Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
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| hepatitis c virus ns3 serine proteinase: trans-cleavage requirements and processing kinetics. | the hepatitis c virus h strain (hcv-h) polyprotein is cleaved to produce at least 10 distinct products, in the order of nh2-c-e1-e2-p7-ns2-ns3-ns4a-ns4b-ns5a-ns5b -cooh. an hcv-encoded serine proteinase activity in ns3 is required for cleavage at four sites in the nonstructural region (3/4a, 4a/4b, 4b/5a, and 5a/5b). in this report, the hcv-h serine proteinase domain (the n-terminal 181 residues of ns3) was tested for its ability to mediate trans-processing at these four sites. by using an ns3-5 ... | 1994 | 7966606 |
| hepatitis c virus variants from vietnam are classifiable into the seventh, eighth, and ninth major genetic groups. | thirty-four (41%) of 83 hepatitis c virus (hcv) isolates from commercial blood donors in vietnam were not classifiable into genotype i/1a, ii/1b, iii/2a, iv/2b, or v/3a; for 15 of them, the sequence was determined for 1.6 kb in the 5'-terminal region and 1.1 kb in the 3'-terminal region. comparison of the 15 vietnamese isolates among themselves and with reported full or partial hcv genomic sequences indicated that they were classifiable into four major groups (groups 6-9) divided into six genoty ... | 1994 | 7972001 |
| processing of e1 and e2 glycoproteins of hepatitis c virus expressed in mammalian and insect cells. | processing of the envelope glycoproteins (e1 and e2) of hepatitis c virus (hcv) was investigated by using cdna clones covering the structural and part of the nonstructural (ns) protein regions. the cdna clones expressed in mammalian and insect cells were immunoprecipitated by serum of a hepatitis c patient and by monoclonal and polyclonal antibodies raised against the recombinant proteins expressed in insect cells or escherichia coli. the e2 protein expressed in both insect and mammalian cells w ... | 1994 | 7975209 |
| sequence variability in the env-coding region of hepatitis c virus isolated from patients infected during a single source outbreak. | the variability of the hepatitis c virus genome was investigated in a group of german patients who developed chronic hepatitis c after parenteral administration of contaminated immunoglobulin to prevent rh sensitization after pregnancy. the nucleotide and deduced amino acid sequence alterations of the e1 and the first hypervariable region of the e2 gene of the hepatitis c virus (hcv) genome from sera of two randomly selected patients were studied by comparison of hcv sequences obtained from the ... | 1994 | 7979995 |
| t cell recognition of hepatitis b and c viral antigens. | the outcome of hepatitis b and c heavily depends on the appropriate virus specific t cell response. both cd8+ and cd4+ t lymphocytes do not recognize native viral proteins but processed peptides bound to mhc class i and class ii, respectively. for therapeutical intervention aimed at t lymphocytes in chronic carriers as well as for the development of new vaccines, a precise identification of immunodominant epitopes, which can be recognized by a majority of patients, is necessary. biological featu ... | 1994 | 7531642 |
| truncating the putative membrane association region circumvents the difficulty of expressing hepatitis c virus protein e1 in escherichia coli. | the putative e1 of hepatitis c virus (hcv) was expressed in escherichia coli using a glutathione-s-transferase (gst) fusion protein system. the full length e1 protein is difficult to express. a series of e1 dna fragments was generated and used for expression vector construction. fusion proteins containing the e1 c-terminal region could not be expressed. when this region was truncated, the fusion proteins were synthesized to high levels. the possibility of this c-terminal region hampering the pro ... | 1994 | 7532651 |
| mhc class i-restricted cytotoxic t lymphocytes to viral antigens destroy hepatocytes in mice infected with e1-deleted recombinant adenoviruses. | the use of e1-deleted recombinant adenoviruses in gene therapy has consistently been associated with transient gene expression and inflammation due to immune-based destruction of the infected cells. we have used murine models of adenovirus-mediated gene transfer to liver to investigate these immunologic mechanisms. adoptive transfer experiments, as well as studies involving genetic knockout mice, confirmed the original hypothesis that cell-mediated immunity induced by e1-deleted adenovirus destr ... | 1994 | 7533647 |
| differential pattern of sequence heterogeneity in the hepatitis c virus e1 and e2/ns1 proteins. | the e1 and e2/ns1 genes, encoding the putative hepatitis c virus envelope proteins, show a high rate of sequence variations. we analyzed the degree and distribution of sequence heterogeneity in serum samples from hepatitis c virus-infected subjects. the mutations in the e1 region were mainly type-specific and the rate of variability was apparently not linked to the clinical phase of the infection. the sequence evolution of the e1 region during interferon treatment was low, regardless of the resp ... | 1994 | 7534322 |
| adaptation of hepatitis c virus for persistent infection in patients with acute hepatitis. | nucleotide sequencing was used to analyze amino acid substitutions in the putative envelope 1 (e1) and envelope 2/nonstructural 1 (e2/ns1) regions of hepatitis c virus (hcv) to clarify a viral mechanism of persistent infection in three patients with acute hepatitis c who developed chronic hepatitis and two patients with chronic hepatitis. the hcv rna titer in serum decreased markedly after the onset of acute hepatitis and then re-elevated. during this period, the substitution rate in the e2/ns1 ... | 1994 | 7545924 |
| analysis of the core and e1 envelope region sequences of a novel variant of hepatitis c virus obtained in indonesia. | hepatitis c virus (hcv) is currently classified into 6 major types, hcv-1 through -6, each of which can be further divided into a few subtypes, e.g., hcv-1a, -1b, -1c, etc., on the basis of sequence variation of the viral genome. the core and e1 envelope regions of hcv genome were amplified from sera of indonesian patients using reverse transcription-polymerase chain reaction. sequence analysis of both core and e1 regions followed by molecular evolutionary phylogenetic analysis identified a nove ... | 1994 | 7545932 |
| high-efficiency gene transfer and high-level expression of wild-type p53 in human lung cancer cells mediated by recombinant adenovirus. | a replication-defective and helper-independent recombinant p53 adenovirus was generated. the virus, ad5cmv-p53, carries an expression cassette that contains human cytomegalovirus e1 promoter, human wild-type p53 cdna, and sv40 early polyadenylation signal. four human non-small-cell lung cancer cell lines representing differences in p53 configuration were used to evaluate the ad5cmv-p53 virus. in the h358 cell line, which has a homozygous deletion of p53, the p53 gene was transferred with 97% to ... | 1994 | 7621238 |
| elevated rubella antibodies in patients with chronic liver disease. | patients with autoimmune chronic active hepatitis (aicah) and certain other chronic liver disorders often have very high titres of haemagglutination-inhibition (hi) antibodies to rubella virus. in this study it is shown, using floatation centrifugation, that the high rubella hi reactivity is not caused by nonspecific lipoprotein inhibitors but rather by antibodies specific for the rubella haemagglutinin (e1 glycoprotein). after sucrose density gradient ultracentrifugation of sera the major hi re ... | 1994 | 7798882 |
| the v-sis oncoprotein loses transforming activity when targeted to the early golgi complex. | the location of autocrine interactions between the v-sis protein and pdgf receptors remains uncertain and controversial. to examine whether receptor-ligand interactions can occur intracellularly, we have constructed fusion proteins that anchor v-sis to specific intracellular membranes. fusion of a cis-golgi retention signal from a coronavirus e1 glycoprotein to v-sis protein completely abolished its transforming ability when transfected into nih3t3 cells. fusion proteins incorporating mutations ... | 1994 | 7806564 |
| visualization of fusion activation in the semliki forest virus spike. | viral spike proteins such as those of semliki forest virus (sfv) undergo a conformational change triggered by low ph which results in the fusion of the viral envelope with cellular membranes. the viral spike precursor of sfv is insensitive to low ph, and hence is fusion incompetent, until it is proteolytically cleaved to give the fusion competent mature form. | 1994 | 7812716 |
| genetic heterogeneity of hepatitis c virus. | there are four hierarchical strata in the genetic heterogeneity of hepatitis c virus (hcv): group above subgroup above isolates above quasispecies. the entire genome sequence has so far been reported for 16 isolates which are classifiable into 3 groups and 6 subgroups. provisional classification of hcv is also possible using a partial sequence of the hcv genome. with the e1 region sequence for example, the present collection of hcv isolates can be classified into 9 groups and 23 subgroups. the r ... | 1994 | 7814244 |
| immunoaffinity purification of baculovirus-expressed rubella virus e1 for diagnostic purposes. | three monoclonal antibodies, termed 4e10, 1e11:10, and 2d9:1, were generated against rubella virus. immunoblot analysis with purified authentic rubella virus or recombinant baculovirus-expressed rubella virus structural proteins e1, e2, and c demonstrated that they were directed against the e1 envelope glycoprotein of the rubella virus particle. by using the yeast ty virus-like particle system, it was possible to map the binding site of 1e11:10 within amino acids 236 to 286 of the e1 protein and ... | 1994 | 7814545 |
| distribution of viral genotypes in italy determined by hepatitis c virus typing by dna immunoassay. | the distribution of hepatitis c virus (hcv) genotypes in italy was investigated by pcr amplification of the e1 region and hybridization with type i- and type ii-specific nonisotopic probes. positive pcr results were obtained for 65 of 72 patients (90.3%). type i was detected in 13 of 72 patients (18%), type ii was detected in 39 patients (54.2%), and a mixed type i-type ii infection was detected in 7 patients (9.7%). six amplification products not classified by this method shared a low level of ... | 1994 | 7814559 |
| exclusion in liver by polymerase chain reaction of hepatitis b and c viruses in acute liver failure attributed to sporadic non-a, non-b hepatitis. | hepatitis b and c viruses have been implicated in a few cases of acute liver failure attributed to sporadic (community acquired) non-a, non-b hepatitis, but reports are conflicting. we determined whether hepatitis b virus and hepatitis c virus were detectable in prospectively stored hepatectomies from seven british patients grafted for acute liver failure attributed to sporadic non-a, non-b hepatitis. for hepatitis b virus, we used nested polymerase chain reaction with primers to the core and su ... | 1994 | 7814806 |
| mutational analysis of human papillomavirus e4 proteins: identification of structural features important in the formation of cytoplasmic e4/cytokeratin networks in epithelial cells. | we have previously demonstrated that human papillomavirus type 1 (hpv 1) and 16 (hpv 16) e4 proteins form cytoplasmic filamentous networks which specifically colocalize with cytokeratin intermediate-filament (if) networks when expressed in simian virus 40-transformed keratinocytes. the hpv 16 (but not the hpv 1) e4 protein induced the collapse of the cytokeratin networks. (s. roberts, i. ashmole, g. d. johnson, j. w. kreider, and p. h. gallimore, virology 197:176-187, 1993). the mode of interact ... | 1994 | 7521917 |
| inactivation of e2a in recombinant adenoviruses improves the prospect for gene therapy in cystic fibrosis. | although first generation recombinant adenoviruses, deleted of sequences spanning e1a and e1b, have been useful for in vivo applications of gene therapy, expression of the recombinant gene has been transient and often associated with the development of inflammation. we show that with first generation adenovirus-mediated gene transfer to the mouse lung, viral proteins are expressed leading to destructive cellular immune responses and repopulation of the lung with nontransgene containing cells. se ... | 1994 | 7522742 |
| [current developments in the diagnosis of hepatitis c]. | since the discovery of hepatitis c virus five years ago eight complete isolates and a large number of partial isolates have been sequenced. by comparing sequences, six hcv types can be differentiated which show more than 35% divergency in the ns5 proteins. the course of hepatitis c and the response rate after interferon therapy may be dependent on the hcv type. serological tests for the diagnosis of acute and chronic hepatitis c have been improved, so that more than 90% of patients seroconvert a ... | 1994 | 7524124 |
| localization of four antigenic sites involved in venezuelan equine encephalomyelitis virus protection. | stable neutralization and protection escape variants of a virulent strain (trinidad donkey) of the vee virus were selected by monoclonal antibodies (mabs). determination of nucleotide sequences of nine variants revealed a clustering of single mutations in four regions of the e1 and e2 glycoproteins. involvement of amino acid residues 206 (site e1-1), 57 and 59 (site e2-2), 180, 182, 213, 214 and 216 (site e2-6) and 232 (site e2-3) in protective epitopes was demonstrated. | 1994 | 7529989 |
| antigenic structure of envelope glycoprotein e1 of hog cholera virus. | envelope glycoprotein e1 (gp51 to gp54) is the most antigenic protein of hog cholera virus or classical swine fever virus (csfv). four antigenic domains, a to d, have been mapped on e1 with a panel of monoclonal antibodies (mabs) raised against csfv strain brescia. the boundaries of these domains have been established by extensive studies on binding of mabs to transiently expressed deletion mutants of e1 (p. a. van rijn, e. j. de meijer, h. g. p. van gennip, and r. j. m. moormann, j. gen. virol. ... | 1994 | 7514680 |
| hepatitis c virus markers in patients with long-term biochemical and histological remission of chronic hepatitis. | we measured hepatitis c virus (hcv) rna and antibodies against hcv recombinant proteins (c22/s1, e1/s2, e2/ns1, c33/ns3, c100/ns4, ns5) in serial serum samples from 22 interferon-treated patients with a long-term follow up (range: 36-44 months). eleven of them showed persistently normal liver function tests and a significant histological amelioration or a complete resolution of chronic hepatitis (long-term responders, ltrs). in the remaining 11 patients (non-responders (nrs)) liver function test ... | 1994 | 7515141 |
| analysis of overlapping t- and b-cell antigenic sites on rubella virus e1 envelope protein. influence of hla-dr4 polymorphism on t-cell clonal recognition. | a ctl antigenic site located between residues 273 and 291 of the e1 envelope protein of rv was identified by 51cr-release assays employing sps. two e1-specific ctl clones were examined for immune recognition of rv wild-type and attenuated vaccine strains and recombinant e1 protein. the exact sequence (273-284) recognized by both clones was delineated by using truncated and overlapping sps covering these residues. the defined t-cell site overlapped almost completely with a virus neutralizing anti ... | 1994 | 7517931 |
| processing in the hepatitis c virus e2-ns2 region: identification of p7 and two distinct e2-specific products with different c termini. | the hepatitis c virus (hcv) h strain polyprotein is cleaved to produce at least nine distinct products: nh2-c-e1-e2-ns2-ns3-ns4a-ns4b-ns5a-ns5b-co oh. in this report, a series of c-terminal truncations and fusion with a human c-myc epitope tag allowed identification of a tenth hcv-encoded cleavage product, p7, which is located between the e2 and ns2 proteins. as determined by n-terminal sequence analysis, p7 begins with position 747 of the hcv h strain polyprotein. p7 is preceded by a hydrophobi ... | 1994 | 7518529 |
| gene therapy for cystic fibrosis using e1-deleted adenovirus: a phase i trial in the nasal cavity. the university of north carolina at chapel hill. | cystic fibrosis (cf) is an autosomal recessive disease that reflects mutations in the cftr gene. multiple mutations in this gene have been detected that lead to a protein (cftr) that is abnormally metabolized, dysfunction, or both. the full spectrum of the activities of the gene product have not been defined, but it is clear that cftr can act as a camp-regulated cl- channel. this type of defect is consistent with the physiologic characterization of cf epithelia, which has revealed abnormalities ... | 1994 | 7519885 |
| cloning and phylogenetic analysis of the core, e2, and ns3/ns4 regions of the hepatitis c virus type 5a. | by means of the line probe assay, a hepatitis c virus type 5a infected serum from a belgian patient was selected. the complete core region (573 bp), the carboxyterminal part of e1 and the aminoterminal part of e2/ns1 (661 bp), and an epitope containing region in ns3-ns4 (1452 bp) were cloned and sequenced. the deduced amino acid sequence revealed type-specific variations in regions of core and ns4 which were previously recognized as evoking a type-specific antibody response. in addition, the ami ... | 1994 | 7520237 |
| mechanism of enhancement of dna expression consequent to cointernalization of a replication-deficient adenovirus and unmodified plasmid dna. | given the knowledge that replication-deficient adenoviruses can mediate the delivery of unlinked plasmid dna into eukaryotic cells (k. yoshimura, m. a. rosenfeld, p. seth, and r. g. crystal, j. biol. chem. 268:2300-2303, 1993), this study focuses on the role of receptor-mediated endocytosis in this process. adcftr (an e1- e3- adenovirus type 5-based replication-deficient adenovirus containing the 4.5-kb human cystic fibrosis transmembrane conductance regulator cdna) was added to cos-7 cells toge ... | 1994 | 7507187 |
| vaccination of chimpanzees against infection by the hepatitis c virus. | a high incidence of community-acquired hepatitis c virus infection that can lead to the progressive development of chronic active hepatitis, liver cirrhosis, and primary hepatocellular carcinoma occurs throughout the world. a vaccine to control the spread of this agent that represents a major cause of chronic liver disease is therefore needed. seven chimpanzees (pan troglodytes) have been immunized with both putative envelope glycoproteins [e1 (gp33) and e2 (gp72)] that were copurified from hela ... | 1994 | 7509068 |
| identification of putative ligand binding sites within i domain of integrin alpha 2 beta 1 (vla-2, cd49b/cd29) | integrin alpha 2 beta 1 is a cell surface adhesion receptor for collagen and echovirus 1. here we localized the epitopes for anti-alpha 2 monoclonal antibodies using interspecies (human/bovine) alpha 2 chimeras with different lengths of human alpha 2 sequence on the amino-terminal side and site-directed mutagenesis. the antibodies that block the collagen and/or echovirus 1 binding to human alpha 2 beta 1 (6f1, rmac11, 12f1, and aa10) recognizes a small region (residues 173-259) within the i doma ... | 1994 | 7511592 |
| differential host-dependent expression of alpha-galactosyl epitopes on viral glycoproteins: a study of eastern equine encephalitis virus as a model. | the carbohydrate epitope gal alpha 1-3gal beta 1-4glcnac-r (alpha-galactosyl) is abundantly expressed on cells of non-primate mammals, prosimians and new world monkeys, where it is synthesized by the enzyme alpha 1,3-galactosyltransferase (alpha 1,3gt). old world monkeys, apes and humans lack alpha 1,3gt and hence do not synthesize alpha-galactosyl epitopes. instead, these species produce a natural antibody, anti-gal, which interacts specifically with alpha-galactosyl epitopes and which constitu ... | 1994 | 7513744 |
| detection of divergent hepatitis c virus envelope sequences. | the nucleotide sequences of the putative envelope region (e1) and the junction between the e1 and envelope 2/nonstructural 1 (e2/ns1) region of the hepatitis c virus (hcv) genome are divergent among different genotypes. to characterize them, we introduced a set of nested primers that are conserved among four different genotypes (types i-iv) of hcv for polymerase chain reaction (pcr) amplification. the amplified products include the variable full-length e1 region, and the 5' end of the e2/ns1 reg ... | 1994 | 11725020 |
| recombinant rubella e1 fusion proteins for antibody screening and diagnosis. | until rubella is eradicated there will be a continuing need for rubella antibody surveillance. antigen production using recombinant dna technology may be a viable alternative to traditional techniques of producing antigens for enzyme immunoassays (eias). | 1994 | 15566762 |
| heart targeting of retroviral expression in avian embryos: a species-independent phenomenon. | a replication-incompetent retroviral vector derived from spleen necrosis virus (snv), in which the viral structural genes gag, pol, and env were replaced with the bacterial β-galactosidase gene lacz, was used to infect embryos from outbred and inbred chicken lines, japanese quail and duck between embryonic day 0 and 13. lacz expression was restricted to a few organs or cell types, and this distribution was not influenced by the different routes of inoculation tested but was specified by the age ... | 1995 | 28305962 |
| tumor regression is associated with a specific immune response to the e2 protein of cottontail rabbit papillomavirus. | cottontail rabbit papillomavirus is the major papillomavirus animal model with which to study host-virus interactions. as with human papillomaviruses, papillomas may spontaneously regress, persist, or progress to carcinoma. here we show that the majority (88%) of regressor rabbits had antibody to the nonstructural protein e2 compared to 29% in animals with persisting papilloma. the antibody response to other nonstructural viral proteins was the same for rabbits with regressing and persisting pap ... | 1995 | 11831711 |
| direct and uninterrupted rna amplification of enteroviruses with colorimetric microwell detection. | enteroviruses (ev) cause a broad spectrum of human diseases, of which aseptic meningitis is among the most common and most clinically vexing. while the clinical symptoms of meningitis caused by bacteria, fungi and viruses are similar, the diagnosis, therapy and outcome of disease caused by these agents vary greatly. in order to appropriately manage meningitis patients, rapid and reliable diagnosis of ev meningitis impacts significantly on patient management. | 1995 | 15566806 |
| antibodies against linear and conformational epitopes of human papillomavirus type 16 that independently associate with incident cervical cancer. | in a seroepidemiological study of incident cervical cancer, 94 cases and 188 population-based controls were used to evaluate the disease-association of igg and iga antibody responses against 6 human papillomavirus (hpv) type-16 antigens. nine of the tested antibody responses were positively associated with cervical cancer, with odds ratios (ors) ranging from 2.5 to 15.0. the antibody responses most strongly associated with cervical cancer were iga against e6:10, an epitope derived from the carbo ... | 1995 | 7530234 |
| differential reactivity of immune sera from human vaccinees with field strains of eastern equine encephalitis virus. | eastern equine encephalitis (eee) virus is a mosquito-borne alphavirus that can produce a severe and often fatal acute encephalitis in humans, with significant neurologic sequelae in survivors. due to the serious nature of the disease, an investigational inactivated eee vaccine (pe-6) is available to individuals at risk for infection. both serologic and recent molecular analyses of eee viruses have demonstrated marked differences between the two antigenic varieties of eee virus, designated north ... | 1995 | 7485719 |
| differential subcellular localization of hepatitis c virus core gene products. | the expression of the core gene of two different hepatitis c virus (hcv) isolates was analyzed. in the presence of its downstream e1 envelope protein sequence, two major core protein products with molecular masses of 21 kda (p21) and 19 kda (p19) and a minor protein product with molecular mass of 16 kda (p16) were detected. in the absence of its downstream e1 envelope protein sequence, p21 and p19 remained the major protein products expressed from the core gene of the hcv-rh isolate, whereas p16 ... | 1995 | 7491770 |
| raised levels of antibodies to human viruses at the clinical onset of autoimmune chronic active hepatitis. | patients with autoimmune chronic active hepatitis (aicah) often have very high titres of antibodies to rubella and/or measles virus. in the present study a young girl at the clinical onset of aicah exhibited very high titres of antibodies against influenza viruses a and b, parainfluenza viruses, rubella virus and varicella-zoster virus. the titres normalized over 2 months except for rubella and varicella-zoster antibodies. strong reactivities were seen against the rubella structural proteins e1, ... | 1995 | 7493312 |
| cellular factors required for papillomavirus dna replication. | in vitro replication of papillomavirus dna has been carried out with a combination of purified proteins and partially purified extracts made from human cells. dna synthesis requires the viral e1 protein and the papillomavirus origin of replication. the e2 protein stimulates dna synthesis in a binding site-independent manner. papillomavirus dna replication is also dependent on the cellular factors replication protein a, replication factor c, and proliferating-cell nuclear antigen as well as a pho ... | 1995 | 7494298 |
| identification of the pore forming element of semliki forest virus spikes. | pore formation at mildly acidic ph by sfv spike proteins was investigated using isolated and modified virions. modification of the virions was performed by limited proteolysis in presence of octylglucoside and resulted in the formation of e1 particles and spikeless particles, respectively. pore formation was detected by measuring the influx of propidium iodide into the viral particles. the results obtained clearly showed that the presence of e1 alone is sufficient to promote pore formation at mi ... | 1995 | 7498462 |
| evaluation of complete genome sequences and sequences of individual gene products for the classification of hepatitis c viruses. | comparisons of genome and polyprotein sequences of hepatitis c virus (hcv) isolates world-wide has led to the identification of nine major genotypes and many subtypes. this classification is based on either complete genome/polyprotein sequences or sequence data from the 5' noncoding region, core, e1, ns3 or ns5b genes. the relative merit of different gene segments as taxonomic markers and the validity of the resulting assignments is not clear at this stage. to resolve the taxonomy of hcv genotyp ... | 1995 | 7503676 |
| expression of the rubella virus structural proteins by an infectious sindbis virus vector. | to assess the potential of an infectious sindbis virus vector (dssin) as a eukaryotic expression vector, dssin recombinants which contain each of the rubella virus (rub) structural proteins (c, e2, and e1) individually were constructed. expression of the rub proteins by each dssin recombinant was robust and processing was similar to that observed when these proteins were expressed using other vectors. the c and e2 recombinants, each of which contains a cassette of less than 1,000 nts, were stabl ... | 1995 | 7503703 |
| presentation of endogenous and exogenous antigens is not affected by inactivation of e1 ubiquitin-activating enzyme in temperature-sensitive cell lines. | little is known regarding the mechanism by which mhc class i-associated peptides are generated. proteins can be targeted for degradation by the covalent attachment of ubiquitin. the first step in ubiquitin conjugation to proteins is its binding to e1 ubiquitin-activating enzyme. to study the role of ubiquitin-targeted protein degradation in ag processing, we used two mutant cell lines with temperature-sensitive e1 proteins, and a recombinant vaccinia virus expressing wild-type human e1. one of t ... | 1995 | 7814864 |
| two e2 binding sites alone are sufficient to function as the minimal origin of replication of human papillomavirus type 18 dna. | replication of papillomaviruses requires an origin of replication and two virus-encoded proteins, e1 and e2. using a transient replication assay for human papillomavirus type 18 (hpv-18) dna, we have found that two adjacent sequences present within the origin of replication can independently support replication. the first, a 77-bp region, contains one e2 binding site (e2bs) and a 16-bp inverted repeat element that probably corresponds to the e1 binding site (e1bs). the other, an 81-bp region, in ... | 1995 | 7815514 |
| cis-acting components of human papillomavirus (hpv) dna replication: linker substitution analysis of the hpv type 11 origin. | papillomavirus dna replication requires the viral trans-acting factors e1 and e2 in addition to the host cell's general replication machinery. the origins of dna replication in bovine and human papillomavirus genomes have been localized to a specific part of the upstream regulatory region (urr) which includes recognition sites for e1 and e2 proteins. to fine map cis-acting elements influencing human papillomavirus type 11 (hpv-11) dna replication and to determine the relative contributions of su ... | 1995 | 7815528 |
| investigation of promoter function in human and animal cells infected with human recombinant adenovirus expressing rotavirus antigen vp7sc. | human adenovirus (ad) vectors are being used increasingly for a variety of applications in vaccination and gene therapy. the ability of vectors to enter cells and the efficiency of promoters expressing the therapeutic gene or vaccine antigen are critical to the outcome of such experiments. to identify promoters which might be suitable for use under a variety of conditions we have investigated the expression of a rotavirus antigen, vp7sc, employing several commonly used promoters carried in e1-su ... | 1995 | 7636477 |
| upregulation of class i major histocompatibility complex antigens by interferon gamma is necessary for t-cell-mediated elimination of recombinant adenovirus-infected hepatocytes in vivo. | recombinant adenoviruses are attractive vehicles for liver-directed gene therapy because of the high efficiency with which they transfer genes to hepatocytes in vivo. first generation recombinant adenoviruses deleted of e1 sequences also express recombinant and early and late viral genes, which lead to development of destructive cellular immune responses. previous studies indicated that class i major histocompatibility complex (mhc)-restricted cytotoxic t lymphocytes (ctls) play a major role in ... | 1995 | 7638177 |
| the hepatitis c virus ns3 serine proteinase and ns4a cofactor: establishment of a cell-free trans-processing assay. | the hepatitis c virus rna genome encodes a long polyprotein that is proteolytically processed into at least 10 products. the order of these cleavage products in the polyprotein is nh2-c-e1-e2-p7-ns2-ns3-ns4a-ns4b-ns5a-ns5b -cooh. a serine proteinase domain located in the n-terminal one-third of nonstructural protein ns3 mediates cleavage at four downstream sites (the 3/4a, 4a/4b, 4b/5a, and 5a/5b sites). in addition to the proteinase catalytic domain, the ns4a protein is required for processing ... | 1995 | 7644466 |
| clearance of adenovirus-infected hepatocytes by mhc class i-restricted cd4+ ctls in vivo. | e1-deleted recombinant adenoviruses have been developed for liver-directed gene therapy because efficient gene transfer to hepatocytes can be achieved in vivo. however, these viruses also express viral proteins in hepatocytes, leading to the development of destructive immune responses. our previous studies indicated that mhc class i-restricted c d8+ctls are major effectors in eliminating virus-infected cells, and cd4+ cells are also necessary in developing a fully competent ctl response by secre ... | 1995 | 7650386 |
| novel zinc chelators with dual activity in the inhibition of the kappa b site-binding proteins hiv-ep1 and nf-kappa b. | both hiv-ep1 (also called prdii-bf1 or mbp-1), a zinc finger protein, and nf-kappa b, a rel family protein, bind to kappa b site present in the enhancer of multiple cellular and viral genes involved in immune function and inflammatory response including hiv-1 ltr and human interferon beta gene. when cells are exposed to extracellular stimuli such as virus or phorbol ester, the activity of both hiv-ep1 and nf-kappa b is induced. thus, kappa b site-directed transcription could be regulated by two ... | 1995 | 7650680 |
| classification of hepatitis c virus into major types and subtypes based on molecular evolutionary analysis. | molecular evolutionary analysis was applied to determine the number of hepatitis c virus (hcv) types and subtypes based on all the hcv nucleotide sequences available from the dna data banks (ddbj, genbank (ncbi), embl) and the literature. there was an excellent concordance among the types and subtypes assigned based on different hcv genomic regions. only one hcv isolate was assigned to different hcv types based on the 5' non-coding (nc) and envelope 1 (e1) regions. the 5' nc region was well cons ... | 1995 | 7653099 |
| in vivo transfection of hepatitis c virus complementary dna into rodent liver by asialoglycoprotein receptor mediated gene delivery. | an in vivo model of hepatitis c virus (hcv) infection is needed to enable investigation of the mechanism of the liver injury that it causes. in this study, we used asialoglycoprotein receptor mediated gene delivery to obtain expression of the complementary dna (cdna) coding the core and part of the envelope 1 protein of hcv because selective delivery to the hepatocytes has been reported to be attained with this method. the optimum carrier-dna ratio was examined using in vitro transfection and fo ... | 1995 | 7657292 |
| the toxicity of aromatic nitrocompounds to bovine leukemia virus-transformed fibroblasts: the role of single-electron reduction. | bovine leukemia virus-transformed lamb embryo fibroblasts (line flk) possess activity of dt-diaphorase of ca. 260 u/mg protein and similar levels of other nadp(h)-oxidizing enzymes: nadh:oxidase, 359 u/mg; nadph:oxidase, 43 u/mg; nadh:cytochrome-c reductase, 141 u/mg; nadph:cytochrome-c reductase, 43 u/mg. in general, the toxicity of aromatic nitrocompounds towards flk cells increases on increase of single-electron reduction potentials (e1(1)) of nitrocompounds or the log of their reduction rate ... | 1995 | 7662703 |
| molecular analysis of intraspousal transmission of hepatitis c virus. | although intraspousal transmission of hepatitis c virus (hcv) has been speculated, there is no direct evidence. | 1995 | 7665861 |
| [genetic regulation of human genital papillomaviruses]. | human papillomavirus (hpv) specifically infect stratified epithelial cells, causing benign and malignant neoplasia. several elements directing this virus' genetic expression are present in a non-coding region called lcr. hpv infection starts in the basal cells of stratified epithelia, where a particular combination of cellular factors interacting with the lcr starts the transcription of the viral e6 and e7 oncogenes. the e6 and e7 genes alter the cell cycle because they interact and inactivate t ... | 1995 | 7676352 |
| attenuated mutants of venezuelan equine encephalitis virus containing lethal mutations in the pe2 cleavage signal combined with a second-site suppressor mutation in e1. | the pe2 cleavage signal in a full-length cdna clone of the alphavirus venezuelan equine encephalitis virus (vee) was ablated by site-directed mutagenesis. rna transcripts derived from the resulting plasmids programmed the production of nonviable particles upon transfection of baby hamster kidney (bhk) cells. however, the mutant rnas also gave rise to a small proportion of viable revertants. analysis of these biological revertants and their molecularly cloned homologs demonstrated that second-sit ... | 1995 | 7676619 |
| trans-complementation of e1-deleted adenovirus: a new vector to reduce the possibility of codissemination of wild-type and recombinant adenoviruses. | treatment of cystic fibrosis by gene therapy will require the development of vectors capable of efficient and safe transfer of a functional cystic fibrosis transmembrane conductance regulator (cftr) cdna to airway epithelia. to achieve this goal, replication-deficient (e1-) adenoviruses (ad) are promising vectors. we have previously demonstrated efficient cftr gene delivery to the airways of cotton rats and rhesus monkeys using a replication-deficient adenovirus, ad-cftr. here, we have investiga ... | 1995 | 7548271 |
| the constitutive expression of the immunomodulatory gp19k protein in e1-, e3- adenoviral vectors strongly reduces the host cytotoxic t cell response against the vector. | the immune response against cells infected by gene therapy vectors may be a major hindrance for gene therapy, destroying infected cells thus limiting the length of exogene expression and quickly eliminating infected cells on repeat administration. adenoviruses and many other pathogens have evolved strategies for escape from immune surveillance, including the gp19k gene, found in the adenovirus e3 region, known to down-regulate major histocompatibility complex class 1 expression on the cell surfa ... | 1995 | 7552985 |
| an efficient procedure to select and recover recombinant adenovirus vectors. | adenoviruses are efficient gene transfer vectors for a variety of cell types. to date, the most widely used methods to construct recombinant adenoviruses involve either in vitro ligation or recombination between one-half of the virus genome, previously cloned in a plasmid vector and engineered to contain the desired expression cassette, and the other half of the virus genome prepared from virions. although quite effective, these approaches produce viral progeny containing a mixture of recombinan ... | 1995 | 7552986 |
| complementation of a human adenovirus early region 4 deletion mutant in 293 cells using adenovirus-polylysine-dna complexes. | the e1 deleted adenoviral vectors are efficient at gene transfer to cells in culture or in animals. however, their use is limited because of an immune-mediated loss of transduced cells. this immune response is believed to result from low-level production of viral antigens from these vectors after gene transfer. the early region 4 (e4) of adenovirus produces a number of proteins that play an important role in adenoviral and host gene regulation during infection of mammalian cells. there is intere ... | 1995 | 7552990 |
| requirement for natural killer cell-produced interferon gamma in defense against murine cytomegalovirus infection and enhancement of this defense pathway by interleukin 12 administration. | the presence of natural killer (nk) cells contributes to early defense against murine cytomegalovirus (mcmv) infection. although nk cells can mediate in vivo protection against mcmv, the mechanism by which they do so has not been defined. the studies presented here evaluate cytokine production by nk cells activated during mcmv infection and the role of nk cell-produced cytokines in early in vivo antiviral defenses. experiments with normal c57bl/6, t cell-deficient c57bl/6 nude, and severe combin ... | 1995 | 7561678 |
| hepatitis c virus variants from thailand classifiable into five novel genotypes in the sixth (6b), seventh (7c, 7d) and ninth (9b, 9c) major genetic groups. | nine (10%) out of 90 hepatitis c virus (hcv) isolates from hepatitis patients and commercial blood donors in thailand were not classifiable into any of genotypes i/1a, ii/1b, iii/2a, iv/2b, v/3a or vi/3b by rt-pcr with type-specific primers deduced from the hcv core gene. these isolates were sequenced over a 1.6 kb stretch of the 5'-terminal sequence and 1.1 kb of the 3'-terminal sequence covering 30% of the entire genome. based on two-by-two comparison and phylogenetic analyses of the nine thai ... | 1995 | 7561773 |
| transfer of the cftr gene to the lung of nonhuman primates with e1-deleted, e2a-defective recombinant adenoviruses: a preclinical toxicology study. | this paper describes a preclinical toxicology study designed to investigate the biological efficacy and safety profile of second-generation adenovirus for cftr gene transfer into the baboon lung. this second-generation virus is deleted of e1 and contains a temperature-sensitive mutation in the e2a gene, which encodes a defective dna-binding protein. two distinct projects were undertaken. group a animals received a first-generation adenovirus (i.e., deleted of e1) in an upper lobe at the time a s ... | 1995 | 7578403 |
| complementation of defective leucine decarboxylation in fibroblasts from a maple syrup urine disease patient by retrovirus-mediated gene transfer. | maple syrup urine disease (msud) is a genetic disease caused by a deficiency of branched-chain keto acid dehydrogenase, a mitochondrial multienzyme complex responsible for the decarboxylation of leucine, isoleucine and valine. the complex consists of three subunits (e1, e2, and e3) and mutations in any subunit result in msud. no satisfactory treatment for msud is currently available. here we report the successful use of retroviral gene transfer to restore leucine decarboxylation activity in fibr ... | 1995 | 7584124 |
| genetic heterogeneity of hepatitis c virus: quasispecies and genotypes. | worldwide, hcv is a major etiologic agent of chronic hepatitis that may lead to the development of liver cirrhosis and hepatocellular carcinoma. thus, significant morbidity and mortality is caused by hcv infection and effective control measures against the spread of this virus are needed. originally, the extent of genetic heterogeneity of hcv was not fully appreciated. however, the breadth of the genetic heterogeneity of hcv is great, and this may have important implications in diagnosis, pathog ... | 1995 | 7597443 |
| pcr for detection of rubella virus rna in clinical samples. | a reverse transcription nested pcr (rt-pcr) assay for the detection of rubella virus rna using primers from the e1 open reading frame was established. this assay was found to be sensitive (detecting approximately two synthetic rna copies and rna extracted from 0.1 50% tissue culture infective dose of rubella virus) and specific; five wild-type rubella strains and four vaccine strains were detected, and no nonspecific amplification of 16 other rna viruses or rnas from seven cell types occurred. r ... | 1995 | 7615708 |
| high-level expression of the measles virus nucleocapsid protein by using a replication-deficient adenovirus vector: induction of an mhc-1-restricted ctl response and protection in a murine model. | replication-deficient adenovirus (ad) vectors provide an efficient technology for direct dna delivery to cells both in vitro and in vivo. we have inserted the measles virus nucleoprotein (n) gene under the control of the strong constitutive cmv major ie promoter into an ad type 5 e1- vector to produce the recombinant virus rad68. following infection of human fibroblasts with rad68 in vitro, recombinant n protein was synthesized as a 60-kda protein that represented up to 20% total soluble cell pr ... | 1995 | 7618280 |
| echovirus 1 interaction with the isolated vla-2 i domain. | the isolated i domain of the integrin vla-2, produced as a bacterial fusion protein, specifically bound echovirus 1 and prevented virus attachment to cells. these results demonstrate that the receptor structures critical for virus attachment are contained solely within the vla-2 i domain and that soluble receptor fragments are capable of preventing infection. | 1995 | 7535868 |
| differential use of the regulatory elements of the alpha b-crystallin enhancer in cultured murine lung (mlg), lens (alpha tn4-1) and muscle (c2c12) cells. | the mouse alpha b-crystallin-encoding gene (alpha b-cry) is highly expressed in the lens and expressed to lesser extents in other tissues. here, we investigated alpha b-cry expression in mouse-lung-derived mlg cells. two sizes of mlg alpha b-cry transcripts comigrated with alpha b-cry transcripts contained in total and poly(a)+rna from mouse lung, with preference for the larger species in the mlg cells. expression of both alpha b-cry promoter/cat reporter gene constructs and alpha b-cry enhancer ... | 1995 | 7536694 |
| sequence variation and biological activity of rubella virus isolates. | haemagglutination (ha) by rubella virus is mediated by the e1 glycoprotein. rubella isolates which haemagglutinate with different avidity have been characterised. a significant reduction of ha titre at ph 6.0 was observed in one isolate in which isoleucine is substituted for threonine at rubella e1 residue 280. this residue is located in an epitope (ep1) which we have previously identified and shown to bind ha inhibiting (ha1) monoclonal antibodies. the isolates studied are also distinguishable ... | 1995 | 7537491 |
| [epitope specificity and protective activity of monoclonal antibodies to venezuelan equine encephalomyelitis virus]. | epitope specificity and protective activity of 5 types of monoclonal antibodies (mab) to strain tm-14 of venezuelan equine encephalomyelitis (vee) virus were studied. the competing vee a4 and vee b5 mab were shown to recognize the conformation-dependent epitope of glycoprotein e2 third site and to possess an extremely high protective activity. vee c6 mab were active in all the studied biological tests (hemagglutination inhibition, neutralization tests, passive defence) and were directed to glyco ... | 1995 | 7539195 |
| generation of rubella virus-neutralising antibodies by vaccination with synthetic peptides. | four short peptides from rubella virus proteins e1 and e2, predicted to contain b cell epitopes, were used to vaccinate balb/c mice. sera from peptide-vaccinated animals reacted with viral antigens in elisa and three of the four induced virus-neutralising antibody (nab) responses. peptide py4, in contrast to the others, induced igg2a responses upon vaccination and stimulated spleen cells in vitro produced ifn gamma in the absence of il-5. it was reasoned that vaccination with py4 caused th1 subs ... | 1995 | 7539669 |
| human monoclonal antibodies for the immunological characterization of a highly conserved protein domain of the hepatitis c virus glycoprotein e1. | although both envelope glycoproteins of the hepatitis c virus, e1 and e2/ns1, show a high degree of sequence variation, the e1 protein includes a well conserved domain, which may be functionally important. we have analysed the human b cell response to a peptide fragment from amino acid residues 314-330 (ep3) covering the central conserved sequence of this domain. anti-hepatitis c virus-positive blood donors were screened for anti-ep3 antibodies with an elisa based on immobilized peptide. thirty ... | 1995 | 7544250 |
| bovine papillomavirus e1 protein can, by itself, efficiently drive multiple rounds of dna synthesis in vitro. | bovine papillomavirus e1 protein was found to be as efficient as the simian virus 40 large t antigen in initiating dna synthesis in a cell-free system derived from cos1 cells. multiple rounds of dna synthesis occur, initiated at the bovine papillomavirus type 1 origin. therefore, e1 functions in vitro as a lytic virus initiator. | 1995 | 7707551 |
| dna polymerase delta holoenzyme: action on single-stranded dna and on double-stranded dna in the presence of replicative dna helicases. | dna polymerase delta requires proliferating cell nuclear antigen and replication factor c to form a holoenzyme efficient in dna synthesis. we have analyzed three different aspects of calf thymus dna polymerase delta holoenzyme: (i) analysis of pausing during dna synthesis, (ii) replication of double-stranded dna in the absence of additional factors, and (iii) replication of double-stranded dna in the presence of the two known replicative dna helicases from simian virus 40 and bovine papilloma vi ... | 1995 | 7711022 |
| use of rubella virus e1 fusion proteins for detection of rubella virus antibodies. | two glutathione s-transferase fusion proteins containing 44 (p1503) and 75 (p1509) amino acid residues of the rubella virus e1 glycoprotein were expressed in escherichia coli with the aim of producing a recombinant rubella virus antigen for use in serological assays. p1503 contained three neutralizing and hemagglutinating epitopes (g. m. terry, l. m. ho-terry, p. londesborough, and k. r. rees, arch. virol. 98:189-197, 1988); p1509 contained the putative neutralization domain described by mitchel ... | 1995 | 7714176 |
| regulation of the constitutive expression of the human cyp1a2 gene: cis elements and their interactions with proteins. | cytochrome p4501a2 (cyp1a2) is a member of the cytochrome p450 family that is involved in phase i drug metabolism in vertebrates. to understand how the constitutive expression of the human cyp1a2 gene is regulated, its 5' flanking region was analyzed. the promoter activity of a human cyp1a2 gene sequence [base pairs (bp) -3203 to +58 bp] was measured in transiently transfected hepg2 cells using fusion constructs containing the luciferase reporter gene. using 5'-end deletion analysis, two functio ... | 1995 | 7723729 |
| monitoring the cdna synthesis of dengue-2 virus by rt pcr. | reverse transcriptase polymerase chain reaction (rt pcr) was utilized to observe the complementary dna (cdna) synthesis from the 10723 base dengue-2 virus template by in vitro reverse transcription. the pcr product amplified from 5'-end of the genome (pcr primers n1a-e1) indicates the completeness of the cdna synthesis because the cdna primer d8b was located at 3'-end and the cdna synthesized encompassed the entire rna template. the integrity of the dengue virus rna was also determined by the cd ... | 1995 | 7730437 |
| rescue, propagation, and partial purification of a helper virus-dependent adenovirus vector. | adenoviral vectors are widely used as highly efficient gene transfer vehicles in a variety of biological research strategies including human gene therapy. one of the limitations of the currently available adenoviral vector system is the presence of the majority of the viral genome in the vector, resulting in leaky expression of viral genes particularly at high multiplicity of infection and limited cloning capacity of exogenous sequences. as a first step to overcome this problem, we attempted to ... | 1995 | 7731995 |
| adenovirus-mediated gene transfer to human bronchial submucosal glands using xenografts. | the cystic fibrosis (cf) transmembrane conductance regulator has been localized to both submucosal glands and surface epithelium, suggesting that both glandular and surface epithelium may be important targets for gene therapy. to determine the distribution and efficiency of recombinant adenovirus-mediated gene transfer to human airway submucosal glands, an in vivo model was developed by heterotopically transplanting human bronchial segments from both normal and cf lung tissue into severe combine ... | 1995 | 7733306 |
| efficient expression of a heterodimer of bone morphogenetic protein subunits using a baculovirus expression system. | recombinant baculoviruses as expression vectors for xenopus bone morphogenetic protein (xbmp)-2, 4 and 7 were generated. the conditioned medium of insect cells infected with the virus for xbmp-2 or 4 showed strong alkaline phosphatase-inducing activity in a mouse osteoblastic cell line, mc3t3-e1, although a large portion of the activity remained in the infected cells. in contrast, xbmp-7 was preferentially secreted into the medium, but had only weak activity. conditioned media following simultan ... | 1995 | 7733977 |
| e1 recognition sequences in the bovine papillomavirus type 1 origin of dna replication: interaction between half sites of the inverted repeats. | the e1 protein encoded by bovine papillomavirus type 1 (bpv-1) is required for viral dna replication, and it binds site specifically to an a/t-rich palindromic sequence within the viral origin of replication. the protein is targeted to this site through cooperative interactions and binding with the virus-encoded e2 protein. to explore the nature of the e1 binding site, we inserted a series of homologous dna linkers at the center of dyad symmetry within the e1 recognition palindrome. the effects ... | 1995 | 7745726 |
| targeting of a heterodimeric membrane protein complex to the golgi: rubella virus e2 glycoprotein contains a transmembrane golgi retention signal. | rubella virus (rv) envelope glycoproteins, e2 and e1, form a heterodimeric complex that is targeted to medial/trans-golgi cisternae. to identify the golgi targeting signal(s) for the e2/e1 spike complex, we constructed chimeric proteins consisting of domains from rv glycoproteins and vesicular stomatitis virus (vsv) g protein. the location of the chimeric proteins in stably transfected chinese hamster ovary cells was determined by immunofluorescence, immunoelectron microscopy, and by the extent ... | 1995 | 7749196 |
| synthesis and processing of the rubella virus p110 polyprotein precursor in baculovirus-infected spodoptera frugiperda cells. | in order to study the processing of rubella virus (rv) structural proteins (capsid protein, of 33 kda; e2 of 42-47 kda; and e1 of 58 kda) in spodoptera frugiperda (fall armyworm) cells, a 24s cdna encoding the polyprotein precursor, p110, was inserted under the transcriptional regulation of the polyhedrin gene promoter of the autographa californica nuclear polyhedrosis virus (acnpv) and expressed during viral infection. by immunoblot analysis using antibodies directed against whole rv and the in ... | 1995 | 7754676 |
| low ph induces swiveling of the glycoprotein heterodimers in the semliki forest virus spike complex. | time-resolved cryoelectron microscopy reveals the first step in the conformational changes that enable membrane fusion in semliki forest virus. the neutral ph structure reveals a central cavity within the spike complex, plate-like extensions forming a layer above the membrane, and the paths of the paired transmembrane domains connecting the trimeric spikes and pentamer-hexamer clustered capsid subunits. low ph treatment results in centrifugal movement of e2, the receptor-binding subunit, centrip ... | 1995 | 7774013 |
| detection of wild-type contamination in a recombinant adenoviral preparation by pcr. | a rapid and sensitive method of detecting wild-type virus contamination is needed for the preparation of recombinant adenoviruses for adenoviral vector applications in which purified vectors free of wild-type virus are required for preclinical studies and clinical trials. in response to this demand, we developed a pcr assay that uses two pairs of primers in the same reaction to detect adenoviral e1 dna with co-amplification of e2b dna as an internal control. template dna preparation was simplifi ... | 1995 | 7779393 |
| role of viral proteins and concanavalin a in in vitro replication of pseudorabies virus in porcine peripheral blood mononuclear cells. | we examined the capability of pseudorabies virus (prv) to replicate in vitro in porcine peripheral blood mononuclear cells (pbmc) and characterized the phenotype of infected cells. in addition, we investigated whether inactivation of various prv proteins or the expression of a foreign gene affected this replication. finally, we studied the replication of prv strains in concanavalin a (con a)-stimulated lymphocytes. the replication of prv mutants with inactivated glycoproteins ge or gg, thymidine ... | 1995 | 7782771 |
| genetic recombination of pseudorabies virus: evidence that homologous recombination between insert sequences is less frequent than between autologous sequences. | we studied in vivo recombination between a thymidine kinase (tk) negative, glycoprotein e (ge) negative, attenuated strain and a virulent strain of pseudorabies virus (prv) in pigs. to simplify the detection of recombination we inserted different but overlapping (375 bp) parts of the e1 gene of classical swine fever virus into the gg locus of both virus strains. recombination between the e1 sequences of these viruses results in reconstitution of the complete e1 coding sequence and expression of ... | 1995 | 7794111 |
| negative regulation of the bovine papillomavirus e5, e6, and e7 oncogenes by the viral e1 and e2 genes. | papillomaviruses induce benign squamous epithelial lesions that infrequently are associated with uncontrolled growth or malignant conversion. the virus-encoded oncogenes are clearly under negative regulation since papillomaviruses can latently infect cells and since different levels of viral oncogene expression are seen within the layers of differentiating infected epitheliomas. we used bovine papillomavirus type 1 (bpv-1) to investigate the mechanisms involved in the negative regulation of tran ... | 1995 | 7983735 |
| immunization with nonstructural proteins e1 and e2 of cottontail rabbit papillomavirus stimulates regression of virus-induced papillomas. | cottontail rabbit papillomavirus is the major animal model for cancer-associated papillomaviruses. here we show that vaccination with the nonstructural proteins e1 and e2 induces the regression of virus-induced papillomas and that vaccination is equally effective when proteins are given with and without adjuvant. there was no correlation between antibody levels and regression, suggesting that tumor regression may be due to a cell-mediated response. | 1995 | 7983764 |
| involvement of the molecular chaperone bip in maturation of sindbis virus envelope glycoproteins. | sindbis virus codes for two membrane glycoproteins, e1 and pe2, which assemble into heterodimers within the endoplasmic reticulum. we have examined the role of the molecular chaperone bip (grp78) in the maturation of these two proteins. e1, which folds into its mature conformation via at least three intermediates differing in the configurations of their disulfide bonds, was found to interact strongly and transiently with bip after synthesis. atp depletion mediated by carbonyl cyanide m-chlorophe ... | 1995 | 7853497 |
| specific restrictions in the progression of venezuelan equine encephalitis virus-induced disease resulting from single amino acid changes in the glycoproteins. | the pathogenesis of venezuelan equine encephalitis virus (vee) was examined in the mouse model using v3000, a virus derived from a molecular clone of the trinidad donkey strain of vee. these results were compared in parallel experiments with avirulent mutants of vee derived by site-directed mutagenesis of the clone. adult mice, inoculated subcutaneously in their left rear footpad with v3000, were followed in a time course study for 6 days in which 15 organs were tested for histopathological chan ... | 1995 | 7856110 |
| nucleocapsid and glycoprotein organization in an enveloped virus. | alphaviruses are a group of icosahedral, positive-strand rna, enveloped viruses. the membrane bilayer, which surrounds the approximately 400 a diameter nucleocapsid, is penetrated by 80 spikes arranged in a t = 4 lattice. each spike is a trimer of heterodimers consisting of glycoproteins e1 and e2. cryoelectron microscopy and image reconstruction of ross river virus showed that the t = 4 quaternary structure of the nucleocapsid consists of pentamer and hexamer clusters of the capsid protein, but ... | 1995 | 7867069 |
| mutations in the putative fusion peptide of semliki forest virus affect spike protein oligomerization and virus assembly. | the two transmembrane spike protein subunits of semliki forest virus (sfv) form a heterodimeric complex in the rough endoplasmic reticulum. this complex is then transported to the plasma membrane, where spike-nucleocapsid binding and virus budding take place. by using an infectious sfv clone, we have characterized the effects of mutations within the putative fusion peptide of the e1 spike subunit on spike protein dimerization and virus assembly. these mutations were previously demonstrated to bl ... | 1995 | 7884895 |
| the oligomerization reaction of the semliki forest virus membrane protein subunits. | the semliki forest virus (sfv) spike is composed of three copies of a membrane protein heterodimer. the two subunits of this heterodimer (p62 and e1) are synthesized sequentially from a common mrna together with the capsid (c) in the order c-p62-e1. in this work heterodimerization of the spike proteins has been studied in bhk 21 cells. the results indicate that: (a) the polyprotein is cotranslationally cleaved into individual chains; (b) the two membrane protein subunits are initially not associ ... | 1995 | 7844143 |
| prevalence of hepatitis c virus sequence variants in south-east asia. | the nature and distribution of hepatitis c virus (hcv) genotypic variants present in south-east asia have not been extensively investigated. we analysed hcv rna obtained from 67 clinical serum samples from singapore, thailand, indonesia, the philippines and south korea. all samples were amplified by semi-nested rt-pcr and the nucleotide sequence determined for four regions within the e1, e2/ns1, ns4 and ns5 genes. each isolate had a unique nucleotide and deduced amino acid sequence, consistent w ... | 1995 | 7844535 |
| differentiation-dependent expression of e1--e4 proteins in cell lines maintaining episomes of human papillomavirus type 31b. | the life cycle of human papillomaviruses (hpvs) is dependent on epithelial differentiation. among the viral proteins expressed in differentiated epithelial cells are the viral capsid proteins, l1 and l2, as well as the e1e4 fusion proteins. in this study, the expression and intracellular localization of the e1e4 proteins of hpv type 31b were examined in both monolayer and raft cultures of the cin-612 cell line which maintains episomal copies of hpv-31b. in this cell line, a high level of e1e4 pr ... | 1995 | 7831825 |