Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
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| utilizing liver-specific microrna-122 to modulate replication of dengue virus replicon. | micrornas (mirnas) are endogenous non-coding rnas that spatiotemporally modulate mrnas in a post-transcriptional manner. the engineering of viruses by insertion of a tissue-specific mirna recognition element (mre) into viral mrna can restrict viral tissue tropism. in this study we employed dengue virus (den) replicons to investigate whether mirnas are able to suppress flavivirus replication through the targeting of non-polyadenylated viral mrna. because liver infection by den may contribute to t ... | 2010 | 20412785 |
| [tick-borne meningoencephalitis: all the family doctor needs to know]. | 2010 | 20394171 | |
| [coding nucleotide sequences of tick-borne encephalitis virus strains isolated from human blood without clinical symptoms of infection]. | genomes of four tick-borne encephalitis virus strains, isolated from the blood of the individuals after tick bites and causing no clinical symptoms of infection, were characterized. analysis of translated polypeptides revealed 21 amino acid positions typical of this group of strains and distinguishing them from the other tickborne encephalitis virus strains of far eastern subtype examined earlier. only three mutations led to substantial amino acid changes, which probably could affect the infecti ... | 2010 | 20391780 |
| peptide inhibitors of dengue-virus entry target a late-stage fusion intermediate. | the mechanism of membrane fusion by "class ii" viral fusion proteins follows a pathway that involves large-scale domain rearrangements of the envelope glycoprotein (e) and a transition from dimers to trimers. the rearrangement is believed to proceed by an outward rotation of the e ectodomain after loss of the dimer interface, followed by a reassociation into extended trimers. the approximately 55-aa-residue, membrane proximal "stem" can then zip up along domain ii, bringing together the transmem ... | 2010 | 20386713 |
| isolation and sequence analysis of culex flavivirus from culex interrogator and culex quinquefasciatus in the yucatan peninsula of mexico. | previously, we reported a high prevalence of culex flavivirus (cxfv) in culex quinquefasciatus (say) in the yucatan peninsula of mexico. to determine whether other culex spp. mosquitoes in this region are susceptible to natural cxfv infection, cx. bahamensis (dyar and knab), cx. coronator (dyar and knab), cx. interrogator (dyar and knab), cx. nigripalpus (theobald) and cx. opisthopus (komp) in the yucatan peninsula of mexico were tested for cxfv. two pools of cx. interrogator were positive. the ... | 2010 | 20379749 |
| flexibility between the protease and helicase domains of the dengue virus ns3 protein conferred by the linker region and its functional implications. | the dengue virus (denv) ns3 protein is essential for viral polyprotein processing and rna replication. it contains an n-terminal serine protease region (residues 1-168) joined to an rna helicase (residues 180-618) by an 11-amino acid linker (169-179). the structure at 3.15 a of the soluble ns3 protein from denv4 covalently attached to 18 residues of the ns2b cofactor region (ns2b(18)ns3) revealed an elongated molecule with the protease domain abutting subdomains i and ii of the helicase (luo, d. ... | 2010 | 20375022 |
| dengue virus life cycle: viral and host factors modulating infectivity. | dengue virus (denv 1-4) represents a major emerging arthropod-borne pathogen. all four denv serotypes are prevalent in the (sub) tropical regions of the world and infect 50-100 million individuals annually. whereas the majority of denv infections proceed asymptomatically or result in self-limited dengue fever, an increasing number of patients present more severe manifestations, such as dengue hemorrhagic fever and dengue shock syndrome. in this review we will give an overview of the infectious l ... | 2010 | 20372965 |
| identification of a class of hcv inhibitors directed against the nonstructural protein ns4b. | new classes of drugs are needed to combat hepatitis c virus (hcv), an important worldwide cause of liver disease. we describe an activity of a key domain, an amphipathic helix we termed 4bah2, within a specific hcv nonstructural protein, ns4b. in addition to its proposed role in viral replication, we validate 4bah2 as essential for hcv genome replication and identify first-generation small-molecule inhibitors of 4bah2 that specifically prevent hcv replication within cells. mechanistic studies re ... | 2010 | 20371471 |
| arboviral survey of mosquitoes in two northern italian regions in 2007 and 2008. | recently, italy-particularly the emilia-romagna region-was the location of consecutive outbreaks of human diseases caused by the arboviruses chikungunya virus and west nile virus. the two outbreaks, spread by different species of mosquitoes, were not related, but pointed out the lack of an arboviral surveillance program in this region. beginning in 2007 entomological surveillance was initiated in the emilia-romagna region, and in 2008 the program was improved and extended at lombardia region. us ... | 2010 | 20370434 |
| detection of flaviviruses and orthobunyaviruses in mosquitoes in the yucatan peninsula of mexico in 2008. | a total of 191,244 mosquitoes from 24 species were collected in the yucatan peninsula of mexico from january to december 2008, and tested for the presence of cytopathic virus by virus isolation in vero cells. eighteen virus isolates were obtained, all of which were orthobunyaviruses. these were identified by reverse transcription-polymerase chain reaction (rt-pcr) and nucleotide sequencing as cache valley virus (n=17) and south river virus (n=1). a subset (n=20,124) of culex quinquefasciatus col ... | 2010 | 20370430 |
| [pathogenicity of west nile virus: molecular markers]. | the review describes the phenotypic properties, structure, and expression pattern of west nile virus genome (flaviviridae, flavivirus, japanese encephalitis antigenic complex), as well as the clinical picture and pathogenesis of its etiologically related disease west nile fever. it also analyzes the available data on the impact of genetic mutations in the genome on the biological properties of the virus. | 2010 | 20364664 |
| rac1 and scribble are targets for the arrest of neurite outgrowth by tbe virus ns5. | tick-borne encephalitis virus (tbev) causes extensive cns disease in humans known as tbe, however, relatively little is known of the molecular mechanisms for its progress. here, we now show that tbev produces defects in neuronal development of pc12 cells through a function of the viral ns5 protein. the methyltransferase domain of ns5 is critical and sufficient for restriction of nerve growth factor induced neurite outgrowth. this effect is reversed by expression of ns5 mutants unable to bind scr ... | 2010 | 20363326 |
| a small molecule inhibits hcv replication and alters ns4b's subcellular distribution. | hepatitis c virus (hcv) is a leading cause of liver disease and represents a significant public health challenge. treatments for this disease are inadequate and improved antiviral therapies are necessary. several such antivirals are in development, most of which target the well-characterized ns3 protease or the ns5b polymerase. in contrast, the nonstructural 4b (ns4b) protein, though essential for hcv rna replication, has been the subject of few pharmacological studies. one of the functions ascr ... | 2010 | 20363257 |
| [efficiency of use of immunoglobulin preparations for the postexposure prevention of tick-borne encephalitis in russia (a review of semi-centennial experience)]. | along with regenerated interest in passive immunization during flavivirus infections, there is an increase in the number of reports with negative opinions as to the expediency of postexposure immunoglobulin prophylaxis (igp) of tick-borne encephalitis (tbe). analysis of the publications (since 1959) on this problem has indicated that more than half of them, including all papers with negative opinions as to igp, contain the results of studies whose design are unsuitable for the solution of the pr ... | 2010 | 20361640 |
| development of a vaccine to prevent japanese encephalitis: a brief review. | japanese encephalitis (icd 10: a83.0) is an important specific viral encephalitis caused by the japanese encephalitis virus, a virus of the flavivirus group. millions of people, especially those in endemic areas of developing countries in asia, are at high risk from this infection. therefore proper management to deal with this virus is essential. there is no specific treatment for japanese encephalitis virus. supportive and symptomatic treatments are usually used, which emphasize the importance ... | 2009 | 20360904 |
| japanese encephalitis virus utilizes the canonical pathway to activate nf-kappab but it utilizes the type i interferon pathway to induce major histocompatibility complex class i expression in mouse embryonic fibroblasts. | flaviviruses have been shown to induce cell surface expression of major histocompatibility complex class i (mhc-i) through the activation of nf-kappab. using ikk1(-/-), ikk2(-/-), nemo(-/-), and ikk1(-/-) ikk2(-/-) double mutant as well as p50(-/-) rela(-/-) crel(-/-) triple mutant mouse embryonic fibroblasts infected with japanese encephalitis virus (jev), we show that this flavivirus utilizes the canonical pathway to activate nf-kappab in an ikk2- and nemo-, but not ikk1-, dependent manner. nf ... | 2010 | 20357096 |
| interplay of rna elements in the dengue virus 5' and 3' ends required for viral rna replication. | dengue virus (denv) is a member of the flavivirus genus of positive-sense rna viruses. denv rna replication requires cyclization of the viral genome mediated by two pairs of complementary sequences in the 5' and 3' ends, designated 5' and 3' cyclization sequences (5'-3' cs) and the 5' and 3' upstream of aug region (5'-3' uar). here, we demonstrate that another stretch of six nucleotides in the 5' end is involved in denv replication and possibly genome cyclization. this new sequence is located do ... | 2010 | 20357095 |
| safety and pharmacokinetics of single intravenous dose of mgawn1, a novel monoclonal antibody to west nile virus. | west nile virus (wnv) is a neurotropic flavivirus that can cause debilitating diseases, such as encephalitis, meningitis, or flaccid paralysis. we report the safety, pharmacokinetics, and immunogenicity of a recombinant humanized monoclonal antibody (mgawn1) targeting the e protein of wnv in a phase 1 study, the first to be performed on humans. a single intravenous infusion of saline or of mgawn1 at escalating doses (0.3, 1, 3, 10, or 30 mg/kg of body weight) was administered to 40 healthy volun ... | 2010 | 20350945 |
| higher catalytic efficiency of n-7-methylation is responsible for processive n-7 and 2'-o methyltransferase activity in dengue virus. | methyltransferases (mtases) from the genus flavivirus encode both n-7 and 2'-o activities needed for type 1 (m(7)gpppnm) cap structure formation. we performed kinetic studies to understand the mechanisms of its progressive n-7 and 2'-o methylations. sequential n-7 to 2'-o methylation occurred via a random bi bi and processive mechanism that does not involve enzyme-rna dissociation. analyses of steady state kinetic parameters showed that n-7 precedes 2'-o methylation as it turnovers rna faster (k ... | 2010 | 20350738 |
| field evaluation of commercial immunoglobulin m antibody capture elisa diagnostic tests for the detection of japanese encephalitis virus infection among encephalitis patients in nepal. | japanese encephalitis (je) is a devastating disease with high rates of death and disability that occurs particularly in resource-limited, rural regions of asia. simple, accurate and inexpensive diagnostics tests are vital for quantifying the burden of illness. this field study evaluated two commercial je immunoglobulin m antibody capture (mac) elisa kits using samples from routine je surveillance. | 2010 | 20346721 |
| tick-borne encephalitis among u.s. travelers to europe and asia - 2000-2009. | tick-borne encephalitis virus (tbev) is the most common arbovirus transmitted by ticks in europe. approximately 10,000 cases of tick-borne encephalitis (tbe) are reported annually in europe and russia. although tbe is endemic in parts of china, information regarding its incidence is limited. tbev is closely related to powassan virus (powv), another tick-borne flavivirus that is a rare cause of encephalitis in north america and russia; tbev and powv can cross-react in serologic tests. before 2000 ... | 2010 | 20339345 |
| infection and vertical transmission of kamiti river virus in laboratory bred aedes aegypti mosquitoes. | kamiti river virus (krv) is an insect-only flavivirus that was isolated from field-collected ae. macintoshi mosquitoes in 1999, and is closely related to cell fusing agent virus. both of these viruses belong to the family flaviviridae, which also contains other viruses of medical importance, such as yellow fever virus, west nile virus and dengue. because ae. macintoshi is the only known natural host to krv, the main objective of this study was to establish the possibility that other mosquito hos ... | 2007 | 20337552 |
| in vitro reconstitution reveals key intermediate states of trimer formation by the dengue virus membrane fusion protein. | the flavivirus dengue virus (dv) infects cells through a low-ph-triggered membrane fusion reaction mediated by the viral envelope protein e. e is an elongated transmembrane protein with three domains and is organized as a homodimer on the mature virus particle. during fusion, the e protein homodimer dissociates, inserts the hydrophobic fusion loop into target membranes, and refolds into a trimeric hairpin in which domain iii (diii) packs against the central trimer. it is clear that e refolding d ... | 2010 | 20335260 |
| antagonism of the complement component c4 by flavivirus nonstructural protein ns1. | the complement system plays an essential protective role in the initial defense against many microorganisms. flavivirus ns1 is a secreted nonstructural glycoprotein that accumulates in blood, is displayed on the surface of infected cells, and has been hypothesized to have immune evasion functions. herein, we demonstrate that dengue virus (denv), west nile virus (wnv), and yellow fever virus (yfv) ns1 attenuate classical and lectin pathway activation by directly interacting with c4. binding of ns ... | 2010 | 20308361 |
| dengue virus replicons: production of an interserotypic chimera and cell lines from different species, and establishment of a cell-based fluorescent assay to screen inhibitors, validated by the evaluation of ribavirin's activity. | the prevention and treatment of flavivirus infections are public health priorities. dengue fever is the most prevalent mosquito-borne viral disease of humans, affecting more than 50 million people annually. despite the urgent need to control dengue infections, neither specific antiviral therapies nor licensed vaccines exist and the molecular basis of dengue pathogenesis is not well understood. in this study we produced a novel dengue virus type 2 (dv2) subgenomic replicon that expresses a fusion ... | 2010 | 20307577 |
| design, structure-based focusing and in silico screening of combinatorial library of peptidomimetic inhibitors of dengue virus ns2b-ns3 protease. | serine protease activity of the ns3 protein of dengue virus is an important target of antiviral agents that interfere with the viral polyprotein precursor processing catalyzed by the ns3 protease (ns3pro), which is important for the viral replication and maturation. recent studies showed that substrate-based peptidomimetics carrying an electrophilic warhead inhibit the ns2b-ns3pro cofactor-protease complex with inhibition constants in the low micromolar concentration range when basic amino acid ... | 2010 | 20306283 |
| detection and in-cell selectivity profiling of the full-length west nile virus ns2b/ns3 serine protease using membrane-anchored fluorescent substrates. | flaviviral ns2b/ns3 heterocomplex serine proteases are a primary target for anti-flavivirus drug discovery. to gain insights into the enzymatic properties and molecular determinants of flaviviral ns2b/ns3 protease substrate specificity in host cells, we developed and applied a novel series of membrane-anchored red-shifted fluorescent protein substrates to detect west nile virus (wnv) ns2b/ns3 endoproteolytic activity in human cells. the substrate consists of a fluorescent reporter group (dsred) ... | 2010 | 20302513 |
| detection of west nile viral rna from field-collected mosquitoes in tropical regions by conventional and real-time rt-pcr. | west nile virus (wnv) is an emerging mosquito-borne flavivirus, which has rapidly spread and is currently widely distributed. therefore, efforts for wnv early detection and ecological surveillance of this disease agent have been increased around the world. although virus isolation is known to be the standard method for detection and identification of viruses, the use of rt-pcr assays as routine laboratory tests provides a rapid alterative suitable for the detection of viral rna on field-collecte ... | 2010 | 20300994 |
| inhibition of dengue virus polymerase by blocking of the rna tunnel. | dengue virus (denv) is the most prevalent mosquito-borne viral pathogen in humans. neither vaccine nor antiviral therapy is currently available for denv. we report here that n-sulfonylanthranilic acid derivatives are allosteric inhibitors of denv rna-dependent rna polymerase (rdrp). the inhibitor was identified through high-throughput screening of one million compounds using a primer extension-based rdrp assay [substrate poly(c)/oligo(g)(20)]. chemical modification of the initial "hit" improved ... | 2010 | 20237086 |
| japanese encephalitis vaccines: recommendations of the advisory committee on immunization practices (acip). | this report updates the 1993 recommendations by cdc's advisory committee on immunization practices (acip) regarding the prevention of japanese encephalitis (je) among travelers (cdc. inactivated japanese encephalitis virus vaccine: recommendations of the advisory committee on immunization practices [acip]. mmwr 1993;42[no. rr-1]). this report summarizes the epidemiology of je, describes the two je vaccines that are licensed in the united states, and provides recommendations for their use among t ... | 2010 | 20224546 |
| flavitrack analysis of the structure and function of west nile non-structural proteins. | the flavitrack database groups flaviviruses (fv), evolutionarily related organisms with high subtype variability, according to their phenotypes. here, pcpmer tools were used to calculate consensus sequences based on conservation of physicochemical properties (pcp) for 919 sequences of ns2a, a non-structural protein involved in preventing host interferon response to infection. conserved pcp-motifs were detected, primarily in the n-terminal half of ns2a. one model structure, based on a nuclear rec ... | 2010 | 20223736 |
| replication of not-known-vector flaviviruses in mosquito cells is restricted by intracellular host factors rather than by the viral envelope proteins. | chimeric yellow fever virus 17d (yfv-17d) and dengue virus type 2 (denv2) carrying the surface proteins of modoc virus (modv), a not-known-vector (nkv) flavivirus, replicated efficiently in mammalian (vero-b) and mosquito (c6/36) cells, whereas modv failed to replicate in mosquito cells. transfection of c6/36 cells with modv rna did not result in virus replication; however, transfection of these mosquito cells with yfv-17d or denv2 rna did. the inability of nkv viruses (such as modv) to infect a ... | 2010 | 20219898 |
| japanese encephalitis: new options for active immunization. | japanese encephalitis (je) is a mosquito-borne flavivirus infection responsible for significant morbidity and mortality across asia. indigenous populations and those who undertake short- and long-term travel to endemic regions are at risk of infection and development of neuroinvasive disease. effective mouse brain-derived vaccines have been available in select countries, including the united states, for decades. limited access in asia and safety concerns with regard to mouse brain products promp ... | 2010 | 20218889 |
| altered effector functions of virus-specific and virus cross-reactive cd8+ t cells in mice immunized with related flaviviruses. | memory cross-reactive cd8+ t-cell responses may induce protection or immunopathology upon secondary viral challenge. to elucidate the potential role of t cells in sequential flavivirus infection, we characterized cross-reactive cd4+ and cd8+ t-cell responses between attenuated and pathogenic japanese encephalitis virus (jev) and pathogenic west nile virus (wnv). a previously reported wnv ns4b cd8+ t-cell epitope and its jev variant elicited cd8+ t-cell responses in both jev- and wnv-infected mic ... | 2010 | 20213733 |
| an inactivated west nile virus vaccine derived from a chemically synthesized cdna system. | a cdna comprising the complete genome of west nile virus (wnv) was generated by chemical synthesis using published sequence data, independent of any preformed viral components. the synthetic wnv, produced by transfection of in vitro transcribed rna into cell culture, exhibited undistinguishable biological properties compared to the corresponding animal-derived wild-type virus. no differences were found concerning viral growth in mammalian and insect cell lines and concerning expression of viral ... | 2010 | 20211218 |
| a flavivirus signal peptide balances the catalytic activity of two proteases and thereby facilitates virus morphogenesis. | two cleavages on either side of a signal peptide separating capsid and prm on the nascent flavivirus polyprotein are uniquely regulated, such that cytosolic capsid cleavage triggers signalase cleavage of prm. here, we show, using two experimental approaches, that this sequential order of cleavages facilitates virus morphogenesis: (i) a murray valley encephalitis virus (mvev) variant, in which both cleavages occurred efficiently and independently of each other, displayed an assembly defect. (ii) ... | 2010 | 20207389 |
| evaluation of an enzyme-linked immunosorbent assay for detection of west nile virus infection based on a recombinant envelope protein produced in trichoplusia ni larvae. | west nile virus (wnv), a flavivirus distributed most widely, is presenting lately variable epidemiological and ecological patterns, including an increasing virulence that has already caused over 1000 human deaths in usa. currently, diagnosis of wnv is achieved mainly by enzyme-linked immunoassays (elisas) based on the use of inactivated whole wnv (iwnv) as antigen, although results have to be confirmed by plaque reduction neutralization tests (prnts). expression of wnv envelope recombinant e (re ... | 2010 | 20170681 |
| identification of micrornas expressed in two mosquito vectors, aedes albopictus and culex quinquefasciatus. | micrornas (mirnas) are small non-coding rnas that post-transcriptionally regulate gene expression in a variety of organisms, including insects, vertebrates, and plants. mirnas play important roles in cell development and differentiation as well as in the cellular response to stress and infection. to date, there are limited reports of mirna identification in mosquitoes, insects that act as essential vectors for the transmission of many human pathogens, including flaviviruses. west nile virus (wnv ... | 2010 | 20167119 |
| thermal stability and inactivation of hepatitis c virus grown in cell culture. | hepatitis c virus (hcv) is a blood-borne flavivirus that infects many millions of people worldwide. relatively little is known, however, concerning the stability of hcv and reliable procedures for inactivating this virus. | 2010 | 20167059 |
| focus on flaviviruses: current and future drug targets. | infection by mosquito-borne flaviviruses (family flaviviridae) is increasing in prevalence worldwide. the vast global, social and economic impact due to the morbidity and mortality associated with the diseases caused by these viruses necessitates therapeutic intervention. there is currently no effective clinical treatment for any flaviviral infection. therefore, there is a great need for the identification of novel inhibitors to target the virus life cycle. | 2009 | 20165556 |
| a high-throughput assay using dengue-1 virus-like particles for drug discovery. | dengue virus (denv) is a mosquito-borne flavivirus responsible for 50-100 million human infections each year. the development of denv chemotherapy requires high-throughput screening (hts) assays. a dengue virus-like particle (vlp) has been constructed using viral structural proteins to package a renilla luciferase reporter replicon. vlp could be produced by either the sequential electroporation of the replicon rnas and the structural gene rnas or by electroporating replicon rna into a stable cel ... | 2010 | 20153777 |
| minocycline differentially modulates macrophage mediated peripheral immune response following japanese encephalitis virus infection. | japanese encephalitis virus (jev) is a neurotropic flavivirus that is the causative agent of a major mosquito-borne encephalitis in the world. evasion of peripheral immune system facilitates the entry of the virus into the central nervous system (cns) where it causes extensive neuronal inflammatory damage that leads to death or severe neuropschychiatric sequel in survivors. it has been proposed that after entry into the body, the virus is carried into the cns by peripheral immune cells that act ... | 2010 | 20153075 |
| arboviruses in blood donors: a study in the amazon region and in a small city with a dengue outbreak. | 2010 | 20149157 | |
| effects of forced egg retention on the temporal progression of west nile virus infection in culex pipiens quinquefasciatus (diptera: culicidae). | environmental factors that impact the biology of mosquito vectors can have epidemiological implications. lack of oviposition sites facilitated by environmental factors such as temperature and drought can often force culex spp. mosquitoes to retain their eggs. culex pipiens quinquefasciatus say were fed blood meals containing west nile virus (wnv; family flaviviridae, genus flavivirus) and either allowed to oviposit or forced to retain their eggs through different time points postinfection (9, 13 ... | 2010 | 20146856 |
| [prospects for treating mosquito-borne flavivirus encephalitides]. | the japanese encephalitis virus and west nile virus belong to the family flaviviridae, genus flavivirus; they have a similar transmission cycle, with birds serving as the natural vertebrate host and mosquitoes, primarily, culex species, both serving as the enzootic vectors and infecting humans. these arboviruses have caused more human cases of severe neuroinvasive disease worldwide during the past decade than other mosquito-borne flaviviruses. the current data and concepts on the clinical manife ... | 2009 | 20141019 |
| an inactivated vero cell-grown japanese encephalitis vaccine formulated with advax, a novel inulin-based adjuvant, induces protective neutralizing antibody against homologous and heterologous flaviviruses. | advax is a polysaccharide-based adjuvant that potently stimulates vaccine immunogenicity without the increased reactogenicity seen with other adjuvants. this study investigated the immunogenicity of a novel advax-adjuvanted vero cell culture candidate vaccine against japanese encephalitis virus (jev) in mice and horses. the results showed that, in mice, a two-immunization, low-dose (50 ng jev antigen) regimen with adjuvanted vaccine produced solid neutralizing immunity comparable to that elicite ... | 2010 | 20130134 |
| infection control guidelines for prevention of health care-associated transmission of hepatitis b and c viruses. | viral hepatitis was first identified as an occupational hazard for health care workers more than 60 years ago. for the past few decades, hepatitis b has been one of the most significant occupational infectious risks for health care providers. with the increasing prevalence of hepatitis c infections around the world, occupational transmission of this flavivirus from infected patients to their providers has also become a significant concern. several factors influence the risk for occupational bloo ... | 2010 | 20123445 |
| west nile virus: is a vaccine needed? | west nile virus (wnv) is a neurotropic flavivirus that was associated with sporadic outbreaks of meningoencephalitis in africa and the middle east until 1999, when a more virulent strain emerged in the us that caused thousands of infections among humans and horses, with reported fatality rates between 10 and 50%. although the epidemiology of wnv is changing into a more endemic pattern in the us, and the incidence of neuroinvasive disease is decreasing, the long-term effects of resolved wnv infec ... | 2010 | 20112163 |
| mechanism and specificity of a symmetrical benzimidazolephenylcarboxamide helicase inhibitor. | this study examines the effects of 1-n,4-n-bis[4-(1h-benzimidazol-2-yl)phenyl]benzene-1,4-dicarboxamide ((bip)(2)b) on the ns3 helicase encoded by the hepatitis c virus (hcv). molecular beacon-based helicase assays were used to show that (bip)(2)b inhibits the ability of hcv helicase to separate a variety of rna and dna duplexes with half-maximal inhibitory concentrations ranging from 0.7 to 5 microm, depending on the nature of the substrate. in single turnover assays, (bip)(2)b only inhibited u ... | 2010 | 20108979 |
| novel inhibitors of dengue virus methyltransferase: discovery by in vitro-driven virtual screening on a desktop computer grid. | dengue fever is a viral disease that affects 50-100 million people annually and is one of the most important emerging infectious diseases in many areas of the world. currently, neither specific drugs nor vaccines are available. here, we report on the discovery of new inhibitors of the viral ns5 rna methyltransferase, a promising flavivirus drug target. we have used a multistage molecular docking approach to screen a library of more than 5 million commercially available compounds against the two ... | 2010 | 20108931 |
| the ns5 protein of the virulent west nile virus ny99 strain is a potent antagonist of type i interferon-mediated jak-stat signaling. | flaviviruses transmitted by arthropods represent a tremendous disease burden for humans, causing millions of infections annually. all vector-borne flaviviruses studied to date suppress host innate responses to infection by inhibiting alpha/beta interferon (ifn-alpha/beta)-mediated jak-stat signal transduction. the viral nonstructural protein ns5 of some flaviviruses functions as the major ifn antagonist, associated with inhibition of ifn-dependent stat1 phosphorylation (py-stat1) or with stat2 d ... | 2010 | 20106931 |
| evidence for ribosomal frameshifting and a novel overlapping gene in the genomes of insect-specific flaviviruses. | flaviviruses have a positive-sense, single-stranded rna genome of approximately 11 kb, encoding a large polyprotein that is cleaved to produce approximately 10 mature proteins. cell fusing agent virus, kamiti river virus, culex flavivirus and several recently discovered flaviviruses have no known vertebrate host and apparently infect only insects. we present compelling bioinformatic evidence for a 253-295 codon overlapping gene (designated fifo) conserved throughout these insect-specific flavivi ... | 2010 | 20097399 |
| isolation and distribution of west nile virus in embryonated chicken eggs. | west nile virus (wnv) was identified from domestic psittacine birds by inoculating embryonated chicken eggs. most of the embryos died 5 days postinoculation; flavivirus was detected in some by negative-staining electron microscopy. immunohistochemistry performed on the embryos and their supporting structures detected the wnv antigen mainly in the chorioallantoic membrane, regardless of the inoculation route or passage number. wnv antigen was also found in the embryonic muscle (both skeletal and ... | 2009 | 20095164 |
| natural japanese encephalitis virus infection among humans in west and east japan shows the need to continue a vaccination program. | japanese encephalitis (je) is a serious disease in asia, but it can be prevented by vaccination. to evaluate the necessity for vaccination in areas with reduced numbers of vector mosquitoes, as well as patients, it is critical to understand the frequency of natural virus exposure. an antibody survey was recently conducted to estimate current natural infection rates in japan, where the vaccination rate has dropped in recent years. serum samples were collected in 2004-2008 from inhabitants of kuma ... | 2010 | 20080072 |
| first human case of usutu virus neuroinvasive infection, italy, august-september 2009. | we report the first worldwide case of usutu virus (usuv) neuroinvasive infection in a patient with diffuse large b cell lymphoma who presented with fever and neurological symptoms and was diagnosed with meningoencephalitits. the cerebrospinal fluid was positive for usuv, and usuv was also demonstrated in serum and plasma samples by rt-pcr and sequencing. partial sequences of the premembrane and ns5 regions of the viral genome were similar to the usuv vienna and budapest isolates. | 2009 | 20070936 |
| usutu virus infection in a patient who underwent orthotropic liver transplantation, italy, august-september 2009. | we report a case of usutu virus (usuv)-related illness in a patient that underwent an orthotropic liver transplant (olt). post transplant, the patient developed clinical signs of a possible neuroinvasive disease with a significant loss of cerebral functions. usuv was isolated in vero e6 cells from a plasma sample obtained immediately before the surgery, and usuv rna was demonstrated by rt-pcr and sequencing. this report enlarges the panel of emerging mosquito-borne flavivirus-related disease in ... | 2009 | 20070935 |
| hepatitis c virus nonstructural protein 4b: a journey into unexplored territory. | hepatitis c virus (hcv) is a positive-strand rna virus that replicates its genome in a membrane-associated replication complex. nonstructural protein 4b (ns4b) induces the specific membrane alteration, designated as membranous web (mw), that harbours this complex. hcv ns4b is an integral membrane protein predicted to comprise four transmembrane segments in its central part. the n-terminal part comprises two amphipathic alpha-helices of which the second has the potential to traverse the membrane ... | 2010 | 20069613 |
| identification of a heparin binding peptide from the japanese encephalitis virus envelope protein. | the flavivirus envelope protein is the dominant antigen in eliciting neutralizing antibodies and plays an important role in inducing immunologic responses in the infected host. it has been shown that highly sulfated forms of heparin sulfate can bind to the envelope protein and are involved in flavivirus infection. among the three structural domains, domain iii is the major antigenic domain of the envelope protein. we have prepared an extended form of the jev domain iii protein with residues rang ... | 2010 | 20069543 |
| gag-binding variants of tick-borne encephalitis virus. | previously different authors described various flavivirus mutants with high affinity to cell glycosaminoglycans and low neuroinvasiveness in mice that were obtained consequently passages in cell cultures or in ticks. in present study the analysis of tbev isolates has shown existence of gag-binding variants in natural virus population. affinity to gag has been evaluated by sorption on heparin-sepharose. gag-binding phenotype corresponds to such virus properties, like small plaque phenotype in pek ... | 2010 | 20064650 |
| co-expression of japanese encephalitis virus prm-e-ns1 antigen with granulocyte-macrophage colony-stimulating factor enhances humoral and anti-virus immunity after dna vaccination. | japanese encephalitis virus (jev) is an agent of japanese encephalitis, and granulocyte-macrophage colony-stimulating factor (gm-csf) is an attractive dna vaccine adjuvant for its antigen presentation. in the present study, we have constructed dna vaccines that carried jev prm-e-ns1 genes with or without the gm-csf gene. immunization with the bicistronic plasmid pcag-jegm that co-expresses gm-csf and viral prm-e-ns1, resulted in the highest igg response and sufficient protection against virus-ch ... | 2010 | 20064558 |
| the ifitm proteins mediate cellular resistance to influenza a h1n1 virus, west nile virus, and dengue virus. | influenza viruses exploit host cell machinery to replicate, resulting in epidemics of respiratory illness. in turn, the host expresses antiviral restriction factors to defend against infection. to find host cell modifiers of influenza a h1n1 viral infection, we used a functional genomic screen and identified over 120 influenza a virus-dependency factors with roles in endosomal acidification, vesicular trafficking, mitochondrial metabolism, and rna splicing. we discovered that the interferon-indu ... | 2009 | 20064371 |
| strategies for development of dengue virus inhibitors. | antiviral drug discovery is becoming increasingly important due to the global threat of viral disease pandemics. many members of the genus flavivirus are significant human pathogens, among which dengue virus (denv) alone poses a public health threat to 2.5 billion worldwide, leading to 50-100 million human infections each year. neither vaccine nor effective therapeutics is currently available for denv. development of a denv vaccine has been challenging, because of the need to simultaneously immu ... | 2010 | 20060421 |
| a novel tetravalent dengue vaccine is well tolerated and immunogenic against all 4 serotypes in flavivirus-naive adults. | background. sanofi pasteur has developed a tetravalent dengue vaccine (tdv) against the world's most common arbovirus infection. methods. we assessed the safety and immunogenicity of the tdv in healthy adults randomized into 2 groups. group 1 received 3 tdv injections at months 0, 4, and 12-15; group 2 received saline placebo at month 0 and then 2 tdv injections at months 4 and 12-15. adverse events were recorded, and biological parameters and viremia levels were measured. neutralizing antibodie ... | 2010 | 20059357 |
| [tick-borne encephalitis after a holiday in southern germany]. | a 56-year-old man was admitted to hospital with complaints of headache, fever and photophobia, 3 weeks after being bitten by ticks in southern germany. two weeks before admission he had experienced a short period of a flu-like illness, from which he spontaneously recovered. based on the tick bites in southern germany and the biphasic course of the illness shortly afterwards, we made the diagnosis tick-borne encephalitis, frühsommer-meningoenzephalitis in german (fsme). the diagnosis was confirme ... | 2009 | 20051165 |
| identification of hepatitis c virus genotype 2a replicon variants with reduced susceptibility to ribavirin. | ribavirin (rbv), a nucleoside analogue, is used in the treatment of hepatitis c virus (hcv) infection in combination with interferons. however, potential mechanisms of rbv resistance during hcv replication remain poorly understood. serial passage of cells harboring hcv genotype 2a replicon in the presence of rbv resulted in the reduced susceptibility of the replicon to rbv. transfection of fresh cells with rna from rbv-resistant replicon cells demonstrated that the rbv resistance observed is lar ... | 2010 | 20043953 |
| serotype-specific structural differences in the protease-cofactor complexes of the dengue virus family. | with an estimated 40% of the world population at risk, dengue poses a significant threat to human health, especially in tropical and subtropical regions. preventative and curative efforts, such as vaccine development and drug discovery, face additional challenges due to the occurrence of four antigenically distinct serotypes of the causative dengue virus (den1 to -4). complex immune responses resulting from repeat assaults by the different serotypes necessitate simultaneous targeting of all form ... | 2010 | 20042502 |
| synthesis and disulfide bond connectivity-activity studies of a kalata b1-inspired cyclopeptide against dengue ns2b-ns3 protease. | kalata b1 is a plant protein with remarkable thermal, chemical and enzymatic stability. its potential applications could be centered on the possibility of using its cyclic structure and cystine knot motif as a scaffold for the design of stable pharmaceuticals. to discover potent dengue ns2b-ns3 protease inhibitors, we have prepared various kalata b1 analogues by varying the amino acid sequence. mass spectrometric and biochemical investigations of these analogues revealed a cyclopeptide whose two ... | 2010 | 20042339 |
| isg15 over-expression inhibits replication of the japanese encephalitis virus in human medulloblastoma cells. | ifn-stimulated gene 15 (isg15), an ubiquitin-like protein, is rapidly induced by ifn-alpha/beta, and isg15 conjugation is associated with the antiviral immune response. japanese encephalitis virus (jev), a mosquito-borne neurotropic flavivirus, causes severe central nervous system diseases. we investigated the potential anti-jev effect of isg15 over-expression. isg15 over-expression in human medulloblastoma cells significantly reduced the jev-induced cytopathic effect and inhibited jev replicati ... | 2010 | 20035788 |
| ccr5 deficiency is a risk factor for early clinical manifestations of west nile virus infection but not for viral transmission. | west nile virus (wnv) is a neurotropic flavivirus transmitted to humans by mosquito vectors. homozygosity for ccr5delta32, a complete loss-of-function mutation in cc chemokine receptor 5 (ccr5), has been previously associated with severe symptomatic wnv infection in patients who present with clinical disease; however, whether it acts at the level of initial infection or in promoting clinical progression is unknown. | 2010 | 20025530 |
| west nile virus seroprevalence in blood donors from central anatolia, turkey. | west nile virus (wnv) is a reemerging flavivirus that has displayed a drastic change in epidemiology in the last decade. data on wnv activity in turkey are currently limited. this study investigated wnv exposure in blood donors from central anatolia, turkey. | 2010 | 20021274 |
| efficient assembly and secretion of recombinant subviral particles of the four dengue serotypes using native prm and e proteins. | flavivirus infected cells produce infectious virions and subviral particles, both of which are formed by the assembly of prm and e envelope proteins and are believed to undergo the same maturation process. dengue recombinant subviral particles have been produced in cell cultures with either modified or chimeric proteins but not using the native forms of prm and e. | 2009 | 20016834 |
| rna elements within the 5' untranslated region of the west nile virus genome are critical for rna synthesis and virus replication. | rna elements within the flavivirus genome may play essential regulatory roles during virus replication. here, recombinant west nile virus (wnv) ns5 protein was used in combination with wnv subgenomic rna templates to establish in vitro rna-dependent rna polymerase and rna-binding assays. these assays identified mutations in the stem-loop a (sla) region of the 5' untranslated region (5'utr) altering ns5 rna synthesis and rna-binding capability. these mutations were then introduced into the full-l ... | 2010 | 20016034 |
| transient reticular gallbladder wall thickening in severe dengue fever: a reliable sign of plasma leakage. | dengue fever (df) is an acute infection caused by a flavivirus. although most patients present mild symptoms, some progress to a severe condition characterized by hypovolemic shock and hemorrhagic phenomena. the main feature of this severe form of df is plasma leakage. gallbladder wall thickening (gbwt), ascites and pleural effusion represent the sonographic triad of plasma leakage in df. | 2010 | 20012951 |
| er targeting and retention of the hcv ns4b protein relies on the concerted action of multiple structural features including its transmembrane domains. | the hepatitis c virus (hcv) ns4b protein, a multispanning endoplasmic reticulum (er) membrane protein, generates intracellular rearrangements of er-derived membranes, essential for hcv replication. in this study, we characterized ns4b elements involved in the process of targeting, association and retention in the er membrane. we investigated the localization and membrane association of a number of c- or n-terminal ns4b deletions expressed as gfp chimeras by biochemical and fluorescence microscop ... | 2010 | 20001747 |
| comparative analysis of american dengue virus type 1 full-genome sequences. | dengue virus (denv; genus flavivirus, family flaviviridae) has been circulating in brazil since at least the mid-1980s and continues to be responsible for sporadic cases of dengue fever and dengue hemorrhagic fever throughout this country. here, we describe the full genomes of two new brazilian denv-serotype 1 (denv-1) variants and analyze these together with all other available american denv-1 full-genome sequences. besides confirming the existence of various country-specific denv-1 founder eff ... | 2010 | 19997970 |
| cross-reactivity of japanese encephalitis virus-vaccinated horse sera in serodiagnosis of west nile virus. | flavivirus-infected sera are known to show cross-reactions in serodiagnoses of heterologous flavivirus infections. japanese encephalitis virus (jev) is endemic in asia and, in japan, many horses are vaccinated against jev. however, the cross-reactivity level of jev-vaccinated horse sera in the serodiagnosis of west nile virus (wnv) has not been clarified. the antibody cross-reactivity of jev-vaccinated horse sera in wnv serological tests, such as the plaque reduction neutralization test (prnt), ... | 2010 | 19996564 |
| pcp consensus sequences of flaviviruses: correlating variance with vector competence and disease phenotype. | computational methods are needed to design multivalent vaccines against flaviviruses (fvs) such as the west nile virus or the dengue virus (denv). | 2010 | 19969003 |
| novel binding between pre-membrane protein and claudin-1 is required for efficient dengue virus entry. | flavivirus pre-membrane (prm) protein is important for proper folding and secretion of envelope (e) protein. however, other functions of prm protein in relation to virus life-cycle are poorly characterized. in this study, we aimed to elucidate if dengue virus (denv) prm protein interacts with host proteins and contributes to viral pathogenesis by screening human liver cdna yeast two-hybrid library. our study identified claudin-1 as a novel interacting partner of denv prm protein. virus productio ... | 2010 | 19962368 |
| update on powassan virus: emergence of a north american tick-borne flavivirus. | powassan virus (pow) (flaviviridae: flavivirus) is the cause of rare but severe neuroinvasive disease in north america and russia. the virus is transmitted among small- and medium-sized mammals by ixodid ticks. human infections occur via spillover from the main transmission cycle(s). since the late 1990s, the incidence of human disease seems to be increasing. in addition, pow constitutes a genetically diverse group of virus genotypes, including deer tick virus, that are maintained in distinct en ... | 2010 | 19961325 |
| seasonal patterns for entomological measures of risk for exposure to culex vectors and west nile virus in relation to human disease cases in northeastern colorado. | we examined seasonal patterns for entomological measures of risk for exposure to culex vectors and west nile virus (family flaviviridae, genus flavivirus, wnv) in relation to human wnv disease cases in a five-county area of northeastern colorado during 2006-2007. studies along habitat/elevation gradients in 2006 showed that the seasonal activity period is shortened and peak numbers occur later in the summer for culex tarsalis coquillett females in foothills-montane areas >1600 m compared with pl ... | 2009 | 19960707 |
| severe winter freezes enhance st. louis encephalitis virus amplification and epidemic transmission in peninsular florida. | mosquito-borne arboviral epidemics tend to strike without warning. the driving force for these epidemics is a combination of biotic (vector, amplification host, and virus) and abiotic (meteorological conditions, especially rainfall and temperature) factors. abiotic factors that facilitate the synchronization and interaction of vector and amplification host populations favor epidemic amplification and transmission. in florida, epidemics of st. louis encephalitis (sle) virus (family flaviviridae, ... | 2009 | 19960704 |
| potential vectors of west nile virus in a semiarid environment: doña ana county, new mexico. | the potential vectors of west nile virus (family flaviviridae, genus flavivirus, wnv) in doña ana county, nm, were determined during 2004 and 2005. trapping was conducted using centers for disease control and prevention miniature light-traps baited with dry ice, and gravid traps baited with a hay infusion. in addition, sentinel chickens were housed at four of the trapping locations to monitor wnv epizootic transmission. in total, 5,576 pools consisting of 115,797 female mosquitoes were tested fo ... | 2009 | 19960700 |
| seasonal variation of potential flavivirus vectors in an urban biological reserve in northeastern brazil. | although yellow fever (yf) has not been reported on the eastern coast of brazil since 1942, there was a reemergence of dengue fever in brazil in 1987 due to the reintroduction of aedes aegypti (l.). to assess areas of potential risk for transmission of vector-borne diseases, a surveillance system was placed in a large atlantic forest reserve in natal, rio grande do norte, brazil, where in 2004 unexplained epizootics were reported among marmosets. the etiologic agent causing the mortality in marm ... | 2009 | 19960696 |
| relationship between distance from major larval habitats and abundance of adult mosquitoes in semiarid plains landscapes in colorado. | we examined the relationship between distance from major larval habitats and abundance of adult mosquitoes in the semiarid plains landscape characteristic of eastern colorado. mosquito collection was conducted from late june to early august 2007 and included trap locations at distances ranging from <10 m up to 20-150 m and 160-373 m from three major larval habitats: one area along a river corridor and two small reservoirs. the study yielded 65,140 mosquitoes of 14 species, and five species were ... | 2009 | 19960672 |
| arrival and establishment of aedes japonicus japonicus (diptera: culicidae) in iowa. | the arrival and establishment of aedes (finlaya) japonicus japonicus (theobald) (diptera: culicidae) in iowa are reported. in total, 518 wild adult specimens were collected through the statewide mosquito and mosquito-borne virus surveillance program in 2007 and 2008. specimens were collected with new jersey light traps, co2-baited cdc light traps, grass infusion-baited gravid traps, and mosquito magnet traps located in 12 counties in central and eastern iowa specimens were identified morphologic ... | 2009 | 19960671 |
| is culex modestus (diptera: culicidae), vector of west nile virus, spreading in the dombes area, france? | as a main vector of west nile (wn) virus (family flaviviridae, genus flavivirus) in europe, culex modestus ficalbi (diptera: culicidae) is commonly found in delta regions, lakes, and ponds. the dombes area is located along one of the main corridors of bird migrations in france and lies 300 km north of the camargue region, a frequent focus of wn virus circulation. it is an important breeding, wintering, and stopover site for many bird species that are putative carriers of viruses of different kin ... | 2009 | 19960670 |
| capturing a flavivirus pre-fusion intermediate. | during cell entry of flaviviruses, low endosomal ph triggers the rearrangement of the viral surface glycoproteins to a fusion-active state that allows the release of the infectious rna into the cytoplasm. in this work, west nile virus was complexed with fab fragments of the neutralizing mab e16 and was subsequently exposed to low ph, trapping the virions in a pre-fusion intermediate state. the structure of the complex was studied by cryo-electron microscopy and provides the first structural glim ... | 2009 | 19956725 |
| detection of a new yellow fever virus lineage within the south american genotype i in brazil. | nucleotide sequences of two regions of the genomes of 11 yellow fever virus (yfv) samples isolated from monkeys or humans with symptomatic yellow fever (yf) in brazil in 2000, 2004, and 2008 were determined with the objective of establishing the genotypes and studying the genetic variation. results of the bayesian phylogenetic analysis showed that sequences generated from strains from 2004 and 2008 formed a new subclade within the clade 1 of the south american genotype i. the new subgroup is her ... | 2010 | 19950229 |
| structure and functionality in flavivirus ns-proteins: perspectives for drug design. | flaviviridae are small enveloped viruses hosting a positive-sense single-stranded rna genome. besides yellow fever virus, a landmark case in the history of virology, members of the flavivirus genus, such as west nile virus and dengue virus, are increasingly gaining attention due to their re-emergence and incidence in different areas of the world. additional environmental and demographic considerations suggest that novel or known flaviviruses will continue to emerge in the future. nevertheless, u ... | 2010 | 19945487 |
| the yellow fever virus vaccine induces a broad and polyfunctional human memory cd8+ t cell response. | the live yellow fever vaccine (yf-17d) offers a unique opportunity to study memory cd8(+) t cell differentiation in humans following an acute viral infection. we have performed a comprehensive analysis of the virus-specific cd8(+) t cell response using overlapping peptides spanning the entire viral genome. our results showed that the yf-17d vaccine induces a broad cd8(+) t cell response targeting several epitopes within each viral protein. we identified a dominant hla-a2-restricted epitope in th ... | 2009 | 19933869 |
| experimental passage of st. louis encephalitis virus in vivo in mosquitoes and chickens reveals evolutionarily significant virus characteristics. | st. louis encephalitis virus (slev; flaviviridae, flavivirus) was the major cause of epidemic flaviviral encephalitis in the u.s. prior to the introduction of west nile virus (wnv) in 1999. however, outbreaks of slev have been significantly more limited then wnv in terms of levels of activity and geographic dispersal. one possible explanation for these variable levels of activity is that differences in the potential for each virus to adapt to its host cycle exist. the need for arboviruses to rep ... | 2009 | 19924238 |
| viruses within the flaviviridae decrease cd4 expression and inhibit hiv replication in human cd4+ cells. | viral infections alter host cell homeostasis and this may lead to immune evasion and/or interfere with the replication of other microbes in coinfected hosts. two flaviviruses are associated with a reduction in hiv replication or improved survival in hiv-infected people (dengue virus (dv) and gb virus type c (gbv-c)). gbv-c infection and expression of the gbv-c nonstructural protein 5a (ns5a) and the dv ns5 protein in cd4(+) t cells inhibit hiv replication in vitro. to determine whether the inhib ... | 2009 | 19923460 |
| distinct antiviral roles for human 2',5'-oligoadenylate synthetase family members against dengue virus infection. | the 2',5'-oligoadenylate synthetase (oas) and its downstream effector rnase l play important roles in host defense against virus infection. oas1b, one of the eight oas1 genes in the mouse genome, has been identified as a murine flavivirus-resistance gene. four genes, oas1, oas2, oas3, and oas-like (oasl), have been identified in the human oas gene family, and 10 isoforms, including oas1 (p42, p44, p46, p48, and p52), oas2 (p69 and p71), oas3 (p100), and oasl (p30 and p59) can be generated by alt ... | 2009 | 19923450 |
| an adenosine nucleoside inhibitor of dengue virus. | dengue virus (denv), a mosquito-borne flavivirus, is a major public health threat. the virus poses risk to 2.5 billion people worldwide and causes 50 to 100 million human infections each year. neither a vaccine nor an antiviral therapy is currently available for prevention and treatment of denv infection. here, we report a previously undescribed adenosine analog, nitd008, that potently inhibits denv both in vitro and in vivo. in addition to the 4 serotypes of denv, nitd008 inhibits other flavivi ... | 2009 | 19918064 |
| evolution of the sequence composition of flaviviruses. | the adaption of pathogens to their host(s) is a major factor in the emergence of infectious disease and the persistent survival of many of the infectious diseases within the population. since many of the smaller viral pathogens are entirely dependent upon host machinery, it has been postulated that they are under selection for a composition similar to that of their host. analyses of sequence composition have been conducted for numerous small viral species including the flavivirus genus. examinat ... | 2010 | 19914402 |
| the dengue virus type 2 envelope protein fusion peptide is essential for membrane fusion. | the flaviviral envelope (e) protein directs virus-mediated membrane fusion. to investigate membrane fusion as a requirement for virus growth, we introduced 27 unique mutations into the fusion peptide of an infectious cdna clone of dengue 2 virus and recovered seven stable mutant viruses. the fusion efficiency of the mutants was impaired, demonstrating for the first time the requirement for specific fp aas in optimal fusion. mutant viruses exhibited different growth kinetics and/or genetic stabil ... | 2010 | 19913272 |
| direct random insertion of an influenza virus immunologic determinant into the ns1 glycoprotein of a vaccine flavivirus. | a live chimeric vaccine virus against japanese encephalitis (je), chimerivax-je, was used to define methods for optimal, random insertion of foreign immunologic determinants into flavivirus glycoproteins. the conserved m2e peptide of influenza a virus was randomly inserted into the yellow fever-specific ns1 glycoprotein of chimerivax-je. a technique combining plaque purification with immunostaining yielded a recombinant virus that stably expressed m2e at ns1-236 site. the site was found permissi ... | 2010 | 19913267 |
| rna-dependent rna polymerases from flaviviruses and picornaviridae. | flaviviruses and picornaviruses are positive-strand rna viruses that encode the rna-dependent rna polymerase (rdrp) required for replicating the viral genome in infected cells. because of their specific and essential role in the virus life cycle, rdrps are prime targets for antiviral drugs. recent structural data have shed light on the different strategies used by rdrps from flaviviruses and picornaviridae to initiate rna polymerization. new details about the catalytic mechanism, the role of met ... | 2009 | 19910184 |
| ns1' of flaviviruses in the japanese encephalitis virus serogroup is a product of ribosomal frameshifting and plays a role in viral neuroinvasiveness. | flavivirus ns1 is a nonstructural protein involved in virus replication and regulation of the innate immune response. interestingly, a larger ns1-related protein, ns1', is often detected during infection with the members of the japanese encephalitis virus serogroup of flaviviruses. however, how ns1' is made and what role it performs in the viral life cycle have not been determined. here we provide experimental evidence that ns1' is the product of a -1 ribosomal frameshift event that occurs at a ... | 2010 | 19906906 |
| antibodies to west nile virus in raccoons and other wild peridomestic mammals in iowa. | surveillance for evidence of west nile virus (wnv) infection in small- and medium-sized wild mammals was conducted in iowa, usa, from may 2005 to june 2007. sera were collected from 325 mammals belonging to nine species and tested for antibodies to wnv and other flaviviruses by epitope-blocking enzyme-linked immunosorbent assay (elisa). all sera that had antibodies to flaviviruses by blocking elisa were further examined by plaque reduction neutralization test (prnt). thirteen mammals were seropo ... | 2009 | 19901390 |