detection of flavivirus antigens in purified infected vero cell plasma membranes.the types of kunjin virus-specified proteins present in purified vero cell plasma membrane were studied. immunofluorescence of unfixed kunjin virus-infected whole cell monolayers, indicated that two structural proteins (envelope and prm) and three non-structural proteins (ns1, 3 and 5) were found at the plasma membrane. there was no obvious progressive accumulation of the observed antigens over the time periods between 8 to 24 h p.i. thus sds-page analysis was performed using purified radiolabel ...19921331144
dispersal of adult females of culex annulirostris in griffith, new south wales, australia.the dispersal of culex annulirostris, a major arbovirus vector in australia, was studied in griffith, n.s.w. using a mark-release-recapture technique. from an empirical model of dispersal, fitted to data on recaptured adults, the average distance dispersed was 6.8 km (95% c.l. 4.1-40.9 km), and 50% of the population dispersed 4.8 km or more. maximum recorded dispersal was 8.7 km, and 2 individuals traveled more than 5 km in 1 day. the relevance of the findings to control strategy is discussed.19921331320
[genomic structure of togavirus and flavivirus]. 19921332117
[replication and gene expression of flavivirus]. 19921332124
[processing of flavivirus proteins]. 19921332128
arboviruses as aetiological agents of encephalitis in the people's republic of china.a serological study was undertaken to determine the role of arboviruses as etiological agents of encephalitis in the people's republic of china (prc). paired sera were collected during mosquito seasons in 1988-1990 from 614 patients with possible viral encephalitis in 15 regions of prc and tested for haemagglutination inhibiting antibodies to selected arboviruses. seroconversions were documented to alphavirus and flavivirus antigens in 13.0 and 18.7% of patients respectively in most of the study ...19921332220
comparative molecular biology of flaviviruses and hepatitis c virus.currently available sequence information suggests that the genome organization of hepatitis c virus is similar to that of flaviviruses. a positive-stranded genomic rna contains a single long open reading frame (orf) which is flanked by 5' and 3' noncoding sequences. this rna codes for structural proteins at the 5' end (starting with the capsid protein) and a set of nonstructural proteins in the remainder of the genome. the latter provide essential virus-specific functions for the viral life cycl ...19921333320
proteins encoded in the 5' region of the pestivirus genome--considerations concerning taxonomy.the first protein encoded within the pestivirus open reading frame is a nonstructural protein which removes itself from the polyprotein by autoproteolytic cleavage. the following nucleocapsid protein ends just before a putative signal sequence preceding three glycosylated proteins. all three glycoproteins are part of the viral envelope and exist in the form of disulfide-linked dimers. pestiviruses have recently been reclassified as members of the family flaviviridae which now comprises three gen ...19921336240
envelope protein sequences of dengue virus isolates th-36 and th-sman, and identification of a type-specific genetic marker for dengue and tick-borne flaviviruses.complementary dnas were synthesized from the envelope protein genes of two isolates of dengue virus (th-36 and th-sman, previously suggested as possible dengue virus type 5 and dengue virus type 6 respectively) and amplified by the polymerase chain reaction using sense and antisense primers designed from conserved dengue virus gene sequences. the amplified cdna clones were sequenced in both directions by double-stranded dideoxynucleotide sequencing. alignment with published dengue virus sequence ...19921339466
[laboratory diagnosis and symptoms of dengue, during an outbreak in the ribeirão preto region, sp, brazil].a dengue type 1 outbreak started in the ribeirao preto region, north of sao paulo state, brazil, in november of 1990. about 3500 dengue cases were confirmed by blood tests until february of 1991. the virus research unit of the faculty of medicine of ribeirao preto-sao paulo state university, studied 502 dengue suspect cases. the serologic diagnosis of dengue type 1 was confirmed by haemagglutination inhibition test (hai) in 19% of the cases. diagnosis was done later by using an enzyme immuno ass ...19921340025
analysis of murine major histocompatibility complex class ii-restricted t-cell responses to the flavivirus kunjin by using vaccinia virus expression.the present paper analyzes the influence of major histocompatibility complex (mhc) class ii (ir) genes on mhc class ii-restricted t-cell responses to west nile virus (wnv) and recombinant vaccinia virus-derived kunjin virus antigens and identifies the immunodominant kunjin virus antigens. generally, mice were primed by intravenous infection with wnv or kunjin virus, and their cd4+ t cells were stimulated in vitro 14 days later with wnv or kunjin virus antigens to pulse macrophage or b-cell antig ...19921349926
arbovirus isolations from mosquitoes collected during 1988 in the senegal river basin.during august and september 1988, we collected adult mosquitoes from 14 locations in the senegal river basin to search for evidence of rift valley fever (rvf) viral activity one year after the 1987 outbreak, which occurred along the senegal-mauritania border. more than 62,000 specimens representing 18 species in seven genera were collected with carbon dioxide-baited, solid-state army miniature light traps and sheep-baited traps. twenty virus isolations from culex, aedes, and anopheles mosquitoes ...19921361722
selective inhibition of arthropod-borne and arenaviruses in vitro by 3'-fluoro-3'-deoxyadenosine.a novel nucleoside analog, 3'-fluoro-3'-deoxyadenosine (3'f3'dado), was evaluated for antiviral activity against several arthropod-borne and arenaviruses in vero cell culture. the following 50% inhibitory concentrations (ec50) of virus plaque formation were obtained against the test viruses: semliki forest (10.3 microm) and venezuelan equine encephalitis (5.3 microm) alphaviruses, lymphocytic choriomeningitis (7.7 microm) and pichinde (greater than 32 microm) arenaviruses, punta toro (greater th ...19921365816
use of recombinant fusion proteins and monoclonal antibodies to define linear and discontinuous antigenic sites on the dengue virus envelope glycoprotein.sixteen overlapping fragments of the dengue-2 virus envelope (e) protein, expressed as trpe-e fusion products in escherichia coli, were used to map the epitopes defined by a panel of 20 monoclonal antibodies (mabs) by immunoblotting. using this technique, the amino acid sequence of six antigenic domains on the e protein was characterized. nonneutralizing mabs were found to define either linear-specific, subcomplex-specific (amino acids 22-58), and complex-specific (amino acids 304-332) epitopes ...19921372140
enhancement of the antibody response to flavivirus b-cell epitopes by using homologous or heterologous t-cell epitopes.we have been investigating the t-helper (th)-cell response to the flavivirus envelope (e) glycoprotein. in our studies with murray valley encephalitis (mve) virus, we previously identified synthetic peptides capable of priming th lymphocytes for an in vitro antivirus proliferative response (j. h. mathews, j. e. allan, j. t. roehrig, j. r. brubaker, and a. r. hunt, j. virol. 65:5141-5148, 1991). we have now characterized in vivo th-cell priming activity of one of these peptides (mve 17, amino aci ...19921374807
broad cross-reactivity with marked fine specificity in the cytotoxic t cell response to flaviviruses.cytotoxic t (tc) cells were generated in mice of five h-2 haplotypes against the flaviviruses kunjin and west nile (wnv). a panel of recombinant vaccinia viruses which between them expressed cdna of the entire kunjin virus genome were used to infect targets. anti-kunjin virus responses to determinants derived from non-structural proteins, especially ns3, ns4a and ns4b, were dominant in most mouse strains; usually only one class i major histocompatibility complex (mhc) restriction element was inv ...19921375278
analysis of tick-borne encephalitis virus antigens by monoclonal antibodies.monoclonal antibodies (mabs) against central european tick-borne encephalitic virus, strain hypr, were used for determination and characterization of viral antigens of infected ps cells. the mabs reacted in immunoblotting with flavivirus glycoprotein e (56 kd), and nonstructural protein ns3 (70 kd). according to enzyme immunoassay with infected cells, ns3 antigen is expressed in the plasmalemma.19921375704
induction of cytotoxic t cells to a cross-reactive epitope in the hepatitis c virus nonstructural rna polymerase-like protein.cytotoxic t lymphocytes (ctl) have been found to mediate protection in vivo against certain virus infections. ctl also may play an important role in control of infection by hepatitis c virus (hcv), but no ctl epitopes have yet been defined in any hcv protein. the nonstructural protein with homology to rna polymerase should be a relatively conserved target protein for ctl. to investigate the epitope specificity of ctl specific for this protein, we used 28 peptides from this sequence to study muri ...19921376366
direct sequencing of large flavivirus pcr products for analysis of genome variation and molecular epidemiological investigations.the polymerase chain reaction (pcr) was used to amplify viral cdnas from selected regions of dengue genomic rna by using appropriate 'consensus' primers. dna amplicons containing the structural genes from all 4 dengue serotypes were prepared and directly sequenced using dengue-virus-specific primers. this method can characterize reliably flavivirus field isolates at the molecular level without extensive virus propagation and molecular cloning, and will be a valuable tool for molecular epidemiolo ...19921379606
a synthetic peptide to the e glycoprotein of murray valley encephalitis virus defines multiple virus-reactive t- and b-cell epitopes.synthetic peptides from the envelope glycoprotein sequence of murray valley encephalitis (mve) virus were previously evaluated in various strains of mice for both the induction of antibody and the in vitro proliferation of peptide-primed t-helper (th) cells. mve peptide 6 (amino acids 230 to 251) elicited reciprocal th- and b-cell reactivity with native mve virus after primary inoculation of c57bl/6 mice. in this study, we prepared overlapping subunit peptides of mve peptide 6 and evaluated thei ...19921383567
a simple and rapid method of preparing large fragments of dengue virus cdna from replicative-form rna using reverse transcriptase and pcr.a method is described for cloning large fragments (1.5 kb to 2 kb) of dengue virus cdna from replicative-form viral rna. aedes albopictus cells (c6/36 clone) infected with dengue virus contain double-stranded, replicative-form rna molecules which were used as a template for an initial reverse transcription using a primer containing sequence homologous to regions of the genome at or near the 3' end of the gene being studied. the product was then used as a template for polymerase chain reaction (p ...19921385464
[the protective activity of preparations made from the tick-borne encephalitis virus grown using different cell cultures].the preparations of tick-borne encephalitis (tbe) virus grown in swine embryo kidney cell culture have been shown to possess pronounced protective activity per unit of virion protein e in comparison with tbe virus preparations derived from cell culture 4647 and chick embryo cell culture. the antigenic activity of all virus preparations under study has proved to be practically the same. the role of post-translation modifications of tbe virus protein e in the manifestation of some of its biologica ...19921414102
purification of native dengue-2 viral proteins and the ability of purified proteins to protect mice.both the envelope structural protein and the non-structural ns1 protein have been purified from the flavivirus dengue-2 by high-pressure liquid chromatography. these purified proteins maintain their reactivity with monoclonal antibodies. when tested in mice, the envelope protein elicited neutralizing antibodies and partially protected the animals against a lethal viral challenge. the mice responded to the non-structural protein by producing antibodies; however, these antibodies were not neutrali ...19921443338
flavivirus induces mhc antigen on human myoblasts: a model of autoimmune myositis?infection of human embryonic myoblasts by west nile virus (wnv), a flavivirus, caused significant upregulation of class i and ii mhc expression as determined by flow cytometry. after 48 hours at a multiplicity of infection of 5 pfu/cell, a sixfold increase in mhc class i expression was induced from initially low levels of expression. in contrast, mhc class ii was induced de novo to five times the control fluorescence level. at least 70% of the cells were infected as determined using fluorescence ...19921488065
infectious japanese encephalitis virus rna can be synthesized from in vitro-ligated cdna templates.japanese encephalitis virus (jev) is a positive-stranded enveloped rna virus that belongs to the family flaviviridae. genomic jev rna is approximately 11 kb long and encodes 10 proteins, 3 structural and 7 nonstructural. a full-length cdna copy of the jev genome was constructed by in vitro ligation of two cdna fragments which encode the 5' (nucleotide positions 1 to 5576) and 3' (nucleotide positions 5577 to 10976) halves of the genome. t7 rna polymerase transcripts of the ligated full-length cd ...19921501281
[expression of the gene for tick-borne viral encephalitis virus ns3 protein in escherichia coli cells].on the base of two overlapping cdna-clones of tick-borne encephalitis virus (tbev) genome and synthetic dna fragments full dna-copy of the tbev ns3 protein gene was constructed and expressed in the e. coli cells. it was demonstrated that the relatively low biosynthesis level of full-length ns3 protein in the bacteria was due to the toxicity of the n-terminal region of the protein, consisting of it's first 180 amino acid residues. a form of the gene with deletion of nucleotides coding for the tox ...19921508165
cleavage of the dengue virus polyprotein at the ns3/ns4a and ns4b/ns5 junctions is mediated by viral protease ns2b-ns3, whereas ns4a/ns4b may be processed by a cellular protease.the cleavage mechanism utilized for processing of the ns3-ns4a-ns4b-ns5 domain of the dengue virus polyprotein was studied by using the vaccinia virus expression system. recombinant vaccinia viruses vns2b-ns3-ns4a-ns4b-ns5, vns3-ns4a-ns4b-ns5, vns4a-ns4b-ns5, and vns4b-ns5 were constructed. these recombinants were used to infect cells, and the labeled lysates were analyzed by immunoprecipitation. recombinant vns2b-ns3-ns4a-ns4b-ns5 expressed the authentic ns3 and ns5 proteins, but the other reco ...19921531368
a short form of the tick-borne encephalitis virus ns3 protein.using monoclonal antibodies to the tick-borne encephalitis virus (tbe) nonstructural protein ns3 two forms of this protein were revealed in tbe-infected mammalian cells: a full-length form (69 kda) and a short form (49 kda) which has not been observed before and was called ns3'. recombinant plasmids were constructed and various fragments of the tbe ns3 gene were expressed in rabbit reticulocyte lysate. by analyzing immune precipitates of 35s-labeled translation products, we could monitor and loc ...19921551439
dengue virus infection of human skin fibroblasts in vitro production of ifn-beta, il-6 and gm-csf.dengue virus is transmitted to humans by the bite of infected mosquitos. in our efforts to understand the pathogenesis of dengue virus infection, we examined whether skin fibroblasts can be infected in vitro with dengue viruses. fibroblasts could be infected with dengue viruses, yellow fever virus and west nile virus. dengue virus antigen-positive cells were detected as early as 4 h and the percentage of dengue virus antigen-positive cells reached maximum levels by 24 h after infection. high tit ...19921571018
comparison of centrifugation methods for molecular and morphological analysis of membranes associated with rna replication of the flavivirus kunjin.kunjin virus-infected cells were lysed and the cytoplasmic extract was subjected to sedimentation analysis. after centrifugation at 16,000 x g for 10 min about 70% of the original rna-dependent rna polymerase (rdrp) was recovered in the pellet; most of this enzymic activity was recovered in the soluble fraction after treatment with np40 detergent. membrane fractions were prepared from cytoplasmic extracts by centrifugation in discontinuous density gradients comprising w/w or w/v sucrose solution ...19921597508
[advances in the diagnosis of non-a non-b viral hepatitis].having constructed the serological diagnostics of hepatitis a and b viruses there remained non identified agent(s): named "non-a, non-b". the non-a, non-b infecting parenterally is a flavivirus, with lipoid envelope and a diameter of 30-60 nm, as stated very early. after having known the simple filament rns genome, named as hepatitis c. in the same time it was tried to isolate the antigen and antibody from ill people, without success. there were not usable the surrogate markers too (anti-hbc and ...19921630799
murray valley encephalitis acquired in western report a recent fatal case of encephalitis associated with evidence of murray valley encephalitis virus infection, only the second fatality from this infection in western australia.19911645843
flavivirus type-specific antigens produced from fusions of a portion of the e protein gene with the escherichia coli trpe gene.based on previous data showing that jev and den-1 fusion proteins can be used as antigens, we engineered analogous fusion proteins for the same regions of the e proteins of den-2, den-3, and den-4, using the polymerase chain reaction. the resulting fusion proteins were tested in a modified elisa for their reactivity with mouse immune ascitic fluids (miaf) generated against 10 different flaviviruses. the results showed that these recombinant antigens could be used as type-specific immunological r ...19911648310
immunoaffinity purification of the ns1 protein of murray valley encephalitis virus: selection of the appropriate ligand and optimal conditions for elution.a novel approach was used to select the most suitable antiviral monoclonal antibody (mab) and elution conditions for immunoaffinity purification of the ns1 protein of murray valley encephalitis virus (mve). crude ns1 protein was subjected to a variety of chemical conditions produced by common elution buffers, and tested with a panel of ns1-specific mabs by elisa to determine which buffers denatured antigenic epitopes. buffers that caused least structural damage to ns1 epitopes were tested by eli ...19911648569
sequencing the termini of capped viral rna by 5'-3' ligation and pcr. 19911651093
monoclonal antibodies to kunjin and kokobera viruses.five monoclonal antibodies (moab) were produced to the envelope (e) protein of kunjin (kun) virus. three of these were specific for the kun/west nile complex, and two reacted with epitopes that were common to the flavivirus family. these moab defined at least four distinct epitopes on the e protein of kun virus. eight moab were also produced to unidentified proteins of kokobera (kok) virus. seven were specific for kok, while the remaining antibody cross-reacted with stratford virus and an unregi ...19911651286
flavivirus enzyme-substrate interactions studied with chimeric proteinases: identification of an intragenic locus important for substrate recognition.the proteins of flaviviruses are translated as a single long polyprotein which is co- and posttranslationally processed by both cellular and viral proteinases. we have studied the processing of flavivirus polyproteins in vitro by a viral proteinase located within protein ns3 that cleaves at least three sites within the nonstructural region of the polyprotein, acting primarily autocatalytically. recombinant polyproteins in which part of the polyprotein is derived from yellow fever virus and part ...19911651406
hepatitis c virus: an may 1988, kuo and houghton and their colleagues in chiron research laboratory, in cooperation with the physicians from nih and cdc, announced their discovery of the agent which is responsible for the majority of non-a non-b hepatitis (nanb) in post-transfusion hepatitis (pth)1,2, concluding a 15-year effort to search for this elusive agent. although it is believed that there is another blood-borne agent responsible for a smaller percentage of the post-transfusion hepatitides, the new agent (a ...19911655677
recurrent outbreaks of japanese encephalitis in nagaland (1985-1989)--a seroepidemiological study.recurrent epidemics of encephalitis in nagaland, a north-eastern state of india, following its first appearance in 1985, were investigated both epidemiologically and virologically. although, no viral agent could be isolated from any of the clinical samples and mosquitoes, detection of je specific igm antibodies in many of the csf and acute blood samples, together with presence of hi and cf antibodies to je antigen in a number of acute and convalescent sera established the etiologic role of je vi ...19911655865
hepatitis c virus: buoyant density of the factor viii-derived isolate in sucrose.physicochemical and molecular characterization studies of hepatitis c virus (hcv), the major causative agent of parenterally transmitted non-a, non-b hepatitis (pt-nanbh), strongly suggest that it is a pesti-/flavivirus-like virus. additional studies show that the buoyant density of plasma-derived hcv in sucrose is significantly lower than that of most tissue culture-derived flaviviruses (1.20 g/cm3). our finding suggests, but does not prove, that at least one physicochemical property of hcv is ...19911655970
prevalence of antibodies to hepatitis c virus (anti-hcv) in different populations in taiwan.the prevalence of antibodies to hepatitis c virus (anti-hcv) was investigated among different populations in taiwan, where anti-hcv was detected in 0.8% (24/2,994) of adult volunteer blood donors, 0.1% (1/1,305) of youngsters and children, 12.5% (8/64) of adult volunteer blood donors with elevated alanine aminotransferase (alt), 36.5% (23/63) of hemodialysis patients, 4.1% (13/318) of male homosexuals, 25.4% (16/63) of cases positive for antibodies to human immunodeficiency virus (anti-hiv), 82. ...19911657545
seroepidemiology of arboviruses among seabirds and island residents of the great barrier reef and coral sea.duplicate neutralization tests were done on 401 avian and 101 human sera from island residents collected in the coral sea and on australia's great barrier reef against 19 known arboviruses. antibodies to a potentially harmful flavivirus, gadget's gully virus, were equally present (4%) in both avian and human sera. antibodies to another flavivirus, murray valley encephalitis, and an ungrouped isolate, csiro 1499, were also present in both populations with non-significantly different incidences. a ...19911657626
genetic selection of a flavivirus-refractory strain of the yellow fever mosquito aedes aegypti.two inbred (isofemale) aedes aegypti mosquito lines were derived that manifested a resistant or susceptible phenotype following ingestion of yellow fever virus; lack of virus movement from the midgut defined the resistant phenotype. other flaviviruses, including dengue 1-4, uganda s, and zika, viruses behaved in a similar fashion in the two mosquito lines. crosses between the two lines produced progeny that were of intermediate susceptibility, indicating codominance; f2 backcrosses to the parent ...19911659238
detection of immobilised murray valley encephalitis virus rna using oligonucleotide probes with varying degrees of mismatch.the design of oligonucleotides used for hybridisation studies often utilises available sequence information of the type strain of a particular virus. if hybridisation studies, using such oligonucleotides, are carried out with field isolates of the same virus, the problem of base pair mismatches and consequent difficulties in detection may arise. this study examined the effect of base pair mismatches on the hybridisation between membrane-bound murray valley encephalitis virus (mve) rna derived fr ...19911660491
detection of stable secondary structure at the 3' terminus of dengue virus type 2 rna.the 3'-terminal sequences of flavivirus genomes within approx. 100 nucleotides (nt) have been suggested to have a highly conserved secondary structure, as based on the known nt sequence data and free-energy calculations using computer programs. to test the existence of a secondary structure in solution, we devised a strategy to generate truncated rna molecules from about 0.3-1.4 kb in length, having the same polarity and nt sequence as dengue virus type 2 (den-2) rna (new guinea-c strain). when ...19911660836
[virus replication and protein processing: flavivirus specific protease]. 19911663638
[the identification of flaviviruses by using highly specific immunoenzyme analysis]. 19911664561
synthetic deoxyoligonucleotide probes for identification of flaviviruses. 19911668693
prevention of flavivirus encephalitides in travellers to endemic areas. 19911669777
nuclear immunofluorescence in porcine kidney cells infected with japanese encephalitis virus.acetone-fixed porcine stable kidney (ps) cells infected with japanese encephalitis (je) virus were stained in indirect fluorescent antibody (fa) assay with anti-je virus monoclonal (moab) and polyclonal (immune pf) antibodies. first positive immunofluorescence (if) occurred in the cytoplasm with moab hs-1 (anti-envelope, je-specific) and immune pf after 7 hr post-infection (p. i.); it became prominent by 15 hr to 48 hr (maximum) when cells reacted strongly also with moab hx-3 (flavivirus crossre ...19911683134
the complex of flavivirus envelope polypeptide with meningococcal proteosomes elicits formation of virus-neutralizing antibodies.polypeptide e of tick-borne encephalitis virus was isolated in sucrose density gradient and mixed with equal weight portion of meningococcal proteosomes in the presence of n-dodecyl-n,n-dimethylglycine. mutual complexing of viral and bacterial molecules occurred after removal of detergent by dialysis. complexed particles appeared in the electron microscope as 40-50 microns thick short-rod structures covered on their surface with both, delicate poppy-like grains, or envelope subunit-like clustere ...19911686957
identification of monoclonal antibodies that distinguish between 17d-204 and other strains of yellow fever virus.eight monoclonal antibodies (mabs) prepared against the flaviviruses saint louis encephalitis, dengue 2 and dengue 3 viruses all recognized epitopes on the envelope protein of the prototype flavivirus, yellow fever (yf) virus. three of these mabs with flavivirus group-common specificity and two mabs with a flavivirus-subgroup specificity were found to distinguish wild-type yf viruses from yf 17d-204 vaccine virus, but not from the closely related 17dd vaccine virus, nor from the french neurotrop ...19901689367
different pathogenicity of encephalitic togaviruses in organotypic cultures of spinal cord slices.the pathogenicity of two encephalitic togaviruses, sindbis virus (sv), an alphavirus, and west nile virus (wnv), a flavivirus, was studied in organotypic cultures of fetal mouse spinal cord slices grown in roller tubes. after about 3 weeks in vitro, during which time the cultures became abundantly myelinated, they were infected either by 5 x 10(5) pfu sv or by 5 x 10(6) pfu wnv per culture. the viruses caused different patterns of cytopathogenicity: sv induced severe cytotoxicity in all glia cel ...19901691307
immunogenicity of a purified fragment of 17d yellow fever envelope protein.information on the immunogenic properties of purified flavivirus proteins may be useful in the development of recombinant or synthetic peptide vaccines. using a monoclonal antibody, an attempt was made to purify the envelope (e) protein of 17d yellow fever virus (17d yf) by affinity chromatography. the purified material could not be identified as intact e protein but it did bear antigenic determinants of e as determined by selective reactivity with anti-e monoclonal antibodies. rabbits immunized ...19901693159
comparative therapeutic efficacy of recombinant interferons-alpha, -beta, and -gamma against alphatogavirus, bunyavirus, flavivirus, and herpesvirus infections.recombinant (r) preparations of interferons (ifn)-alpha, -beta, and -gamma were shown to protect mice against experimental virus infections with herpes simplex virus type 2 (hsv-2), and with three rna-containing viruses from different families: banzi, a flavivirus; semliki forest virus (sfv), an alphatogavirus; and caraparu, a bunyavirus. the antiviral effects of the three different types of ifn were different with each virus. hsv-2 was the most sensitive virus, followed by sfv. against banzi vi ...19901696607
defined epitope blocking with murray valley encephalitis virus and monoclonal antibodies: laboratory and field an attempt to develop a specific serological test for murray valley encephalitis (mve) virus antibodies, a panel of mve monoclonal antibodies was utilised in defined-epitope blocking elisa tests. in sera of mice immunised singly and in combinations of mve, alfuy (alf), and kunjin (kun) viruses, blocking patterns usually distinguished mve infections from those of the other flaviviruses. when blocking tests with selected mabs were applied to 468 flavivirus antibody positive sera collected from ...19901700805
sequence of the 3' half of the murray valley encephalitis virus genome and mapping of the nonstructural proteins ns1, ns3, and ns5.we have determined the nucleotide sequence of the 3'-terminal half of the rna genome of murray valley encephalitis virus (mve) using seven overlapping cdna clones; an estimated 80-90 nucleotides at the extreme 3'-end remain to be sequenced. in conjunction with previous sequence data for the 5' half (16), we can conclude that the mve genome contains a long open reading frame of 10,302 nucleotides that encodes a polyprotein of 3434 residues. comparison of the mve deduced amino acid sequence with t ...19901702914
computer analysis of antigenic domains and rgd-like sequences (rgwg) in the e glycoprotein of flaviviruses: an approach to vaccine development.antigenic domains and rgd-like sequences in the e glycoprotein of the flaviviruses japanese encephalitis virus, yellow fever virus, west nile virus, dengue type 4 virus, and tick-borne encephalitis virus were analyzed by computer programs that provide information on the physical properties of the polypeptides. the use of computer programs for the development of vaccines based on the synthesis of antigenic peptides is discussed. synthetic viral peptides are proposed to be used for topical applica ...19901702915
epitope analysis of the envelope and non-structural glycoproteins of murray valley encephalitis virus.previous studies have shown that antibodies produced against strategic flavivirus epitopes play an important role in recovery and immunity. definition of the conformation and location of these epitopes and the degree of their conservation among flaviviruses is important to understanding the humoral response to flavivirus infection. in this study we have examined epitopes recognized by 14 monoclonal antibodies (mabs) produced to the envelope (e) and non-structural (ns1) proteins of murray valley ...19901703213
dengue virus-specific, human cd4+ cd8- cytotoxic t-cell clones: multiple patterns of virus cross-reactivity recognized by ns3-specific t-cell clones.thirteen dengue virus-specific, cytotoxic cd4+ cd8- t-cell clones were established from a donor who was infected with dengue virus type 3. these clones were examined for virus specificity and human leukocyte antigen (hla) restriction in cytotoxic assays. six patterns of virus specificities were determined. two serotype-specific clones recognized only dengue virus type 3. two dengue virus subcomplex-specific clones recognized dengue virus types 2, 3, and 4, and one subcomplex-specific clone recog ...19911705990
recognition of helper t cell epitopes in envelope (e) glycoprotein of japanese encephalitis, west nile and dengue viruses.helper t (th) cell antigenic sites were predicted from the primary amino acid sequence (approximately 500 in length) of the envelope (e) glycoprotein (gp) of japanese encephalitis (je), west nile (wn) and dengue (den) i-iv flaviviruses. prediction of th epitopes was done by analyzing the occurrence of amphipathic segments, rothbard-taylor tetra/pentamer motifs and presence of alpha helix-preferring amino acids. the simultaneous occurrence of all these parameters in segments of e gp were used as ...19911707135
fusion activity of flaviviruses: comparison of mature and immature (prm-containing) tick-borne encephalitis virions.the fusion activity of flaviviruses [tick-borne encephalitis (tbe) virus and japanese encephalitis virus] was assessed by inducing fusion from without of c6/36 mosquito cells with purified virus preparations. membrane fusion and polykaryocyte formation was observed only after incubating the viruses at acidic ph. two groups of monoclonal antibodies reacting with distinct non-overlapping antigenic domains on the tbe virus protein e inhibited fusion from without. one of these domains contains the m ...19911710648
presence of poly(a) in a flavivirus: significant differences between the 3' noncoding regions of the genomic rnas of tick-borne encephalitis virus strains.a poly(a) tail was identified on the 3' end of the prototype tick-borne encephalitis (tbe) virus strain neudoerfl. this is in contrast to the general lack of poly(a) in the genomic rnas of mosquito-borne flaviviruses analyzed so far. analysis of several closely related strains of tbe virus, however, revealed the existence of two different types of 3' noncoding (nc) regions. one type (represented by strain neudoerfl) is only 114 nucleotides long and carries a 3'-terminal poly(a) structure. this w ...19911712858
preliminary analysis of murine cytotoxic t cell responses to the proteins of the flavivirus kunjin using vaccinia virus expression.a series of recombinant vaccinia viruses expressing various parts of the entire kunjin virus (kun) coding region was used to analyse the cytotoxic t (tc) cell responses to kun. cba/h mice inoculated with kun or west nile virus were shown to develop responses to kun or various vaccinia virus expression constructs in either primary cytotoxic assays, or after secondary stimulation of the tc cells in vitro with kun antigens. tc cells from cba mice showed the strongest response to target cells infect ...19911713261
detection of flaviviruses by reverse-transcriptase polymerase chain reaction.rna sequences of five flaviviruses were detected by a modified polymerase chain reaction (pcr) that incorporated a reverse transcriptase and rnase inhibitor. oligonucleotide primer pairs were synthesized to amplify sequences from st. louis encephalitis (sle), japanese encephalitis (jbe), yellow fever (yf), dengue 2 (den-2), and dengue 4 (den-4) viruses. the amplified products were visualized as bands of appropriate size on ethidium bromide-stained agarose gels. the identity of these products was ...19911713265
antigenic analysis of tick-borne encephalitis complex viruses by time-resolved fluoroimmunoassay with monoclonal antibodies.the antigenic structure of 5 strains of tick-borne encephalitis (tbe) virus and 7 other viruses of the tbe complex was examined by the highly sensitive and specific technique of time-resolved fluoroimmunoassay (tr-fia). a collection of 8 monoclonal antibodies to the austrian strain. neudörfl, was used in this study. the findings demonstrate the uniformity of the antigenic structure of tbe viruses from different geographic regions of the ussr. in addition, an epitope was detected which is charact ...19911713917
the particle size of hepatitis c virus estimated by filtration through microporous regenerated cellulose estimate the particle size of hepatitis c virus (hcv), a major causative agent of post-transfusion non-a, non-b hepatitis, we filtered plasma or serum samples through microporous cellulose fibres with different pore sizes. the amount of hcv particles in samples before and after filtration was determined by a quantitative reverse transcriptase polymerase chain reaction (pcr) method. since there is no quantitative biological assay for hcv, except for that in chimpanzees, the hcv titre obtained ...19911714947
the carboxy-terminal part of the ns 3 protein of the west nile flavivirus can be isolated as a soluble protein after proteolytic cleavage and represents an rna-stimulated ntpase.recently it has been reported that a membrane fraction can be isolated from west nile virus-infected bhk cells which contains the viral nonstructural (ns) proteins as major constituents (wengler et al., 1990). in this report we show that treatment of these membranes with subtilisin releases the carboxy-terminal segment of the ns 3 protein as a soluble protein of about 50 kda apparent molecular weight. this molecule, which is called the p50-s protein, can be purified by standard chromatographic p ...19911716026
the flavivirus envelope protein e: isolation of a soluble form from tick-borne encephalitis virus and its the use of limited trypsin digestion of purified virions, we generated a membrane anchor-free and crystallizable form of the tick-borne encephalitis virus envelope glycoprotein e. it retained its reactivity with a panel of monoclonal antibodies, and only subtle structural differences from the native protein e were recognized. treatment with the bifunctional cross-linker dimethylsuberimidate resulted in the formation of a dimer. crystallization experiments yielded hexagonal rod-shaped crystals ...19911716695
sequence of the genes encoding the structural proteins of the low-virulence tick-borne flaviviruses langat tp21 and yelantsev.the structural protein coding regions of the genomes of langat virus (strain tp21) and yelantsev virus, which was originally described to be a low virulence natural isolate of tick-borne encephalitis virus, were cloned and sequenced. these viruses had both been used as experimental live vaccines against tick-borne encephalitis in czechoslovakia and russia, respectively. peptide mapping and monoclonal antibody binding experiments yielded identical reaction patterns for langat virus and yelantsev ...19911720591
in vitro t-cell proliferative response to the flavivirus, west nile.west nile virus (wnv)-specific murine t-cell proliferation in vitro was investigated in terms of conditions that optimize antigen-specific responses and reduce background proliferation. the responder populations consisted of splenocytes from wnv-primed mice enriched for l3t4+ t cells. ia+ antigen-presenting cells (apc) were derived from splenocytes of wnv-primed or naive mice. antigen was a lysate prepared from wnv-infected vero cells at 12 h postinfection. strong virus-specific proliferative re ...19911722099
processing of dengue virus type 2 structural proteins containing deletions in hydrophobic domains.the 5' end of the genome of the dengue virus type 2 encoding the structural proteins was expressed using recombinant vaccinia virus. three additional recombinants derived by deletion of selected dengue sequences within the parental construct were also expressed. they were designed to assess the role of hydrophobic domains in the processing of the viral polyprotein in intact cells. the first construct contained a deletion of nucleotides encoding most of the c protein; nucleotides encoding the hyd ...19921729986
recombinant vaccinia virus producing the prm and e proteins of yellow fever virus protects mice from lethal yellow fever encephalitis.four recombinant vaccinia viruses were constructed for expression of different portions of the 17d yellow fever virus (yfv-17d) open reading frame. a recombinant, vp869, expressing prm and e induced high titers of neutralizing and hemagglutination inhibiting antibodies in mice and was protective against intracranial challenge with the french neurotropic strain of yfv. levels of protection were equivalent to those achieved by immunization with the yfv-17d vaccine virus. recombinant vaccinia virus ...19921736531
dengue surveillance in french polynesia: an attempt to use the excess number of laboratory requests for confirmation of dengue diagnosis as an indicator of dengue activity.the excess number of weekly laboratory requests for confirmation of dengue diagnosis over the expected number of requests forecasted by the modified serfling method is proposed for the surveillance of dengue in french polynesia, in addition to conventional methods. retrospective analysis of the seasonal curves of dengue activity related to the number of laboratory requests is described for the years 1982-1987 where dengue type 4 was the only active flavivirus at the time when the forecast was in ...19911783054
[preliminary study on the presence of arbovirus in the populations of corrientes and misiones].human seroprevalence of flavivirus was determined by hemagglutination inhibition tests on 479 sera from misiones and 49 from corrientes provinces. paraná and uruguay river bank communities from argentina and neighbouring countries carry out frequent traffic across the rivers. with the aim of searching for a possible introduction of dengue virus from brasil or/and paraguay, reactivity among people from paraná and uruguay river communities was compared with those from mountain communities. two ser ...19911815271
the sensitivity of cell-associated dengue virus proteins to trypsin and the detection of trypsin-resistant fragments of the nonstructural glycoprotein ns1.extracts of vero cells infected with dengue virus type 2 were digested by trypsin in the presence and absence of detergents. the experiments were designed to test the models proposed for flavivirus translation in which the glycoproteins prm, e, and ns1 are inserted into the endoplasmic reticulum of the cell, whereas certain other nonstructural proteins are not. viral polypeptides were detected by the use of radiolabel, by immunoprecipitation, or by immunoblotting. the results obtained for ns3 an ...19911824904
in vitro synthesis of west nile virus proteins indicates that the amino-terminal segment of the ns3 protein contains the active centre of the protease which cleaves the viral polyprotein after multiple basic amino acids.a virus-encoded protease that cleaves after multiple basic amino acid residues has been implicated in the processing of the flavivirus polyprotein. recently, a computer search of amino acid residues which might form the active site of a protease led to the suggestion that the amino-terminal segment of the ns3 protein represents a serine protease. to examine this possibility we constructed an mrna which encodes a polyprotein with an amino-terminal signal sequence derived from the influenza virus ...19911826736
glycosylation and secretion of yellow fever virus nonstructural protein ns1.the flavivirus genome codes for structural and nonstructural proteins which are produced from a common polyprotein precursor by proteolytic processing. the nonstructural protein ns1 is hypothesized to be involved in virus assembly and maturation as well as in protective immunity. this paper describes the synthesis of several forms of yellow fever (yf) virus ns1 protein during virus cultivation in vitro. these include cell-associated and secreted ns1 forms, the major difference among these being ...19911828321
t-helper cell and associated antibody response to synthetic peptides of the e glycoprotein of murray valley encephalitis virus.a battery of 16 synthetic peptides, selected primarily by computer analysis for predicted b- and t-cell epitopes, was prepared from the deduced amino acid sequence of the envelope (e) glycoprotein of murray valley encephalitis (mve) virus. we examined all of the peptides for t-helper (th)-cell recognition and antibody induction in three strains of mice: c57bl/6, balb/c, and c3h. lymphoproliferative and interleukin-2 assays were performed on splenic t cells from mice inoculated with peptides in f ...19911832722
processing of the yellow fever virus nonstructural polyprotein: a catalytically active ns3 proteinase domain and ns2b are required for cleavages at dibasic sites.the vaccinia virus-t7 transient expression system was used to further examine the role of the ns3 proteinase in processing of the yellow fever (yf) virus nonstructural polyprotein in bhk cells. yf virus-specific polyproteins and cleavage products were identified by immunoprecipitation with region-specific antisera, by size, and by comparison with authentic yf virus polypeptides. a yf virus polyprotein initiating with a signal sequence derived from the e protein fused to the n terminus of ns2a an ...19911833562
variable and hypervariable domains are found in the regions of hcv corresponding to the flavivirus envelope and ns1 proteins and the pestivirus envelope glycoproteins.based on the flavi- and pestivirus model of genome organization for the hepatitis c virus (hcv) (1-5), the nucleotide and deduced amino acid sequences of the putative envelope (e1) and the junction between the e1 and ns1/envelope 2 (e2) region from six different human isolates of hcv were compared with the nucleotide and predicted amino acid sequences of the prototype hepatitis c virus (hcv-1) (5). the overall percentage of nucleotide and amino acid changes among all six isolates, including hcv- ...19911846505
the relationship between the flaviviruses skalica and langat as revealed by monoclonal antibodies, peptide mapping and rna sequence analysis.the flavivirus skalica was isolated from a bank vole in czechoslovakia in 1976. it can be serologically distinguished from prototype strains of tick-borne encephalitis (tbe) virus and has a decreased virulence for adult mice. we have further defined the relationship of skalica virus to other members of the tbe serocomplex (tbe european and far eastern subtypes, langat and louping ill virus) by using a panel of 22 monoclonal antibodies, peptide mapping and rna sequence analyses. by these criteria ...19911847173
persistent infection of vero cells by the flavivirus murray valley encephalitis virus.murray valley encephalitis (mve) virus strain or2 was serially passaged on vero cells to establish a persistent infection which was maintained for over 300 days. supernatants from infected cells protected vero cells from c.p.e. and caused up to a 95% reduction of wild-type virus yield. these protective and interfering effects suggest that defective interfering (di) particles are responsible for the establishment and maintenance of the mve virus persistent infection. the persistently infected cel ...19911848592
molecular structure of the japanese hepatitis c viral genome.the amino acid sequence of the polyprotein deduced from the nucleotide sequence of the japanese hepatitis c virus genome (n. kato et al. (1990) proc. natl. acad. sci. usa 87, 9524-9528) indicated that this virus is a member of a new class of positive-stranded rna viruses. several domains of this polyprotein also showed weak homology with those of flaviviruses and pestiviruses including the chymotrypsin-like serine proteinase, ntpase and rna-dependent rna polymerase.19911849488
production of dimer-specific and dengue virus group cross-reactive mouse monoclonal antibodies to the dengue 2 virus non-structural glycoprotein ns1.a panel of mouse monoclonal antibodies (mabs) raised against the non-structural glycoprotein ns1 of dengue 2 virus (pr159) was studied for cross-reactivity with the ns1 protein of other dengue virus serotypes and other members of the flaviviridae using immunoblotting. most of the 35 anti-ns1 mabs were found to be specific for dengue 2 virus ns1 (some of which were specific for the native, dimeric form of this protein), but others were found to cross-react within the dengue virus group. this latt ...19911849979
development of cross-reactive antibodies to plasminogen during the immune response to dengue virus infection.the four serotypes of dengue virus (a mosquito-borne flavivirus) cause an acute febrile illness (dengue fever) or a more prolonged illness with plasma leakage resulting in hypovolemia (dengue hemorrhagic fever). hemorrhage may accompany either. epidemiologic data suggest a role for dengue antibodies in pathogenesis. computer analysis revealed a 20-residue region of similarity in amino acid sequence between the dengue type 4 envelope glycoprotein (e) and a family of clotting factors, including pl ...19911856477
in vitro homotypic and heterotypic interference by defective interfering particles of west nile virus.defective interfering (di) particles of the flavivirus west nile (wn) were generated after as few as two high multiplicity serial passages in vero and llc-mk2 cells. six cell lines (vero, llc-mk2, l929, hela, bhk-21 and sw13) were used to assay interference by di particles in a yield reduction assay. interference was found to vary depending on the cell type used. the highest levels of interference were obtained in llc-mk2 cells, whereas no detectable effect was observed in bhk-21 and sw13 cells. ...19911940867
[gene structure and replication of togavirus and flavivirus]. 19901962973
[the wesselsbron virus, a new arbovirus for madagascar].wesselsbron virus, an african arbovirus group flavivirus, has been isolated in 1989 for the first time in madagascar from aedes circumluteolus collected inside primary forest near the village of marovitsika. serological studies in man using haemagglutination inhibition test have permitted to think that wesselsbron virus have circulated quietly in madagascar. the detection of wesselsbron antibodies in lemurs sets the problem of the biological cycle.19901964039
[use of micromethod in the neutralization reaction in the laboratory diagnosis of human flavivirus infections]. 19901964517
overview of flavivirus molecular biology and future vaccine development via recombinant dna.studies in many laboratories over the last several years have elucidated the structures of several different flavivirus genomes. conserved features include the production of at least 10 different virus encoded proteins from a single long open reading frame by a combination of host and virus-encoded proteases. the established gene order is 5'-c- prm(m)-e-ns1-ns2a-ns2b-ns3-ns4a-ns4b-ns 5-3' and these proteins exhibit varying degrees of homology in comparisons among flaviviruses. conserved rna sequ ...19901965931
anti-mosquito antibodies reduce the susceptibility of aedes aegypti to arbovirus infection.aedes aegypti (l.) mosquitoes showed a significant reduction in susceptibility to infection with ross river virus and murray valley encephalitis virus when they were fed on a blood-virus mixture containing rabbit antibodies to mosquito midgut components. presence of the antibodies did not demonstrably affect virus titres in infected mosquitoes, nor the transmission of virus from infected mosquitoes to vertebrates.19901966777
comparison of skalica, hypr, and langat viruses by kinetic haemagglutination-inhibition test.the skalica virus has been compared with hypr and langat viruses by kinetic haemagglutination-inhibition (hi) test. using hypr antigen, differences were observed between skalica, hypr, and langat viruses. by the use of skalica antigen, a close relationship between hypr and skalica viruses was detected, however, it was possible to differentiate the langat virus. when langat antigen was tested, a close relationship among all the three viruses was found.19901975983
[reappearance of dengue in new caledonia from 1985 to 1988].from 1971 to 1980, dengue outbreaks occurred in new-caledonia due to dengue viruses type 2, 1 and 4 successively. after an eclipse of four years, dengue reappeared in 1985 through 1988. out of 109 cases confirmed by virus isolation, dengue serotypes 1, 2, 3 and 4 caused 15, 23, 17 and 54 cases respectively; in 28 other cases, the flavivirus type could not be identified and in 26 cases an alphavirus (ross river) was pointed out. the den 3 virus, unknown in new-caledonia before 1985, was discretel ...19901982249
the effect of chloroquine prophylaxis on yellow fever vaccine antibody response: comparison of plaque reduction neutralization test and enzyme-linked immunosorbent assay.weekly oral chloroquine prophylaxis for malaria has been associated with impaired antibody response to intradermal rabies vaccination. experimental data indicate that chloroquine may inhibit yellow fever virus in vitro, yet there has been no clinical evidence to suggest that antibody response to yellow fever vaccine is impaired by concomitant oral administration of chloroquine. a prospective trial was undertaken to evaluate the antibody response to yellow fever 17d vaccine (connaught laboratorie ...19911996743
both nonstructural proteins ns2b and ns3 are required for the proteolytic processing of dengue virus nonstructural proteins.the cleavages at the junctions of the flavivirus nonstructural (ns) proteins ns2a/ns2b, ns2b/ns3, ns3/ns4a, and ns4b/ns5 share an amino acid sequence motif and are presumably catalyzed by a virus-encoded protease. we constructed recombinant vaccinia viruses expressing various portions of the ns region of the dengue virus type 4 polyprotein. by analyzing immune precipitates of 35s-labeled lysates of recombinant virus-infected cells, we could monitor the ns2a/ns2b, ns2b/ns3, and ns3/ns4a cleavages ...19912016768
ph-dependent fusion of tick-borne encephalitis virus with artificial fusion of tbe virus with artificial membranes was effective at slightly acidic ph with maximum at 6.4. the influence of various changes in e protein conformation on fusion process was studied.19912048972
infectious rna transcribed from stably cloned full-length cdna of dengue type 4 virus.dengue virus is an enveloped positive-strand rna virus with a genome approximately 11 kilobases in length. the four serotypes of dengue virus are currently the most important members of the flavivirus family in terms of geographical distribution and the incidence of infection in humans. in this communication we describe successful cloning of a stable full-length cdna copy of dengue type 4 virus that can be used as the template for in vitro transcription of infectious rna. evidence is presented t ...19912052593
adjuvant effect of human growth hormone with an inactivated flavivirus vaccine.vaccines made by inactivating pathogenic microorganisms have been dramatically successful in controlling diseases in humans and animals. despite their successes, they have a major disadvantage in that several inoculations are required for them to be effective. to overcome this problem, a commercial inactivated vaccine preparation against tickborne encephalitis was combined with human growth hormone (hgh). this formulation produced complete protection in a murine model with only one dose of vacci ...19912056204
membrane association and secretion of the japanese encephalitis virus ns1 protein from cells expressing ns1 cdna.the biosynthesis of the flavivirus nonstructural glycoprotein, ns1, has important implications for (1) vaccine production, since ns1 immunity can protect animals from flavivirus infection; and (2) virion maturation, since ns1 is coretained with immature forms of the structural glycoprotein e in the endoplasmic reticulum (er) of infected cells. to examine the molecular basis for ns1 retention within the er we have expressed fragments of japanese encephalitis virus (jev) cdna encoding ns1 in bhk c ...19902142554
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