes two mutually interacting rna replication proteins: 1a, which contains rna capping and helicase-like domains, and the polymerase-like 2a protein. in cells from the natural plant hosts of bmv, 1a and 2a colocalize on the endoplasmic reticulum (er). 1a and 2a also direct bmv rna replicatio ... | 1999 | 10559348 |
| infection of neonatal mice with sindbis virus results in a systemic inflammatory response syndrome. | laboratory strains of viruses may contain cell culture-adaptive mutations which result in significant quantitative and qualitative alterations in pathogenesis compared to natural virus isolates. this report suggests that this is the case with sindbis virus strain ar339. a cdna clone comprising a consensus sequence of sindbis virus strain ar339 has been constructed (w. b. klimstra, k. d. ryman, and r. e. johnston, j. virol. 72:7357-7366, 1998). this clone (ptr339) regenerates a sequence predicted ... | 1999 | 10559357 |
| a single nucleotide change in the 5' noncoding region of sindbis virus confers neurovirulence in rats. | two pairs of sindbis virus (sv) variants that differ in their neuroinvasive and neurovirulent traits in mice have been isolated. recently, we mapped the genetic determinants responsible for neuroinvasiveness in weanling mice. here, we extend this study to newborn and adult rats and to rat neuronal cultures. remarkably, certain aspects of the pathogenesis of these strains in rats were found to be quite distinct from the mouse model. suckling rats were susceptible to all four isolates, and replica ... | 1999 | 10559362 |
| infecting larval arthropods with a chimeric, double subgenomic sindbis virus vector to express genes of interest. | 1999 | 10572634 | |
| ectopic gene expression and homeotic transformations in arthropods using recombinant sindbis viruses. | the morphological diversity of arthropods makes them attractive subjects for studying the evolution of developmental mechanisms. comparative analyses suggest that arthropod diversity has arisen largely as a result of changes in expression patterns of genes that control development. direct analysis of how a particular gene functions in a given species during development is hindered by the lack of broadly applicable techniques for manipulating gene expression. | 1999 | 10574759 |
| dna and rna-based vaccines: principles, progress and prospects. | dna vaccines were introduced less than a decade ago but have already been applied to a wide range of infectious and malignant diseases. here we review the current understanding of the mechanisms underlying the activities of these new vaccines. we focus on recent strategies designed to enhance their function including the use of immunostimulatory (cpg) sequences, dendritic cells (dc), co-stimulatory molecules and cytokine- and chemokine-adjuvants. although genetic vaccines have been significantly ... | 1999 | 10580187 |
| the african swine fever virus prenyltransferase is an integral membrane trans-geranylgeranyl-diphosphate synthase. | in a previous study, it was shown that the protein encoded by the gene b318l of african swine fever virus (asfv) is a trans-prenyltransferase that catalyzes in vitro the condensation of farnesyl diphosphate and isopentenyl diphosphate to synthesize geranylgeranyl diphosphate and longer chain prenyl diphosphates (alejo, a., yáñez, r. j., rodríguez, j. m., viñuela, e., and salas, m. l. (1997) j. biol. chem. 272, 9417-9423). to investigate the in vivo function of the viral enzyme, we have determine ... | 1999 | 10364254 |
| characterization of an equine arteritis virus replicase mutant defective in subgenomic mrna synthesis. | equine arteritis virus (eav) is a positive-stranded rna virus that synthesizes a 5'- and 3'-coterminal nested set of six subgenomic mrnas. these mrnas all contain a common leader sequence which is derived from the 5' end of the genome. subgenomic mrna transcription and genome replication are directed by the viral replicase, which is expressed in the form of two polyproteins and subsequently processed into smaller nonstructural proteins (nsps). during the recent construction of an eav infectious ... | 1999 | 10364273 |
| in vitro assembly of alphavirus cores by using nucleocapsid protein expressed in escherichia coli. | the production of the alphavirus virion is a multistep event requiring the assembly of the nucleocapsid core in the cytoplasm and the maturation of the glycoproteins in the endoplasmic reticulum and the golgi apparatus. these components associate during the budding process to produce the mature virion. the nucleocapsid proteins of sindbis virus and ross river virus have been produced in a t7-based escherichia coli expression system and purified. in the presence of single-stranded but not double- ... | 1999 | 10364277 |
| combinatorial screening and intracellular antiviral activity of hairpin ribozymes directed against hepatitis b virus. | a combinatorial screening method has been used to identify hairpin ribozymes that inhibit hepatitis b virus (hbv) replication in transfected human hepatocellular carcinoma (hcc) cells. a hairpin ribozyme library (5 x 10(5) variants) containing a randomized substrate-binding domain was used to identify accessible target sites within 3.3 kb of full-length in vitro-transcribed hbv pregenomic rna. forty potential target sites were found within the hbv pregenomic rna, and 17 sites conserved in all fo ... | 1999 | 10364285 |
| nonhomologous rna recombination in bovine viral diarrhea virus: molecular characterization of a variety of subgenomic rnas isolated during an outbreak of fatal mucosal disease. | four bovine viral diarrhea virus type 2 (bvdv-2) pairs consisting of cytopathogenic (cp) and noncp bvdv-2 were isolated during an outbreak of mucosal disease. comparative sequence analysis showed that the four noncp bvdv-2 isolates were almost identical. for the cp bvdv-2 isolates, viral subgenomic rnas were shown by northern blot to have a length of about 8 kb, which is about 4.3 kb shorter than the genome of noncp bvdv. cytopathogenicity and the expression of ns3 were both strictly correlated ... | 1999 | 10364314 |
| neutralizing antibodies inhibit axonal spread of herpes simplex virus type 1 to epidermal cells in vitro. | the ability of antibodies to interfere with anterograde transmission of herpes simplex virus (hsv) from neuronal axons to the epidermis was investigated in an in vitro model consisting of human fetal dorsal root ganglia innervating autologous skin explants in a dual-chamber tissue culture system. the number and size of viral cytopathic plaques in epidermal cells after axonal transmission from hsv type 1 (hsv-1)-infected dorsal root ganglionic neurons were significantly reduced by addition to the ... | 1999 | 10364346 |
| poliovirus induces apoptosis in the mouse central nervous system. | poliovirus (pv) is the etiological agent of human paralytic poliomyelitis. paralysis results from the destruction of motoneurons, a consequence of pv replication. however, the pv-induced process leading to the death of motoneurons is not well known. we investigated whether pv-induced central nervous system (cns) injury is associated with apoptosis by using mice as animal models. transgenic mice expressing the human pv receptor were infected intracerebrally with either the neurovirulent pv-1 maho ... | 1999 | 10364359 |
| svmpa, a mutant of sindbis virus resistant to mycophenolic acid and ribavirin, shows an increased sensitivity to chick interferon. | svmpa is a mutant of sindbis virus, selected for its ability to replicate in mycophenolic acid (mpa)-treated mosquito cells. svmpa has another phenotype: although able to replicate normally in primary cultures of chick embryo fibroblasts (cef), its replication is restricted in secondary cultures prepared from aged primary cef cultures. the mutations responsible for these phenotypes mapped to the region of the viral genome that codes for nsp1. we report here that svmpa has yet another phenotype. ... | 1999 | 10364507 |
| effect of rho and adp-ribosylation factor gtpases on phospholipase d activity in intact human adenocarcinoma a549 cells. | phospholipase d (pld) has been implicated as a crucial signaling enzyme in secretory pathways. two 20-kda guanine nucleotide-binding proteins, rho and adp-ribosylation factor (arf), are involved in the regulation of secretion and can activate pld in vitro. we investigated in intact (human adenocarcinoma a549 cells) the role of rhoa and arf in activation of pld by phorbol 12-myristate 13-acetate, bradykinin, and/or sphingosine 1-phosphate. to express recombinant clostridium botulinum c3 exoenzyme ... | 1999 | 10373471 |
| phorbol ester promotes endocytosis by activating a factor involved in endosome fusion. | previous studies indicate that a zinc- and phorbol ester-binding factor is necessary for in vitro endosome fusion and for the effect of rab5 on endosome fusion. rab5 is a small gtpase that regulates membrane fusion between early endosomes derived from either receptor-mediated endocytosis or fluid-phase endocytosis. in its gtp-bound form, rab5 promotes endocytosis and enhances fusion among early endosomes. to determine if pma stimulates endocytosis by activating a factor required for endosome fus ... | 1999 | 10393811 |
| endoprotease pace4 is ca2+-dependent and temperature-sensitive and can partly rescue the phenotype of a furin-deficient cell strain. | pace4 is a member of the eukaryotic subtilisin-like endoprotease family. the expression of human pace4 in rpe.40 cells (furin-null mutants derived from chinese hamster ovary k1 cells) resulted in the rescue of a number of wild-type characteristics, including sensitivity to sindbis virus and the ability to process the low-density-lipoprotein receptor-related protein. expression of pace4 in these cells failed to restore wild-type sensitivity to pseudomonas exotoxin a. co-expression of human pace4 ... | 1999 | 10215603 |
| seroprevalence of dengue, chikungunya and sindbis virus infections in german aid workers. | vector-borne virus infections were studied in 670 german overseas aid workers who had spent an average of 37.7 months in tropical areas of africa and asia. antibodies to dengue viruses (den) were detected by indirect immunofluorescence assay in 43/670 (6.4%) aid workers. of these 43, 41 (95.3%) were also positive for antibodies to dengue by haemagglutination inhibition assay. the highest seroprevalence was in aid workers returning from thailand (19.4%), benin (14.8%) and burkina faso (9.2%). ant ... | 1999 | 10219635 |
| decreased intracellular superoxide levels activate sindbis virus-induced apoptosis. | infection of many cultured cell types with sindbis virus (sv), an alphavirus, triggers apoptosis through a commonly utilized caspase activation pathway. however, the upstream signals by which sv activates downstream apoptotic effectors, including caspases, remain unclear. here we report that in at-3 prostate carcinoma cells, sv infection decreases superoxide (o-2) levels within minutes of infection as monitored by an aconitase activity assay. this sv-induced decrease in o-2 levels appears to act ... | 1999 | 10224137 |
| genetic interaction of flavivirus nonstructural proteins ns1 and ns4a as a determinant of replicase function. | nonstructural protein 1 (ns1) of yellow fever virus (yf) is a glycoprotein localized to extracytoplasmic compartments within infected cells. we have previously shown that ns1 can be supplied in trans and is required for viral rna replication, a process thought to occur in membrane-bound cytoplasmic complexes. here we report that the ns1 gene from a related virus, dengue virus (den), is unable to function in the process of yf rna replication. this virus-specific incompatibility leads to a lack of ... | 1999 | 10233920 |
| mutational analysis, using a full-length rubella virus cdna clone, of rubella virus e1 transmembrane and cytoplasmic domains required for virus release. | we report on the construction of a full-length cdna clone, pbrm33, derived from wild-type rubella virus m33 strain. the rna transcripts synthesized in vitro from pbrm33 are highly infectious, and the viruses produced retain the phenotypic characteristics of the parental m33 virus in growth rate and plaque size. this cdna clone was used to study the role of e1 transmembrane and cytoplasmic domains in virus assembly by site-directed mutagenesis. three different alanine substitutions were introduce ... | 1999 | 10233921 |
| dengue virus structural differences that correlate with pathogenesis. | the understanding of dengue virus pathogenesis has been hampered by the lack of in vitro and in vivo models of disease. the study of viral factors involved in the production of severe dengue, dengue hemorrhagic fever (dhf), versus the more common dengue fever (df), have been limited to indirect clinical and epidemiologic associations. in an effort to identify viral determinants of dhf, we have developed a method for comparing dengue type 2 genomes (reverse transcriptase pcr in six fragments) dir ... | 1999 | 10233934 |
| human cd46 enhances nitric oxide production in mouse macrophages in response to measles virus infection in the presence of gamma interferon: dependence on the cd46 cytoplasmic domains. | cd46 is a transmembrane complement regulatory protein widely expressed on nucleated human cells. laboratory-adapted strains of measles virus (mv) bind to the extracellular domains of cd46 to enter human cells. the cytoplasmic portion of cd46 consists of a common juxtamembrane region and different distal sequences called cyt1 and cyt2. the biological functions of these cytoplasmic sequences are unknown. in this study, we show that expression of human cd46 with the cyt1 cytoplasmic domain in mouse ... | 1999 | 10233938 |
| characterization of a chinese hamster ovary cell line developed by retroviral insertional mutagenesis that is resistant to sindbis virus infection. | the alphavirus sindbis virus (sv) has a wide host range and infects many types of cultured cells in vitro. the outcome of infection is dependent on the strain of virus used for infection and the properties of the cells infected. to identify cellular determinants of susceptibility to sv infection we mutagenized chinese hamster ovary (cho) cells by retroviral insertion with a vector containing the neomycin resistance gene that allowed selection for integration into transcriptionally active genes. ... | 1999 | 10233953 |
| oligomerization within virions and subcellular localization of human immunodeficiency virus type 1 integrase. | previous biochemical and genetic evidence indicated that the functional form of retroviral integrase protein (in) is a multimer. a direct demonstration of in oligomerization during the infectious cycle was, however, missing, due to the absence of a sensitive detection method. we describe here the generation of infectious human immunodeficiency virus type 1 (hiv-1) viral clones carrying in protein tagged with highly antigenic epitopes. in this setting, we could readily visualize in both in produc ... | 1999 | 10233971 |
| infection of primary cultures of human kupffer cells by dengue virus: no viral progeny synthesis, but cytokine production is evident. | we investigated the ability of dengue virus to invade human primary kupffer cells and to complete its life cycle. the virus effectively penetrated kupffer cells, but the infection did not result in any viral progeny. dengue virus-replicating kupffer cells underwent apoptosis and were cleared by phagocytosis. infected kupffer cells produced soluble mediators that could intervene in dengue virus pathogenesis. | 1999 | 10233989 |
| reducing cytotoxicity induced by sindbis viral vectors. | sindbis virus has been recognized as a potentially useful virus vector for gene therapy. in an effort to improve its utility and provide cell-targeting capability to gene therapy vectors, we recently developed sindbis virus vectors possessing chimeric envelopes with cell-specific targeting ability [k. ohno et al. nature biotechnol 15:763-767, 1997; k. sawai et al. biochem biophys res commun 248:315-323, 1998]. however, a residual problem associated with sindbis virus vectors is the apoptotic eff ... | 1999 | 10329021 |
| mechanisms of t-cell activation by human t-cell lymphotropic virus type i. | the interactions between human t-cell lymphotropic virus type i (htlv-i) and the cellular immune system can be divided into viral interference with functions of the infected host t cell and the subsequent interactions between the infected t cell and the cellular immune system. htlv-i-mediated activation of the infected host t cell is induced primarily by the viral protein tax, which influences transcriptional activation, signal transduction pathways, cell cycle control, and apoptosis. these prop ... | 1999 | 10357853 |
| packaging of aednv-gfp transducing virus by expression of densovirus structural proteins from a sindbis virus expression system. | genetic recombination resulting in the production of wild-type infectious virus is an obstacle in the current system for producing densovirus transducing particles. in order to eliminate this problem, a double subgenomic sindbis virus (te/3'2j/vp) was engineered that expresses the structural proteins (vps) of aedes densonucleosis virus (aednv) from the second subgenomic promoter. expression of aednv vps from te/3'2j/vp was confirmed by northern analysis of rna from infected c6/36 (aedes albopict ... | 1999 | 10208920 |
| genetic and fitness changes accompanying adaptation of an arbovirus to vertebrate and invertebrate cells. | the alternating host cycle and persistent vector infection may constrain the evolution of arboviruses. to test this hypothesis, eastern equine encephalitis virus was passaged in bhk or mosquito cells, as well as in alternating (both) host cell passages. high and low multiplicities were used to examine the effect of defective interfering particles. clonal bhk and persistent mosquito cell infections were also evaluated. fitness was measured with one-step growth curves and competition assays, and m ... | 1999 | 10196330 |
| a brome mosaic virus intergenic rna3 replication signal functions with viral replication protein 1a to dramatically stabilize rna in vivo. | brome mosaic virus (bmv), a positive-strand rna virus in the alphavirus-like superfamily, encodes two rna replication proteins. the 1a protein has putative helicase and rna-capping domains, whereas 2a contains a polymerase-like domain. saccharomyces cerevisiae expressing 1a and 2a is capable of replicating a bmv rna3 template produced by in vivo transcription of a dna copy of rna3. although insufficient for rna3 replication, the expression of 1a protein alone results in a dramatic and specific s ... | 1999 | 10074107 |
| expression of murine coronavirus recombinant papain-like proteinase: efficient cleavage is dependent on the lengths of both the substrate and the proteinase polypeptides. | proteolytic processing of the replicase gene product of mouse hepatitis virus (mhv) is essential for viral replication. in mhv strain a59 (mhv-a59), the replicase gene encodes two predicted papain-like proteinase (plp) domains, plp-1 and plp-2. previous work using viral polypeptide substrates synthesized by in vitro transcription and translation from the replicase gene demonstrated both cis and trans cleavage activities for plp-1. we have cloned and overexpressed the plp-1 domain in escherichia ... | 1999 | 10074111 |
| primary and secondary structural elements required for synthesis of barley yellow dwarf virus subgenomic rna1. | barley yellow dwarf luteovirus (bydv) generates three 3'-coterminal subgenomic rnas (sgrnas) in infected cells. the promoter of sgrna1 is a putative hot spot for rna recombination in luteovirus evolution. the sgrna1 transcription start site was mapped previously to either nucleotide 2670 or nucleotide 2769 of bydv genomic rna (grna) in two independent studies. our data support the former initiation site. the boundaries of the sgrna1 promoter map between nucleotides 2595 and 2692 on genomic rna. ... | 1999 | 10074135 |
| rotavirus capsid protein vp5* permeabilizes membranes. | proteolytic cleavage of the vp4 outer capsid spike protein into vp8* and vp5* proteins is required for rotavirus infectivity and for rotavirus-induced membrane permeability. in this study we addressed the function of the vp5* cleavage fragment in permeabilizing membranes. expressed vp5* and truncated vp5* proteins were purified by nickel affinity chromatography and assayed for their ability to permeabilize large unilamellar vesicles (luvs) preloaded with carboxyfluorescein (cf). vp5* and vp5* tr ... | 1999 | 10074166 |
| differentiation of m1 myeloid precursor cells into macrophages results in binding and infection by theiler's murine encephalomyelitis virus and apoptosis. | infection of susceptible mouse strains with bean, a less virulent strain of theiler's murine encephalomyelitis virus (tmev), results in immune system-mediated demyelinating lesions in the central nervous system (cns) similar to those in multiple sclerosis. since macrophages appear to carry the major detectable antigen burden in vivo, and purification of sufficient cell numbers from the cns for detailed analysis is difficult, macrophage-like cell lines provide an accessible system with which to s ... | 1999 | 10074176 |
| long-term follow-up of chimpanzees inoculated with the first infectious clone for hepatitis c virus. | two chimpanzees (ch1535 and ch1536) became infected with hepatitis c virus (hcv) following intrahepatic inoculation with rna transcribed from a full-length cdna clone of the virus. both animals were persistently infected and have been followed for 60 weeks. they showed similar responses to infection, with transient liver enzyme elevations and liver inflammatory responses, which peaked at weeks 17 (ch1535) and 12 (ch1536) postinoculation (p.i.). antibody responses to structural and nonstructural ... | 1999 | 10074186 |
| acute and persistent infection of human neural cell lines by human coronavirus oc43. | human coronaviruses (hucv) are recognized respiratory pathogens. data accumulated by different laboratories suggest their neurotropic potential. for example, primary cultures of human astrocytes and microglia were shown to be susceptible to an infection by the oc43 strain of hucv (a. bonavia, n. arbour, v. w. yong, and p. j. talbot, j. virol. 71:800-806, 1997). we speculate that the neurotropism of hucv will lead to persistence within the central nervous system, as was observed for murine corona ... | 1999 | 10074188 |
| mutagenic analysis of the 3' cis-acting elements of the rubella virus genome. | thermodynamically predicted secondary structure analysis of the 3'-terminal 305 nucleotides (nt) of the rubella virus (rub) genome, a region conserved in all rub defective interfering rnas, revealed four stem-loop (sl) structures; sl1 and sl2 are both located in the e1 coding region, while sl3 and sl4 are within the 59-nt 3' untranslated region (utr) preceding the poly(a) tract. sl2 is a structure shown to interact with human calreticulin (cal), an autoantigen potentially involved in rub rna rep ... | 1999 | 10074193 |
| infectious pancreatic necrosis virus: identification of a vp3-containing ribonucleoprotein core structure and evidence for o-linked glycosylation of the capsid protein vp2. | virions of infectious pancreatic necrosis virus (ipnv) were completely disintegrated upon dialysis against salt-free buffers. direct visualization of such preparations by electron microscopy revealed 5.0- to 6.5-nm-thick entangled filaments. by using a specific colloidal gold immunolabeling technique, these structures were shown to contain the viral protein vp3. isolation by sucrose gradient centrifugation of the filaments, followed by serological analysis, demonstrated that the entire vp3 conte ... | 1999 | 10074207 |
| rapid dendritic morphogenesis in ca1 hippocampal dendrites induced by synaptic activity. | activity shapes the structure of neurons and their circuits. two-photon imaging of ca1 neurons expressing enhanced green fluorescent protein in developing hippocampal slices from rat brains was used to characterize dendritic morphogenesis in response to synaptic activity. high-frequency focal synaptic stimulation induced a period (longer than 30 minutes) of enhanced growth of small filopodia-like protrusions (typically less than 5 micrometers long). synaptically evoked growth was long-lasting an ... | 1999 | 10082466 |
| geographic distribution and evolution of sindbis virus in australia. | the molecular epidemiology and evolution of sindbis (sin) virus in australia was examined. several sin virus strains isolated from other countries were also included in the analysis. two regions of the virus genome were sequenced including a 418 bp region of the e2 gene and a 484 bp region containing part of the junction region and the 5' end of the c gene. analysis of the nucleotide and deduced amino acid sequence data from 40 sin virus isolates clearly separated the paleoarctic/ethiopian and o ... | 1999 | 10092014 |
| antiviral effect of hyperthermic treatment in rhinovirus infection. | human rhinoviruses (hrv) are recognized as the major etiologic agents for the common cold. starting from the observation that local hyperthermic treatment is beneficial in patients with natural and experimental common colds, we have studied the effect of brief hyperthermic treatment (ht) on hrv replication in hela cells. we report that a 20-min ht at 45 degrees c is effective in suppressing hrv multiplication by more than 90% when applied at specific stages of the virus replication cycle. synthe ... | 1999 | 10103186 |
| attenuated vesicular stomatitis viruses as vaccine vectors. | we showed previously that a single intranasal vaccination of mice with a recombinant vesicular stomatitis virus (vsv) expressing an influenza virus hemagglutinin (ha) protein provided complete protection from lethal challenge with influenza virus (a. roberts, e. kretzschmar, a. s. perkins, j. forman, r. price, l. buonocore, y. kawaoka, and j. k. rose, j. virol. 72:4704-4711, 1998). because some pathogenesis was associated with the vector itself, in the present study we generated new vsv vectors ... | 1999 | 10196265 |
| resistance of interleukin-1beta-deficient mice to fatal sindbis virus encephalitis. | interleukin-1beta (il-1beta) concentrations are frequently elevated in central nervous system (cns) viral infections, but the pathophysiologic significance of such elevations is not known. to examine the role of il-1beta in cns viral pathogenesis, we compared the natural histories of il-1beta-deficient and wild-type 129 sv(ev) mice infected with a neurovirulent viral strain, neuroadapted sindbis virus (nsv). we found that the incidence of severe paralysis and death was markedly decreased in nsv- ... | 1999 | 9971844 |
| the inflammatory response to nonfatal sindbis virus infection of the nervous system is more severe in sjl than in balb/c mice and is associated with low levels of il-4 mrna and high levels of il-10-producing cd4+ t cells. | sjl mice are susceptible to inflammatory autoimmune diseases of the central nervous system (cns), while balb/c mice are relatively resistant. to understand differences in immune responses that may contribute to autoimmune neurologic disease, we compared the responses of sjl and balb/c mice to infection with sindbis virus, a virus that causes acute nonfatal encephalomyelitis in both strains of mice. clearance of virus was similar, but sjl mice developed a more intense inflammatory response in the ... | 1999 | 9973422 |
| rubella virus-induced apoptosis varies among cell lines and is modulated by bcl-xl and caspase inhibitors. | rubella virus (rv) causes multisystem birth defects in the fetuses of infected women. to investigate the cellular basis of this pathology, we examined the cytopathic effect of rv in three permissive cell lines: vero 76, rk13, and bhk21. electron microscopy and the tunel assay showed that the cytopathic effect resulted from rv-induced programmed cell death (apoptosis) in all three cell lines, but the extent of apoptosis varied among these cells. at 48 h postinfection, the rk13 cell line showed th ... | 1999 | 10049827 |
| proteolytic processing of the open reading frame 1b-encoded part of arterivirus replicase is mediated by nsp4 serine protease and is essential for virus replication. | the open reading frame (orf) 1b-encoded part of the equine arteritis virus (eav) replicase is expressed by ribosomal frameshifting during genome translation, which results in the production of an orf1ab fusion protein (345 kda). four orf1b-encoded processing products, nsp9 (p80), nsp10 (p50), nsp11 (p26), and nsp12 (p12), have previously been identified in eav-infected cells (l. c. van dinten, a. l. m. wassenaar, a. e. gorbalenya, w. j. m. spaan, and e. j. snijder, j. virol. 70:6625-6633, 1996). ... | 1999 | 9971783 |
| capsid structure of simian cytomegalovirus from cryoelectron microscopy: evidence for tegument attachment sites. | we have used cryoelectron microscopy and image reconstruction to study b-capsids recovered from both the nuclear and the cytoplasmic fractions of cells infected with simian cytomegalovirus (scmv). scmv, a representative betaherpesvirus, could thus be compared with the previously described b-capsids of the alphaherpesviruses, herpes simplex virus type 1 (hsv-1) and equine herpesvirus 1 (ehv-1), and of channel catfish virus, an evolutionarily remote herpesvirus. nuclear b-capsid architecture is ge ... | 1999 | 9971801 |
| class i mhc molecule-mediated inhibition of sindbis virus replication. | the threshold for systemic viral infection relies on the amplification of virus at a primary infection site. we have identified that class i mhc molecules can trigger the inhibition of replication of sindbis virus in a haplotype- and allele-specific manner. class i mhc molecules of h-2d haplotypes exhibit a strong inhibitory effect whereas h-2k haplotypes show minimal inhibition of sindbis viral replication. by a single gene transfection of h-2d class i mhc molecules, into cells that express cla ... | 1999 | 9886371 |
| a balance of signaling by rho family small gtpases rhoa, rac1 and cdc42 coordinates cytoskeletal morphology but not cell survival. | rho family gtpases are known to be involved in cytoskeletal reorganization. we examined the possibility that these functions may be dictated by a balance of rho family gtpase signaling. using transient viral expression of rhoa, rac1, cdc42 and their mutants, as well as c3 exoenzyme, we altered cytoskeletal organization under normal growth conditions. overexpression of wild-type or constitutively active forms of the rho family gtpases led to their respective activation phenotypes. overexpression ... | 1999 | 9926919 |
| cell-specific targeting of a thymidine kinase/ganciclovir gene therapy system using a recombinant sindbis virus vector. | transfer of the herpes simplex virus type i thymidine kinase (hsv-tk) gene into tumor cells using virus-based vectors in conjunction with ganciclovir (gcv) exposure provides a potential gene therapy strategy for the treatment of cancer. the possibility of using a novel targetable sindbis virus expression vector containing the hsv-tk gene was examined. baby hamster kidney (bhk) cells and several human tumor cells infected with a sindbis virus containing the hsv-tk gene showed strong expression of ... | 1999 | 9935240 |
| eps15 is recruited to the plasma membrane upon epidermal growth factor receptor activation and localizes to components of the endocytic pathway during receptor internalization. | eps15 is a substrate for the tyrosine kinase of the epidermal growth factor receptor (egfr) and is characterized by the presence of a novel protein:protein interaction domain, the eh domain. eps15 also stably binds the clathrin adaptor protein complex ap-2. previous work demonstrated an essential role for eps15 in receptor-mediated endocytosis. in this study we show that, upon activation of the egfr kinase, eps15 undergoes dramatic relocalization consisting of 1) initial relocalization to the pl ... | 1999 | 9950686 |
| two-helper rna system for production of recombinant semliki forest virus particles. | alphavirus expression systems based on suicidal virus particles carrying recombinant replicons have proven to be a very efficient way to deliver genes for heterologous protein expression. however, present strategies for production of such particles have biosafety limitations due to the generation, by rna recombination, of replication-proficient viruses (rpvs). here we describe a new packaging system for semliki forest virus (sfv) based on a the use of a two-helper system in which the capsid and ... | 1999 | 9882310 |
| endoproteolytic processing of the ebola virus envelope glycoprotein: cleavage is not required for function. | proteolytic processing is required for the activation of numerous viral glycoproteins. here we show that the envelope glycoprotein from the zaire strain of ebola virus (ebo-gp) is proteolytically processed into two subunits, gp1 and gp2, that are likely covalently associated through a disulfide linkage. murine leukemia virions pseudotyped with ebo-gp contain almost exclusively processed glycoprotein, indicating that this is the mature form of ebo-gp. mutational analysis identified a dibasic moti ... | 1999 | 9882347 |
| alternative splicing results in differential expression, activity, and localization of the two forms of arginyl-trna-protein transferase, a component of the n-end rule pathway. | the n-end rule relates the in vivo half-life of a protein to the identity of its n-terminal residue. the underlying ubiquitin-dependent proteolytic system, called the n-end rule pathway, is organized hierarchically: n-terminal aspartate and glutamate (and also cysteine in metazoans) are secondary destabilizing residues, in that they function through their conjugation, by arginyl-trna-protein transferase (r-transferase), to arginine, a primary destabilizing residue. we isolated cdna encoding the ... | 1999 | 9858543 |
| evaluation of recombinant dense granule antigen 7 (gra7) of toxoplasma gondii for detection of immunoglobulin g antibodies and analysis of a major antigenic domain. | dense granule protein 7 (gra7) of toxoplasma gondii was expressed in escherichia coli as a fusion protein. the leader peptide contained a 25-amino-acid mouse tumor necrosis factor fragment and six histidyl residues. after purification by metal chelate affinity chromatography, the antigen was evaluated in an enzyme-linked immunosorbent assay for detection of immunoglobulin g (igg). for two sets of igg-positive human serum samples, obtained from routine screening, an overall sensitivity of 81% was ... | 1999 | 9874659 |
| persistent hz-1 virus infection in insect cells: evidence for insertion of viral dna into host chromosomes and viral infection in a latent status. | persistent/latent viral infections of insect cells are a prominent though poorly understood phenomenon. in this study, the long-term association between the hz-1 virus and insect host cells, conventionally referred to as persistent viral infection, is described. with the aid of a newly developed fluorescent cell-labeling system, we found that productive viral replication occurs by spontaneous viral reactivation in fewer than 0.2% of persistently infected cell lines over a 5-day period. once vira ... | 1999 | 9847315 |
| processing of the human coronavirus 229e replicase polyproteins by the virus-encoded 3c-like proteinase: identification of proteolytic products and cleavage sites common to pp1a and pp1ab. | replicase gene expression by the human coronavirus 229e involves the synthesis of two large polyproteins, pp1a and pp1ab. experimental evidence suggests that these precursor molecules are subject to extensive proteolytic processing. in this study, we show that a chymotrypsin-like enzyme, the virus-encoded 3c-like proteinase (3clpro), cleaves within a common region of pp1a and pp1ab (amino acids 3490 to 4068) at four sites. trans-cleavage assays revealed that polypeptides of 5, 23, 12, and 16 kda ... | 1999 | 9847320 |
| porcine reproductive and respiratory syndrome virus comparison: divergent evolution on two continents. | porcine reproductive and respiratory syndrome virus (prrsv) is a recently described arterivirus responsible for disease in swine worldwide. comparative sequence analysis of 3'-terminal structural genes of the single-stranded rna viral genome revealed the presence of two genotypic classes of prrsv, represented by the prototype north american and european strains, vr-2332 and lelystad virus (lv), respectively. to better understand the evolution and pathogenicity of prrsv, we obtained the 12,066-ba ... | 1999 | 9847330 |
| immunization of woodchucks with plasmids expressing woodchuck hepatitis virus (whv) core antigen and surface antigen suppresses whv infection. | dna vaccination can induce humoral and cellular immune response to viral antigens and confer protection to virus infection. in woodchucks, we tested the protective efficacy of immune response to woodchuck hepatitis core antigen (whcag) and surface antigen (whsag) of woodchuck hepatitis virus (whv) elicited by dna-based vaccination. plasmids pwhcim and pwhsim containing whv c- or pre-s2/s genes expressed whcag and whsag in transient transfection assays. pilot experiments in mice revealed that a s ... | 1999 | 9847331 |
| selection of functional variants of the ns3-ns4a protease of hepatitis c virus by using chimeric sindbis viruses. | the ns3-ns4a serine protease of hepatitis c virus (hcv) mediates four specific cleavages of the viral polyprotein and its activity is considered essential for the biogenesis of the hcv replication machinery. despite extensive biochemical and structural characterization, the analysis of natural variants of this enzyme has been limited by the lack of an efficient replication system for hcv in cultured cells. we have recently described the generation of chimeric hcv-sindbis viruses whose propagatio ... | 1999 | 9847361 |
| persistent infection promotes cross-species transmissibility of mouse hepatitis virus. | persistent infection with mouse hepatitis virus (mhv) strain a59 in murine dbt (delayed brain tumor) cells resulted in the emergence of host range variants, designated v51a and v51b, at 210 days postinfection. these host range mutants replicated efficiently in normally nonpermissive chinese hamster ovary (cho), in human hepatocarcinoma (hepg2), and to a lesser extent in human breast carcinoma (mcf7) cell lines. little if any replication was noted in baby hamster kidney (bhk), green african monke ... | 1999 | 9847369 |
| sendai virus infection induces apoptosis through activation of caspase-8 (flice) and caspase-3 (cpp32). | sendai virus (sv) infection and replication lead to a strong cytopathic effect with subsequent death of host cells. we now show that sv infection triggers an apoptotic program in target cells. incubation of infected cells with the peptide inhibitor z-vad-fmk abrogated sv-induced apoptosis, indicating that proteases of the caspase family were involved. moreover, proteolytic activation of two distinct caspases, cpp32/caspase-3 and, as shown for the first time in virus-infected cells, flice/caspase ... | 1999 | 9847376 |
| new mouse model for dengue virus vaccine testing. | several dengue (den) virus vaccines are in development; however, the lack of a reliable small animal model in which to test them is a major obstacle. because evidence suggests that interferon (ifn) is involved in the human anti-den virus response, we tested mice deficient in their ifn functions as potential models. intraperitoneally administered mouse-adapted den 2 virus was uniformly lethal in ag129 mice (which lack alpha/beta ifn and gamma ifn receptor genes), regardless of age. immunized mice ... | 1999 | 9847388 |
| open reading frame 1a-encoded subunits of the arterivirus replicase induce endoplasmic reticulum-derived double-membrane vesicles which carry the viral replication complex. | the replicase of equine arteritis virus (eav; family arteriviridae, order nidovirales) is expressed in the form of two polyproteins (the open reading frame 1a [orf1a] and orf1ab proteins). three viral proteases cleave these precursors into 12 nonstructural proteins, which direct both genome replication and subgenomic mrna transcription. immunofluorescence assays showed that most eav replicase subunits localize to membranes in the perinuclear region of the infected cell. using replicase-specific ... | 1999 | 9971782 |
| use of vegetable-derived tween 80 for virus inactivation by solvent/detergent treatment. | 1999 | 10652181 | |
| an outbreak of west nile fever among migrants in kisangani, democratic republic of congo. | in february 1998, an outbreak of acute febrile illness was reported from the kapalata military camp in kisangani, the democratic republic of congo. the illness was characterized by an acute onset of fever associated with severe headache, arthralgia, backache, neurologic signs, abdominal pain, and coughing. in 1 individual, hemorrhagic manifestations were observed. the neurologic signs included an altered level of consciousness, convulsions, and coma. malaria was initially suspected, but the pati ... | 1999 | 10674664 |
| efficient gene delivery into adult cardiomyocytes by recombinant sindbis virus. | somatic gene therapy as a potential strategy for the treatment of myocardial diseases relies on an efficient gene transfer into cardiac muscle cells. the difficulty of delivering genes into adult cardiomyocytes exists not only in vivo but also in primary culture systems. therefore, possibilities for ex vivo gene transfer and the in vitro study of physiological processes by reverse genetics are limited. we investigated the potential of an alphavirus-based vector system to transduce adult rat card ... | 1999 | 10682322 |
| recombinant semliki forest virus and sindbis virus efficiently infect neurons in hippocampal slice cultures. | gene transfer into nervous tissue is a powerful tool for the analysis of gene function. by using a rat hippocampal slice culture preparation, we show here that semliki forest virus (sfv) and sindbis virus (sin) vectors are useful for the effective infection of neurons. the stratum pyramidale and/or the granular cell layer were injected with recombinant virus encoding beta-galactosidase (lacz) or green fluorescent protein (gfp). by using low concentrations of injected sfv-lacz or sin-lacz, we det ... | 1999 | 10359835 |
| replication and packaging of transmissible gastroenteritis coronavirus-derived synthetic minigenomes. | the sequences involved in the replication and packaging of transmissible gastroenteritis virus (tgev) rna have been studied. the structure of a tgev defective interfering rna of 9.7 kb (di-c) was described previously (a. mendez, c. smerdou, a. izeta, f. gebauer, and l. enjuanes, virology 217: 495-507, 1996), and a cdna with the information to encode di-c rna was cloned under the control of the t7 promoter. the molecularly cloned di-c rna was replicated in trans upon transfection of helper virus- ... | 1999 | 9882359 |
| in vivo addition of poly(a) tail and au-rich sequences to the 3' terminus of the sindbis virus rna genome: a novel 3'-end repair pathway. | alphaviruses are mosquito-transmitted rna viruses that cause important diseases in both humans and livestock. sindbis virus (sin), the type species of the alphavirus genus, carries a 11.7-kb positive-sense rna genome which is capped at its 5' end and polyadenylated at its 3' end. the 3' nontranslated region (3'ntr) of the sin genome carries many au-rich motifs, including a 19-nucleotide (nt) conserved element (3'cse) and a poly(a) tail. this 3'cse and the adjoining poly(a) tail are believed to r ... | 1999 | 9971825 |
| mutant influenza viruses with a defective ns1 protein cannot block the activation of pkr in infected cells. | a short model genome rna and also the genome rna of influenza a virus bearing both 5'- and 3'-terminal common sequences activated the interferon-induced double-stranded-rna-dependent protein kinase, pkr, by stimulating autophosphorylation in vitro. the activated pkr catalyzed phosphorylation of the alpha subunit of eucaryotic translation initiation factor 2 (eif2alpha). the ns1 protein efficiently eliminated the pkr-activating activity of these rnas by binding to them. two mutant ns1 proteins, e ... | 1999 | 9971827 |
| alphaviruses as tools in neurobiology and gene therapy. | the broad host range and superior infectivity of alphaviruses have encouraged the development of efficient expression vectors for semliki forest virus (sfv) and sindbis virus (sin). the generation of high-titer recombinant alphavirus stocks has allowed high-level expression of a multitude of nuclear, cytoplasmic, membrane-associated and secreted proteins in a variety of different cell lines and primary cell cultures. despite the viral cytopathogenic effects, functional assays on recombinant prot ... | 1999 | 10071792 |
| selection of rna replicons capable of persistent noncytopathic replication in mammalian cells. | the natural life cycle of alphaviruses, a group of plus-strand rna viruses, involves transmission to vertebrate hosts via mosquitoes. chronic infections are established in mosquitoes (and usually in mosquito cell cultures), but infection of susceptible vertebrate cells typically results in rapid shutoff of host mrna translation and cell death. using engineered sindbis virus rna replicons expressing puromycin acetyltransferase as a dominant selectable marker, we identified mutations allowing pers ... | 1999 | 10196280 |
| genetic and phenotypic changes accompanying the emergence of epizootic subtype ic venezuelan equine encephalitis viruses from an enzootic subtype id progenitor. | recent studies have indicated that epizootic venezuelan equine encephalitis (vee) viruses can evolve from enzootic, subtype id strains that circulate continuously in lowland tropical forests (a. m. powers, m. s. oberste, a. c. brault, r. rico-hesse, s. m. schmura, j. f. smith, w. kang, w. p. sweeney, and s. c. weaver, j. virol. 71:6697-6705, 1997). to identify mutations associated with the phenotypic changes leading to epizootics, we sequenced the entire genomes of two subtype ic epizootic vee v ... | 1999 | 10196323 |
| the cholesterol requirement for sindbis virus entry and exit and characterization of a spike protein region involved in cholesterol dependence. | semliki forest virus (sfv) and sindbis virus (sin) are enveloped alphaviruses that enter cells via low-ph-triggered fusion in the endocytic pathway and exit by budding from the plasma membrane. previous studies with cholesterol-depleted insect cells have shown that sfv requires cholesterol in the cell membrane for both virus fusion and efficient exit of progeny virus. an sfv mutant, srf-3, shows efficient fusion and exit in the absence of cholesterol due to a single point mutation in the e1 spik ... | 1999 | 10196324 |
| stable alphavirus packaging cell lines for sindbis virus and semliki forest virus-derived vectors. | alphavirus vectors are being developed for possible human vaccine and gene therapy applications. we have sought to advance this field by devising dna-based vectors and approaches for the production of recombinant vector particles. in this work, we generated a panel of alphavirus vector packaging cell lines (pcls). these cell lines were stably transformed with expression cassettes that constitutively produced rna transcripts encoding the sindbis virus structural proteins under the regulation of t ... | 1999 | 10200308 |
| virus reduction in the preparation of intravenous immune globulin: in vitro experiments. | while immune globulins for intravenous administration (igiv) have an excellent record with respect to virus safety, concern regarding these preparations has been raised by reports of transmission of hepatitis c virus (hcv) to patients treated with igiv and the presence of genetic material for hcv in igiv preparations. | 1999 | 10204586 |
| mutagenesis of the rgd motif in the yellow fever virus 17d envelope protein. | the envelope protein of yellow fever virus 17d (yfv-17d) contains a solvent-exposed rgd motif, which has led to the suggestion that integrins may function as cellular receptors for yfv-17d. we found that mutating the rgd motif to rge had no effect on viral titers, whereas changing rgd to tgd, tge, tad, tae, or rgs led to reduced titers. substitution of rgd by rad or rae yielded rna genomes that replicated in mammalian cells but could not spread to neighboring cells at 37 degrees c. these mutants ... | 1999 | 10603320 |
| primary megakaryocytes reveal a role for transcription factor nf-e2 in integrin alpha iib beta 3 signaling. | platelet integrin alphaiibbeta3 responds to intracellular signals by binding fibrinogen and triggering cytoskeletal reorganization, but the mechanisms of alphaiibbeta3 signaling remain poorly understood. to better understand this process, we established conditions to study alphaiibbeta3 signaling in primary murine megakaryocytes. unlike platelets, these platelet precursors are amenable to genetic manipulation. cytokine-stimulated bone marrow cultures produced three arbitrary populations of alpha ... | 1999 | 10613901 |
| the role of host immunocompetence in neuroinvasion of sindbis virus. | viral infections of the central nervous system (cns) following peripheral inoculation of sindbis viruses were studied. the use of viral strains, which vary in their neuroinvasive and neurovirulent properties, and various strains of mice, which differ in immunocompetence, revealed several pathways of viral neuroinvasion in adult mice. a genetic-trait dependent mechanism was exhibited by the neuroinvasive viruses, showing a similar pattern in all mice strains tested. a second mechanism, dependent ... | 1999 | 10446650 |
| association of a cellular 21-kda transmembrane protein (vap21) with enveloped viruses. | we reported previously that the rabies virions contained a 21-kda cellular transmembrane protein (referred to as vap21) as a minor component (sagara, j. et al, microbiol. immunol. 41(12): 947-955, 1997). in this study, we further examined the possible interactions of vap21 with other enveloped viruses, including the vesicular stomatitis virus (vsv; negative-stranded rna virus), sindbis virus (positive-stranded rna virus) and herpes simplex virus type 1 (hsv-1; double-stranded dna virus). an immu ... | 1999 | 10449251 |
| pathogenesis of chimeric mhv4/mhv-a59 recombinant viruses: the murine coronavirus spike protein is a major determinant of neurovirulence. | the mouse hepatitis virus (mhv) spike glycoprotein, s, has been implicated as a major determinant of viral pathogenesis. in the absence of a full-length molecular clone, however, it has been difficult to address the role of individual viral genes in pathogenesis. by using targeted rna recombination to introduce the s gene of mhv4, a highly neurovirulent strain, into the genome of mhv-a59, a mildly neurovirulent strain, we have been able to directly address the role of the s gene in neurovirulenc ... | 1999 | 10438865 |
| intracellular distribution of rubella virus nonstructural protein p150. | antiserum prepared against an amino-terminal fragment of rubella virus (rub) nonstructural polyprotein was used to study rub-infected vero cells. replicase protein p150 was associated with vesicles and vacuoles of endolysosomal origin and later with large, convoluted, tubular membrane structures. newly incorporated bromouridine was associated with the same structures and specifically with small membrane invaginations, spherules, indicating that these structures may be the sites of viral rna synt ... | 1999 | 10438871 |
| induction of manganese-superoxide dismutase in mrc-5 cells persistently infected with an alphavirus, sindbis. | sindbis virus (sv), a single-stranded positive-sense rna virus, multiplies in a variety of cells and causes various outcomes of infection. as we described acute infection of sv induces stress response of small heat shock protein hsp27 and activation of mitogen-activated protein kinase (map) signaling pathway (nakatsue, t., et al., biochem. biophys. res. commun. 253, 59-64, 1998). in contrast to lytic infection in vero cells, mrc-5 cells, a human fetus lung cell line, resulted in persistent infec ... | 1999 | 10405336 |
| a salmonella virulence protein that inhibits cellular trafficking. | salmonella enterica requires a type iii secretion system, designated spi/ssa, to survive and proliferate within macrophages. the spi/ssa system is encoded within the spi-2 pathogenicity island and appears to function intracellularly. here, we establish that the spi-2-encoded spic protein is exported by the spi/ssa type iii secretion system into the host cell cytosol where it interferes with intracellular trafficking. in j774 macrophages, wild-type salmonella inhibited fusion of salmonella-contai ... | 1999 | 10406797 |
| inhibition of virus-induced neuronal apoptosis by bax. | the bax protein is widely known as a pro-apoptotic bcl-2 family member that when overexpressed can trigger apoptosis in multiple cell types and is important for the developmental cell death of neurons. however, bax was found here to be a potent inhibitor of neuronal cell death in mice infected with sindbis virus. newborn mice, which are highly susceptible to a fatal infection with neurotropic sindbis virus, were significantly protected from neuronal apoptosis and fatal disease when infected with ... | 1999 | 10395331 |
| membrane permeabilization by small hydrophobic nonstructural proteins of japanese encephalitis virus. | infection with japanese encephalitis virus (jev), a mosquito-borne flavivirus, may cause acute encephalitis in humans and induce severe cytopathic effects in various types of cultured cells. we observed that jev replication rendered infected baby hamster kidney (bhk-21) cells sensitive to the translational inhibitor hygromycin b or alpha-sarcine, to which mock-infected cells were insensitive. however, little is known about whether any jev nonstructural (ns) proteins contribute to virus-induced c ... | 1999 | 10400716 |
| the furin protease cleavage recognition sequence of sindbis virus pe2 can mediate virion attachment to cell surface heparan sulfate. | cell culture-adapted sindbis virus strains attach to heparan sulfate (hs) receptors during infection of cultured cells (w. b. klimstra, k. d. ryman, and r. e. johnston, j. virol. 72:7357-7366, 1998). at least three e2 glycoprotein mutations (e2 arg 1, e2 lys 70, and e2 arg 114) can independently confer hs attachment in the background of the consensus sequence sindbis virus (tr339). in the studies reported here, we have investigated the mechanism by which the e2 arg 1 mutation confers hs-dependen ... | 1999 | 10400721 |
| the cc-chemokine rantes increases the attachment of human immunodeficiency virus type 1 to target cells via glycosaminoglycans and also activates a signal transduction pathway that enhances viral infectivity. | we have studied the mechanisms by which the cc-chemokine rantes can enhance the infectivities of human immunodeficiency virus type 1 (hiv-1) and other enveloped viruses, when present at concentrations in excess of 500 ng/ml in vitro. understanding the underlying mechanisms might throw light on fundamental processes of viral infection, in particular for hiv-1. our principal findings are twofold: firstly, that oligomers of rantes can cross-link enveloped viruses, including hiv-1, to cells via glyc ... | 1999 | 10400729 |
| selective irreversible inactivation of replicating mengovirus by nucleoside analogues: a new form of viral interference. | we describe the selective irreversible inhibition of mengovirus growth in cultured cells by a combination of two pyrrolopyrimidine nucleoside analogues, 5-bromotubercidin (brtu) and tubercidin (tu). at a concentration of 5 microgram/ml, brtu reversibly blocked the synthesis of cellular mrna and rrna but did not inhibit either mengovirus rna synthesis or multiplication. brtu is a potent inhibitor of adenosine kinase, and low concentrations of brtu (e.g., 0.5 microgram/ml), which did not by themse ... | 1999 | 10400738 |
| identification of a linear heparin binding domain for human respiratory syncytial virus attachment glycoprotein g. | respiratory syncytial virus (rsv) is the leading cause of lower respiratory tract disease in infants and young children worldwide. infection is mediated, in part, by an initial interaction between attachment protein (g) and a highly sulfated heparin-like glycosaminoglycan (gag) located on the cell surface. synthetic overlapping peptides derived from consensus sequences of the g protein ectodomain from both rsv subgroups a and b were tested by heparin-agarose affinity chromatography for their abi ... | 1999 | 10400758 |
| the h gene of rodent brain-adapted measles virus confers neurovirulence to the edmonston vaccine strain. | molecular determinants of neuropathogenesis have been shown to be present in the hemagglutinin (h) protein of measles virus (mv). an h gene insertion vector has been generated from the edmonston b vaccine full-length infectious clone of mv. using this vector, it is possible to insert complete h open reading frames into the parental (edtag) background. the h gene from a rodent brain-adapted mv strain (cam/rb) was inserted into this vector, and a recombinant virus (edtagcamh) was rescued by using ... | 1999 | 10400789 |
| lipoproteins account for part of the broad non-specific antiviral activity of human serum. | several antiviral substances have been detected in human serum but few have been shown to possess broad antiviral activity. these broadly active antiviral molecules could be of significance as innate defense mechanisms. we have previously identified and characterized a broadly antiviral glycoprotein, uti3, which accounts for 50 antiviral units/ml of human and mammalian sera. in addition there are reports of antiviral activity of human serum apolipoprotein a-1 (apo a-1), an important constituent ... | 1999 | 10443533 |
| immunogenicity of dna vaccines expressing tuberculosis proteins fused to tissue plasminogen activator signal sequences. | novel tuberculosis dna vaccines encoding native esat-6, mpt-64, katg, or hbha mycobacterial proteins or the same proteins fused to tissue plasminogen activator (tpa) signal sequences were evaluated for their capacity to elicit humoral, cell-mediated, and protective immune responses in vaccinated mice. while all eight plasmids induced specific humoral responses, the constructs expressing the tpa fusions generally evoked higher antibody responses in vaccinated hosts. although most of the dna vacci ... | 1999 | 10456931 |
| binding of tumour necrosis factor-alpha (tnf-alpha) to tnf-ri induces caspase(s)-dependent apoptosis in human cholangiocarcinoma cell lines. | cholangiocarcinoma (cca), a tumour of the bile duct epithelium, occurs with a higher incidence in south-east asian countries than in europe and north america. the prognosis is poor, due to the unavailability of early diagnosis and the tumours being relatively resistant to chemotherapy. in the present study one of the fatal routes of this tumour was studied. this death was stimulated by tnf-alpha. tnf-alpha at a concentration of 760 pg/ml and 100 pg/ml in the presence of 1 microgram/ml actinomyci ... | 1999 | 10209503 |