Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| development of multiplex real-time reverse transcriptase pcr assays for detecting eight medically important flaviviruses in mosquitoes. | a multiplex real-time reverse transcriptase pcr has been developed for the rapid detection and identification of eight medically important flaviviruses from laboratory-reared, virus-infected mosquito pools. the method used involves the gene-specific amplification of yellow fever virus (yfv), japanese encephalitis virus (jev), west nile virus (wnv), st. louis encephalitis virus (slev), and dengue virus (denv) serotypes 1 to 4 (denv-1 to denv-4, respectively) by use of the flavivirus consensus amp ... | 2007 | 17108075 |
| enhancement of recombinant soluble dengue virus 2 envelope domain iii protein production in escherichia coli trxb and gor double mutant. | the dengue virus is currently the most important flavivirus causing human diseases in the tropical and subtropical regions of the world. the envelope protein domain iii of dengue virus type 2 (d2eiii), which induces protective and neutralizing antibodies, was expressed as an n-terminal fusion to a hexa-histidine tag in escherichia coli. the expression of recombinant d2eiii of 103 amino acids in the soluble form can be achieved using suitable host strains, such as origami, at a low induction temp ... | 2006 | 17116581 |
| seroprevalence of west nile virus in saskatchewan's five hills health region, 2003. | the five hills health region of saskatchewan reported the highest west nile virus (wnv) case rates in the 2003 outbreak. a serologic and telephone survey was undertaken to assess the seroprevalence of the virus and the knowledge, attitudes and behaviours of the residents. | 2006 | 17120874 |
| [changes in range of mosquito-borne diseases affected by global climatic fluctuations]. | climate models suggest the strong possibility of range increase of the diseases transmitted by parasitic arthropods, mostly mosquitoes. in predicting processes of malaria and dengue diseases dispersion the estimation of risk is based mostly on reproduction rate of vector species. these models allow to calculate the critical threshold of host density which is necessary to maintain parasites and pathogens transmission. such studies based on integrated mathematical modelling indicate widespread inc ... | 2006 | 17120987 |
| west nile virus nonstructural protein ns1 inhibits complement activation by binding the regulatory protein factor h. | the complement system, by virtue of its dual effector and priming functions, is a major host defense against pathogens. flavivirus nonstructural protein (ns)-1 has been speculated to have immune evasion activity, because it is a secreted glycoprotein, binds back to cell surfaces, and accumulates to high levels in the serum of infected patients. herein, we demonstrate an immunomodulatory function of west nile virus ns1. soluble and cell-surface-associated ns1 binds to and recruits the complement ... | 2006 | 17132743 |
| defective interfering rnas of japanese encephalitis virus found in mosquito cells and correlation with persistent infection. | defective interfering (di) rnas are deletion mutants of viral genomes that are known in many cases to contribute to persistent infection and modification of viral pathogenesis. cell type also plays a critical role in the establishment of viral persistence. in this study we have identified for the first time the generation of di rnas of japanese encephalitis virus in c6/36 mosquito cells. a persistent infection was established by replacing growth medium on surviving cells and continued cell passa ... | 2007 | 17134784 |
| enzymatic characterization of a trypsin-like serine protease encoded by the genome of cell fusing agent virus. | cell fusing agent virus (cfav) is a positive strand rna insect virus first isolated from a mosquito cell line. based on viral morphology, phenotypic and phylogenetic studies, cfav had been tentatively assigned to the genus flavivirus (family flaviviridae). the determination of the cfav polyprotein complete sequence showed a putative serine protease domain analogue to the flaviviral ns2b/ns3 complex. this complex had been extensively studied, because it represented one of the main targets for ant ... | 2007 | 17143721 |
| flavivirus nonstructural protein ns1: complementary surprises. | 2006 | 17146046 | |
| immunopathology of flavivirus infections. | with the recent emergence of the flavivirus, west nile virus (wnv), in particular, the new york strain of lineage i wnv in north america in 1999, there has been a significant increase in activity in neurotropic flavivirus research. these viruses cause encephalitis that can result in permanent neurological sequelae or death. attempts to develop vaccines have made progress, but have been variably successful, despite considerable commercial underwriting. thus, the discovery of ways and means to com ... | 2007 | 17146465 |
| antiviral peptides targeting the west nile virus envelope protein. | west nile virus (wnv) can cause fatal murine and human encephalitis. the viral envelope protein interacts with host cells. a murine brain cdna phage display library was therefore probed with wnv envelope protein, resulting in the identification of several adherent peptides. of these, peptide 1 prevented wnv infection in vitro with a 50% inhibition concentration of 67 mum and also inhibited infection of a related flavivirus, dengue virus. peptide 9, a derivative of peptide 1, was a particularly p ... | 2007 | 17151121 |
| mutation analysis of the fusion domain region of st. louis encephalitis virus envelope protein. | the immune response to flavivirus infections produces both species-specific and flavivirus cross-reactive antibodies. the presence of cross-reactive antibodies complicates serodiagnosis of flavivirus infections, especially secondary infections caused by a heterologous virus. a successful public health response to the growing global threat posed by flaviviruses necessitates the development of virus-specific diagnostic antigens. the flavivirus envelope (e) glycoprotein is the principle antigen sti ... | 2007 | 17157348 |
| detection of west nile virus in formalin-fixed, paraffin-embedded human tissues by rt-pcr: a useful adjunct to conventional tissue-based diagnostic methods. | west nile virus (wnv), a member of genus flavivirus, causes febrile illness, encephalitis, meningitis, myelitis, and occasional deaths in humans. although several reverse transcription-polymerase chain reaction (rt-pcr) assays have been developed for detection of wnv in serum, cerebrospinal fluid, and fresh tissues, the usefulness of wnv rt-pcr assays for rna extracted from formalin-fixed human tissues has not previously been demonstrated. | 2007 | 17161650 |
| murray valley encephalitis in an adult traveller complicated by long-term flaccid paralysis: case report and review of the literature. | murray valley encephalitis (mve) virus, a mosquito-borne flavivirus, is the most common cause of viral encephalitis in the tropical 'top end' of northern australia. clinical encephalitis due to mve virus has a mortality rate of approximately 30%, with a similar proportion of patients being left with significant neurological deficits. we report the case of a 25-year-old man from the uk who acquired mve while travelling through northern australia. he required prolonged admission to the intensive c ... | 2007 | 17161855 |
| oviposition activity patterns and west nile virus infection rates for members of the culex pipiens complex at different habitat types within the hybrid zone, shelby county, tn, 2002 (diptera: culicidae). | oviposition activity and west nile virus (family flaviviridae, genus flavivirus, wnv) infection rates were assessed for members of the culex pipiens complex from july through december 2002 by using gravid traps placed at four ecologically different sites in the southern portion of the hybrid zone in shelby county, tn. molecular assays identified three members of the cx. pipiens complex: cx. pipiens pipiens l., cx. p. quinquefasciatus say, and cx. p. pipiens-cx. p. quinquefasciatus hybrids (hybri ... | 2006 | 17162958 |
| dengue virus rna polymerase ns5: a potential therapeutic target? | dengue fever (df)/dengue haemorrhagic fever (dhf) is the most common arthropod-borne viral infection, where it is now estimated that 2.5-3 billion people world-wide are at risk of infection. currently there is no available treatment, in the form of vaccine or drug, making eradication of the mosquito vector the only viable control measure, which has proved costly and of limited success. there are a number of different vaccines undergoing testing, but whilst a dengue vaccine is clearly desirable, ... | 2006 | 17168837 |
| construction and biological properties of yellow fever 17d/dengue type 1 recombinant virus. | dengue virus, a mosquito-borne flavivirus, is one of the most formidable public health threats in tropical and subtropical regions. as yet, there is no licensed vaccine to protect against the disease. a chimeric yellow fever (yf) 17d/dengue (den) type 1 virus was constructed by replacing the pre-membrane and envelope genes of yf 17d virus with those from den 1 vemir95 virus, a venezuelan isolate. the chimeric yf 17d/den 1 vemir95 virus was regenerated from full-length infectious clones stably pr ... | 2007 | 17169387 |
| genetic characterization of tick-borne flaviviruses: new insights into evolution, pathogenetic determinants and taxonomy. | here, we analyze the complete coding sequences of all recognized tick-borne flavivirus species, including gadgets gully, royal farm and karshi virus, seabird-associated flaviviruses, kadam virus and previously uncharacterized isolates of kyasanur forest disease virus and omsk hemorrhagic fever virus. significant taxonomic improvements are proposed, e.g. the identification of three major groups (mammalian, seabird and kadam tick-borne flavivirus groups), the creation of a new species (karshi viru ... | 2007 | 17169393 |
| [inhibition of ifn-gamma receptor signaling by hepatitis c virus non-structural protein ns4b]. | the function of ns4b is incompletely understood. the aim of the study is to understand the influence of ns4b on anti-viral response. after cell line stably expressing ns4b established, the influence of ifn-alpha of different concentration on vsv was studied using plaque assay; cell expression profiling caused by ns4b was studied using dna microarray, and the ifngr1 fluorescence intensity was analyzed. our data showed that hcv-ns4b could suppress immuno-associated gene expression, in particular, ... | 2006 | 17172032 |
| characterization of sepik and entebbe bat viruses closely related to yellow fever virus. | yellow fever virus has a special place in medical history as the first animal virus isolated and as the prototype virus in the genus flavivirus, which contains many serious human pathogens. only recently, its closely related viruses within the group were identified phylogenetically. in this study, we obtained complete or near complete genome sequences of two viruses most closely related to yellow fever virus: sepik virus of papua new guinea and entebbe bat virus of africa. based on full-genomic ... | 2006 | 17172387 |
| a mouse cell-adapted ns4b mutation attenuates west nile virus rna synthesis. | an adaptive mutation (e249g) within west nile virus (wnv) ns4b gene was consistently recovered from replicon rnas in c3h/he mouse cells. the e249g is located at the c-terminal tail of ns4b predicted to be on the cytoplasmic side of the endoplasmic reticulum membrane. the e249g substitution reduced replicon rna synthesis. compared with the wild-type ns4b, the e249g mutant protein exhibited a similar efficiency in evasion of interferon-beta response. recombinant e249g virus exhibited smaller plaqu ... | 2007 | 17178141 |
| substrate specificity of recombinant dengue 2 virus ns2b-ns3 protease: influence of natural and unnatural basic amino acids on hydrolysis of synthetic fluorescent substrates. | a recombinant dengue 2 virus ns2b-ns3 protease (ns means non-structural virus protein) was compared with human furin for the capacity to process short peptide substrates corresponding to seven native substrate cleavage sites in the dengue viral polyprotein. using fluorescence resonance energy transfer peptides to measure kinetics, the processing of these substrates was found to be selective for the dengue protease. substrates containing two or three basic amino acids (arg or lys) in tandem were ... | 2007 | 17184724 |
| a simplified pcr methodology for semiquantitatively analyzing dengue viruses. | the standard methodology for titrating dengue viruses, the plaque assay, is slow, time consuming and relatively expensive. other methods require machinery that may not be routinely accessible to all researchers, particularly those in developing nations. we therefore sought to develop a rapid, simplified semiquantitative polymerase chain reaction (pcr) methodology based on the use of a template mimic. in particular, it was desired that the mimic should be applicable for use a dna template to avoi ... | 2006 | 17186958 |
| characterization of the west nile virus protease substrate specificity and inhibitors. | west nile virus (wnv), a mosquito-borne member of flaviviridae, is a human pathogen causing widespread disease for which there is no vaccine or chemotherapy. the two-component viral serine protease consists of a heterodimeric complex between the hydrophilic domain of the cofactor, ns2b (ns2bh) and the protease domain (ns3-pro). the protease is essential for polyprotein processing followed by assembly of viral replicase and genome replication. therefore, the protease is an excellent target for de ... | 2007 | 17188926 |
| expression and purification of a two-component flaviviral proteinase resistant to autocleavage at the ns2b-ns3 junction region. | regulated proteolysis of the polyprotein precursor of west nile virus (wnv) by the essential ns2b-ns3(pro)tease, a promising drug target for wnv inhibitors, is required for the propagation of infectious virions. structural and drug design studies, however, require pilot-scale quantities of a pure and catalytically active wnv protease that is resistant to self-proteolysis. autolytic cleavage at the ns2b-ns3 boundary leads to individual, non-covalently associated, ns2b and ns3 domains, together wi ... | 2007 | 17189703 |
| caspase 3-dependent cell death of neurons contributes to the pathogenesis of west nile virus encephalitis. | west nile virus (wnv) is a neurotropic, arthropod-borne flavivirus that has become a significant global cause of viral encephalitis. to examine the mechanisms of wnv-induced neuronal death and the importance of apoptosis in pathogenesis, we evaluated the role of a key apoptotic regulator, caspase 3. wnv infection induced caspase 3 activation and apoptosis in the brains of wild-type mice. notably, congenic caspase 3(-/-) mice were more resistant to lethal wnv infection, although there were no sig ... | 2007 | 17192305 |
| full-length sequencing and genomic characterization of bagaza, kedougou, and zika viruses. | many members of the genus flavivirus are the agents of important diseases of humans, livestock, and wildlife. currently, no complete genome sequence is available for the three african viruses, bagaza, zika, and kedougou viruses, each representing a distinct virus subgroup according to the latest virus classification. in this study, we obtained a complete genome sequence of each of those three viruses and characterized the open reading frames (orfs) with respect to gene sizes, cleavage sites, pot ... | 2007 | 17195954 |
| the envelope glycoprotein domain iii of dengue virus serotypes 1 and 2 inhibit virus entry. | dengue virus (dv) is a flavivirus and its urban transmission is maintained largely by its mosquito vectors and vertebrate host, often human. in this study, investigation was carried out on the involvement of domain iii of the envelope (e) glycosylated protein of dengue virus serotypes 1 and 2 (dv-1 and dv-2 diii) in binding to host cell surfaces, thus mediating virus entry. domain iii protein of flavivirus can also serve as an attractive target in inhibiting virus entry. the respective dv diii p ... | 2007 | 17196419 |
| viral infections of the central nervous system in brazil. | epidemiological studies have shown that most central nervous system (cns) infections are viral. the objective of this study is to contribute to the knowledge base concerning viral cns infections in ribeirão preto, brazil. | 2007 | 17198733 |
| [west nile virus: a reality in mexico]. | west nile virus (wnv) is a rna virus of the flaviridae, genus flavivirus family. it is a neuropathogenic virus causing disease in birds, horses and humans. wnvis transmitted by the vector mosquito culex sp. the virus life 's cycle includes mosquitoes as vectors and birds as natural hosts. humans are accidental hosts. since the introduction of the epidemiological surveillance program at the ministry ofhealth. we have documented 90 positive test results among birds out of 1,223 cases studied in me ... | 2006 | 17201112 |
| prophylactic treatment with recombinant eimeria protein, alone or in combination with an agonist cocktail, protects mice from banzi virus infection. | a recombinant eimeria protozoan protein antigen (rea) has been shown to have antitumor and antiviral activity. the purpose of this study was to determine the effect of rea treatment alone or in combination with an agonist cocktail consisting of granulocyte macrophage colony stimulating factor (gm-csf), interferon gamma (ifn-gamma), interleukin 4 (il-4), and anti cd-40 antibody, in the treatment of banzi virus (bv) disease in balb/c mice. treatment with rea resulted in a significant increase in s ... | 2007 | 17210189 |
| [change in the antigenic structure of surface glycoprotein e of tick-borne encephalitis virus during its adaptation to ticks and mammals]. | enzyme immunoassay and immunoprecipitation test of viral proteins, by applying a tick-borne encephalitis (tbe) viral protein e monoclonal antibody kit, have shown that tbe adaptation to ticks and mammals may cause a considerable change in the antigenic structure of surface glycoprotein e, by involving different antigenic domains, including a neutralizing epitope that seems to participate at the early stages of interaction of virions with the cell membrane. | 2006 | 17214080 |
| t7 phage display of ep15 peptide for the detection of wnv igg. | west nile virus (wnv) is one of the major emerging infectious diseases in north america. wnv belongs to the genus flavivirus, and its rapid and extensive global spread has highlighted the necessity for accurate and specific assays for diagnosis of wnv infection. this study presents the first phage displayed peptide based elisa for detection of wnv immunoglobulin g (igg). the ep15 epitope, derived from the wnv e protein diii, was cloned into a t7 phage display system that was then used as recombi ... | 2007 | 17215048 |
| origin and evolution of 3'utr of flaviviruses: long direct repeats as a basis for the formation of secondary structures and their significance for virus transmission. | the 3' untranslated regions (3'utrs) of flaviviruses are reviewed and analyzed in relation to short sequences conserved as direct repeats (drs). previously, alignments of the 3'utrs have been constructed for three of the four recognized flavivirus groups, namely mosquito-borne, tick-borne, and nonclassified flaviviruses (mbfv, tbfv, and ncfv, respectively). this revealed (1) six long repeat sequences (lrss) in the 3'utr and open-reading frame (orf) of the tbfv, (2) duplication of the 3'utr of th ... | 2007 | 17222695 |
| correlation between breakdown of the blood-brain barrier and disease outcome of viral encephalitis in mice. | changes in the permeability of the blood-brain barrier (bbb) were evaluated in two mouse models of viral encephalitis. the ability of sodium fluorescein (nafl) to cross the bbb from the serum into the central nervous system was assayed in animals inoculated with virulent strains of either banzi or semliki forest viruses. to test the hypothesis that increases in bbb permeability were associated with poor disease outcome subsequent experiments measured bbb permeability in conjunction with treatmen ... | 2007 | 17223204 |
| west nile virus. | west nile virus is a mosquito-borne flavivirus originally isolated in 1937 from the blood of a febrile woman in the west nile province of uganda. the virus is widely distributed in africa, europe, australia, and asia, and, since 1999, it has spread rapidly throughout the western hemisphere, including the usa, canada, mexico, and the caribbean and into parts of central and south america. before 1994, outbreaks of west nile virus were sporadic and occurred primarily in the mediterranean region, af ... | 2007 | 17239804 |
| serologic evidence of west nile virus exposure in north american mesopredators. | sera from 936 mammalian mesopredators (virginia opossums, gray foxes, striped skunks, hooded skunks, raccoons, a bobcat, and a red fox) were collected during 2003 and 2004 in california, arizona, texas, louisiana, ohio, and wyoming and screened for flavivirus-specific antibodies by an epitope-blocking enzyme-linked immunosorbent assay (blocking elisa). serum samples positive for antibodies against flaviviruses were screened for west nile virus (wnv)-specific antibodies by blocking elisa and sele ... | 2007 | 17255248 |
| the distribution of den infected people in dushan and xingyi area of yunnan-guizhou plateau, china. | the dengue viruses (den, genus flavivirus, family flaviviridae) are mosquito borne and have caused 100 million cases of dengue fever each year in most tropical and subtropical areas of the world. however, in the southwest area of yunnan-guizhou plateau, china, the previous work demonstrated that different geographic strains of aedes albopictus were susceptible to dengue virus. in this study, we collected 456 sera samples from patients with fever and 994 sera samples from healthy population in du ... | 2006 | 17257502 |
| structure and function of flavivirus ns5 methyltransferase. | the plus-strand rna genome of flavivirus contains a 5' terminal cap 1 structure (m7gpppamg). the flaviviruses encode one methyltransferase, located at the n-terminal portion of the ns5 protein, to catalyze both guanine n-7 and ribose 2'-oh methylations during viral cap formation. representative flavivirus methyltransferases from dengue, yellow fever, and west nile virus (wnv) sequentially generate gpppa-->m7gpppa-->m7gpppam. the 2'-o methylation can be uncoupled from the n-7 methylation, since m ... | 2007 | 17267492 |
| american society of tropical medicine and hygiene--55th annual meeting. vaccine development against flaviviruses. 12-16 november 2006, atlanta, ga, usa. | 2007 | 17285458 | |
| crystal structure of the rna polymerase domain of the west nile virus non-structural protein 5. | viruses of the family flaviviridae are important human and animal pathogens. among them, the flaviviruses dengue (denv) and west nile (wnv) cause regular outbreaks with fatal outcomes. the rna-dependent rna polymerase (rdrp) activity of the non-structural protein 5 (ns5) is a key activity for viral rna replication. in this study, crystal structures of enzymatically active and inactive wnv rdrp domains were determined at 3.0- and 2.35-a resolution, respectively. the determined structures were sho ... | 2007 | 17287213 |
| west nile virus: recent trends in diagnosis and vaccine development. | west nile virus (wnv) is a mosquito-borne flavivirus, native to africa, europe, and western asia. in many respects, wnv is an outstanding example of a zoonotic pathogen that has leaped geographical barriers and can cause severe disease in human and horse. before the emergence of wnv in the usa, only few methods of diagnosis were available. recently, many changes in the fields of wn diagnosis and prevention have happened. this paper will review all these new tools. after a description of the main ... | 2007 | 17292514 |
| host range specificity of flaviviruses: correlation with in vitro replication. | vector-borne flaviviruses have been traditionally grouped into either mosquito-borne or tick-borne group. however, this vector range specificity has sometimes been questioned because of the puzzling records of occasional isolation of mosquito-borne viruses from ticks and of tick-borne viruses from mosquitoes. in this study, host range of the flaviviruses representing not only the two vector-borne groups but also insect flaviviruses and vertebrate viruses that are not arboviruses was comprehensiv ... | 2007 | 17294926 |
| west nile virus infection in mosquitoes in the mid-south usa, 2002-2005. | west nile virus (family flaviviridae, genus flavivirus, wnv) was first detected in the tennessee valley and in alabama in august 2001. in summer 2002, intensive viral activity was seen, but in subsequent years, viral activity settled into an enzootic pattern. here, we report an analysis of viral activity in the mosquito fauna in the mid-south from 2002 (the first year viral activity was detected in mosquitoes) through 2005. eight mosquito species were infected with wnv during 2002. however, vira ... | 2007 | 17294929 |
| chronic st. louis encephalitis virus infection in the golden hamster (mesocricetus auratus). | to further study the phenomenon of flavivirus persistent infection, golden hamsters (mesocricetus auratus) were inoculated intraperitoneally with a low pathogenicity strain of st. louis encephalitis virus (slev). after inoculation, the animals remained asymptomatic and developed high levels of specific neutralizing antibodies in their sera. however, about one half of the hamsters continued to shed infectious slev in their urine for prolonged periods of time. by co-cultivation, slev was recovered ... | 2007 | 17297039 |
| distinct rna elements confer specificity to flavivirus rna cap methylation events. | the 5' end of the flavivirus plus-sense rna genome contains a type 1 cap (m(7)gpppamg), followed by a conserved stem-loop structure. we report that nonstructural protein 5 (ns5) from four serocomplexes of flaviviruses specifically methylates the cap through recognition of the 5' terminus of viral rna. distinct rna elements are required for the methylations at guanine n-7 on the cap and ribose 2'-oh on the first transcribed nucleotide. in a west nile virus (wnv) model, n-7 cap methylation require ... | 2007 | 17301144 |
| crystal structure of the dengue virus rna-dependent rna polymerase catalytic domain at 1.85-angstrom resolution. | dengue fever, a neglected emerging disease for which no vaccine or antiviral agents exist at present, is caused by dengue virus, a member of the flavivirus genus, which includes several important human pathogens, such as yellow fever and west nile viruses. the ns5 protein from dengue virus is bifunctional and contains 900 amino acids. the s-adenosyl methionine transferase activity resides within its n-terminal domain, and residues 270 to 900 form the rna-dependent rna polymerase (rdrp) catalytic ... | 2007 | 17301146 |
| switching the substrate specificity of the two-component ns2b-ns3 flavivirus proteinase by structure-based mutagenesis. | the flavivirus ns2b-ns3(pro)teinase is an essential element in the proteolytic processing of the viral precursor polyprotein and therefore a potential drug target. recently, crystal structures and substrate preferences of ns2b-ns3pro from dengue and west nile viruses (dv and wnv) were determined. we established that the presence of gly-gly at the p1'-p2' positions is optimal for cleavage by wnv ns3pro, whereas dv ns3pro tolerates well the presence of bulky residues at either p1' or p2'. structur ... | 2007 | 17301157 |
| a single m protein mutation affects the acid inactivation threshold and growth kinetics of a chimeric flavivirus. | numerous viruses of the flaviviridae family, including dengue, yellow fever, japanese encephalitis, and west nile, cause significant disease in humans and animals. the structure and function of the molecular components of the flavivirus envelope are therefore of significant interest. to our knowledge, a membrane (m) protein mutation which affects the ph at which flavivirus particles are inactivated in vitro has never been reported. here we show that substitution of proline for glutamine at resid ... | 2007 | 17303204 |
| characterization of a structural intermediate of flavivirus membrane fusion. | viral membrane fusion proceeds through a sequence of steps that are driven by triggered conformational changes of viral envelope glycoproteins, so-called fusion proteins. although high-resolution structural snapshots of viral fusion proteins in their prefusion and postfusion conformations are available, it has been difficult to define intermediate structures of the fusion pathway because of their transient nature. flaviviruses possess a class ii viral fusion protein (e) mediating fusion at acidi ... | 2007 | 17305426 |
| immunization of flavivirus west nile recombinant envelope domain iii protein induced specific immune response and protection against west nile virus infection. | the domain iii of the west nile virus (wnv) envelope glycoprotein (e) was shown to serve as virus attachment domain to the cellular receptor, and neutralizing abs have been mapped to this specific domain. in this study, domain iii of the wnv e protein (wnv e diii) was expressed as a recombinant protein and its potential as a subunit vaccine candidate was evaluated in balb/c mice. immunization of wnv e diii protein with oligodeoxynucleotides (cpg-dna) adjuvant by i.p. injection was conducted over ... | 2007 | 17312111 |
| attenuating characteristics of den-2 pdk53 in flavivirus-naïve peripheral blood mononuclear cells. | a live-attenuated den-2 virus, den-2 strain 16681-pdk53, has been found to be attenuated for both humans and mice with an unknown mechanism. to partially answer this question, responses of flavivirus-naïve primary human pbmc to infection with attenuated den-2 pdk53 (d2/ic-vv45r) virus and its parental, virulent den-2 16681 virus (d2/ic-30p-a) were investigated at the cellular and genetic levels using cdna array analysis. both den-2 viruses produced similar replication kinetics in flavivirus-naïv ... | 2007 | 17316931 |
| molecular biology of flaviviruses. | flaviviruses are enveloped viruses with a single-stranded, 10.7kb positive-sense rna genome. the genomic rna, which has a 5' cap but no poly(a) tail, is translated as a single polyprotein that is then cleaved into three structural proteins and seven non-structural (ns) proteins by both viral and host proteases. the ns proteins include an rna-dependent rna polymerase (ns5), a helicase/protease (ns3), and other proteins that form part of the viral replication complex. sequences and structures in t ... | 2006 | 17319152 |
| development of novel antivirals against flaviviruses. | dengue virus is responsible for a significant amount of human disease in predominantly tropical areas of the world. much effort has focused on the development of vaccines against the four serotypes of dengue, and within the next few years a vaccine is anticipated. less progress has been made at developing antivirals that might reduce disease severity. recent advances in the structural biology of dengue virus and other flaviviruses have opened new possibilities for the rational design of small mo ... | 2006 | 17319153 |
| entry functions and antigenic structure of flavivirus envelope proteins. | the envelope proteins (e) of flaviviruses form an icosahedral cage-like structure of homodimers that cover completely the surface of mature virions and are responsible for receptor-binding and membrane fusion. fusion is triggered by the acidic ph in endosomes which induces dramatic conformational changes of e that drive the merger of the membranes. we have identified an alternative trigger that induces the first phase of the fusion process only, but then leads to an arrest at an intermediate sta ... | 2006 | 17319154 |
| multiple enzyme activities of flavivirus proteins. | dengue viruses (denv) have 5'-capped rna genomes of (+) polarity and encode a single polyprotein precursor that is processed into mature viral proteins. ns2b, ns3 and ns5 proteins catalyse/activate enzyme activities that are required for key processes in the virus life cycle. the heterodimeric ns2b/ns3 is a serine protease required for processing. using a high-throughput protease assay, we screened a small molecule chemical library and identified -200 compounds having > or = 50% inhibition. more ... | 2006 | 17319155 |
| towards the design of flavivirus helicase/ntpase inhibitors: crystallographic and mutagenesis studies of the dengue virus ns3 helicase catalytic domain. | infectious diseases caused by flaviviruses are important emerging public health concerns and new vaccines and therapeutics are urgently needed. the ns3 protein from flavivirus is a multifunctional protein with protease, helicase and nucleoside 5' triphosphatase activities (ntpase). thus, ns3 plays a crucial role in viral replication and represents an interesting target for the development of specific antiviral inhibitors. we have solved the structure of an enzymatically active fragment of the de ... | 2006 | 17319156 |
| finding new medicines for flaviviral targets. | with the incidence of dengue fever increasing all over the world, there is an urgent need for therapies. while drug discovery for any disease is a long and difficult process with uncertain success, dengue fever poses an additional complication in that most of the target patient population is young and lives in developing countries with very limited health care budgets. recent progress in drug discovery for dengue and an analysis of approaches toward hepatitis c virus (hcv) therapeutics suggest t ... | 2006 | 17319157 |
| organization of flaviviral replicase proteins in virus-induced membranes: a role for ns1' in japanese encephalitis virus rna synthesis. | the organization of flaviviral replicase proteins within the membrane-bound replication complexes of west nile (wnv), dengue (denv) and japanese encephalitis viruses (jev) was probed by investigating the combined effect of detergents and trypsin on both viral replicase activity and profile of metabolically labelled viral proteins. while trypsin treatment of virus-induced membrane fractions degraded the vast majority of replicase proteins, viral rna-dependent rna polymerase (rdrp) activity remain ... | 2006 | 17319159 |
| crm1-dependent nuclear export of dengue virus type 2 ns5. | the dengue virus multidomain rna polymerase ns5 has been observed in the nucleus in mammalian infected cell systems. we previously showed that ns5 nuclear localization is mediated by two nuclear targeting signals within the ns5 interdomain region that are recognized by distinct members of the importin superfamily of intracellular transporters. intriguingly, we have recently found that ns5 also possesses the ability to be exported from the nucleus by the importin family member crm1 (exportin 1) b ... | 2006 | 17319160 |
| developing vaccines against flavivirus diseases: past success, present hopes and future challenges. | vaccination still remains the most cost-effective way of protecting large populations against infectious disease. safe and effective vaccines are available against most pathogenic flaviviruses and in recent years substantial progress has been made in developing vaccines against dengue. dengue vaccines based on conventional and recombinant dna technologies are being assessed and initial results are encouraging. many other experimental vaccines have been developed, but despite the intensity of eff ... | 2006 | 17319163 |
| mouse and hamster models for the study of therapy against flavivirus infections. | small animal models that are reminiscent of flaviviral disease in human will be instrumental in identifying therapeutic strategies against flavivirus infections. here we review models in mice and hamsters for the most clinically important flaviviruses: dengue virus, yellow fever virus, west nile virus, japanese encephalitis virus and tick-borne encephalitis virus. in addition, models are discussed that employ no known vector viruses such as the modoc virus. these viruses can be manipulated in bs ... | 2006 | 17319165 |
| secretion of flaviviral non-structural protein ns1: from diagnosis to pathogenesis. | flaviviruses are major arthropod-borne human pathogens responsible for life-threatening encephalitis, hepatitis and haemorrhagic fevers. these enveloped, single-stranded, positive-sense rna viruses encode a polyprotein precursor of about 3400 amino acids, processed into three structural and seven non-structural proteins. the non-structural glycoprotein ns1 is essential for flavivirus viability. during host-cell infection in vitro, ns1 is found associated with intracellular organelles as a requis ... | 2006 | 17319166 |
| role of the mutant spectrum in adaptation and replication of west nile virus. | west nile virus (wnv) has successfully spread throughout the usa, canada, mexico, the caribbean and parts of central and south america since its 1999 introduction into north america. despite infecting a broad range of both mosquito and avian species, the virus remains highly genetically conserved. this lack of evolutionary change over space and time is common with many arboviruses and is frequently attributed to the adaptive constraints resulting from the virus cycling between vertebrate hosts a ... | 2007 | 17325359 |
| purification and crystallization of kokobera virus helicase. | kokobera virus is a mosquito-borne flavivirus belonging, like west nile virus, to the japanese encephalitis virus serocomplex. the flavivirus genus is characterized by a positive-sense single-stranded rna genome. the unique open reading frame of the viral rna is transcribed and translated as a single polyprotein which is post-translationally cleaved to yield three structural and seven nonstructural proteins, one of which is the ns3 gene that encodes a c-terminal helicase domain consisting of 431 ... | 2007 | 17329812 |
| interference in dengue virus adsorption and uncoating by carrageenans. | this study demonstrated that the lambda- and iota-carrageenans, sulfated polysaccharides containing linear chains of galactopyranosyl residues, are potent inhibitors of dengue virus type 2 (denv-2) and 3 (denv-3) multiplication in vero and hepg2 cells, with values of effective concentration 50% from 0.14 to 4.1 microg/ml. this activity was assayed by plaque reduction, virus yield inhibition and antigen expression tests, and was independent of the input multiplicity of infection in the range 0.00 ... | 2007 | 17337028 |
| functional characterization of cis and trans activity of the flavivirus ns2b-ns3 protease. | flaviviruses are serious human pathogens for which treatments are generally lacking. the proteolytic maturation of the 375-kda viral polyprotein is one target for antiviral development. the flavivirus serine protease consists of the n-terminal domain of the multifunctional nonstructural protein 3 (ns3) and an essential 40-residue cofactor (ns2b(40)) within viral protein ns2b. the ns2b-ns3 protease is responsible for all cytoplasmic cleavage events in viral polyprotein maturation. this study desc ... | 2007 | 17337448 |
| monitoring of usutu virus activity and spread by using dead bird surveillance in austria, 2003-2005. | usutu virus has been causing avian mortality in austria since its emergence in 2001. between 2003 and 2005 a total of 504 dead birds were examined by reverse-transcriptase polymerase chain reaction and immunohistochemistry for the presence of usutu virus nucleic acid and antigen, respectively. in 2003, 92 birds (out of 177 birds) belonging to five different species were positive, while in 2004, only 11 (of 224) birds, and in 2005, 4 (of 103) birds proved positive, all of which were blackbirds (t ... | 2007 | 17346908 |
| assessing flavivirus, lentivirus, and herpesvirus exposure in free-ranging ring-tailed lemurs in southwestern madagascar. | the ring-tailed lemur (lemur catta) is an endangered species found in southwestern madagascar, and understanding infectious disease susceptibility is an essential step towards the preservation of wild and captive lemur populations. lemurs are primates that are widely dispersed throughout the island of madagascar and may serve as hosts or reservoirs for zoonotic infections. the aim of this study was to determine the prevalence of antibodies to west nile virus (wnv), simian immunodeficiency virus ... | 2007 | 17347392 |
| c-src protein kinase inhibitors block assembly and maturation of dengue virus. | dengue virus is a mosquito-borne flavivirus that represents an important emerging infectious disease and is an international health concern. currently, there is no vaccine or effective antiviral therapy to prevent or to treat dengue virus infection. the slow progress in developing antiviral agents might be alleviated by the availability of efficient high-throughput anti-dengue virus screening assays. in this study, we report an immunofluorescence image-based assay suitable for identification of ... | 2007 | 17360676 |
| alkhurma hemorrhagic fever virus in ornithodoros savignyi ticks. | evidence for the tickborne nature of alkhurma hemorrhagic fever virus (ahfv) is indirect because ahfv has not been detected in arthropods. one ornithodoros savignyi tick from saudi arabia contained ahfv rna. this is the first direct evidence that ahfv is a tickborne flavivirus and confirms the association between human ahfv cases and tickbite history. | 2007 | 17370534 |
| west nile virus strain kunjin ns5 polymerase is a phosphoprotein localized at the cytoplasmic site of viral rna synthesis. | using west nile virus strain kunjin virus (wnv(kun)) as a model system for flavivirus replication, we showed that the virus replication complex (rc) is associated with the dsrna template located in induced membranes only in the cytoplasm. in this report we established for the first time that the rna-dependent rna polymerase ns5 is located in flavivirus-induced membranes, including the site of viral rna replication. we found no evidence for nuclear localization of the essential rc components ns5 ... | 2007 | 17374759 |
| a detailed mutagenesis study of flavivirus cross-reactive epitopes using west nile virus-like particles. | human flavivirus infections elicit virus species-specific and cross-reactive immune responses. the flavivirus envelope (e) glycoprotein is the primary antigen inducing protective immunity; however, the presence of cross-reactive antibodies in human sera creates problems for serodiagnosis. using a west nile virus-like particle system, we performed mutagenesis across all three e protein functional domains to identify epitope determinants for a panel of monoclonal antibodies (mabs) raised against d ... | 2007 | 17374760 |
| in situ reactions of monoclonal antibodies with a viable mutant of murray valley encephalitis virus reveal an absence of dimeric ns1 protein. | studies on the ns1 protein of flaviviruses have concluded that formation of a stable homodimer is required for virus replication. however, previous work has reported that substitution of a conserved proline by leucine at residue 250 in ns1 of kunjin virus (kunv) eliminated dimerization, but allowed virus replication to continue. to assess whether this substitution has similar effects on other flaviviruses, it was introduced into an infectious clone of murray valley encephalitis virus (mvev). con ... | 2007 | 17374761 |
| identification of dengue virus in respiratory specimens from a patient who had recently traveled from a region where dengue virus infection is endemic. | dengue is the most important arthropod-borne viral disease, and it is a major public health problem in subtropical and tropical regions. the virus is transmitted to humans by the bite of infected female mosquitoes of the genus aedes. the global resurgence of dengue is thought to be due to failure to control the aedes populations, uncontrolled urbanization, population growth, climate change, and increased airplane travel. in this paper we describe the methods used to detect dengue virus infection ... | 2007 | 17376878 |
| [immunochemical properties of west nile virus protein prm and protein m c-end]. | complementary dna fragments (nucleotides 466-966 and 878-1088) encoding prm protein and polypeptide m31-75-e1-30 of west nile virus (wnv), strain leiv-vlg99-27889-human, were obtained and cloned. recombinant polypeptides prm and m3175-e1-30 having amino acid sequences corresponding to the cloned cdna fragments were purified by affinity chromatography. according to elisa and western blotting prm protein interacted with polyclonal antibodies against wnv. this is indicative the immunochemical simil ... | 2007 | 17380886 |
| membrane-containing viruses with icosahedrally symmetric capsids. | viruses with an icosahedrally symmetric protein capsid and a membrane infect hosts from all three domains of life. similar architectural principles are shared by different viral families, as exemplified by double-stranded dna viruses such as prd1 and stiv. during virus assembly, the membrane lipids are selectively acquired from the host cell. the x-ray structure of bacteriophage prd1 revealed that the lipids are asymmetrically distributed between the two leaflets and facet length is controlled b ... | 2007 | 17387010 |
| genetic and phenotypic differences between isolates of murray valley encephalitis virus in western australia, 1972-2003. | murray valley encephalitis virus (mvev) is a medically important mosquito-borne flavivirus found in australia and papua new guinea (png). partial envelope gene nucleotide sequences of 28 isolates of mvev from western australia (wa) between 1972 and 2003 were aligned and compared phylogenetically with the prototype mve-1-51 from victoria in 1951 and isolates from northern queensland and png. monoclonal antibody-binding patterns were also investigated. results showed that the majority of isolates ... | 2007 | 17393295 |
| structural evidence for regulation and specificity of flaviviral proteases and evolution of the flaviviridae fold. | pathogenic members of the flavivirus family, including west nile virus (wnv) and dengue virus (dv), are growing global threats for which there are no specific treatments. the two-component flaviviral enzyme ns2b-ns3 cleaves the viral polyprotein precursor within the host cell, a process that is required for viral replication. here, we report the crystal structure of wnv ns2b-ns3pro both in a substrate-free form and in complex with the trypsin inhibitor aprotinin/bpti. we show that aprotinin bind ... | 2007 | 17400917 |
| development and evaluation of sybr green i-based one-step real-time rt-pcr assay for detection and quantitation of japanese encephalitis virus. | one-step sybr green i-based real-time rt-pcr assay for rapid detection as well as quantitation of japanese encephalitis virus (jev) in acute-phase patient csf samples by targeting the ns3 gene was developed. the assay developed in this study was found to be more sensitive as compared to conventional rt-pcr. the specificity of the reported assay system was established through melting curve analysis as well as by cross-reactivity studies with related members of flavivirus. the applicability of rea ... | 2007 | 17403544 |
| bird species potentially involved in introduction, amplification, and spread of west nile virus in a mediterranean wetland, the camargue (southern france). | west nile virus (wnv) is a mosquito-transmitted flavivirus with a transmission cycle involving birds as amplifying hosts. wild birds are also believed to carry wnv over large distances and are able to introduce it into new areas during migration and dispersal. in this paper, our objective is to provide lists of birds potentially involved in the introduction, the amplification and the spread of wnv in the camargue, a mediterranean wetland in the south of france where several wnv outbreaks have oc ... | 2007 | 17417954 |
| early evening questing and oviposition activity by the culex (diptera: culicidae) vectors of west nile virus in northeastern north america. | to determine whether the culex (diptera: culicidae) mosquitoes that transmit west nile virus (family flaviviridae, genus flavivirus, wnv) in the northeastern united states seek hosts and oviposit contemporaneously, we recorded when these mosquitoes attacked caged birds and when they deposited eggs. they traversed oviposition sites most frequently approximately 2 h after astronomical sunset, and eggs generally were deposited at that time. although they most frequently approached avian hosts appro ... | 2007 | 17427688 |
| is nonviremic transmission of west nile virus by culex mosquitoes (diptera: culicidae) nonviremic? | inter- and intraspecific transfer of west nile virus (family flaviviridae, genus flavivirus, wnv) occurred infrequently when donor culex tarsalis coquillett fed concurrently on house finches with recipient culex quinquefasciatus say and cx. tarsalis. five of six of these house finches had wnv in blood samples collected by jugular venipuncture 30-45 min postfeeding, with titers ranging from 2.3 to 4.2 log10 plaque-forming units (pfu)/ml. after 2-wk incubation at 26 degrees c, three cx. quinquefas ... | 2007 | 17427700 |
| does feeding on infected mosquitoes (diptera: culicidae) enhance the role of song sparrows in the transmission of arboviruses in california? | song sparrows, melopiza melodia, inoculated subcutaneously with either western equine encephalomyelitis virus (family togaviridae, genus alphavirus, weev) or west nile virus (family flaviviridae, genus flavivirus, wnv) developed elevated viremias, and they were considered to be competent experimental hosts for both viruses. however, birds that ingested from three to 20 mosquitoes containing comparable amounts of either weev or wnv failed to become infected, indicating limited oral susceptibility ... | 2007 | 17427703 |
| ability of transstadially infected ixodes pacificus (acari: ixodidae) to transmit west nile virus to song sparrows or western fence lizards. | the hypothesis that ixodes pacificus cooley & kohls (acari: ixodidae) may serve as a reservoir and vector of west nile virus (family flaviviridae, genus flavivirus, wnv) in california was tested by determining the ability of this tick species to become infected with the ny99 strain of wnv while feeding on viremic song sparrows, to maintain the infection transstadially, and then to transmit wnv to recipient naive song sparrows and western fence lizards during the nymphal stage. the percentage of ... | 2007 | 17427704 |
| effect of cantharidin, cephalotaxine and homoharringtonine on "in vitro" models of hepatitis b virus (hbv) and bovine viral diarrhoea virus (bvdv) replication. | the effect as antiviral agents versus viral hepatitis b and c of three compounds purified from natural products commonly used as remedies in traditional chinese medicine, cantharidin, cephalotaxine and homoharingtonine, was investigated. to assess the activity of these compounds against flavivirus, we used bovine viral diarrhoea virus (bvdv) as a surrogate for hepatitis c virus (hcv). anti-bvdv activity was determined by reduction in bvdv-rna production and protection of infected embryonic bovin ... | 2007 | 17458779 |
| the opioid receptor antagonist, naloxone, protects spinal motor neurons in a murine model of alphavirus encephalomyelitis. | spread of neuroadapted sindbis virus (nsv) to motor neurons (mn) of the spinal cord (sc) causes severe hind limb weakness in c57bl/6 mice and models the paralysis that can accompany alphavirus and flavivirus encephalomyelitis in humans. the fate of spinal mn dictates the severity of nsv-induced paralysis, and recent data suggest that mn damage can occur indirectly via the actions of activated microglial cells. because the opioid receptor antagonist, naloxone (nal), blocks microglial-mediated neu ... | 2007 | 17459376 |
| essential role of dengue virus envelope protein n glycosylation at asparagine-67 during viral propagation. | dengue virus envelope protein (e) contains two n-linked glycosylation sites, at asn-67 and asn-153. the glycosylation site at position 153 is conserved in most flaviviruses, while the site at position 67 is thought to be unique for dengue viruses. n-linked oligosaccharide side chains on flavivirus e proteins have been associated with viral morphogenesis, infectivity, and tropism. here, we examined the relevance of each n-linked glycan on dengue virus e protein by removing each site in the contex ... | 2007 | 17459925 |
| identification of residues critical for the interferon antagonist function of langat virus ns5 reveals a role for the rna-dependent rna polymerase domain. | all pathogenic flaviviruses examined thus far inhibit host interferon (ifn) responses by suppressing the janus kinase-signal transducer and activator of transcription (jak-stat) pathway. both langat virus (lgtv; a member of the tick-borne encephalitis virus serogroup) and japanese encephalitis virus use the nonstructural protein ns5 to suppress jak-stat signaling. however, ns5 is also critical to virus replication, contributing methyltransferase and rna-dependent rna polymerase (rdrp) activities ... | 2007 | 17459929 |
| functional determinants of ns2b for activation of japanese encephalitis virus ns3 protease. | japanese encephalitis virus (jev) is a mosquito-borne flavivirus, causing severe central nerve system diseases without specific treatments. the ns2b-ns3 protease of flaviviruses mediates several cleavages on the flavivirus polyprotein, being believed to be a target for antiviral therapy. ns2b is the cofactor of the viral serine protease, correlating with stabilization and substrate recognition of the ns3 protease. in this study, we investigate the functional determinants in the jev ns2b for the ... | 2007 | 17467838 |
| structural bases for substrate recognition and activity in meaban virus nucleoside-2'-o-methyltransferase. | viral methyltransferases are involved in the mrna capping process, resulting in the transfer of a methyl group from s-adenosyl-l-methionine to capped rna. two groups of methyltransferases (mtases) are known: (guanine-n7)-methyltransferases (n7mtases), adding a methyl group onto the n7 atom of guanine, and (nucleoside-2'-o-)-methyltransferases (2'omtases), adding a methyl group to a ribose hydroxyl. we have expressed and purified two constructs of meaban virus (mv; genus flavivirus) ns5 protein m ... | 2007 | 17473012 |
| [synthetic fragments of the ns1 protein of the tick-borne encephalitis virus exhibiting a protective effect]. | potentially immunoactive regions of the ns1 nonstructural protein of the tick-borne encephalitis virus that can stimulate the antibody formation in vivo and protect animals from this disease were chosen on the basis of theoretical calculations. eleven 16- to 27-aa peptides containing the chosen regions were synthesized. the ability of the free peptides (without any high-molecular-mass carrier) to stimulate the production of antipeptide antibodies in mice of three lines and ensure the formation o ... | 2007 | 17476983 |
| conservation of the pentanucleotide motif at the top of the yellow fever virus 17d 3' stem-loop structure is not required for replication. | the pentanucleotide (pn) sequence 5'-cacag-3' at the top of the 3' stem-loop structure of the flavivirus genome is well conserved in the arthropod-borne viruses but is more variable in flaviviruses with no known vector. in this study, the sequence requirements of the pn motif for yellow fever virus 17d (yfv) replication were determined. in general, individual mutations at either the second, third or fourth positions were tolerated and resulted in replication-competent virus. mutations at the fif ... | 2007 | 17485534 |
| tick-borne flavivirus infection in ixodes scapularis larvae: development of a novel method for synchronous viral infection of ticks. | following a bite from an infected tick, tick-borne flaviviruses cause encephalitis, meningitis and hemorrhagic fever in humans. although these viruses spend most of their time in the tick, little is known regarding the virus-vector interactions. we developed a simple method for synchronously infecting ixodes scapularis larvae with langat virus (lgtv) by immersion in media containing the virus. this technique resulted in approximately 96% of ticks becoming infected. lgtv infection and replication ... | 2007 | 17490700 |
| surveillance of viral haemorrhagic fevers in ghana: entomological assessment of the risk of transmission in the northern regions. | summary | 2006 | 17496987 |
| prevalence of west nile virus neutralizing antibodies in colonial aquatic birds in southern spain. | the rapid expansion of west nile virus (wnv) throughout the new world has raised interest in understanding the population dynamics and patterns of dispersal of emerging infectious diseases by wildlife. wnv affects humans, although its main reservoirs are various species of birds. here we analyse the prevalence of wnv-neutralizing antibodies in nearly full-grown chicks belonging to seven different species of colonial waterbirds at three localities in southern spain. chicks with neutralizing antib ... | 2007 | 17497333 |
| interaction of tia-1/tiar with west nile and dengue virus products in infected cells interferes with stress granule formation and processing body assembly. | the west nile virus minus-strand 3' terminal stem loop (sl) rna was previously shown to bind specifically to cellular stress granule (sg) components, t cell intracellular antigen-1 (tia-1) and the related protein tiar. in vitro tiar binding was 10 times more efficient than tia-1. the 3'(-)sl functions as the promoter for genomic rna synthesis. colocalization of tiar and tia-1 with the viral replication complex components dsrna and ns3 was observed in the perinuclear regions of west nile virus- a ... | 2007 | 17502609 |
| characterization of the dengue virus envelope glycoprotein expressed in pichia pastoris. | the full-length and truncated forms of recombinant envelope (e) glycoprotein from dengue virus type 1, singapore strain s275/90 were expressed in the yeast, pichia pastoris, using a secretory vector. a truncated form of the e protein in which the transmembrane domain was deleted was secreted successfully into the culture medium. the e protein was also co-expressed with c and prm proteins using a non-secretory yeast vector. the co-expression of c, prm and e proteins resulted in the spontaneous fo ... | 2007 | 17502678 |
| combinatorial computational approaches to identify tetracycline derivatives as flavivirus inhibitors. | limited structural information of drug targets, cellular toxicity possessed by lead compounds, and large amounts of potential leads are the major issues facing the design-oriented approach of discovering new leads. in an attempt to tackle these issues, we have developed a process of virtual screening based on the observation that conformational rearrangements of the dengue virus envelope protein are essential for the mediation of viral entry into host cells via membrane fusion. screening was bas ... | 2007 | 17502914 |
| west nile virus encephalitis: sequential histopathological and immunological events in a murine model of infection. | west nile virus (wnv) has emerged as an important cause of encephalitis in humans and horses in north america. although there is significant knowledge about the pathogenesis of disease caused by this flavivirus and about the immunity against it, no reports exist describing the sequence of pathological changes and their correlation to the immune response in the brain following infection with wnv. in this report the authors describe the major histopathological changes, as well as changes in cytoki ... | 2007 | 17505981 |
| structural and functional comparison of the non-structural protein 4b in flaviviridae. | flaviviridae are evolutionarily related viruses, comprising the hepatitis c virus (hcv), with the non-structural protein 4b (ns4b) as one of the least characterized proteins. ns4b is located in the endoplasmic reticulum membrane and is assumed to be a multifunctional protein. however, detailed structure information is missing. the hydrophobic nature of ns4b is a major difficulty for many experimental techniques. we applied bioinformatics methods to analyse structural and functional properties of ... | 2007 | 17507273 |