Publications

peptide inhibitors of dengue virus ns3 protease. part 1: warhead.	substrate-based tetrapeptide inhibitors with various warheads were designed, synthesized, and evaluated against the dengue virus ns3 protease. effective inhibition was achieved by peptide inhibitors with electrophilic warheads such as aldehyde, trifluoromethyl ketone, and boronic acid. a boronic acid has the highest affinity, exhibiting a k(i) of 43 nm.	2006	16246553
peptide inhibitors of dengue virus ns3 protease. part 2: sar study of tetrapeptide aldehyde inhibitors.	with the aim of discovering potent and selective dengue ns3 protease inhibitors, we systematically synthesized and evaluated a series of tetrapeptide aldehydes based on lead aldehyde 1 (bz-nle-lys-arg-arg-h, k(i)=5.8 microm). in general, we observe that interactions of p(2) side chain are more important than p(1) followed by p(3) and p(4). tripeptide and dipeptide aldehyde inhibitors also show low micromolar activity. additionally, an effective non-basic, uncharged replacement of p(1) arg is ide ...	2006	16246563
west nile flavivirus polioencephalomyelitis in a harbor seal (phoca vitulina).	a 12-year-old male harbor seal presented with progressive signs of neurologic dysfunction including head tremors, muzzle twitching, clonic spasms, and weakness. lesions included polioencephalomyelitis with glial nodules, spheroids, neuronophagia, ring hemorrhages, and a few neutrophils. neurons, fibers, and glial nodules were multifocally colonized with intracytoplasmic west nile flavivirus antigens that were demonstrated using indirect immunohistochemical analysis. flavivirus on cultured cells ...	2006	16407488
energetics of rna binding by the west nile virus rna triphosphatase.	the west nile virus (wnv) rna genome harbors the characteristic methylated cap structure present at the 5' end of eukaryotic mrnas. in the present study, we report a detailed study of the binding energetics and thermodynamic parameters involved in the interaction between rna and the wnv rna triphosphatase, an enzyme involved in the synthesis of the rna cap structure. fluorescence spectroscopy assays revealed that the initial interaction between rna and the enzyme is characterized by a high entha ...	2006	16413541
west nile virus discriminates between dc-sign and dc-signr for cellular attachment and infection.	the c-type lectins dc-sign and dc-signr bind mannose-rich glycans with high affinity. in vitro, cells expressing these attachment factors efficiently capture, and are infected by, a diverse array of appropriately glycosylated pathogens, including dengue virus. in this study, we investigated whether these lectins could enhance cellular infection by west nile virus (wnv), a mosquito-borne flavivirus related to dengue virus. we discovered that dc-signr promoted wnv infection much more efficiently t ...	2006	16415006
antibodies against west nile virus nonstructural protein ns1 prevent lethal infection through fc gamma receptor-dependent and -independent mechanisms.	the flavivirus nonstructural protein ns1 is a highly conserved secreted glycoprotein that does not package with the virion. immunization with ns1 elicits a protective immune response against yellow fever, dengue, and tick-borne encephalitis flaviviruses through poorly defined mechanisms. in this study, we purified a recombinant, secreted form of west nile virus (wnv) ns1 glycoprotein from baculovirus-infected insect cells and generated 22 new ns1-specific monoclonal antibodies (mabs). by perform ...	2006	16415011
class ii virus membrane fusion proteins.	enveloped animal viruses fuse their membrane with a host cell membrane, thus delivering the virus genetic material into the cytoplasm and initiating infection. this critical membrane fusion reaction is mediated by a virus transmembrane protein known as the fusion protein, which inserts its hydrophobic fusion peptide into the cell membrane and refolds to drive the fusion reaction. this review describes recent advances in our understanding of the structure and function of the class ii fusion prote ...	2006	16364734
a rapid and quantitative assay for measuring antibody-mediated neutralization of west nile virus infection.	west nile virus (wnv) is a neurotropic flavivirus within the japanese encephalitis antigenic complex that is responsible for causing west nile encephalitis in humans. the surface of wnv virions is covered by a highly ordered icosahedral array of envelope proteins that is responsible for mediating attachment and fusion with target cells. these envelope proteins are also primary targets for the generation of neutralizing antibodies in vivo. in this study, we describe a novel approach for measuring ...	2006	16325883
immunological properties of recombinant classical swine fever virus ns3 protein in vitro and in vivo.	classical swine fever (csf) is a highly contagious and often fatal disease of pigs characterised by fever, severe leukopenia and haemorrhages. with vaccines having an importance in disease control, studies are seeking improved protein-based subunit vaccine against the virus (csfv). in this respect, recombinant viral ns3 protein was analysed for its immunopotentiating capacity, particularly in terms of cytotoxic immune responses. ns3 was effective at inducing in vitro responses, quantified by lym ...	2006	16336932
end-to-end communication in the modulation of translation by mammalian rna viruses.	a 5'-3' end interaction leading to stimulation of translation has been described for many cellular and viral mrnas. enhancement of viral translational efficiency mediated by 5' and 3' untranslated regions (utrs) has been shown to occur via rna-rna interactions or novel rna-protein interactions. mammalian rna viruses make use of end-to-end communication in conjunction with both viral and cellular factors to regulate multiple processes including translation initiation and the switch between transl ...	2006	16307817
a single immunization with a minute dose of a lentiviral vector-based vaccine is highly effective at eliciting protective humoral immunity against west nile virus.	lentiviral vectors, due to their capacity to transduce non-dividing cells, have become precious and worldwide used gene transfer systems. their ability to efficiently and stably transduce dendritic cells (dcs) has led to their successful use as vaccination vectors for eliciting strong, specific and protective cellular immune responses mostly in anti-tumoral but also in anti-viral applications. however, the ability of lentiviral vectors to elicit an antibody-based protective immunity has, to date ...	2006	16308885
antiviral effect of the heparan sulfate mimetic, pi-88, against dengue and encephalitic flaviviruses.	many viruses, including flaviviruses, display affinity for cell surface heparan sulfate (hs) proteoglycans with biological relevance in virus attachment/entry. this raises the possibility of the application of hs mimetics in antiviral therapy. we have evaluated the antiviral effect of the sulfated polysaccharides, suramin, pentosan polysulfate (pps) and pi-88, which are currently approved or in trial for clinical use, against dengue virus (den) and the encephalitic flaviviruses, japanese encepha ...	2006	16309754
molecular characterization of attenuated japanese encephalitis live vaccine strain ml-17.	the japanese encephalitis (je) zoonotic vaccine strain ml-17 was sequenced and compared to related je virus strains to identify genomic attenuation markers. relative to its parental strain, jaoh0566, 25 nucleotide alterations and 10 amino acid changes to, prm/m(2), ns2a(1), ns4b(3) and ns5(4) proteins were recorded. both structural-gene changes were in the prm/m region (127met-->ile and 274asn-->thr). to study the effects of these prm/m changes, mutants bearing the changes were prepared using an ...	2006	16303214
recent advances in flavivirus antiviral drug discovery and vaccine development.	many flaviviruses, including yellow fever virus, dengue virus, japanese encephalitis virus, tick-borne encephalitis virus, and west nile virus, are globally important human pathogens. despite an emergence and resurgence of flavivirus-mediated disease, specific therapies are not yet available; however, significant progress has been made toward the prevention and treatment of flavivirus infections. in this article we review recent advances made in the areas of (i) flavivirus vaccine development, a ...	2006	18221133
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
[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
cleavage targets and the d-arginine-based inhibitors of the west nile virus ns3 processing proteinase.	mosquito-borne wnv (west nile virus) is an emerging global threat. the ns3 proteinase, which is essential for the proteolytic processing of the viral polyprotein precursor, is a promising drug target. we have isolated and biochemically characterized the recombinant, highly active ns3 proteinase. we have determined that the ns3 proteinase functions in a manner that is distantly similar to furin in cleaving the peptide and protein substrates. we determined that aprotinin and d-arginine-based 9-12- ...	2006	16229682
alkhurma hemorrhagic fever virus is an emerging tick-borne flavivirus.		2006	16216331
a multigene analysis of the phylogenetic relationships among the flaviviruses (family: flaviviridae) and the evolution of vector transmission.	the genus flavivirus (family flaviviridae) presently comprises around 70 single-strand positive-sense rna viruses. these replicate in a range of vertebrate and invertebrate cells and may be mosquito-borne, tick-borne or have no-known-vector. since transmission mode correlates strongly with phylogeny, the flaviviruses constitute a valuable model for the evolution of vector-borne disease. attempts to resolve the higher-level taxonomic relationships of the flaviviruses through molecular phylogeneti ...	2006	16172840
immunogenicity of combination dna vaccines for rift valley fever virus, tick-borne encephalitis virus, hantaan virus, and crimean congo hemorrhagic fever virus.	dna vaccines for rift valley fever virus (rvfv), crimean congo hemorrhagic fever virus (cchfv), tick-borne encephalitis virus (tbev), and hantaan virus (htnv), were tested in mice alone or in various combinations. the bunyavirus vaccines (rvfv, cchfv, and htnv) expressed gn and gc genes, and the flavivirus vaccine (tbev) expressed the prem and e genes. all vaccines were delivered by gene gun. the tbev dna vaccine and the rvfv dna vaccine elicited similar levels of antibodies and protected mice f ...	2006	16174542
antigenicity of chimeric and cyclic synthetic peptides based on nonstructural proteins of gbv-c/hgv.	in this work, new putative epitopes located in nonstructural proteins of gbv-c/hgv were synthesized using solid-phase chemistry for their use in immunoassays. the antigens were obtained in linear, chimeric and cyclic forms with the main aim of improving the sensitivity of the enzyme immunoassays. our results showed, on one hand, that the combination of different antigens seems to be necessary to ensure good sensitivity and more specificity and, on the other hand, that cyclic compounds show highe ...	2006	16180243
flavivirus induces interferon-beta gene expression through a pathway involving rig-i-dependent irf-3 and pi3k-dependent nf-kappab activation.	in this study, we found that infection with flaviviruses, such as japanese encephalitis virus (jev) and dengue virus serotype 2 (den-2), leads to interferon-beta (ifn-beta) gene expression in a virus-replication- and de novo protein-synthesis-dependent manner. nf-kappab activation is essential for ifn-beta induction in jev- and den-2-infected cells. however, these two viruses seem to preferentially target different members of the interferon regulatory factor (irf) family. the activation of const ...	2006	16182584
determining genetic stabilities of chimeric dengue vaccine candidates based on dengue 2 pdk-53 virus by sequencing and quantitative taqmama.	the genetic stabilities of the three attenuation loci of the candidate dengue 2 (d2) pdk-53 vaccine virus were evaluated for the pdk-53 virus and pdk-53-vectored chimeric d2/1, d2/3, and d2/4 viruses following 10 sequential passages in vero cells. sequencing revealed that the dominant ns1-53-asp and the ns3-250-val attenuation loci were extremely stable, whereas reversion occurred at the 5'ncr-57-u locus in 10 of the 18 viral lineages tested. a more sensitive and quantitative assay, the taqman m ...	2006	16087248
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
field effectiveness of vaccination against tick-borne encephalitis.	tick-borne encephalitis (tbe) is a vaccine-preventable disease caused by a flavivirus (tbe virus) that is endemic in many european countries and large parts of central and eastern asia. in europe, highly purified formalin-inactivated whole virus vaccines are in widespread use, but the vaccination coverage differs significantly between countries with tbe endemicity. austria presents an exceptional situation because 88% of the total population have a history of tbe vaccination, with 58% being regu ...	2007	17869389
west nile virus-induced cytoplasmic membrane structures provide partial protection against the interferon-induced antiviral mxa protein.	the human mxa protein is a type i and iii interferon (ifn)-induced protein with proven antiviral activity against rna viruses. in this study, we investigated the effect of mxa expression on the replication of west nile virus strain kunjin (wnv(kun)). pretreatment of a549 cells with ifn-alpha lead to increased expression of mxa, which contributed to inhibition of wnv(kun) replication and secretion. however, in vero cells stably expressing the mxa protein, wnv(kun) replication, maturation and secr ...	2007	17947524
a short treatment of cells with the lanthanide ions la3+, ce3+, pr3+ or nd3+ changes the cellular chemistry into a state in which rna replication of flaviviruses is specifically blocked without interference with host-cell multiplication.	alpha- and flaviviruses contain class ii fusion proteins, which form ion-permeable pores in the target membrane during virus entry. the pores generated during entry of the alphavirus semliki forest virus have been shown previously to be blocked by lanthanide ions. here, analyses of the influence of rare earth ions on the entry of the flaviviruses west nile virus and uganda s virus revealed an unexpected effect of lanthanide ions. the results showed that a 30 s treatment of cells with an appropri ...	2007	17947525
construction and characterization of recombinant flaviviruses bearing insertions between e and ns1 genes.	the yellow fever virus, a member of the genus flavivirus, is an arthropod-borne pathogen causing severe disease in humans. the attenuated yellow fever 17d virus strain has been used for human vaccination for 70 years and has several characteristics that are desirable for the development of new, live attenuated vaccines. we described here a methodology to construct a viable, and immunogenic recombinant yellow fever 17d virus expressing a green fluorescent protein variant (egfp). this approach too ...	2007	17971212
safety and efficacy in geese of a per.c6-based inactivated west nile virus vaccine.	studies were performed with an inactivated vaccine against the mosquito-borne flavivirus, west nile virus (wnv). the mammalian cell line, per.c6, was selected as the platform for wnv growth since both the neurovirulent strains ny99 and isr98 that cause epidemics in humans and high mortality in geese, respectively, could be propagated to high titers (10(9) to 10(10)tcid(50)/ml) on these cells. based on the high dna homology of the wnv envelope (e) protein and non-structural protein 5 (ns5), and i ...	2007	17977629
recent change of the antigenicity and genotype of japanese encephalitis viruses distributed on okinawa island, japan.	in this study, five isolates of japanese encephalitis virus (jev) were obtained from swine serum samples collected on okinawa island, japan, between 2002 and 2003. all five jev isolates belonged to genotype 1, and jev isolates obtained from the island before 1992 were genotype 3. genotype 1 was known to be distributed from northern thailand to cambodia and recently expanded to australia, vietnam, the republic of korea, and japan. however, phylogenetic analysis showed that the source of the newly ...	2007	17978081
maculopathy associated with dengue fever in a military pilot.	dengue fever is the most prevalent vector-borne flavivirus infection in humans. its ocular manifestations have only recently been reported with increasing frequency. we present a case of an air force rotary wing pilot who presented with dengue-related maculopathy and decrement in visual function. the pilot ultimately recovered full visual function and was returned to full unrestricted flying duties with the proviso of regular ophthalmic monitoring. dengue-related maculopathy may present with ret ...	2007	18018440
a real-time rt-pcr method for the universal detection and identification of flaviviruses.	here we describe an optimized molecular protocol for the universal detection and identification of flaviviruses. it combines the convenient real-time polymerase chain reaction (pcr) format with a broad spectrum of flavivirus detection. this assay, based on the amplification of a 269-272 nt (depending on the flavivirus tested) region at the n terminal end of the ns5 gene, enabled the amplification of 51 flavivirus species and 3 tentative species. sequencing of the amplicons produced by reverse tr ...	2007	18020965
expression of gb virus c ns5a protein from genotypes 1, 2, 3 and 5 and a 30 aa ns5a fragment inhibit human immunodeficiency virus type 1 replication in a cd4+ t-lymphocyte cell line.	gb virus type c (gbv-c) is a common human flavivirus that has been associated with prolonged survival in hiv-positive individuals in several, though not all, epidemiological studies. there are five distinct gbv-c genotypes that are geographically localized, and it has been speculated that gbv-c genotypic differences may explain variable outcomes observed in different clinical studies. expression of an 85 aa fragment of the gbv-c ns5a phosphoprotein (genotype 2) in a cd4+ t cell line (jurkat) res ...	2007	18024904
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
the continuing spread of west nile virus in the western hemisphere.	west nile virus (wnv) has historically been considered to be among the least virulent of the japanese serogroup viruses of the family flaviviridae, genus flavivirus. however, recent epidemics associated with severe and fatal neuroinvasive disease have changed that perception. the emergence of a virus subtype with greater epidemic potential and virulence in the early 1990s facilitated the geographic expansion and westward spread of wnv; in 1999, it first appeared in the western hemisphere. becaus ...	2007	17879923
type- and subcomplex-specific neutralizing antibodies against domain iii of dengue virus type 2 envelope protein recognize adjacent epitopes.	neutralization of flaviviruses in vivo correlates with the development of an antibody response against the viral envelope (e) protein. previous studies demonstrated that monoclonal antibodies (mabs) against an epitope on the lateral ridge of domain iii (diii) of the west nile virus (wnv) e protein strongly protect against infection in animals. based on x-ray crystallography and sequence analysis, an analogous type-specific neutralizing epitope for individual serotypes of the related flavivirus d ...	2007	17881453
virtual screening and bioassay study of novel inhibitors for dengue virus mrna cap (nucleoside-2'o)-methyltransferase.	we report high-throughput structure-based virtual screening of putative flavivirus 2'-o-methyltransferase inhibitors together with results from subsequent bioassay tests of selected compounds. potential inhibitors for the s-adenosylmethionine binding site were explored using 2d similarity searching, pharmacophore filtering and docking. the inhibitory activities of 15 top-ranking compounds from the docking calculations were tested on a recombinant methyltransferase with the rna substrate (7me)gpp ...	2007	17888664
structure of the murray valley encephalitis virus rna helicase at 1.9 angstrom resolution.	murray valley encephalitis virus (mvev), a mosquito-borne flavivirus endemic to australia, is closely related to japanese encephalitis virus and west nile virus. nonstructural protein 3 (ns3) is a multifunctional enzyme with serine protease and dexh/d-box helicase domains, whose activity is central to flavivirus replication and is therefore a possible target for anti-flaviviral compounds. cloning, purification, and crystal structure determination to 1.9 angstrom resolution of the ns3 helicase of ...	2007	17893366
prevalence and genotypes of hepatitis g virus/gb virus c in a multirisk group in hungary.	hgv/gbv-c is a mainly parenterally transmitted flavivirus that causes a persistent infection. so far no disease has been associated with hgv/gbv-c infection, but its beneficial role in co-infection with the human immunodeficiency virus has been shown in many recent studies. the aim of our study was to determine the frequency of ongoing hgv/gbv-c infections among a sociologically unique group of the hungarian population, who are at great risk for parenterally transmitted diseases. viral rna was d ...	2007	17896477
different contribution of co-stimulatory molecules b7.1 and b7.2 to the immune response to recombinant modified vaccinia virus ankara vaccine expressing prm/e proteins of japanese encephalitis virus and two hepatitis b virus vaccines.	this study clarifies the role of co-stimulatory molecules b7.1 and b7.2 in the immune response to 3 types of vaccines: a/ recombinant modified vaccinia virus ankara (mva) (vjh9) expressing prm/e proteins of japanese encephalitis virus (jev), b/ recombinant yeast-expressed hepatitis b virus (yhbv), c/ human plasma-derived hepatitis b virus (phbv). we constructed plasmids expressing b7.1 and b7.2 molecules and found that the expression level of b7.2 protein in transfected cho-k1 cells was higher t ...	2007	17900219
knock-in of the oas1b(r) allele into a flavivirus-induced disease susceptible mouse generates the resistant phenotype.	inheritance patterns in mice suggested that resistance to flavivirus-induced disease was conferred by a single autosomal dominant allele (flv(r)). a positional cloning strategy followed by comparison of flv interval gene sequences from congenic resistant c3h.pri-flv(r) and susceptible c3h/he mouse strains identified the 2'-5'-oligoadenylate synthetase 1b (oas1b) gene as flv. however, since these mouse strains differ by a 31 cm region, the possible involvement of differences in other linked genes ...	2007	17904183
abrogation of macrophage migration inhibitory factor decreases west nile virus lethality by limiting viral neuroinvasion.	the flavivirus west nile virus (wnv) is an emerging pathogen that causes life-threatening encephalitis in susceptible individuals. we investigated the role of the proinflammatory cytokine macrophage migration inhibitory factor (mif), which is an upstream mediator of innate immunity, in wnv immunopathogenesis. we found that patients suffering from acute wnv infection presented with increased mif levels in plasma and in cerebrospinal fluid. mif expression also was induced in wnv-infected mice. rem ...	2007	17909632
emergence of usutu virus in hungary.	in 2001, usutu virus (usuv), a mosquito-borne flavivirus of the japanese encephalitis virus serogroup related to west nile virus and previously restricted to sub-saharan africa, emerged in wild and zoo birds in and around vienna, austria. in order to monitor the spread of the infection, a dead bird surveillance program was established in austria and in neighboring hungary. in hungary, 332 dead birds belonging to 52 species were tested for usuv infection between 2003 and 2006. in the first 2 year ...	2007	17913929
expectoration of flaviviruses during sugar feeding by mosquitoes (diptera: culicidae).	biological transmission of arboviruses to a vertebrate host occurs when virions are expelled along with saliva during blood feeding by a hematophagous arthropod. we undertook experiments to determine whether mosquitoes expectorate flaviviruses in their saliva while sugar feeding. batches of culex annulirostris skuse and culex gelidus theobald (diptera: culicidae) were orally infected with japanese encephalitis (family flaviviridae, genus flavivirus, jev), kunjin (family flaviviridae, genus flavi ...	2007	17915518
evaluation of circulating natural type 1 interferon-producing cells in hiv/gbv-c and hiv/hcv coinfected patients: a preliminary study.	gb virus-c (gbv-c) is a flavivirus that probably influences hiv infection-associated disease among hiv/gbv-c coinfected patients and inhibits the progression of hiv infection to aids. to address the possibility of immune-modulating effects of gbv-c coinfection in hiv patients, we evaluated interferon-producing cells in hiv/gbv-c coinfected patients and compared them to hiv-infected patients.	2007	17923269
west nile virus-infected dead corvids increase the risk of infection in culex mosquitoes (diptera: culicidae) in domestic landscapes.	a comparative study of west nile virus (family flaviviridae, genus flavivirus, wnv) infection rates in culex mosquitoes collected at 13 sites, seven reporting wnv-positive dead corvids (case sites) and six without reported dead birds (control sites) was conducted in davis, ca, from 14 to 21 july at the beginning of the 2006 wnv outbreak. in total, 3051 culex mosquitoes were collected using gravid traps and co2-baited traps; wnv-infected mosquitoes were only collected with co2-baited traps. wnv-i ...	2007	18047208
west nile virus infection decreases fecundity of culex tarsalis females.	west nile virus (family flaviviridae, genus flavivirus, wnv) persistently infects many mosquito tissues, and it has been associated with cytopathological changes in midgut muscles and salivary glands. however, the effects of wnv infection on mosquito fitness (survival and reproduction) are not known. we conducted a life table study of individually housed female culex tarsalis coquillett. after an initial bloodmeal from a wnv-infected or uninfected chicken, mosquitoes were provided sucrose and of ...	2007	18047209
nocturnal activity of mosquitoes (diptera: culicidae) in a west nile virus focus in connecticut.	six species of mosquitoes (diptera: culicidae) were collected in sufficient numbers for analysis in segregating traps set at 2-h intervals by using co2 and light as attractants in a west nile virus (family flaviviridae, genus flavivirus, wnv) focus in stratford, ct. the kolmogorov-smirnov one-sided test for two samples was used to analyze the data. mosquito activity began shortly before sunset and continued until shortly after sunrise the next morning. all species had geometric means that were s ...	2007	18047212
spatiotemporal investigation of adult mosquito (diptera: culicidae) populations in an eastern iowa county, usa.	landscape and climatic factors regulate distributions of mosquitoes (diptera: culicidae) over time and space. the anthropogenic control of mosquito populations is often carried out at a local administrative scale, and it is applied based on the relevant agency's experiential knowledge rather than systematic analysis of spatial and temporal data. to address this shortcoming, a spatial and temporal analysis of landscape and climatic parameters in relation to mosquito populations in black hawk coun ...	2007	18047216
optic neuropathy from viruses and spirochetes.		2007	18049280
[molecular epidemiology of tick-borne encephalitis].	the review presents information on the development of studies into the molecular epidemiology of tick-borne encephalitis (tbe) in russia and foreign countries. the existence of three major virus genotypes has been established by various techniques, such as genomic fragment sequencing, molecular hybridization using genotype-specific probes, and restriction fragment length polymorphism test. each of the genotypes prevails in different parts of a natural habitat; the ural-siberian genotype (a siber ...	2007	18050710
[biological and molecular genetic characteristics of a far-eastern tick-borne encephalitis virus population and its pathogenetic implication].	the authors have got an idea of the structure of the tick-borne encephalitis (tbe) virus population forming in the human body after tick bite in the south of the far east. a hundred and forty-five antigen-positive samples were virologically studied in enzyme immunoassays. human blood leukocytic virus isolation on the first day of tick suction testified to the capacity of the virus to adsorb and multiply just in the peripheral blood immunocompetent cells. the bulk (as high as 70%) of the tbe viru ...	2007	18050711
[development of amplification technology-based methods for tick-borne encephalitis virus detection and genotyping].	the development of methods for tick-borne encephalitis (tbe) virus genotyping, such as determination of nucleotide sequences, analysis of restriction fragment length polymorphism, polymerase chain reaction using genotype-specific probes with hybridization-fluorescence detection, is under consideration. the capacities and application area of varions typing techniques, such as tbe detection and genotyping in the field, autoptic, and cultural materials; study of circulating genotypes in different n ...	2007	18050712
[evolution of tick-borne encephalitis and a problem of evolution of its causative agent].	the evolution of tick-borne encephalitis (tbe) is marked by the expanded nosological area, the transformation of landscapes, the formation of anthropurgic foci, the change of environmental systems, the increase of mortality rate mainly among urban dwellers, as well as pathomorphism. the evolution of natural tbe virus (tbev) populations was studied in eastern and western siberia, middle urals, and the european part of the nosological area. the paper first describes the types of evolutionary trans ...	2007	18041219
[complex environmental and virological monitoring in the primorye territory in 2003-2006].	the paper presents the results of monitoring of viruses of western nile (wn), japanese encephalitis (je), tick-borne encephalitis (tbe), geta, influenza a, as well as avian paramicroviruses type i (virus of newcastle disease (nd)) and type 6 (apmv-6) in the primorye territory in 2003-2006. totally throughout the period, specific antibodies to the viruses were detected by neutralization test in wild birds (7.3%, wn; 8.0%, geta; 0.7% batai; 2.8%, alpine hare (lepus timidus); by hemagglutination-in ...	2007	18041224
safety of an attenuated west nile virus vaccine, live flavivirus chimera in horses.	west nile virus (wnv) infection is endemic and able to cause disease in naive hosts. it is necessary therefore to evaluate the safety of new vaccines.	2007	18065304
efficacy, duration, and onset of immunogenicity of a west nile virus vaccine, live flavivirus chimera, in horses with a clinical disease challenge model.	west nile virus (wnf) is a flavivirus responsible for a life-threatening neurological disease in man and horses. development of improved vaccines against flavivirus infections is therefore important.	2007	18065305
incidence of primary dengue virus infections in southern vietnamese children and reactivity against other flaviviruses.	to study the incidence of asymptomatic primary dengue infections among children and reactivity against other flaviviruses.	2007	18076564
complement protein c1q inhibits antibody-dependent enhancement of flavivirus infection in an igg subclass-specific manner.	severe dengue virus infection can occur in humans with pre-existing antibodies against the virus. this observation led to the hypothesis that a subneutralizing antibody level in vivo can increase viral burden and cause more severe disease. indeed, antibody-dependent enhancement of infection (ade) in vitro has been described for multiple viruses, including the flaviviruses dengue virus and west nile virus. here, we demonstrate that the complement component c1q restricts ade by anti-flavivirus igg ...	2007	18078693
detection and isolation of japanese encephalitis virus from blood clots collected during the acute phase of infection.	clinical specimens from an encephalitis outbreak in the lakhimpur area of uttar pradesh, india, were investigated for identification and characterization of the etiologic agent. igm capture elisa showed recent japanese encephalitis virus (jev) infection. jev isolation was attempted from white blood cells (wbcs) separated from blood clots of 12 patients (9 igm positive and 3 negative) by serial co-culturing with phytohemagglutinin p-stimulated peripheral blood mononuclear leukocytes (pbmcs) obtai ...	2007	18165537
flavivirus-like particles in the cardiac myocyte of a patient with arrhythmogenic right ventricular cardiomyopathy.		2007	18167234
epidemiological study of tick-borne encephalitis virus in northern greece.	serum samples from 921 apparently healthy individuals living in different prefectures of northern greece were investigated for the presence of antibodies against tick-borne encephalitis (tbe) virus. in addition, serum and cerebrospinal fluid samples of 302 patients with central nervous system (cns) infection were tested for the presence of specific igg and igm antibodies and tbe virus rna. two percent of the general population was found to have antibodies to the virus, with no significant differ ...	2007	18171108
ultrastructural evidence of the ehrlichial developmental cycle in naturally infected ixodes persulcatus ticks in the course of coinfection with rickettsia, borrelia, and a flavivirus.	ehrlichiae are small gram-negative obligately intracellular bacteria that multiply within vacuoles of their host cells and are associated for a part of their life cycle with ticks, which serve as vectors for vertebrate hosts. two morphologically and physiologically different ehrlichial cell types, reticulate cells (rc) and dense-cored cells (dc), are observed during experimental infection of cell cultures, mice, and ticks. dense-cored cells and reticulate cells in vertebrate cell lines alternate ...	2007	18171109
hts identifies novel and specific uncompetitive inhibitors of the two-component ns2b-ns3 proteinase of west nile virus.	west nile virus (wnv), a member of the flavividae family, is a mosquito-borne, emerging pathogen. in addition to wnv, the family includes dengue, yellow fever, and japanese encephalitis viruses, which affect millions of individuals worldwide. because countermeasures are currently unavailable, flaviviral therapy is urgently required. the flaviviral two-component nonstructural ns2b-ns3 proteinase (protease [pro]) is essential for viral life cycle and, consequently, is a promising drug target. we r ...	2007	18181690
flavivirus dna vaccines--good science, uncertain future.		2007	18190248
a west nile virus dna vaccine induces neutralizing antibody in healthy adults during a phase 1 clinical trial.	west nile virus (wnv) is a mosquito-borne flavivirus that can cause severe meningitis and encephalitis in infected individuals. we report the safety and immunogenicity of a wnv dna vaccine in its first phase 1 human study.	2007	18190252
antibodies targeting linear determinants of the envelope protein protect mice against west nile virus.	the flavivirus envelope (e) protein mediates cellular attachment and fusion with host cell membranes and is recognized by virus-neutralizing antibodies. we raised antibodies against a broad range of epitopes by immunizing a horse with recombinant west nile virus (wnv) e protein. to define epitopes recognized by protective antibodies, we selected, by affinity chromatography, immunoglobulins against immobilized linear peptides derived from parts of the e protein. immunoglobulins binding 9 differen ...	2007	18190253
[west nile fever/encephalitis].	west nile virus (wnv), a member of the family flaviviridae (genus flavivirus), is a mosquito-borne virus first isolated in 1937 in the west nile district of uganda. the disease in humans is characterized by a dengue-like illness with fever, and a more severe form is characterized by central nervous system involvement, including encephalitis, meningitis, and myelitis. wn encephalitis was first reported in the western hemisphere in the summer of 1999, there was an outbreak in new york city. epidem ...	2007	18357758
[global warming: trailblazer for tropical infections in germany?].	since 1850, the co (2) content of the atmosphere has increased from 280 to 360 ppm, and the average surface temperature has risen from 14.6 to 15.3 c . a further increase between 1.8 and 4.0 c is expected for the 21st century. temperate and cold climate zones are affected predominantly, but tropical regions are not spared. at the same time, the world wide climate effects of the "el niño southern oscillation" are amplified. global warming enhances the growth of tropical pathogens (malarial plasmo ...	2007	18033654
the internal initiation of translation in bovine viral diarrhea virus rna depends on the presence of an rna pseudoknot upstream of the initiation codon.	bovine viral diarrhea virus (bvdv) is the prototype representative of the pestivirus genus in the flaviviridae family. it has been shown that the initiation of translation of bvdv rna occurs by an internal ribosome entry mechanism mediated by the 5' untranslated region of the viral rna 1. the 5' and 3' boundaries of the ires of the cytopathic bvdv nadl have been mapped and it has been suggested that the ires extends into the coding of the bvdv polyprotein 2. a putative pseudoknot structure has b ...	2007	18034871
proliferative index in astrocytic tumours.	the accurate grading of astrocytic tumours is of prime importance because it is critical to the patient management and survival/outcome. although internationally accepted who grading system of cns tumours is based on histological features of h&e stained sections, yet there are cases where differentiation between grade ii and grade iii is difficult particularly when the biopsy is small. proliferative index derived from mib-1 immunostaining has been found to be useful in the distinction between va ...	2007	18306542
analysis of the domain interactions between the protease and helicase of ns3 in dengue and hepatitis c virus.	flaviviridae non-structural 3 protein (ns3) is a multifunctional enzyme, composed by a protease domain (ns3pro) and an rna helicase domain (ns3hel). the activities present in ns3 have proved to be critical for viral replication. the replicative cycle of flaviviridae requires coordinated regulation of all the activities present in the full-length ns3 protein, however, the exact nature of these interactions remains unclear. the present work aimed to determine common structural features between ns3 ...	2007	16762573
preparation and immunogenic properties of a recombinant west nile subunit vaccine.	while several west nile vaccines are being developed, none are yet available for humans. in this study aimed at developing a vaccine for humans, west nile virus (wnv) envelope protein (e) and non-structural protein 1 (ns1) were produced in the drosophila s2 cell expression system. the c-terminal 20% of the e protein, which contains the membrane anchor portion, was deleted, thus allowing for efficient secretion of the truncated protein (80e) into the cell culture medium. the proteins were purifie ...	2007	16996661
cell-specific adaptation of two flaviviruses following serial passage in mosquito cell culture.	west nile virus (wnv) is a mosquito-borne flavivirus that was introduced into the u.s. in the new york city area in 1999. despite its successful establishment and rapid spread in a naive environment, wnv has undergone limited evolution since its introduction. this evolutionary stability has been attributed to compromises made to permit alternating cycles of viral replication in vertebrate hosts and arthropod vectors. outbreaks of a close relative of wnv, st. louis encephalitis virus (slev), occu ...	2007	16963095
yellow fever: a disease that has yet to be conquered.	yellow fever virus (yfv) is the prototype member of the genus flavivirus, a group of viruses that are transmitted between vertebrates by arthropod vectors. the virus is found in tropical regions of africa and south america and is transmitted to primates by mosquitoes: aedes spp. in africa and haemagogus and sabethes spp. in south america. despite the availability of an effective vaccine, yellow fever (yf) is considered a reemerging disease owing to its increased incidence in the past 25 years. m ...	2007	16913829
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
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
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