Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| an infectious and selectable full-length replicon system with hepatitis c virus jfh-1 strain. | aim: the hepatitis c virus (hcv) strain jfh-1 was cloned from a patient with fulminant hepatitis. a jfh-1 subgenomic replicon and full-length jfh-1 rna efficiently replicate in cultured cells. in this study, an infectious, selectable hcv replicon containing full-length jfh-1 cdna was constructed. methods: the full-genome replicon was constructed using the neomycin-resistant gene, emcv ires and wild-type jfh-1 cdna. huh7 cells were transfected with rna synthesized in vitro, and then cultured with ... | 2007 | 17437527 |
| viral translation is coupled to transcription in sindbis virus-infected cells. | during the late phase of sindbis virus infection, the viral subgenomic mrna is translated efficiently in bhk cells, whereas host protein synthesis is inhibited. however, transfection of in vitro-generated sindbis virus subgenomic mrna leads to efficient translation in uninfected bhk cells, whereas it is a poor substrate in infected cells. therefore, the structure of the subgenomic mrna itself is not sufficient to confer its translatability in infected cells. in this regard, translation of the su ... | 2007 | 17442713 |
| efficient expression and purification of human interferon alpha2b in the methylotrophic yeast, pichia pastoris. | the human interferon alpha2b (hifn-alpha2b) is the most widely used member of ifnalpha family, and it exerts many biological actions including broad-spectrum antiviral effects, inhibition of tumor cell proliferation and enhancement of immune functions. herein, the cdna coding for hifn-alpha2b has been cloned into the secreting expression organism pichia pastoris, and the high level expression of hifn-alpha2b has been achieved. sds-page and western blotting assays of culture broth from a methanol ... | 2007 | 17468009 |
| partitioning and inactivation of viruses by the caprylic acid precipitation followed by a terminal pasteurization in the manufacturing process of horse immunoglobulins. | caprylic acid (octanoic acid), has been used for over 50 years as a stabilizer of human albumin during pasteurization. in addition caprylic acid is of great interest, by providing the advantage of purifying mammalian immunoglobulins and clearing viruses infectivity in a single step. exploiting these two properties, we sequentially used the caprylic acid precipitation and the pasteurization to purify horse hyperimmune globulins used in the manufacturing of sérocytol. to evaluate the effectiveness ... | 2007 | 17470396 |
| loss of dexd/h box rna helicase lgp2 manifests disparate antiviral responses. | the dexd/h box rna helicase retinoic acid-inducible gene i (rig-i) and the melanoma differentiation-associated gene 5 (mda5) are key intracellular receptors that recognize virus infection to produce type i ifn. a third helicase gene, lgp2, is homologous to rig-i and mda5 but lacks a caspase activation and recruitment domain. we generated lgp2-deficient mice and report that the loss of this gene greatly sensitizes cells to cytosolic polyinosinic/polycytidylic acid-mediated induction of type i ifn ... | 2007 | 17475874 |
| insights into rna virus mutant spectrum and lethal mutagenesis events: replicative interference and complementation by multiple point mutants. | rna virus behavior can be influenced by interactions among viral genomes and their expression products within the mutant spectra of replicating viral quasispecies. here, we report the extent of interference of specific capsid and polymerase mutants of foot-and-mouth disease virus (fmdv) on replication of wild-type (wt) rna. the capsid and polymerase mutants chosen for this analysis had been characterized biochemically and structurally. upon co-electroporation of bhk-21 cells with wt rna and a te ... | 2007 | 17481660 |
| oral administration of candesartan improves the survival of mice with viral myocarditis through modification of cardiac adiponectin expression. | we examined the effects of the angiotensin ii receptor type 1 blocker candesartan on myocarditis injury in a murine model of acute myocarditis. we hypothesized that candesartan improves cardiac damage by inducing cardiac expression of adiponectin. | 2007 | 17484035 |
| poly(a)-binding protein is differentially required for translation mediated by viral internal ribosome entry sites. | the 3' poly(a) tail present on the majority of mature eukaryotic mrnas is an important regulator of protein synthesis and mrna stability. the poly(a) tail improves the efficiency of translation initiation through recruitment of pabp, enabling its interaction with eif4f located at the mrna 5'-end. recent evidence has also implicated a possible role for pabp and the poly(a) tract in translation control at steps beyond the initiation phase. similar to conventional mrnas, plus-strand rna virus genom ... | 2007 | 17652408 |
| small self-rna generated by rnase l amplifies antiviral innate immunity. | antiviral innate immunity is initiated in response to rna molecules that are produced in virus-infected cells. these rnas activate signalling cascades that activate the genes that encode alpha- and beta-interferon (ifn). signalling occurs through the interaction of the rnas with either of two pathogen recognition receptors, retinoic acid-inducible gene-i (rig-i, also known as ddx58) and melanoma differentiation associated gene-5 (mda5, also known as ifih1), which contain amino-terminal caspase a ... | 2007 | 17653195 |
| microrna inhibition of translation initiation in vitro by targeting the cap-binding complex eif4f. | micrornas (mirnas) play an important role in gene regulatory networks in animals. yet, the mechanistic details of their function in translation inhibition or messenger rna (mrna) destabilization remain controversial. to directly examine the earliest events in this process, we have developed an in vitro translation system using mouse krebs-2 ascites cell-free extract that exhibits an authentic mirna response. we show here that translation initiation, specifically the 5' cap recognition process, i ... | 2007 | 17656684 |
| measles virus n protein inhibits host translation by binding to eif3-p40. | the nonsegmented, negative-sense rna genome of measles virus (mv) is encapsidated by the virus-encoded nucleocapsid protein (n). in this study, we searched for n-binding cellular proteins by using mv-n as bait and screening the human t-cell cdna library by yeast two-hybrid assay and isolated the p40 subunit of eukaryotic initiation factor 3 (eif3-p40) as a binding partner. the interaction between mv-n and eif3-p40 in mammalian cells was confirmed by coimmunoprecipitation. since eif3-p40 is a tra ... | 2007 | 17686838 |
| characterization of a novel bioflocculant, p-kg03, from a marine dinoflagellate, gyrodinium impudicum kg03. | the flocculating activity of an exopolysaccharide, p-kg03, produced by a marine dinoflagellate gyrodinium impudicum kg03 was investigated. the p-kg03 was a highly sulfated exopolysaccharide that showed strong antiviral activity against encephalomyocarditis virus (emcv) and immunostimulating activity by nk cell activation. for the industrial applications of p-kg03, as the bioflocculant agent, p-kg03 showed that more than 90% of the flocculating activity in kaolin suspension occurred at concentrat ... | 2007 | 16473007 |
| toll-like receptor 3 is an essential component of the innate stress response in virus-induced cardiac injury. | enterovirus-induced myocardial injury can lead to severe heart failure. to date, little is known about the early innate stress response that contributes to host defense in the heart. toll-like receptor 3 (tlr3) is important in the initiation of the innate antiviral response. we investigated the involvement of tlr3, which recognizes viral double-stranded rna, on encephalomyocarditis virus (emcv) infection. to examine the contribution of tlr3 in protection from emcv infection, we infected mice def ... | 2007 | 16936008 |
| design, synthesis, and biological evaluation of novel iso-d-2',3'-dideoxy-3'-fluorothianucleoside derivatives. | novel iso-d-2',3'-dideoxythianucleoside derivatives 1-4 were designed and asymmetrically synthesized as a bioisostere of lamivudine to search for new anti-hiv agents. the information about using sulfur participation occurred on dast fluorination and mitsunobu reaction will be of great help in synthesizing sulfur-containing compounds. final compounds 1-4 were evaluated against hiv-1 and 2, hsv-1 and 2, emcv, cox. b3, vsv, flua (taiwan), flua (johan.), fcv, and fip. only cytosine analogue 3 showed ... | 2007 | 17046264 |
| the degree of apoptosis as an immunostimulant for a dna vaccine against hiv-1 infection. | to regulate the expression of the apoptotic gene, we constructed bicistronic dna vaccines that encode for hiv env and caspase-3 mutant (casp 3m) that are expressed via the encephalomyocarditis virus internal ribosomal entry site (ires) or cytomegalovirus (cmv) promoter-dependent translations. while ires-casp 3m induced weak apoptosis and caused little reduction in antigen expression, cmv-casp 3m elicited strong apoptosis and led to a marked decrease in the antigen expression. therefore, ires-cas ... | 2007 | 17079059 |
| factors related to the incidence of clinical encephalomyocarditis virus (emcv) infection on belgian pig farms. | we set up a matched case-control study of potential risk factors for clinical encephalomyocarditis virus (emcv) in 58 pig farms in west flanders (belgium). in total, 29 farms experienced a clinical outbreak of emcv confirmed by emc virus isolation. mortality was seen only among suckling piglets (18 case farms), in piglets and other age-groups (4 case farms), or only among fattening pigs (7 case farms). five farms had reproductive problems among the sows. control farms were matched geographically ... | 2007 | 17098310 |
| viral infections as potential triggers of type 1 diabetes. | during the last decades, the incidence of type 1 diabetes (t1d) has increased significantly, reaching percentages of 3% annually worldwide. this increase suggests that besides genetical factors environmental perturbations (including viral infections) are also involved in the pathogenesis of t1d. t1d has been associated with viral infections including enteroviruses, rubella, mumps, rotavirus, parvovirus and cytomegalovirus (cmv). although correlations between clinical presentation with t1d and th ... | 2007 | 17103489 |
| helper virus-independent trans-replication of hepatitis c virus-derived minigenome. | we have previously described a synthetic t7-driven cdna minigenome containing the antisense sequence of luciferase gene and internal ribosome entry site of encephalomyocarditis virus flanked by 5'- and 3'-end sequences of hepatitis c virus (hcv) that contain cis-acting replication elements. synthesis of minus-strand rna from the artificial minigenome was determined by using huh-7 cells harboring autonomously replicating hcv subgenome as a helper for provision of functional replication components ... | 2007 | 17112469 |
| neutralizing antibodies to interferon beta in multiple sclerosis: analytical evaluation for validation of a cytopathic effect assay. | recent guidelines have recommended the use of validated assays for the measurement of neutralizing antibodies (nabs) to interferon beta (ifnbeta) in patients with multiple sclerosis (ms). in an attempt of validation, we studied the analytical performance of a bioassay based on antiviral cytopathic effect (cpe) using wish cells and the vesicular stomatitis virus (wish/vsv cpe). | 2007 | 17123498 |
| viruses cause type 1 diabetes in animals. | more than 10 viruses have been reported to be associated with the development of type 1 diabetes-like symptoms in animals, with the best evidence coming from studies on the d variant of encephalomyocarditis (emc-d) virus in mice and kilham rat virus (krv) in rats. a high titer of emc-d viral infection results in the development of diabetes within 3 days, primarily due to the rapid destruction of beta cells by viral replication within the cells. a low titer of emc-d viral infection results in the ... | 2006 | 17130545 |
| internal ribosome entry sequence-mediated translation initiation triggers nonsense-mediated decay. | in eukaryotes, a surveillance pathway known as nonsense-mediated decay (nmd) regulates the abundance of messenger rnas containing premature termination codons (ptcs). in mammalian cells, it has been asserted that the nmd-relevant first round of translation is special and involves initiation by a specific protein heterodimer, the nuclear cap-binding complex (cbc). arguing against a requirement for cbc-mediated translation initiation, we show that ribosomal recruitment by the internal ribosomal en ... | 2006 | 16799467 |
| cd1d mediates t-cell-dependent resistance to secondary infection with encephalomyocarditis virus (emcv) in vitro and immune response to emcv infection in vivo. | the innate and adaptive immune responses have evolved distinct strategies for controlling different viral pathogens. encephalomyocarditis virus (emcv) is a picornavirus that can cause paralysis, diabetes, and myocarditis within days of infection. the optimal innate immune response against emcv in vivo requires cd1d. interaction of antigen-presenting cell cd1d with distinct natural killer t-cell ("nkt") populations can induce rapid gamma interferon (ifn-gamma) production and nk-cell activation. t ... | 2006 | 16809320 |
| the gamma interferon (ifn-gamma) mimetic peptide ifn-gamma (95-133) prevents encephalomyocarditis virus infection both in tissue culture and in mice. | we have demonstrated previously that the c-terminal gamma interferon (ifn-gamma) mimetic peptide consisting of residues 95 to 133 [ifn-gamma(95-133)], which contains the crucial ifn-gamma nuclear localization sequence (nls), has antiviral activity in tissue culture. here we evaluate the efficacy of this peptide and its derivatives first in vitro and then in an animal model of lethal viral infection with the encephalomyocarditis (emc) virus. deletion of the nls region from the ifn-gamma mimetic p ... | 2006 | 16893996 |
| role of mapk in the regulation of double-stranded rna- and encephalomyocarditis virus-induced cyclooxygenase-2 expression by macrophages. | in response to virus infection or treatment with dsrna, macrophages express the inducible form of cyclooxygenase-2 (cox-2) and produce proinflammatory prostaglandins. recently, we have shown that nf-kappab is required for encephalomyocarditis virus (emcv)- and dsrna-stimulated cox-2 expression in mouse macrophages. the dsrna-dependent protein kinase r is not required for emcv-stimulated cox-2 expression, suggesting the presence of protein kinase r-independent pathways in the regulation of this a ... | 2006 | 16920983 |
| ionic contra-viral therapy (icvt); a new approach to the treatment of dna virus infections. | the sequestration of cellular k(+) has been shown elsewhere to elicit a broad spectrum of antiviral activity. the obligatory, coupled cotransports of na(+), k(+) and cl(-) (nkcc1) and of na(+) and k(+) (nkatpase) effect net cellular k(+) influx. we examined the effects of specific inhibitors of these transports; a cardiac glycoside (digoxin) and a loop diuretic (furosemide) on virus replication in vitro. the replication of the dna viruses, herpes simplex virus, varicella zoster virus, human cyto ... | 2006 | 16932984 |
| pathogenesis of experimental encephalomyocarditis: a histopathological, immunohistochemical and virological study in mice. | mice (n=20) aged 8 weeks were infected, either by oronasal inoculation or by contact, with one of two different myocardial strains of encephalomyocarditis virus (emcv), namely, the greek strain 424/90 and the belgian strain b279/95. the animals were killed at 18-59 days post-infection (dpi), except for two mice that died at 6 and 32 dpi, and samples of brain, heart, pancreas, kidney, peyer's patches, spleen, lung and thymus were processed for virological, histopathological and immunohistochemica ... | 2006 | 16952370 |
| differential cleavage of eif4gi and eif4gii in mammalian cells. effects on translation. | two isoforms of the translation initiation factor eif4g, eif4gi and eif4gii, have been described in eukaryotic cells. the exact function of each isoform during the initiation of protein synthesis is still under investigation. we have developed an efficient and reliable method of expressing poliovirus 2apro, which differentially proteolyzes eif4gi and eif4gii in a time- and dose-dependent manner. this system is based on the electroporation of an in vitro transcribed mrna that contains the encepha ... | 2006 | 16959778 |
| transmission of encephalomyocarditis virus in pigs estimated from field data in belgium by means of r0. | transmission of encephalomyocarditis-virus (emcv) has been estimated in experiments, but never using field data. in this field study, a farm in belgium was selected where the presence of emcv was confirmed by necropsy and virus isolation. serology was used to estimate the transmission parameter r0. in one compartment with 630 pigs, 6 pens were fully sampled, in the remaining 38 pens, 2 randomly selected pigs were bled. the 151 pigs were bled twice and their serum was tested in a virus neutralisa ... | 2006 | 16973116 |
| translational efficiency of emcv ires in bicistronic vectors is dependent upon ires sequence and gene location. | the internal ribosomal entry site (ires)from encephalomyocarditis virus (emcv) is a popular rna element used widely in experimental and pharmaceutical applications to express proteins in eukaryotic cells or cell-free extracts. inclusion of the wild-type element in monocistronic or bicistronic messenger rnas (mrnas) confers a high level of cap-independent translation activity to appropriately configured cistrons. the history of this element and the experimental consequences of sequence derivation ... | 2006 | 16989088 |
| production of biopharmaceuticals and vaccines in plants via the chloroplast genome. | transgenic plants offer many advantages, including low cost of production (by elimination of fermenters), storage and transportation; heat stability; and absence of human pathogens. when therapeutic proteins are orally delivered, plant cells protect antigens in the stomach through bioencapsulation and eliminate the need for expensive purification and sterile injections, in addition to development of both systemic and mucosal immunity. chloroplast genetic engineering offers several advantages, in ... | 2006 | 17004305 |
| effects of picornavirus 3a proteins on protein transport and gbf1-dependent cop-i recruitment. | the 3a protein of the coxsackievirus b3 (cvb3), an enterovirus that belongs to the family of the picornaviruses, inhibits endoplasmic reticulum-to-golgi transport. recently, we elucidated the underlying mechanism by showing that cvb3 3a interferes with adp-ribosylation factor 1 (arf1)-dependent cop-i recruitment to membranes by binding and inhibiting the function of gbf1, a guanine nucleotide exchange factor that is required for the activation of arf1 (e. wessels et al., dev. cell 11:191-201, 20 ... | 2006 | 17005635 |
| rig-i-mediated antiviral responses to single-stranded rna bearing 5'-phosphates. | double-stranded rna (dsrna) produced during viral replication is believed to be the critical trigger for activation of antiviral immunity mediated by the rna helicase enzymes retinoic acid-inducible gene i (rig-i) and melanoma differentiation-associated gene 5 (mda5). we showed that influenza a virus infection does not generate dsrna and that rig-i is activated by viral genomic single-stranded rna (ssrna) bearing 5'-phosphates. this is blocked by the influenza protein nonstructured protein 1 (ns ... | 2006 | 17038589 |
| serological survey of encephalomyocarditis virus infection in pigs in france. | samples of serum from 76 gilts, 1440 sows, 1473 piglets and 3093 finishing pigs from 96 farrow-to-finish herds were tested for antibodies to encephalomyocarditis virus (emcv) in microtitre serum neutralisation tests employing two strains of virus, one associated with myocarditis and the other with reproductive failure. the total seroprevalence of emcv infection was 2.48 per cent. there was no significant difference between the seroprevalence of the reproductive failure strain (1.6 per cent) and ... | 2006 | 17041064 |
| impaired expression of cardiac adiponectin in leptin-deficient mice with viral myocarditis. | a mouse model of encephalomyocarditis (emc) virus-induced myocarditis was used to investigate the expression of adiponectin in damaged cardiomyocytes. we intraperitoneally injected emc virus into leptin-deficient ob/ob (ob) mice and wild-type (wt) mice. ob mice were divided into two subgroups consisting of mice with no intervention and mice receiving leptin replacement starting simultaneously with viral inoculation. we determined differences in heart weight, cardiac histological score, numbers o ... | 2006 | 16479046 |
| [expression of interferon alpha family gene of chinese marmot in eukaryotic and prokaryotic cells]. | to investigate the function of interferon alpha (ifnalpha) in a chinese marmot model of hepatitis b, we expressed the chinese marmot (marmota himalayana) ifnalpha family gene (ifna) in eukaryotic cells and prokaryotic cells. | 2006 | 16494783 |
| nucleocytoplasmic traffic disorder induced by cardioviruses. | some picornaviruses, for example, poliovirus, increase bidirectional permeability of the nuclear envelope and suppress active nucleocytoplasmic transport. these activities require the viral protease 2a(pro). here, we studied nucleocytoplasmic traffic in cells infected with encephalomyocarditis virus (emcv; a cardiovirus), which lacks the poliovirus 2a(pro)-related protein. emcv similarly enhanced bidirectional nucleocytoplasmic traffic. by using the fluorescent "timer" protein, which contains a ... | 2006 | 16501080 |
| destruction of human retinoblastoma after treatment by the e variant of encephalomyocarditis virus. | the oncolytic effects of encephalomyocarditis (emc) virus were examined in human retinoblastoma cell (y79) cultures which were infected with 10(4 )tissue culture infectious doses (tcids) of the e variant of emc (emc-e) virus. the tcids were used to titer the maximum effect of emc virus on l-929 cells. in-vitro studies showed 90% cytopathic effect (cpe) at 24 h and 100% cpe at 52 h. the cpe was used to observe pathologic effects of the cells. in-vivo studies employing human retinoblastoma grown a ... | 2006 | 16528457 |
| multicistronic lentiviral vectors containing the fmdv 2a cleavage factor demonstrate robust expression of encoded genes at limiting moi. | a number of gene therapy applications would benefit from vectors capable of expressing multiple genes. in this study we explored the feasibility and efficiency of expressing two or three transgenes in hiv-1 based lentiviral vector. bicistronic and tricistronic self-inactivating lentiviral vectors were constructed employing the internal ribosomal entry site (ires) sequence of encephalomyocarditis virus (emcv) and/or foot-and-mouth disease virus (fmdv) cleavage factor 2a. we employed enhanced gree ... | 2006 | 16539700 |
| viral safety of nanogam, a new 15 nm-filtered liquid immunoglobulin product. | producers of plasma derivatives continuously improve the viral safety of their products by, for example, introducing additional virus-reducing steps into the manufacturing process. here we present virus-elimination studies undertaken for a number of steps employed in a new manufacturing process for liquid intravenous immunoglobulin (nanogam) that comprises two specific virus-reducing steps: a 15-nm filtration step combined with pepsin treatment at ph 4.4 (ph 4.4/15nf); and solvent-detergent (sd) ... | 2006 | 16359352 |
| a link between translation of the hepatitis c virus polyprotein and polymerase function; possible consequences for hyperphosphorylation of ns5a. | hyperphosphorylation of ns5a is thought to play a key role in controlling hepatitis c virus (hcv) rna replication. using a tetracycline-regulable baculovirus delivery system to introduce non-culture-adapted hcv replicons into hepg2 cells, we found that a point mutation in the active site of the viral polymerase, ns5b, led to an increase in ns5a hyperphosphorylation. although replicon transcripts lacking elements downstream of ns5a also had altered ns5a hyperphosphorylation, this did not explain ... | 2006 | 16361421 |
| production and characterization of guinea pig recombinant gamma interferon and its effect on macrophage activation. | gamma interferon (ifn-gamma) plays a critical role in the protective immune responses against mycobacteria. we previously cloned a cdna coding for guinea pig ifn-gamma (gpifn-gamma) and reported that bcg vaccination induced a significant increase in the ifn-gamma mrna expression in guinea pig cells in response to living mycobacteria and that the virulent h37rv strain of mycobacterium tuberculosis stimulated less ifn-gamma mrna than did the attenuated h37ra strain. in this study, we successfully ... | 2006 | 16368975 |
| genetic variability of encephalomyocarditis virus (emcv) isolates. | in order to evaluate the variability of encephalomyocarditis virus (emcv), field isolates originating from different european regions and inducing different clinical pictures in pigs have been molecularly characterised. the regions targeted were the poly(c) tract, a part of the 5'-utr (360 nucleotides), the leader gene (201 nucleotides), the complete capsid coding region (2502 nucleotides), the 2a gene (403 nucleotides), the end of the 3d polymerase gene (305 nucleotides) and the 3'-utr (123 nuc ... | 2006 | 16406410 |
| n-terminally pegylated human interferon-beta-1a with improved pharmacokinetic properties and in vivo efficacy in a melanoma angiogenesis model. | pegylation of ifn-alpha has been used successfully to improve the pharmacokinetic properties and efficacy of the drug. to prepare a pegylated form of human interferon-beta-1a (ifn-beta-1a) suitable for testing in vivo, we have synthesized 20 kda mpeg-o-2-methylpropionaldehyde and used it to modify the n-terminal alpha-amino group of the cytokine. the pegylated protein retained approximately 50% of the activity of the unmodified protein and had significantly improved pharmacokinetic properties fo ... | 2006 | 16417267 |
| estimation of seroprevalence of encephalomyocarditis in dutch sow herds using the virus neutralization test. | encephalomyocarditis virus (emcv) has been found on pig farms worldwide and can cause myocarditis in young pigs and reproduction disorders in sows. so far, clinical signs of emcv have not been reported in the netherlands. the aim of this study was to estimate the seroprevalence of emcv infection in dutch sow herds. a total of 277 dutch sow herds were randomly selected, from which 3237 serum samples were collected. these samples were tested for emcv antibodies using the virus neutralization test ... | 2006 | 16454087 |
| characterization of a recombinant encephalomyocarditis virus expressing the enhanced green fluorescent protein. | a recombinant encephalomyocarditis virus (remcv2887a-egfp) expressing the enhanced green fluorescent protein (egfp) was produced. the egfp gene was inserted in frame within the leader protein coding sequence of a full-length cdna clone of emcv. rna transcripts derived from the recombinant full-length cdna were synthesized in vitro and transfected into bhk-21 cells. the recombinant transcript rna remained infectious despite the insertion of egfp as shown by cytopathic effects on bhk-21 cells and ... | 2006 | 16575480 |
| cardiovirus leader proteins are functionally interchangeable and have evolved to adapt to virus replication fitness. | the leader (l) proteins encoded by picornaviruses of the genus cardiovirus [theiler's murine encephalomyelitis virus (tmev) and encephalomyocarditis virus (emcv)] are small proteins thought to exert important functions in virus-host interactions. the l protein of persistent tmev strains was shown to be dispensable for virus replication in vitro, but crucial for long-term persistence of the virus in the central nervous system of the mouse. the phenotype of chimeric viruses generated by exchanging ... | 2006 | 16603526 |
| lambda interferon (ifn-lambda), a type iii ifn, is induced by viruses and ifns and displays potent antiviral activity against select virus infections in vivo. | type iii interferons (ifns) (interleukin-28/29 or lambda interferon [ifn-lambda]) are cytokines with ifn-like activities. here we show that several classes of viruses induce expression of ifn-lambda1 and -lambda2/3 in similar patterns. the ifn-lambdas were-unlike alpha/beta interferon (ifn-alpha/beta)-induced directly by stimulation with ifn-alpha or -lambda, thus identifying type iii ifns as ifn-stimulated genes. in vitro assays revealed that ifn-lambdas have appreciable antiviral activity agai ... | 2006 | 16611910 |
| differential roles of mda5 and rig-i helicases in the recognition of rna viruses. | the innate immune system senses viral infection by recognizing a variety of viral components (including double-stranded (ds)rna) and triggers antiviral responses. the cytoplasmic helicase proteins rig-i (retinoic-acid-inducible protein i, also known as ddx58) and mda5 (melanoma-differentiation-associated gene 5, also known as ifih1 or helicard) have been implicated in viral dsrna recognition. in vitro studies suggest that both rig-i and mda5 detect rna viruses and polyinosine-polycytidylic acid ... | 2006 | 16625202 |
| lentiviral vectors harboring a dual-gene system allow high and homogeneous transgene expression in selected polyclonal human embryonic stem cells. | genetic modification of human embryonic stem cells (hescs) is highly valuable for their exploitation in basic science and therapeutic applications. here we developed lentiviral vectors (lvs) constitutively expressing a reporter and a selectable marker to enable high and homogeneous transgene expression within polyclonal hescs. lvs carrying gfp and a downstream puromycin resistance gene, linked by the encephalomyocarditis virus (emcv) or poliovirus internal ribosome entry sites (ires), allowed ho ... | 2006 | 16632408 |
| integrin alpha 11 is a novel type i interferon stimulated gene. | interferons (ifns) are a family of cytokines that have many biological functions in the cell, including regulation of cellular growth, differentiation, immunomodulation, and viral replication by inducing a set of interferon stimulated genes (isgs). based on their structure and biological activities ifns are subdivided into two groups: type i ifns, which includes ifn-alpha and ifn-beta and type ii ifns, represented by ifn-gamma. the aim of this work was to investigate whether integrin alpha 11 (i ... | 2006 | 16697656 |
| relevance of inflammatory cell infiltrates for complete atrioventricular block in experimental murine myocarditis. | there are few systemic pathologic studies on myocarditis. this study aimed to clarify the pathologic characteristics of murine myocarditis. | 2006 | 16697926 |
| essential role of mda-5 in type i ifn responses to polyriboinosinic:polyribocytidylic acid and encephalomyocarditis picornavirus. | the innate immune system recognizes viral dsrna through two distinct pathways; the toll-like receptor 3 (tlr3) pathway detects dsrna phagocytosed in endosomes; the helicases retinoic acid-induced protein i (rig-i) and melanoma differentiation-associated gene-5 (mda-5) detect cytoplasmic dsrna generated during viral replication. both rig-i and mda-5 can bind polyriboinosinic:polyribocytidylic acid (polyi:c), the synthetic analog of viral dsrna, and mediate type i ifn responses to polyi:c and mult ... | 2006 | 16714379 |
| successful implantation of intravenously administered stem cells correlates with severity of inflammation in murine myocarditis. | the present study was designed to determine whether cardiac inflammation is important for the successful homing of stem cells to the heart after intravenous injection in a murine myocarditis model. male bagg albino/c mice were infected with encephalomyocarditis virus (emcv) to produce myocarditis. subgroups of mice received single injections by tail vein of embryonic stem cells (escs) transfected with green fluorescent protein (gfp) as a marker at days 3, 14, or 60 after infection; other subgrou ... | 2006 | 16715295 |
| blocking of interferon-induced jak-stat signaling by japanese encephalitis virus ns5 through a protein tyrosine phosphatase-mediated mechanism. | japanese encephalitis virus (jev), a mosquito-borne flavivirus that causes severe human disease, has been shown to block the interferon (ifn)-induced janus kinase signal transducer and activation of transcription (jak-stat) signaling cascade by preventing tyk2 tyrosine phosphorylation and stat activation. in this study, we demonstrate that expression of the jev nonstructural protein ns5 readily blocked ifn-stimulated jak-stat signaling events such as stat1 nuclear translocation and tyrosine phos ... | 2006 | 16731929 |
| qualitative and quantitative analysis of antibody response against ifnbeta in patients with multiple sclerosis. | to date, inter- and intra-laboratory consistency of binding assays for measuring anti-interferon (ifn)beta antibodies has not been assessed. in this investigation, two independent laboratories tested a library of 80 serum specimens obtained from multiple sclerosis (ms) patients treated with ifnbeta. for binding antibodies (babs) evaluations, each laboratory used both a capture-elisa (celisa) and an enzyme-immuno-assay (eia), which is commercially available. samples were also tested for neutraliz ... | 2006 | 17263001 |
| encepalomyocarditis virus-induced apoptosis and ultrastructural changes in the lacrimal and parotid glands of mice. | development of acinar cell apoptosis and ultrastructural changes in the exorbital lacrimal and parotid glands was examined in dba/2 mice infected with 10(2) pfu/mouse of emc-d virus. pyknotic acinar cells, most of which were positive for tunel and cleaved caspase-3 and had ultrastructural characteristics of apoptotic cells, developed earlier and were more frequently observed in the parotid gland than in the exorbital lacrimal gland, while the total damage of acinar cells and interstitial infiltr ... | 2006 | 16038897 |
| the polypyrimidine tract-binding protein (ptb) is required for efficient replication of hepatitis c virus (hcv) rna. | our earlier work found that the polypyrimidine tract-binding protein (ptb) specifically interacts with the poly(u/c) tract of the hepatitis c virus (hcv) 3' untranslated region (3'utr) [luo, g., 1999. cellular proteins bind to the poly(u) tract of the 3' untranslated region of hepatitis c virus rna genome. virology 256, 105-118]. we report here that the phosphorylated form of ptb is associated with the membrane-bound hcv replication complex. to determine whether the ptb is required for hcv rna r ... | 2006 | 16102869 |
| control of myeov protein synthesis by upstream open reading frames. | the myeov gene has been isolated by the tumorigenicity assay and is localized at chromosome 11q13, a frequent site for chromosomal rearrangements in various carcinomas and b-cell neoplasms. in addition, myeov is coamplified with cyclin d1 and overexpressed in carcinomas of various organs. the mechanisms of myeov regulation remain enigmatic. the 5'-untranslated region (5'-utr) of the myeov gene is long, encompasses several upstream augs, and is predicted to fold in a strong secondary structure, s ... | 2006 | 16275643 |
| an efficient mammalian cell-free translation system supplemented with translation factors. | development of an efficient cell-free translation system from mammalian cells is an important goal. we examined whether supplementation of hela cell extracts with any translation initiation factor or translational regulator could enhance protein synthesis. eif2 (eukaryotic translation initiation factor 2) and eif2b augmented translation of capped, uncapped and encephalomyocarditis virus-internal ribosome entry site-promoted mrnas. eif4e specifically stimulated capped mrna translation, while p97, ... | 2006 | 16289705 |
| pathogenesis of experimental encephalomyocarditis: a histopathological, immunohistochemical and virological study in rats. | rats (n=40) aged 8 weeks were infected, either by oronasal inoculation or by contact, with one of two different myocardial strains of encephalomyocarditis virus (emcv), namely, the greek strain 424/90 and the belgian strain b279/95. the animals were killed at 11-62 days post-infection (dpi) and samples of brain, heart, pancreas, kidney, peyer's patches, spleen, lung and thymus were processed for virological, histopathological and immunohistochemical evaluation. this experimental infection was in ... | 2006 | 16330040 |
| pathogenesis of encephalomyocarditis experimental infection in young piglets: a potential animal model to study viral myocarditis. | the pathogenesis of encephalomyocarditis (emc) due to the emc virus (emcv) was studied in 24 piglets oro-nasally infected with the field isolate b279/95. two pigs were kept as negative controls and were euthanised at hour 0. the remaining 24 were euthanised every 6 h up to 78-h post infection (hpi). virus isolation, histological examination and emcv immunodetection were performed on the spleen, intestine, pancreas, liver, kidneys, heart, lungs, lymph nodes, tonsils and brain. emcv was isolated a ... | 2006 | 16336922 |
| [comparative study of variola virus and monkeypox virus interferon-gamma-binding]. | dna fragments containing genes for coding ifn-gamma-binding proteins (ifngammabps) of variola virus (varv) and monkeypox virus (mpxv) were obtained from viral genomes using pcr. isolated genes coding desired proteins were expressed in the insect sf21 cells using baculovirus expression system. secreted recombinant ifngammabps were isolated from culture medium of infected sf21 cells through affinity chromatography procedure. sds-paag and western blot analysis of culture medium of infected insect c ... | 2005 | 16358743 |
| antiviral profile of nyctanthes arbortristis l. against encephalitis causing viruses. | the ethanolic extracts, various fractions and two pure compounds isolated from the plant n. arbortris were tested against encephalomyocarditis virus (emcv) and semliki forest virus (sfv). pronounced in vitro virus inhibitory activity was observed with the ethanolic and n-butanol fractions as well as with the pure compounds arbortristoside a and arbortristoside c. in addition, ethanolic extracts and n-butanol fraction protected emcv infected mice to the extent of 40 and 60% respectively against s ... | 2005 | 16359127 |
| synthesis and antiviral activity of novel anomeric branched carbocyclic nucleosides. | novel anomeric branched carbocyclic nucleosides were synthesized from 1,3-dihydroxy acetone. 4'-hydroxymethyl was installed by [3,3]-sigmatropic rearrangement reaction and 1'-methyl group was introduced by carbonyl addition of methylmagnesium bromide. the coupling of nucleosidic bases and desilylation afforded a series of novel nucleosides. the synthesized compounds 16-19 were evaluated for their antiviral activity against hiv-1, hsv-1, hsv-2, and emcv. compounds 16 and 19 exhibit toxicity non-r ... | 2005 | 16276962 |
| infections and autoimmune diseases. | the high percentage of disease-discordant pairs of monozygotic twins demonstrates the central role of environmental factors in the etiology of autoimmune diseases. efforts were first focussed on the search for triggering factors. the study of animal models has clearly shown that infections may trigger autoimmune diseases, as in the case of coxsackie b4 virus in type i diabetes and the encephalomyocarditis virus in autoimmune myositis, two models in which viruses are thought to act by increasing ... | 2005 | 16278064 |
| eukaryotic translation initiation factor 4e availability controls the switch between cap-dependent and internal ribosomal entry site-mediated translation. | translation of m7g-capped cellular mrnas is initiated by recruitment of ribosomes to the 5' end of mrnas via eukaryotic translation initiation factor 4f (eif4f), a heterotrimeric complex comprised of a cap-binding subunit (eif4e) and an rna helicase (eif4a) bridged by a scaffolding molecule (eif4g). internal translation initiation bypasses the requirement for the cap and eif4e and occurs on viral and cellular mrnas containing internal ribosomal entry sites (iress). here we demonstrate that eif4e ... | 2005 | 16287867 |
| micrornas control translation initiation by inhibiting eukaryotic initiation factor 4e/cap and poly(a) tail function. | micrornas (mirnas) repress translation of target mrnas by interaction with partially mismatched sequences in their 3' utr. the mechanism by which they act on translation has remained largely obscure. we examined the translation of mrnas containing four partially mismatched mirna-binding sites in the 3' utr in hela cells cotransfected with a cognate mirna. the mrnas were prepared by in vitro transcription and were engineered to employ different modes of translation initiation. we find that the 5' ... | 2005 | 16287976 |
| down-regulation of p53 by double-stranded rna modulates the antiviral response. | p53 has been well characterized as a tumor suppressor gene, but its role in antiviral defense remains unclear. a recent report has demonstrated that p53 can be induced by interferons and is activated after vesicular stomatitis virus (vsv) infection. we observed that different nononcogenic viruses, including encephalomyocarditis virus (emcv) and human parainfluenza virus type 3 (hpiv3), induced down-regulation of p53 in infected cells. double-stranded rna (dsrna) and a mutant vaccinia virus lacki ... | 2005 | 16103161 |
| inhibition of cyclooxygenase-2 enhances myocardial damage in a mouse model of viral myocarditis. | to determine critical role of cyclooxygenase-2 (cox-2) for development of viral myocarditis, a mouse model of encephalomyocarditis virus-induced myocarditis was used. the virus was intraperitoneally given to cox-2 gene-deficient heterozygote mice (cox-2+/-) and wild-type mice (wt). we examined differences in heart weights, cardiac histological scores, numbers of infiltrating or apoptotic cells in myocardium, cardiac expression levels of cox-2, tumor necrosis factor-alpha (tnf-alpha), and adipone ... | 2005 | 16107267 |
| inducible control of transgene expression with ecdysone receptor: gene switches with high sensitivity, robust expression, and reduced size. | the ecdysone receptor (ecr)-based gene regulation system is a tool for controlling gene expression. to improve the sensitivity of this system, we evaluated many two-hybrid format synthetic gene constructs in which the gal4 dna binding domain was fused to the ligand binding domain of the choristoneura fumiferana ecr mutant v390i/y410e (gevy), and various activation domains--vp16, p53, p65, or e2f-i--were fused to the ef domains of chimeric human rxr. these gene switches were assayed in nih3t3 cel ... | 2005 | 16116792 |
| polyclonal antibodies against a structure mimicking the covalent linkage unit between picornavirus rna and vpg: an immunochemical study. | we propose that therapy of patients with anticancer drugs that poison dna topoisomerases induces formation of covalent complexes of cellular rnas and dna topoisomerases. the appearance of these complexes can be detected with antibodies against a synthetic hapten mimicking the covalent linkage unit tyr-pu(p) of picornavirus rna and vpg. we synthesized hapten [n(ac),co(nh2)]tyr-(5 p --> o)up-o-(ch2)6nh2, conjugated it with bsa, and immunized rabbits with the antigen obtained. the raised polyclonal ... | 2005 | 16266277 |
| encephalomyocarditis virus induces pkr-independent mitogen-activated protein kinase activation in macrophages. | in this study, we provide evidence that the double-stranded rna-dependent protein kinase (pkr) is not required for virus-induced expression of inducible nitric oxide synthase (inos) or the activation of specific signaling pathways in macrophages. the infection of raw264.7 cells with encephalomyocarditis virus (emcv) induces inos expression and nitric oxide production, which are unaffected by a dominant-negative mutant of pkr. emcv infection also activates the mitogen-activated protein kinase, cy ... | 2005 | 16051816 |
| co-expression of the complement regulatory proteins human daf and cd59 with an ires-mediated dicistronic mammalian vector enhances their cell protective effects. | the human complement regulatory proteins (hcrps) decay accelerating factor (daf/cd55) and protectin cd59 transfected into non-human cells could confer protection against human complement. the combination of daf and cd59 would be an effective strategy to help overcome host complement-induced hyperacute rejection in xenotransplantation. we constructed a dicistronic mammalian expression vector pcdna3-cd59iresdaf by using the internal ribosomal entry sites (ires) of the encephalomyocarditis virus (e ... | 2005 | 16077947 |
| effect of n-acetylcystein on butyrate-treated chinese hamster ovary cells to improve the production of recombinant human interferon-beta-1a. | sodium butyrate (nabu) is used as a productivity enhancer for the production of therapeutic recombinant proteins in chinese hamster ovary (cho) cells. however, nabu is well-known for having a cytotoxic effect, thereby inducing apoptosis. as an endeavor to reduce this defect, we studied 11 antioxidants known for inhibiting apoptosis, according to a plackett-burman statistical design on cho cells producing recombinant interferon-beta-1a (ifn-beta). none of the antioxidants that we tested were as e ... | 2005 | 16080696 |
| regulation of the cell-cycle-dependent internal ribosome entry site of the pitslre protein kinase: roles of unr (upstream of n-ras) protein and phosphorylated translation initiation factor eif-2alpha. | the pitslre kinases belong to the large family of cyclin-dependent protein kinases. their function has been related to cell-cycle regulation, splicing and apoptosis. we have previously shown that the open reading frame of the p110(pitslre) transcript contains an ires (internal ribosome entry site) that allows the expression of a smaller p58(pitslre) isoform during the g2/m stage of the cell cycle. in the present study we investigated further the role of cis- and trans-acting factors in the regul ... | 2005 | 15330758 |
| encephalomyocarditis (emc) virus-induced sialodacryoadenitis in mice. | the mode of occurrence of the d variant of encephalomyocarditis (emc-d) virus-induced acute sialodacryoadenitis was investigated using three strains of mice differing in their sensitivity to emc-d virus-induced diabetes (c57bl/6: resistant; balb/c: moderately sensitive; dba/2: highly sensitive). mice were intranasally inoculated with high (10(5) pfu/mouse) or low dose (10(2) pfu/mouse) of emc-d virus. although there were individual differences, the blood virus titer generally reached the peak ea ... | 2005 | 15596062 |
| sindbis virus translation is inhibited by a pkr/rnase l-independent effector induced by alpha/beta interferon priming of dendritic cells. | the tropism of sindbis virus (sb) for cells of the dendritic cell (dc) lineage and the virulence of sb in vivo are largely determined by the efficacy of alpha/beta interferon (ifn-alpha/beta)-mediated antiviral responses. these responses are essentially intact in the absence of pkr and/or rnase l (k. d. ryman, l. j. white, r. e. johnston, and w. b. klimstra, viral immunol. 15:53-76, 2002). in the present studies, we investigated the nature of antiviral effects and identity of antiviral effectors ... | 2005 | 15650175 |
| fatal inflammatory heart disease in a bonobo (pan paniscus). | we report the first probable identification of encephalomyocarditis virus (emcv) in a bonobo (pan paniscus) that had been part of a forest re-introduction programme. clinical presentation was of episodic acute on chronic heart failure and cerebral infarction with end-stage renal failure rather than sudden death which is more commonly associated with emcv infection. a postmortem diagnosis of probable emcv was made using gross pathological and histopathological examination. findings included acute ... | 2005 | 15667344 |
| establishment of a subgenomic replicon for bovine viral diarrhea virus in huh-7 cells and modulation of interferon-regulated factor 3-mediated antiviral response. | we describe the development of a selectable, bi-cistronic subgenomic replicon for bovine viral diarrhea virus (bvdv) in huh-7 cells, similar to that established for hepatitis c virus (hcv). the selection marker and reporter (luc-ubi-neo) in the bvdv replicon was fused with the amino-terminal protease n(pro), and expression of the nonstructural proteins (ns3 to ns5b) was driven by an encephalomyocarditis virus internal ribosome entry site. this bvdv replicon allows us to compare rna replication o ... | 2005 | 15708997 |
| toll-like receptor 3 promotes cross-priming to virus-infected cells. | cross-presentation of cell-associated antigens plays an important role in regulating cd8+ t cell responses to proteins that are not expressed by antigen-presenting cells (apcs). dendritic cells are the principal cross-presenting apcs in vivo and much progress has been made in elucidating the pathways that allow dendritic cells to capture and process cellular material. however, little is known about the signals that determine whether such presentation ultimately results in a cytotoxic t cell (ctl ... | 2005 | 15711573 |
| two mechanisms of caspase 9 processing in double-stranded rna- and virus-triggered apoptosis. | viral double-stranded rna (dsrna) is a ubiquitous intracellular "alert signal" used by cells to detect viral infection and to mount anti-viral responses. dsrna triggers a rapid (complete within 2-4 h) apoptosis in the highly-susceptible hela cell line. here, we demonstrate that the apical event in this apoptotic cascade is the activation of procaspase 8. downstream of caspase 8, the apoptotic signaling cascade bifurcates into a mitochondria-independent caspase 8/caspase 3 arm and a mitochondria- ... | 2005 | 15711931 |
| inhibition of vsv and emcv replication by the interferon-induced gtpase, mgbp-2: differential requirement for wild-type gtp binding domain. | interferons (ifns) exert their anti-viral activities through the induction of anti-viral proteins. one member of the guanylate binding protein (gbp) family of ifn-induced gtpases, hgbp-1, has previously been shown to contribute to the antiviral activities of ifns. murine gbp-2 inhibited the replication of both vesicular stomatitis virus (vsv) and encephalomyocarditis virus (emcv). a wild type gtp binding motif was not required for vsv inhibition but was required for inhibition of emcv. this is t ... | 2005 | 15717119 |
| comparison of biological activity of recombinant woodchuck interferon gamma and tumor necrosis factor alpha produced in baculovirus and escherichia coli expression systems. | the full-length cdnas of recombinant woodchuck interferon gamma (rwifn gamma) and woodchuck tumor necrosis factor alpha (rwtnf alpha) were cloned into baculovirus transfer vectors and expressed in insect sf9 cells. the recombinant proteins secreted by the insect cells, bac-rwifn gamma and bac-rwtnf alpha, were found to be functionally competent. their biological activities were compared to those of rwifn gamma and rwtnf alpha produced in the escherichia coli (e. coli) expression system. the bac- ... | 2005 | 15784409 |
| replication of a recombinant hepatitis e virus genome tagged with reporter genes and generation of a short-term cell line producing viral rna and proteins. | hepatitis e virus (hev) replication has been demonstrated in hepg2 cells transfected with full-length in vitro transcripts of an infectious cdna clone. this cdna clone was modified to generate several subgenomic hev replicons with fused reporter genes. in vitro-transcribed capped rnas generated from these were transfected into hepg2 cells. negative-strand rna was detected, indicating the occurrence of replication. the replicon containing an in-frame fusion of hev orf2 with enhanced green fluores ... | 2005 | 15784913 |
| adiponectin replacement therapy attenuates myocardial damage in leptin-deficient mice with viral myocarditis. | the effects of adiponectin replacement therapy on myocardial damage were studied in leptin-deficient (ob) mice with acute viral myocarditis. encephalomyocarditis virus was injected intraperitoneally into ob and wild-type (wt) mice. one subgroup of ob mice received no intervention and another subgroup received daily adiponectin replacement, simultaneously with viral inoculation. differences in heart weight, cardiac histological score, numbers of infiltrating or apoptotic cells in the myocardium a ... | 2005 | 15790132 |
| noninvasive monitoring of target gene expression by imaging reporter gene expression in living animals using improved bicistronic vectors. | indirect, noninvasive imaging of therapeutic gene expression based on levels of reporter gene expression is a powerful tool to devise improved therapeutic strategies in cancer gene therapy. the use of bicistronic vectors carrying internal ribosome entry sites (iress) allows the coexpression of multiple gene products from the same promoter but leads to considerable attenuation of the downstream gene. in this study, we describe the use of 10 linked copies of the gtx (homeodomain protein) ires (abb ... | 2005 | 15809490 |
| high-efficiency protein expression mediated by enterovirus 71 internal ribosome entry site. | an internal ribosome entry site (ires) has been used to facilitate the expression of more than one protein in a single transcript. in this study, we examined the translational activities of several ires elements derived from different rna viruses. the protein expression of encephalomyocarditis virus (emcv) ires is similar to that of hepatitis c virus (hcv) ires in mammalian cells. notably, the protein expression of enterovirus 71 (ev71) ires was 23-fold higher than the efficiency of emcv ires fo ... | 2005 | 15818561 |
| dengue virus inhibits alpha interferon signaling by reducing stat2 expression. | alpha/beta interferon (ifn-alpha/beta) is a key mediator of innate antiviral responses but has little effect on the established replication of dengue viruses, which are mosquito-borne flaviviruses of immense global health importance. understanding how the ifn system is inhibited in dengue virus-infected cells would provide critical insights into disease pathogenesis. in a recent study analyzing the ability of individual dengue virus-encoded proteins to antagonize the ifn response, nonstructural ... | 2005 | 15827155 |
| peptide mimetics of gamma interferon possess antiviral properties against vaccinia virus and other viruses in the presence of poxvirus b8r protein. | we have developed peptide mimetics of gamma interferon (ifn-gamma) that play a direct role in the activation and nuclear translocation of stat1alpha transcription factor. these mimetics do not act through recognition by the extracellular domain of ifn-gamma receptor but rather bind to the cytoplasmic domain of the receptor chain 1, ifngr-1, and thereby initiate the cellular signaling. thus, we hypothesized that these mimetics would bypass the poxvirus virulence factor b8r protein that binds to i ... | 2005 | 15827178 |
| cryptic promoter activity in the dna sequence corresponding to the pim-1 5'-utr. | the serine/threonine kinase pim-1 mrna contains a long and g/c rich 5'-untranslated region (5'-utr). previous work suggested that the pim-1 5'-utr harbors an internal ribosomal entry site (ires) allowing for internal initiation of translation. however, several previously reported eukaryotic ires elements actually contain cryptic promoter activity. to test whether an ires or a cryptic promoter is present in the pim-1 5'-utr, the 5'-utr was re-examined using stringent test procedures. our results ... | 2005 | 15843687 |
| small interfering rna-mediated inhibition of hepatitis g virus gene expression in human hepatoma cell huh-7. | the rna interference (rnai) phenomenon is a recently observed process in which the introduction of a double-stranded, small interfering rna (sirna) into a cell causes the specific degradation of a homologous single-stranded rna. it represents an exciting new technology that could have therapeutic applications for the treatment of viral infections. since hepatitis g virus (hgv) genome is a positive-sense single-stranded rna, the replication of hgv does not lead to an integrated dna genome, sugges ... | 2005 | 15844358 |
| exploiting cis-acting replication elements to direct hepatitis c virus-dependent transgene expression. | we describe here a novel targeting gene therapy strategy to direct gene expression responsive to hepatitis c virus (hcv). the goal was approached by engineering a construct containing the antisense sequence of the transgene and internal ribosome entry site of encephalomyocarditis virus flanked by 5'- and 3'-end sequences of hcv cdna that contain cis-acting replication elements. thus, expression of the transgene is only promoted when the minus-strand rna has been synthesized by the functional rep ... | 2005 | 15857978 |
| the polypyrimidine tract binding protein is required for efficient picornavirus gene expression and propagation. | mammalian host factors required for efficient viral gene expression and propagation have been often recalcitrant to genetic analysis. a case in point is the function of cellular factors that trans-activate internal ribosomal entry site (ires)-driven translation, which is operative in many positive-stranded rna viruses, including all picornaviruses. these ires trans-acting factors have been elegantly studied in vitro, but their in vivo importance for viral gene expression and propagation has not ... | 2005 | 15858002 |
| investigation of factors responsible for cell line cytoplasmic expression differences. | previous work has described a novel cytoplasmic expression system that results in a 20-fold increase in the levels of gene expression over a standard cmv-based nuclear expression system, as compared with a 2-3 fold increase seen with previous similar systems. while this increase was seen with bhk and neuro-2a cells, further studies revealed that some cell lines, such as cos-7, demonstrated relatively poor levels of cytoplasmic expression. the objective of this study was to determine what factors ... | 2005 | 15888202 |
| the 5'-terminal region of the aichi virus genome encodes cis-acting replication elements required for positive- and negative-strand rna synthesis. | aichi virus is a member of the family picornaviridae. it has already been shown that three stem-loop structures (sl-a, sl-b, and sl-c, from the 5' end) formed at the 5' end of the genome are critical elements for viral rna replication. in this study, we further characterized the 5'-terminal cis-acting replication elements. we found that an additional structural element, a pseudoknot structure, is formed through base-pairing interaction between the loop segment of sl-b (nucleotides [nt] 57 to 60) ... | 2005 | 15890931 |
| internal initiation of translation of the trkb mrna is mediated by multiple regions within the 5' leader. | translational regulation of the dendritically localized mrna encoding for the neurotrophin receptor trkb has important ramifications for synaptic function. we examined whether the trkb mrna is translated through an internal initiation entry site (ires). the human trkb 5' leaders are derived from the use of alternative promoters and alternative splicing, but all 5' leaders share a common exon. insertion of a full-length 5' leader, as well as the common exon into the intercistronic region of a dic ... | 2005 | 15908588 |
| interferons alpha, beta, gamma each inhibit hepatitis c virus replication at the level of internal ribosome entry site-mediated translation. | interferon (ifn)-alpha is the standard therapy for the treatment of chronic hepatitis c, but the mechanisms underlying its antiviral action are not well understood. in this report, we demonstrated that ifn-alpha, -beta and -gamma inhibit replication of the hepatitis c virus (hcv) in a cell culture model at concentrations between 10 and 100 iu/ml. we demonstrated that the antiviral actions each of each these ifns are targeted to the highly conserved 5' untranslated region of the hcv genome, and t ... | 2005 | 15910496 |
| evaluation of virus decontamination techniques for porcine embryos produced in vitro. | the objective of this study was to explore approaches to decontaminate embryos either contaminated naturally or under experimental conditions with different viruses. embryos were obtained from in vitro maturation and fertilisation of porcine oocytes. after 7 days of development, morula and blastocyst stages were exposed for 1 h to the following viruses: encephalomyocarditis virus (emcv), porcine circovirus type 2 (pcv2), porcine parvovirus (ppv), porcine reproductive and respiratory syndrome vir ... | 2005 | 15910918 |
| propranolol ameliorates and epinephrine exacerbates progression of acute and chronic viral myocarditis. | recent studies point to important interactions between proinflammatory cytokines and neurohumoral mediators in heart failure. here we investigate the influence of the beta-adrenergic system on cytokines and neurohumoral factors and the sequelae of viral myocarditis. in an experimental model with virus-infected balb/c mice, we studied the acute and chronic effects of epinephrine and propranolol on myocardial morphology, cytokine gene expression, and survival. balb/c mice were inoculated with the ... | 2005 | 15923319 |
| in vitro expression and analysis of secreted fowlpox virus cc chemokine-like proteins fpv060, fpv061, fpv116 and fpv121. | the four cc chemokine-like proteins (fpv060, fpv061, fpv116 and fpv121) of fowlpox virus (fwpv) were over-expressed as his-tagged versions from a t7 promoter/emcv ires construct in vitro, by coupled transcription/translation, or in cell culture, by co-infection with two recombinant fwpvs (one expressing the chemokine-like protein and one expressing t7 rna polymerase). all, except fpv116, appeared to be glycosylated in the presence of microsomal membranes in vitro. in culture, all were secreted ( ... | 2005 | 15931460 |