Publications

the importance of the q motif in the atpase activity of a viral helicase.	ns3 proteins of flaviviruses contain motifs which indicate that they possess protease and helicase activities. the helicases are members of the dexd/h box helicase superfamily and ns3 proteins from some flaviviruses have been shown to possess atpase and helicase activities in vitro. the q motif is a recently recognised cluster of nine amino acids common to most dexd/h box helicases which is proposed to regulate atp binding and hydrolysis. in addition a conserved residue occurs 17 amino acids ups ...	2003	14623116
serologic diagnosis of west nile virus infection.	the epidemic of west nile virus (wnv) in the usa in 2002 represents the largest outbreak of meningoencephalitis in the western hemisphere ever reported. besides natural transmission by mosquitoes, five new modes of wnv transmission to humans have been reported: blood transfusion, organ transplantation, transplacental transmission, breastfeeding and laboratory-acquired infection. the recognition of these new transmission routes has made the development of rapid and accurate serological diagnosis ...	2003	14628901
epizootic activity of murray valley encephalitis and kunjin viruses in an aboriginal community in the southeast kimberley region of western australia: results of mosquito fauna and virus isolation studies.	we undertook annual surveys of flavivirus activity in the community of billiluna in the southeast kimberley region of western australia between 1989 and 2001 [corrected]. culex annulirostris was the dominant mosquito species, particularly in years of above average rains and flooding. murray valley encephalitis (mve) virus was isolated in 8 of the 13 years of the study from seven mosquito species, but more than 90% of the isolates were from cx. annulirostris. the results suggest that mve virus is ...	2003	14628944
antibody prophylaxis and therapy against west nile virus infection in wild-type and immunodeficient mice.	west nile virus (wnv) is a mosquito-borne flavivirus that causes encephalitis in a subset of susceptible humans. current treatment for wnv infections is supportive, and no specific therapy or vaccine is available. in this study, we directly tested the prophylactic and therapeutic efficacy of polyclonal antibodies against wnv. passive administration of human gamma globulin or mouse serum prior to wnv infection protected congenic wild-type, b-cell-deficient ( micro mt), and t- and b-cell-deficient ...	2003	14645550
protection of mice against experimental japanese encephalitis virus infections by neutralizing anti-glycoprotein e monoclonal antibodies.	neutralizing monoclonal antibodies (mabs) to glycoprotein e (gpe) of japanese encephalitis (je) virus given intraperitoneally (i.p.) (0.1 ml of immune ascitic fluid (af) diluted 1:10 per mouse) to about 4-week-old swiss mice 1 day prior or 2 days after the virus challenge (100 ld50 of je virus administered intracerebrally (i.c.)) resulted in a decreased mortality along with an increased survival of the animals as demonstrated by the hai-positive virus-specific (hs) mabs. the protective effect pr ...	2003	14658841
molecular biology of flaviviruses.		2003	14696326
flavivirus structure and membrane fusion.		2003	14696327
kunjin rna replication and applications of kunjin replicons.	the kunjin virus (kunv) has provided a useful laboratory model for flavivirus rna replication. the synthesis of progeny rna(+) strands occurs via asymmetric and semiconservative replication on a template of recycling double-stranded rna (dsrna) or replicative form (rf). kinetics of viral rna synthesis indicated a cycle period of about 15 min during which, on average, a single nascent rna (+) strand displaces the pre-existing rna(+) strand in the replicative intermediate. data on the composition ...	2003	14696328
antigenic structure of flavivirus proteins.	the increased activity of dengue virus in the tropical regions of the world and the recent movement of west nile virus from the eastern to the western hemisphere emphasize the fact that vector-borne flaviviruses are medically important emerging infectious diseases. these facts warrant continued efforts to decode all facets of flavivirus immunology. this chapter reviews current understanding of the antigenic fine structure of flaviviral structural and nonstructural (ns) proteins and their involve ...	2003	14696329
5'- and 3'-noncoding regions in flavivirus rna.		2003	14696330
manipulation of cell surface macromolecules by flaviviruses.	cell surface macromolecules play a crucial role in the biology and pathobiology of flaviviruses, both as receptors for virus entry and as signaling molecules for cell-cell interactions in the processes of vascular permeability and inflammation. this review examines the cell tropism and pathogenesis of flaviviruses from the standpoint of cell surface molecules, which have been implicated as receptors in both virus-cell as well as cell-cell interactions. the emerging picture is one that encompasse ...	2003	14696331
origins, evolution, and vector/host coadaptations within the genus flavivirus.	although viruses in the genus flavivirus share complex antigenic interrelationships, they can be divided into four phylogenetic/ecological groups: two mosquito-borne groups, a tick-borne group, and nonvectored viruses. these divisions largely reflect the selective constraints imposed on the viruses by the vertebrate hosts, the invertebrate vectors, and the associated ecologies. phylogenetic trees based on the flavivirus genetic sequence show characteristic branching patterns that reflect these g ...	2003	14696332
west nile virus: the indian scenario.	west nile virus (wnv) is an important arthropod borne flavivirus; usually causes a mild infection called west nile fever (wnf) in human and horses. mosquitoes are the principal vectors of wnv. various culex species are found to act as vectors in different geographical regions. the virus is maintained in a bird-mosquito cycle in nature. in india, culex mosquitoes are tentatively incriminated as vectors of wnv. experimental studies have shown that culex tritaeniorhynchus, cx. vishnui, cx. bitaenio ...	2003	14700342
flavivirus isolations from mosquitoes collected from western cape york peninsula, australia, 1999-2000.	after the 1st appearance of japanese encephalitis virus (je) on mainland australia in 1998, a study was undertaken to investigate whether je had become established in enzootic transmission cycles on western cape york peninsula. adult mosquitoes were collected during the late wet season from kowanyama and pormpuraaw in april 1999, and pormpuraaw and barr's yard in april 2000. despite processing 269,270 mosquitoes for virus isolation, no isolates of je were obtained. however, other flaviviruses co ...	2003	14710742
serodiagnosis of flaviviral infections and vaccinations in humans.		2003	14714429
molecular amplification assays for the detection of flaviviruses.	over the past 10 years, a number of molecular amplification assays have been developed for the detection of flaviviruses. most of these assays utilize the reverse transcriptase-polymerase chain reaction (rt-pcr) as the amplification format with detection by either agarose gel electrophoresis and ethidium bromide staining or hybridization with molecular probes. recently, a modification of the standard rt-pcr using fluorescent-labeled oligonucleotide probes for detection (taqman) has been describe ...	2003	14714430
tick-borne flaviviruses.	tick-borne encephalitis (tbe), one of the most dangerous neuroinfections in europe and asia, is caused by tick-borne encephalitis virus (tbev) and currently involves approximately 11,000 human cases annually, mostly in russia. this chapter describes the main problems associated with the epidemiology, ecology, pathogenesis, and control of this disease. we have attempted to review the factors that influence the incidence and distribution of tbe, and to discuss possible reasons for the different cl ...	2003	14714436
epidemiology of other arthropod-borne flaviviruses infecting humans.		2003	14714437
formalin-inactivated whole virus and recombinant subunit flavivirus vaccines.	the flaviviridae is a family of arthropod-borne, enveloped, rna viruses that contain important human pathogens such as yellow fever (yf), japanese encephalitis (je), tick-borne encephalitis (tbe), west nile (wn), and the dengue (den) viruses. vaccination is the most effective means of disease prevention for these viral infections. a live-attenuated vaccine for yf, and inactivated vaccines for je and tbe have significantly reduced the incidence of disease for these viruses, while licensed vaccine ...	2003	14714438
dna vaccines for flaviviruses.		2003	14714440
chimeric flaviviruses: novel vaccines against dengue fever, tick-borne encephalitis, and japanese encephalitis.	many arthropod-borne flaviviruses are important human pathogens responsible for diverse illnesses, including yf, je, tbe, and dengue. live, attenuated vaccines have afforded the most effective and economical means of prevention and control, as illustrated by yf 17d and je sa14-14-2 vaccines. recent advances in recombinant dna technology have made it possible to explore a novel approach for developing live attenuated flavivirus vaccines against other flaviviruses. full-length cdna clones allow co ...	2003	14714441
prospects for antiviral therapy.		2003	14714442
[specific determination of flaviviruses by molecular hybridization with synthetic deoxyoligonucleotide probes].	molecular probes were designed for the purpose of specific determination of flavioviruses transmitted by the ticks of tick-borne encephalitis (tbe) and omsk hemorrhagic fever (ohv) as well as by mosquitoes of japanese encephalitis (je), north nile (nn), murrey valley encephalitis (mve), saint-lois encephalitis (sle), dengue 1-4 and of yellow fever (yf). the probes are synthetic deoxyoligonucleotides with the 18-20 long basis and complementary for the rna fragments defined by computer analysis. t ...	2003	12894476
antigen-expressed recombinant salmonella typhimurium driven by an in vivo-activated promoter is capable of inducing cellular immune response in transgenic mice.	to explore the approaches and mechanisms for reversing the immune tolerance in transgenic mouse, and the pathogenicity of hepatitis g virus (hgv), the promoter of phop-activated gene (p(pagc)) of salmonella typhimurium was used as a transcriptionally regulating element to construct an attenuated s. typhimurium expressing hgv ns3. the recombinant s. typhimurium was orally administered to hgv transgenic mice. as the results, hgv antigen in serum and liver as well as hgv mrna in liver were decrease ...	2003	12897963
screening for t cell-eliciting proteins of japanese encephalitis virus in a healthy je-endemic human cohort using recombinant baculovirus-infected insect cell preparations.	the analysis of cell-mediated immune responses in virus-exposed but healthy individuals may contribute to define the features of the t cell response associated with resistance. we report, for the first time, on adaptive t cell responses to 5 largest of the 10 proteins that together constitute 76% of the coding potential of the japanese encephalitis virus (jev) genome in a naturally exposed healthy je-immune human cohort. fixed and sonified whole cell preparations of insect cells individually exp ...	2003	12898332
hepatitis c: a review.	hepatitis c virus is an rna virus in the flavivirus family that was identified in 1989. since then, blood donor screening has reduced the incidence of acute infections; however, because this virus frequently leads to asymptomatic chronic infection, the prevalence of infection remains high. chronic infection leads to increased risks of cirrhosis and hepatocellular carcinoma, as well as extrahepatic manifestations. guidelines for widespread screening continue to evolve, and early diagnosis is like ...	2003	12900622
discrimination of west nile virus and japanese encephalitis virus strains using rt-pcr rflp analysis.	west nile (wn) virus is a mosquito-borne flavivirus that induces lethal encephalitis in humans and horses. since an outbreak of wn encephalitis in humans and horses occurred in new york city in late august 1999, the possibility exists that wn virus will invade regions that have close links with the united states, such as japan. we developed a genetic diagnostic method that discriminates between strains of wn virus and japanese encephalitis (je) virus. the method involves rt-pcr restriction fragm ...	2003	12906104
chronic hepatitis associated with gb virus b persistence in a tamarin after intrahepatic inoculation of synthetic viral rna.	progress in understanding the pathogenesis of hepatitis c virus (hcv) has been slowed by the absence of tractable small animal models. whereas gb virus b (gbv-b, an unclassified flavivirus) shares a phylogenetic relationship and several biologic attributes with hcv, including hepatotropism, it is not known to cause persistent infection, a hallmark of hcv. here, we document persistent gbv-b infection in one of two healthy tamarins (saguinus oedipus) inoculated intrahepatically with infectious syn ...	2003	12907703
characterization of rna-dependent rna polymerase activity of csfv ns5b proteins expressed in escherichia coli.	the full-length ns5b protein, and the truncated ns5b proteins of classical swine fever virus (csfv) resulted from deletion of 24, 36, 65 or 82, amino acid residues at the c terminal were expressed in escherichia coli cells and purified with a c-terminal hexahistidine tag. in addition to the full-length ns5b protein, those truncated ns5b proteins with deletion of 24, 36, or 65 amino acid residues were demonstrated to have rna-dependent rna polymerase (rdrp) activity, which was not found in the tr ...	2003	12913359
mr findings in murray valley encephalitis.	murray valley encephalitis (mve) is caused by a flavivirus related to west nile and st. louis encephalitis viruses. we report a case of mve resulting in quadriplegia and respiratory failure. mr imaging demonstrated thalamic hyperintensity on t2-weighted images, with similar involvement of the red nucleus, substantia nigra, and cervical cord. these findings preceded serologic diagnosis and are similar to those of japanese encephalitis. in the appropriate setting, thalamic t2 hyperintensity is sug ...	2003	12917132
evidence for antigen production in muscles by dengue and japanese encephalitis dna vaccines and a relation to their immunogenicity in mice.	this study demonstrated viral antigen production in muscle tissues following inoculation with dna vaccines and examined its relation to antibody induction in mice using the flavivirus system. to achieve detectable levels of antigen production, we used a needle-free jet injector and examined 10% homogenate of quadriceps muscle for viral antigens in a sandwich enzyme-linked immunosorbent assay. we compared dna vaccines against dengue type 1 (designated pcd1me), dengue type 2 (pcd2me) and japanese ...	2003	12922102
induction of cross-protection against two wild-type taiwanese isolates of japanese encephalitis virus using beijing-1 strain dna vaccine.	japanese encephalitis virus (jev), a mosquito-borne flavivirus, is an important human pathogen. mouse brain-derived, inactivated jev vaccines have contributed greatly to the reduction in numbers of je patients in several countries, including taiwan. however, mice immunized with the nakayama strain inactivated vaccine show lower protection against a lethal strain of beijing-1 jev than those immunized with the homologous vaccine. dna vaccine encoding the envelope (e) protein gene appears to provid ...	2003	12922129
large genetic differentiation and low variation in vector competence for dengue and yellow fever viruses of aedes albopictus from brazil, the united states, and the cayman islands.	we conducted a population genetic analysis of aedes albopictus collected from 20 sites in brazil, the united states (florida, georgia, and illinois), and the cayman islands. using isoenzyme analysis, we examined genetic diversity and patterns of gene flow. high genetic differentiation was found among brazilian samples, and between them and north american samples. regression analysis of genetic differentiation according to geographic distances indicated that ae. albopictus samples from florida we ...	2003	12932107
growth characteristics of the veterinary vaccine candidate chimerivax-west nile (wn) virus in aedes and culex mosquitoes.	in 1999 west nile (wn) virus was introduced to north america where this flavivirus has spread rapidly among wildlife (especially birds) transmitted by various species of mosquitoes (diptera: culicidae). increasing numbers of cases and deaths among humans, horses and other domestic animals require development of effective vaccines. 'chimerivax-west nile(vet)' is being developed for use as a veterinary vaccine to protect against wn infection. this chimeric virus contains the pre-membrane (prm) and ...	2003	12941006
functional analysis of mosquito-borne flavivirus conserved sequence elements within 3' untranslated region of west nile virus by use of a reporting replicon that differentiates between viral translation and rna replication.	we have developed a reporting replicon of west nile virus (wnv) that could be used to quantitatively distinguish viral translation and rna replication. a renilla luciferase (rluc) gene was fused in-frame with the open reading frame of a subgenomic replicon in the position where the viral structural region was deleted, resulting in rlucrep. transfection of bhk cells with rlucrep rna yielded two distinctive rluc signal peaks, one between 2 and 10 h and the other after 26 h posttransfection. by con ...	2003	12941911
acute encephalitis, a poliomyelitis-like syndrome and neurological sequelae in a hamster model for flavivirus infections.	infection of hamsters with the murine flavivirus modoc results in (meningo)encephalitis, which is, during the acute phase, frequently associated with flaccid paralysis, as also observed in patients with west nile virus encephalitis. twenty percent of the hamsters that recover from the acute encephalitis develop life-long neurological sequelae, reminiscent of those observed, for example, in survivors of japanese encephalitis. magnetic resonance imaging and histology revealed severe lesions predom ...	2003	12946018
analysis of the complete genome of the tick-borne flavivirus omsk hemorrhagic fever virus.	omsk hemorrhagic fever virus (ohf) is a tick-borne flavivirus endemic to western siberia. this virus is the only known tick-borne flavivirus to cause hemorrhagic disease in humans in the absence of encephalitis. ohf virus circulates within a small, defined niche in which other tick-borne complex flaviviruses are also present. the objectives of this study were to genetically classify ohf virus based on its complete genome and to identify genetic determinants that might be involved in tissue tropi ...	2003	12951023
west nile virus in the united states: an update on an emerging infectious disease.	west nile virus is a mosquito-borne flavivirus and human neuropathogen. since the virus was recognized in new york city in 1999, it has spread rapidly across the united states, with human disease documented in 39 states and the district of columbia. west nile virus can cause a broad range of clinical syndromes, including fever, meningitis, encephalitis, and a flaccid paralysis characteristic of a poliomyelitis-like syndrome. approximately one in 150 infections results in severe neurologic illnes ...	2003	12952382
structural basis of a flavivirus recognized by its neutralizing antibody: solution structure of the domain iii of 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. we have determined the solution structure of the major antigenic domain (domain iii) of the japanese encephalitis virus (jev) envelope protein. the jev domain iii forms a beta-barrel type structure composed of six antiparallel beta-strands resembling the immunoglobulin constant domain. we have also identified epitopes of ...	2003	12952958
immunoassay targeting nonstructural protein 5 to differentiate west nile virus infection from dengue and st. louis encephalitis virus infections and from flavivirus vaccination.	west nile virus (wnv) is an emerging flavivirus that has caused frequent epidemics since 1996. besides natural transmission by mosquitoes, wnv can also be transmitted through blood transfusion and organ transplantation, thus heightening the urgency of development of a specific and rapid serologic assay of wnv infection. the current immunoassays lack specificity because they are based on detection of antibodies against wnv structural proteins and immune responses to structural proteins among flav ...	2003	12958248
diagnosis of tick-borne encephalitis by a mu-capture immunoglobulin m-enzyme immunoassay based on secreted recombinant antigen produced in insect cells.	acute tick-borne encephalitis is diagnosed by detection of igm antibodies to tick-borne encephalitis virus (tbev) (genus flavivirus) in patient serum. tbev membrane (m) and envelope (e) proteins have previously been shown to form virus-like particles when expressed in mammalian cells. we expressed the prm/m and e proteins in insect cells with a recombinant baculovirus system and obtained antigenic protein secreted into the cell culture medium, as evidenced by detection by a panel of five monoclo ...	2003	12958266
west nile virus: epidemiology, clinical presentation, diagnosis, and prevention.	west nile virus was recognized in the united states for the first time in 1999, when it caused an epidemic of encephalitis and meningitis in new york city, ny. since then, the disease has been steadily moving westward, and human cases were recognized in 39 states and the district of columbia in 2002. the infection is caused by a flavivirus that is transmitted from birds to humans through the bite of culicine mosquitoes. most infections are mild, with symptoms primarily being fever, headache, and ...	2003	12962168
proteasome activator pa28gamma-dependent nuclear retention and degradation of hepatitis c virus core protein.	hepatitis c virus (hcv) core protein plays an important role in the formation of the viral nucleocapsid and a regulatory protein involved in hepatocarcinogenesis. in this study, we have identified proteasome activator pa28gamma (11s regulator gamma) as an hcv core binding protein by using yeast two-hybrid system. this interaction was demonstrated not only in cell culture but also in the livers of hcv core transgenic mice. these findings are extended to human hcv infection by the observation of t ...	2003	12970408
significance in replication of the terminal nucleotides of the flavivirus genome.	point mutations that resulted in a substitution of the conserved 3'-penultimate cytidine in genomic rna or the rna negative strand of the self-amplifying replicon of the flavivirus kunjin virus completely blocked in vivo replication. similarly, substitutions of the conserved 3'-terminal uridine in the rna negative or positive strand completely blocked replication or caused much-reduced replication, respectively. the same preference for cytidine in the 3'-terminal dinucleotide was noted in report ...	2003	12970446
dengue virus m protein contains a proapoptotic sequence referred to as apoptom.	the induction of apoptotic cell death is a prominent cytopathic effect of dengue (den) viruses. one of the key questions to be addressed is which viral components induce apoptosis in den virus-infected cells. this study investigated whether the small membrane (m) protein was involved in the induction of apoptosis by den virus. this was addressed by using a series of enhanced green fluorescent protein-fused den proteins. evidence is provided that intracellular production of the m ectodomains (res ...	2003	13679613
association of japanese encephalitis virus ns3 protein with microtubules and tumour susceptibility gene 101 (tsg101) protein.	previously reported findings by our group showed that non-structural protein 3 (ns3) of japanese encephalitis virus (jev) was localized mainly in the jev-induced convoluted membrane (cm), which has been proposed to originate from rough endoplasmic reticulum (rer), golgi apparatus or the trans-golgi network (tgn), and serves as a reservoir for viral proteins during virus assembly. earlier findings indicated that ns3 of kunjin virus interacts with microtubules. in addition, one of the golgi-associ ...	2003	13679614
serological evidence of west nile virus, usutu virus and sindbis virus infection of birds in the uk.	the introduction and rapid dispersal of the african flavivirus west nile virus (wnv) throughout north america, and the high fatality rate due to encephalitis in birds, horses, other wildlife species and humans, has attracted major attention worldwide. usutu virus, another flavivirus, came to prominence in 2001, when it was identified as the agent responsible for a drop in the bird population in austria; previously this encephalitic virus was found only in birds and mosquitoes in africa. sindbis ...	2003	13679615
mutations which enhance the replication of dengue virus type 4 and an antigenic chimeric dengue virus type 2/4 vaccine candidate in vero cells.	mutations which increase the replication of dengue viruses in cell culture would greatly facilitate the manufacture of both a live attenuated or inactivated dengue virus vaccine. we have identified eight missense mutations in dengue virus type 4 (den4) that increase the plaque size and kinetics of replication of recombinant den4 virus in vero cells. den4 viruses bearing these vero cell adaptation mutations were also evaluated for the level of replication in the brains of mice. two of these eight ...	2003	14505914
genetic systems of west nile virus and their potential applications.	prevention and treatment of west nile virus (wnv) and other flavivirus infections have become a global public health priority. this fact is highlighted by the recent epidemic of wnv in the us. since the first outbreak of wnv in the us in 1999, the virus has caused over 4000 known human cases and at least 263 human deaths. the epidemic of wnv in the us in 2002 represents the largest meningoencephalitis outbreak in the western hemisphere, and the largest wnv outbreak ever reported. reverse genetic ...	2003	14508880
sentinel chicken surveillance program in australia, july 2002 to june 2003.	detection of flavivirus seroconversions in sentinel chicken flocks located throughout australia is used to provide an early warning of increased levels of murray valley encephalitis (mve) and kunjin (kun) virus activity in the region. during the 2002-2003 season low levels of flavivirus activity were detected in northern australia compared to previous years. mve and kun virus activity was detected in the kimberley and pilbara regions of western australia and the northern territory but not in nor ...	2003	14510063
west nile virus-associated meningoencephalitis in two chronically immunosuppressed renal transplant recipients.	west nile virus is a mosquito-borne, single-stranded rna virus of the flaviviridae family. approximately 1 in 150 patients who have serologic evidence of west nile virus infection develop encephalitis or meningitis. we report two chronically immunosuppressed renal transplant recipients with confirmed west nile virus meningoencephalitis acquired through community exposure. both patients presented with fever and neurological changes in the autumn of 2002. flavivirus-specific immunoglobulin m in an ...	2003	14510707
molecularly engineered live-attenuated chimeric west nile/dengue virus vaccines protect rhesus monkeys from west nile virus.	two molecularly engineered, live-attenuated west nile virus (wn) vaccine candidates were highly attenuated and protective in rhesus monkeys. the vaccine candidates are chimeric viruses (designated wn/den4) bearing the membrane precursor and envelope protein genes of wn on a backbone of dengue 4 virus (den4) with or without a deletion of 30 nucleotides (delta 30) in the 3' noncoding region of den4. viremia in wn/den4- infected monkeys was reduced 100-fold compared to that in wn- or den4-infected ...	2003	14517072
rna-dependent rna polymerase activity of classical swine fever virus ns5b protein expressed in natural host cells.	the ns5b gene, cloned from classical swine fever virus (csfv) genome, was expressed in porcine kidney cells pk-15, natural host of csfv. in purifying cytoplasmic extracts from these cells by means of different concentrations of salt, glycerol and detergent four fractions, namely crude supernatant (sc) and different purified supernatants (s1, s2 and s3) were obtained. using western blot analysis the ns5b protein was found in all these fractions, showing that it was soluble in both higher and lowe ...	2003	14524473
characterisation of human tick-borne encephalitis virus from sweden.	viruses of the tick-borne encephalitis (tbe) antigenic complex, within the family flaviviridae, cause a variety of diseases including uncomplicated febrile illness, meningo-encephalitis and haemorrhagic fever. different wildlife species act as reservoir hosts with ixodid tick species as vectors. tbe virus (tbev) causes 40-130 cases confirmed serologically in sweden each year. characteristics of tbev strains circulating in sweden have not been investigated previously and no viral sequence data ha ...	2003	14556277
two distinct size classes of immature and mature subviral particles from tick-borne encephalitis virus.	flaviviruses assemble in the endoplasmic reticulum by a mechanism that appears to be driven by lateral interactions between heterodimers of the envelope glycoproteins e and prm. immature intracellular virus particles are then transported through the secretory pathway and converted to their mature form by cleavage of the prm protein by the cellular protease furin. earlier studies showed that when the prm and e proteins of tick-borne encephalitis virus are expressed together in mammalian cells, th ...	2003	14557621
dengue 2 pdk-53 virus as a chimeric carrier for tetravalent dengue vaccine development.	attenuation markers of the candidate dengue 2 (d2) pdk-53 vaccine virus are encoded by mutations that reside outside of the structural gene region of the genome. we engineered nine dengue virus chimeras containing the premembrane (prm) and envelope (e) genes of wild-type d1 16007, d3 16562, or d4 1036 virus within the genetic backgrounds of wild-type d2 16681 virus and the two genetic variants (pdk53-e and pdk53-v) of the d2 pdk-53 vaccine virus. expression of the heterologous prm-e genes in the ...	2003	14557629
zooprophylaxis or zoopotentiation: the outcome of introducing animals on vector transmission is highly dependent on the mosquito mortality while searching.	zooprophylaxis, the diversion of disease carrying insects from humans to animals, may reduce transmission of diseases such as malaria. however, as the number of animals increases, improved availability of blood meals may increase mosquito survival, thereby countering the impact of diverting feeds.	2003	14565850
cytochrome p450 2a6: a new hepatic autoantigen in patients with chronic hepatitis c virus infection.	cytochromes p4502a6 (cyp2a6) and p4501a2 (cyp1a2) were described as hepatic autoantigens in the autoimmune polyglandular syndrome type-1 (aps-1). we evaluated the significance of anti-cyp2a6 and anti-cyp1a2 in several hepatic diseases in the absence of aps-1.	2003	14568264
evolutionary relationship between old world west nile virus strains. evidence for viral gene flow between africa, the middle east, and europe.	little is known about the genetic relationships between european and other old-world strains of west nile virus (wnv) and persistence of wnv north of mediterranean. we characterized the complete genomes of three wnv strains from france (horse-2000), tunisia (human-1997) and kenya (mosquito-1998), and the envelope, ns3 and ns5 genes of the koutango virus. phylogenetic analyses including all available full-length sequences showed that: (1) koutango virus is a distant variant of wnv; (2) the three ...	2003	14585341
incorporation of tick-borne encephalitis virus replicons into virus-like particles by a packaging cell line.	rna replicons derived from flavivirus genomes show considerable potential as gene transfer and immunization vectors. a convenient and efficient encapsidation system is an important prerequisite for the practical application of such vectors. in this work, tick-borne encephalitis (tbe) virus replicons and an appropriate packaging cell line were constructed and characterized. a stable cho cell line constitutively expressing the two surface proteins prm/m and e (named cho-me cells) was generated and ...	2003	12885909
brazilian flavivirus phylogeny based on ns5.	in this work, a comprehensive phylogenetic study based on 600 base pair nucleotide and on putative 200 amino acid sequences of ns5 was carried out in order to establish genetic relationships among 15 strains of 10 brazilian flaviviruses: bussuquara, cacipacore, dengue type 1, 2 and 4, iguape, ilheus, rocio, saint louis encephalitis (sle), and yellow fever. phylogenetic trees were created by neighbor-joining and maximum parsimony methods. these trees showed brazilian flaviviruses grouped into thr ...	2003	12886419
wicking assays for the rapid detection of west nile and st. louis encephalitis viral antigens in mosquitoes (diptera: culicidae).	the recent outbreaks of west nile (wn) encephalitis and st. louis encephalitis (sle) in the united states have highlighted the need for rapid and specific methods of detecting arboviral antigens in mosquitoes. we evaluated rapid, field-usable assays for detecting and differentiating wn and sle viruses in mosquito pools, based on a patent-pending, immunochromatographic technology (vectest) formatted on a dipstick. the device provides results in less than 20 min and can be used in laboratories wit ...	2003	12597660
spinal cord disease in west nile virus infection.		2003	12575663
architecture of the flaviviral replication complex. protease, nuclease, and detergents reveal encasement within double-layered membrane compartments.	flavivirus infection causes extensive proliferation and reorganization of host cell membranes to form specialized structures called convoluted membranes/paracrystalline arrays and vesicle packets (vp), the latter of which is believed to harbor flaviviral replication complexes. using detergents and trypsin and micrococcal nuclease, we provide for the first time biochemical evidence for a double membrane compartment that encloses the replicative form (rf) rna of the three pathogenic flaviviruses w ...	2003	12700232
role of heparan sulfate for attachment and entry of tick-borne encephalitis virus.	attachment of the flavivirus tick-borne encephalitis (tbe) virus to different permissive cell lines was investigated by a newly established quantitative assay using fluorescence-labeled virus. previous work had shown that bhk-21 cell-adapted mutants of tbe virus had acquired potential heparan sulfate (hs) binding sites on the outer surface of protein e. quantitative analysis of one of these mutants indicated that it attached to hs-expressing cell lines with a 10- to 13-fold higher affinity than ...	2003	12706093
recent advances in japanese encephalitis.	japanese encephalitis (je), the most important cause of epidemic encephalitis worldwide, is confined to asia, but its geographical area is spreading. west nile virus, and other closely related flaviviruses, cause similar disease elsewhere. recent cryoelectron microscopic studies have characterized the flavivirus envelope protein as a new class of viral fusion protein (class ii), and examined its arrangement on the virion surface. changes in the envelope protein's hinge region, or its putative re ...	2003	12707858
interferon, ribavirin, 6-azauridine and glycyrrhizin: antiviral compounds active against pathogenic flaviviruses.	ribavirin, interferon-alpha (ifn-alpha), 6-azauridine and glycyrrhizin were tested in vitro for their antiviral activities against 11 pathogenic flaviviruses belonging to principal antigenic complexes or individual serogroups of medical importance: dengue, japanese encephalitis, mammalian tick-borne and yellow fever virus (yfv) groups. antiviral activity was estimated by the reduction of the cytopathic effect of each flavivirus in vero cells and by the reduction in virus titer. cytotoxicity was ...	2003	12719009
temperature sensitive mutations in the genes encoding the ns1, ns2a, ns3, and ns5 nonstructural proteins of dengue virus type 4 restrict replication in the brains of mice.	using reverse genetics, it is possible to readily add well-defined attenuating mutations to the genome of wild type or incompletely attenuated dengue (den) viruses to generate vaccine candidates that exhibit the desired balance between attenuation and immunogenicity. here, we describe the identification of eight temperature sensitive missense mutations distributed in four non-structural protein genes that specify a 60- to 10,000-fold range of restricted replication in the suckling mouse brain co ...	2003	12721805
viral internal ribosome entry site structures segregate into two distinct morphologies.	an increasing number of viruses have been shown to initiate protein synthesis by a cap-independent mechanism involving internal ribosome entry sites (iress). predictions of the folding patterns of these rna motifs have been based primarily on sequence and biochemical analyses. biophysical confirmation of the models has been achieved only for the ires of hepatitis c virus (hcv), which adopts an open structure consisting of two major stems. we have conducted an extensive comparison of flavivirus a ...	2003	12743317
is flavivirus resistance interferon type i-independent?	interferon type i comprises a group of major virus-inducible host antiviral factors that control infection with a great number of human and animal viruses. they are ubiquitously expressed cytokines that interfere with virus replication within different cell types by activating a number of host genes and several parallel antiviral pathways. two major intracellular actors of ifn-i-induced antiviral states are ribonucleic acid-dependent protein kinase and 2'-5'-oligoadenylate synthetases/rnase l, b ...	2003	12752687
the membrane proteins of flaviviruses form ion-permeable pores in the target membrane after fusion: identification of the pores and analysis of their possible role in virus infection.	recently, we presented evidence that the e1 fusion protein of the alphavirus semliki forest virus forms ion-permeable pores in the target membrane after fusion. we proposed that the homologous fusion proteins of flaviviruses and hepatitis c virus form similar pores. to test this hypothesis for the e fusion protein of flaviviruses, the release of [(3)h]choline from liposomes by the flavivirus west nile (wn) virus was determined. [(3)h]choline was released at mildly acid ph. the ph threshold depen ...	2003	12810864
antibody-dependent enhancement of murray valley encephalitis virus virulence in mice.	enhancement of flavivirus infection in vitro in the presence of subneutralizing concentrations of homologous or heterologous antiserum has been well described. however, the importance of this phenomenon in the enhancement of flavivirus infection in vivo has not been established. in order to study antibody-mediated enhancement of flavivirus infection in vivo, we investigated the effect of passive immunization of mice with japanese encephalitis virus (je) antiserum on the outcome of infection with ...	2003	12810865
distribution of three arbovirus antibodies among monkeys (macaca fascicularis) in the philippines.	serum samples from 54 monkeys were collected from healthy individuals in a monkey farm in luzon island, philippines, in 1999, and examined by igm-capture elisa and indirect igg elisa for the presence of dengue (den), japanese encephalitis (je) and chikungunya (chik) viruses. the positive rates for igm elisa were 3.7, 35.2 and 14.8% against den, je and chik, respectively. higher positive rates were obtained when indirect igg elisa was used: 100% against flaviviruses (je or den) and 59.3% against ...	2003	12823631
development of a quantitative real-time rt-pcr assay with internal control for the laboratory detection of tick borne encephalitis virus (tbev) rna.	tick borne encephalitis virus (tbev), is a human flavivirus causing tick borne encephalitis (tbe), a viral infection of the central nervous system endemic in europe and asia.	2003	12829035
kunjin virus replicon vectors for human immunodeficiency virus vaccine development.	we have previously demonstrated the ability of the vaccine vectors based on replicon rna of the australian flavivirus kunjin (kun) to induce protective antiviral and anticancer cd8+ t-cell responses using murine polyepitope as a model immunogen (i. anraku, t. j. harvey, r. linedale, j. gardner, d. harrich, a. suhrbier, and a. a. khromykh, j. virol. 76:3791-3799, 2002). here we showed that immunization of balb/c mice with kun replicons encoding hiv-1 gag antigen resulted in induction of both gag- ...	2003	12829819
molecular and functional analyses of kunjin virus infectious cdna clones demonstrate the essential roles for ns2a in virus assembly and for a nonconservative residue in ns3 in rna replication.	a number of full-length cdna clones of kunjin virus (kun) were previously prepared; it was shown that two of them, pakun and flsdx, differed in specific infectivities of corresponding in vitro transcribed rnas by approximately 100,000-fold (a. a. khromykh et al., j. virol. 72:7270-7279, 1998). in this study, we analyzed a possible genetic determinant(s) of the observed differences in infectivity initially by sequencing the entire cdnas of both clones and comparing them with the published sequenc ...	2003	12829820
involvement of lipids in different steps of the flavivirus fusion mechanism.	flavivirus membrane fusion is triggered by acidic ph and mediated by the major envelope protein e. a structurally very similar fusion protein is found in alphaviruses, and these molecules are designated class ii viral fusion proteins. in contrast to that of flaviviruses, however, alphavirus fusion has been shown to be absolutely dependent on the presence of cholesterol and sphingomyelin in the target membrane, suggesting significant differences in the fusion protein-membrane interactions that le ...	2003	12829825
clinical and laboratory findings on the first imported case of murray valley encephalitis in europe.	murray valley encephalitis (mve) is an important mosquitoborne flavivirus infection endemic to australia and papua new guinea. we report the first imported case of mve in europe. a 23-year-old tourist developed severe encephalitis after having returned to germany from a long-term trip across the australian continent. the diagnosis was suspected on the basis of clinical findings and the patient's travel history and was confirmed by serological findings. the patient made a prolonged but complete r ...	2003	12856229
managing occupational risks for hepatitis c transmission in the health care setting.	hepatitis c virus (hcv) infection is a significant contemporary health problem in the united states and elsewhere. because it is primarily transmitted via blood, hepatitis c infection presents risks for both nosocomial transmission to patients and occupational spread to health care workers. recent insights into the pathogenesis, immunopathogenesis, natural history, and treatment of infection caused by this unique flavivirus provide a rationale for the use of new strategies for managing occupatio ...	2003	12857782
dengue virus type 2 ns3 protease and ns2b-ns3 protease precursor induce apoptosis.	apoptosis was detected in vero cell cultures expressing transfected dengue virus type 2 (denv-2) genes. approximately 17.5 and 51.5 % of cells expressing ns3 serine protease and ns2b-ns3(185) serine protease precursor protein [ns2b-ns3(185)(pro)] genes, respectively, were apoptotic. the percentage of apoptotic cells was significantly higher in cell cultures expressing ns2b-ns3(185)(pro). ns2b-ns3(185)(pro) was detected as ns2b-ns3(185)(pro)-egfp fusion protein in cytoplasmic vesicular structures ...	2003	12867651
novel, potent phenethylamide inhibitors of the hepatitis c virus (hcv) ns3 protease: probing the role of p2 aryloxyprolines with hybrid structures.	synthesis of hybrid hcv ns3 protease/ns4a inhibitors having the 4,4-difluoroaminobutyric acid (difluoroabu) phenethylamides as p1-p1' and quinolyloxyprolines as p2 fragments led to 7 (ic(50) 54 nm). molecular modelling suggests that this potent tripeptide inhibitor utilizes interactions in the s1', s1, s2, s3 and s4 sites of the protease.	2003	12873506
isolation of a new flavivirus related to cell fusing agent virus (cfav) from field-collected flood-water aedes mosquitoes sampled from a dambo in central kenya.	cell fusing agent virus (cfav) is an rna insect virus that was isolated from a line of aedes aegypti mosquito cells and has been assigned to the family flaviviridae, genus flavivirus. we report here the first isolation of a cfa-like virus from field-collected mosquitoes. mosquito larvae and pupae were sampled from flooded dambos in central province, kenya during the short rain season of 1999. specimens were reared to adults, identified and pooled by species and were tested for the presence of vi ...	2003	12756616
genetic and phenotypic characterization of the newly described insect flavivirus, kamiti river virus.	we have described in the accompanying paper by sang, et al., ([57], arch virol 2003, in press) the isolation and identification of a new flavivirus, kamiti river virus (krv), from ae. macintoshi mosquitoes that were collected as larvae and pupae from flooded dambos in central province, kenya. among known flaviviruses, krv was shown to be most similar to, but genetically and phenotypically distinct from, cell fusing agent virus (cfav). krv was provisionally identified as an insect-only flavivirus ...	2003	12756617
[west nile fever may even be spread to sweden].	west nile virus (wnv) is a flavivirus, which was first isolated in uganda 1937. this virus has attracted attention in the past years. wnv is one of the worlds most widespread flaviviruses and has caused recent outbreaks among humans and animals. west nile fever (wnf) is a mosquito borne zoonotic disease. the last decade the epidemiological pattern of the virus and the severity of the outbreaks have changed. this article reviews the epidemiological changes and current situation of wnf, presents a ...	2003	12756695
natural and nosocomial infection in a patient with west nile encephalitis and extrapyramidal movement disorders.	since its first recognition in north america in 1999, west nile virus (wnv) has spread rapidly across the continent, but in many communities, rapid diagnostic tests for detection of wnv infection are not fully available. we describe a patient with extrapyramidal movement disorders and changes in the basal ganglia noted on magnetic resonance images that are characteristic of other flavivirus encephalitides and may help in the recognition of patients with west nile encephalitis. detailed molecular ...	2003	12766856
flavivirus capsid is a dimeric alpha-helical protein.	the capsid proteins of two flaviviruses, yellow fever virus and dengue virus, were expressed in escherichia coli and purified to near homogeneity suitable for biochemical characterization and structure determination by nuclear magnetic resonance. the oligomeric properties of the capsid protein in solution were investigated. in the absence of nucleic acid, both proteins were predominantly dimeric in solution. further analysis of both proteins with far-uv circular dichroism spectroscopy indicated ...	2003	12768036
structures of immature flavivirus particles.	structures of prm-containing dengue and yellow fever virus particles were determined to 16 and 25 a resolution, respectively, by cryoelectron microscopy and image reconstruction techniques. the closely similar structures show 60 icosahedrally organized trimeric spikes on the particle surface. each spike consists of three prm:e heterodimers, where e is an envelope glycoprotein and prm is the precursor to the membrane protein m. the pre-peptide components of the prm proteins in each spike cover th ...	2003	12773377
crystallization and preliminary x-ray diffraction analysis of langat virus envelope protein domain iii.	the putative receptor-binding domain (domain iii) of the flavivirus langat envelope glycoprotein has been crystallized using the hanging-drop vapor-diffusion method at 277 k. two distinct crystal morphologies were observed to grow under the same conditions. the crystal forms both belong to a trigonal space group, p3(1)21 or p3(2)21, with unit-cell parameters a = 80.93, c = 132.1 a and a = 104.8, c = 219.5 a for forms i and ii, respectively. complete data sets to 2.9 and 3.35 a, respectively, hav ...	2003	12777770
molecular detection of west nile virus rna.	west nile virus is a mosquito-borne flavivirus that is primarily maintained in nature in a mosquito-bird-mosquito transmission cycle. mammals, including humans and horses, are incidentally infected through biting by mosquitoes infected with west nile virus. since 1994, west nile virus outbreaks have occurred with a high incidence of severe disease in humans and horses. in the usa, west nile virus was first detected in 1999 in new york city and has since spread to 39 states in humans. the virus h ...	2003	12779009
traditional and novel approaches to flavivirus vaccines.	yellow fever, dengue, japanese encephalitis and tick-borne encephalitis viruses are the medically most important members of the flavivirus genus composed primarily of arboviruses. in this paper, we review the commercially available traditional flavivirus vaccines against yellow fever, japanese encephalitis, and tick-borne encephalitis, as well as modern approaches to flavivirus vaccines. formalin inactivation technology has been employed to produce killed vaccines. flaviviruses have been attenua ...	2003	12782056
dendritic-cell-specific icam3-grabbing non-integrin is essential for the productive infection of human dendritic cells by mosquito-cell-derived dengue viruses.	dengue virus (dv) is a mosquito-borne flavivirus that causes haemorrhagic fever in humans. dv primarily targets immature dendritic cells (dcs) after a bite by an infected mosquito vector. here, we analysed the interactions between dv and human-monocyte-derived dcs at the level of virus entry. we show that the dc-specific icam3-grabbing non-integrin (dc-sign) molecule, a cell-surface, mannose-specific, c-type lectin, binds mosquito-cell-derived dvs and allows viral replication. conclusive evidenc ...	2003	12783086
the extent of homologous recombination in members of the genus flavivirus.	the family flaviviridae includes important human pathogens, such as dengue (den) virus, yellow fever (yf) virus and hepatitis c virus, many of which have emerged or re-emerged in recent years. until recently, flavivirus evolution was thought to proceed in a clonal manner, with diversity generated mainly through the accumulation of mutational changes. however, this assumption has now been shown to be invalid, with homologous recombination demonstrated in all three genera of the flaviviridae: sinc ...	2003	12560576
interferons, interferon inducers, and interferon-ribavirin in treatment of flavivirus-induced encephalitis in mice.	we evaluated the prophylactic and therapeutic efficacy of interferon alpha-2b, pegylated interferon alpha-2b, poly(i. c), and ampligen against modoc virus encephalitis in an animal model for flavivirus infections. all compounds significantly delayed virus-induced morbidity (paralysis) and mortality (due to progressive encephalitis). viral load (as measured on day 7 postinfection) was significantly reduced by 80 to 100% in the serum, brain, and spleen in mice that had been treated with either int ...	2003	12543691
role of the transmembrane domains of prm and e proteins in the formation of yellow fever virus envelope.	flavivirus envelope proteins have been shown to play a major role in virus assembly. these proteins are anchored into cellular and viral membranes by their c-terminal domain. these domains are composed of two hydrophobic stretches separated by a short hydrophilic segment containing at least one charged residue. we investigated the role of the transmembrane domains of prm and e in the envelope formation of the flavivirus yellow fever virus (yfv). alanine scanning insertion mutagenesis has been us ...	2003	12502797
characterization of a siberian virus isolated from a patient with progressive chronic tick-borne encephalitis.	a strain of tick-borne encephalitis virus designated zausaev (za) was isolated in siberia from a patient who died of a progressive (2-year) form of tick-borne encephalitis 10 years after being bitten by a tick. the complete genomic sequence of this virus was determined, and an attempt was made to correlate the sequence with the biological characteristics of the virus. phylogenetic analysis demonstrated that this virus belongs to the siberian subtype of tick-borne encephalitis virus. comparison o ...	2003	12477807
spontaneous mutations restore the viability of tick-borne encephalitis virus mutants with large deletions in protein c.	the capsid protein, c, of tick-borne encephalitis virus has recently been found to tolerate deletions up to a length of 16 amino acid residues that partially removed the central hydrophobic domain, a sequence element conserved among flaviviruses which may be crucial for virion assembly. in this study, mutants with deletion lengths of 19, 21, 27, or 30 residues, removing more or all of this hydrophobic domain, were found to yield viable virus progeny, but this was without exception accompanied by ...	2003	12477849
cleavage of protein prm is necessary for infection of bhk-21 cells by tick-borne encephalitis virus.	flavivirus particles are synthesized in an immature form containing heterodimers of the proteins prm and e. shortly before release from the cell, prm is cleaved by the host protease furin to yield mature virions. in this study, the furin-mediated cleavage of the tick-borne encephalitis (tbe) virus protein prm was prevented by specific mutagenesis of the cleavage site. this resulted in the production of immature tbe virions, which were shown to be completely non-infectious in bhk-21 cells. this f ...	2003	12533715
polystyrene derivatives substituted with arginine interact with babanki (togaviridae) and kedougou (flaviviridae) viruses.	outbreaks of new or old diseases appear primarily in tropical zones such as africa, south and central america, or asia. among these diseases, those induced by arboviruses (the best known of which are being yellow fever, dengue, ebola, and sindbis) are under intensive observation by the world health organization. rapid isolation and identification of the viral species is the first step in the diagnosis, study, and control of epidemics. one major problem with the isolation of viruses is capturing ...	2003	12601758
role of type i and type ii interferon responses in recovery from infection with an encephalitic flavivirus.	we have investigated the contribution of the interferon (ifn)-alpha/beta system, ifn-gamma and nitric oxide to recovery from infection with murray valley encephalitis virus, using a mouse model for flaviviral encephalitis where a small dose of virus was administered to 6-week-old wild-type and gene knockout animals by the intravenous route. we show that a defect in the ifn-alpha/beta responses results in uncontrolled extraneural virus growth, rapid virus entry into the brain and 100 % mortality. ...	2003	12604807
enzyme-linked immunosorbent assay using recombinant antigens expressed in mammalian cells for serodiagnosis of tick-borne encephalitis.	a recombinant plasmid that expresses the tick-borne encephalitis (tbe) virus premembrane (prm) and envelope (e) proteins in mammalian cells was constructed. recombinant proteins retained antigenic and conformational structures similar to those of native virus proteins, and transfected cells released virus-like particles (vlps), which were 1.13-1.14 g/ml in density and 20-30 nm in diameter, into the culture medium. recombinant e proteins were used for the development of an enzyme-linked immunosor ...	2003	12609684