Publications
| Title | Abstract | Year(sorted descending) Filter | PMID Filter |
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| dna vaccine coding for the full-length infectious kunjin virus rna protects mice against the new york strain of west nile virus. | a plasmid dna directing transcription of the infectious full-length rna genome of kunjin (kun) virus in vivo from a mammalian expression promoter was used to vaccinate mice intramuscularly. the kun viral cdna encoded in the plasmid contained the mutation in the ns1 protein (pro-250 to leu) previously shown to attenuate kun virus in weanling mice. kun virus was isolated from the blood of immunized mice 3-4 days after dna inoculation, demonstrating that infectious rna was being transcribed in vivo ... | 2003 | 12917491 |
| kunjin rna replication and applications of kunjin replicons. | the kunjin virus (kunv) has provided a useful laboratory model for flavivirus rna replication. the synthesis of progeny rna(+) strands occurs via asymmetric and semiconservative replication on a template of recycling double-stranded rna (dsrna) or replicative form (rf). kinetics of viral rna synthesis indicated a cycle period of about 15 min during which, on average, a single nascent rna (+) strand displaces the pre-existing rna(+) strand in the replicative intermediate. data on the composition ... | 2003 | 14696328 |
| replication of a cytopathic strain of bovine viral diarrhea virus activates perk and induces endoplasmic reticulum stress-mediated apoptosis of mdbk cells. | endoplasmic reticulum (er) stress signaling is an adaptive cellular response to the loss of er ca(2+) homeostasis and/or the accumulation of misfolded, unassembled, or aggregated proteins in the er lumen. er stress-activated signaling pathways regulate protein synthesis initiation and can also trigger apoptosis through the er-associated caspase 12. viruses that utilize the host cell er as an integral part of their life cycle would be predicted to cause some level of er stress. bovine viral diarr ... | 2002 | 12208938 |
| sentinel chicken surveillance programme in australia, 1 july 2001 to 30 june 2002. | detection of flavivirus seroconversions in sentinel chicken flocks located throughout australia is used to provide an early warning of increased levels of murray valley encephalitis (mve) and kunjin virus activity in the region. during the 2001/2002 season low levels of flavivirus activity were detected in northern australia compared to previous years. mve and kunjin virus activity was detected in the kimberley and pilbara regions of western australia and the northern territory but not in north ... | 2002 | 12416705 |
| the ecology and epidemiology of kunjin virus. | 2002 | 12082993 | |
| kunjin virus replicon vaccine vectors induce protective cd8+ t-cell immunity. | the ability of self-replicating rna (replicon) vaccine vectors derived from the australian flavivirus kunjin (kun) to induce protective alphabeta cd8+ t-cell responses was examined. kun replicons encoding a model immunogen were delivered by three different vaccine modalities: (i) as naked rna transcribed in vitro, (ii) as plasmid dna constructed to allow in vivo transcription of replicon rna by cellular rna polymerase ii (dna based), and (iii) as replicon rna encapsidated into virus-like particl ... | 2002 | 11907219 |
| reappearance of human cases due to murray valley encephalitis virus and kunjin virus in central australia after an absence of 26 years. | murray valley encephalitis (mve) and kunjin virus disease are endemic in the tropical parts of the northern territory and western australia, but have been absent from central australia since 1974. in 2000, 5 laboratory-confirmed cases of encephalitis occurred over a short period in the normally dry inland region of central australia. the sudden occurrence of cases in march and april 2000 followed unusually high rainfall in the preceding months and evidence of flavivirus activity in the endemic a ... | 2002 | 11950201 |
| expression of hepatitis c virus proteins induces distinct membrane alterations including a candidate viral replication complex. | plus-strand rna viruses characteristically replicate their genome in association with altered cellular membranes. in the present study, the capacity of hepatitis c virus (hcv) proteins to elicit intracellular membrane alterations was investigated by expressing, in tetracycline-regulated cell lines, a comprehensive panel of hcv proteins individually as well as in the context of the entire hcv polyprotein. as visualized by electron microscopy (em), expression of the combined structural proteins co ... | 2002 | 12021330 |
| capsid protein c of tick-borne encephalitis virus tolerates large internal deletions and is a favorable target for attenuation of virulence. | deletions ranging in size from 4 to 21 amino acid residues were introduced into the capsid protein of the flavivirus tick-borne encephalitis (tbe) virus. these deletions incrementally affected a hydrophobic domain which is present at the center of all flavivirus capsid protein sequences and part of which may form an amphipathic alpha-helix. in the context of the full-length tbe genome, the deletions did not measurably affect protein expression and up to a deletion length of 16 amino acid residue ... | 2002 | 11884577 |
| hepatitis c virus-like particle morphogenesis. | although much is known about the hepatitis c virus (hcv) genome, first cloned in 1989, little is known about hcv structure and assembly due to the lack of an efficient in vitro culture system for hcv. using a recombinant semliki forest virus replicon expressing genes encoding hcv structural proteins, we observed for the first time the assembly of these proteins into hcv-like particles in mammalian cells. this system opens up new possibilities for the investigation of viral morphogenesis and viru ... | 2002 | 11907246 |
| mutations in the yellow fever virus nonstructural protein ns2a selectively block production of infectious particles. | little is known about the function of flavivirus nonstructural protein ns2a. two forms of ns2a are found in yellow fever virus-infected cells. full-length ns2a (224 amino acids) is the product of cleavage at the ns1/2a and ns2a/2b sites. ns2aalpha, a c-terminally truncated form of 190 amino acids, results from partial cleavage by the viral ns2b-3 serine protease at the sequence qk /t within ns2a. exchange of serine for lysine at this site (qkt-->qst) blocks the production of both ns2aalpha and i ... | 2002 | 11967294 |
| infectious cdna clone of the epidemic west nile virus from new york city. | we report the first full-length infectious clone of the current epidemic, lineage i, strain of west nile virus (wnv). the full-length cdna was constructed from reverse transcription-pcr products of viral rna from an isolate collected during the year 2000 outbreak in new york city. it was cloned into plasmid pbr322 under the control of a t7 promoter and stably amplified in escherichia coli hb101. rna transcribed from the full-length cdna clone was highly infectious upon transfection into bhk-21 c ... | 2002 | 12021317 |
| complementation analysis of the flavivirus kunjin ns3 and ns5 proteins defines the minimal regions essential for formation of a replication complex and shows a requirement of ns3 in cis for virus assembly. | we have previously reported successful trans-complementation of defective kunjin virus genomic rnas with a range of large lethal deletions in the nonstructural genes ns1, ns3, and ns5 (a. a. khromykh et al., j. virol. 74:3253-3263, 2000). in this study we have mapped further the minimal region in the ns5 gene essential for efficient trans-complementation of genome-length rnas in repbhk cells to the first 316 of the 905 codons. to allow amplification and easy detection of complemented defective r ... | 2002 | 12368319 |
| cell-free replication of the hepatitis c virus subgenomic replicon. | the hepatitis c virus (hcv) contains a plus-strand rna genome. the 5' noncoding region (ncr) of the viral genome functions as an internal ribosome entry site, and its unique 3' ncr is required for the assembly of the replication complex during initiation of hcv rna replication. lohmann et al. (v. lohmann, f. korner, j.-o. koch, u. herian, l. theilman, and r. batenschlager, science 285:110-113, 1999) developed a subgenomic hcv replicon system, which represents an important tool in studying hcv re ... | 2002 | 12414942 |
| induction of inflammation by west nile virus capsid through the caspase-9 apoptotic pathway. | west nile virus (wnv) is a member of the flaviviridae family of vector-borne pathogens. clinical signs of wnv infection include neurologic symptoms, limb weakness, and encephalitis, which can result in paralysis or death. we report that the wnv-capsid by itself induces rapid nuclear condensation and cell death in tissue culture. apoptosis is induced through the mitochondrial pathway resulting in caspase-9 activation and downstream caspase-3 activation. capsid gene delivery into the striatum of m ... | 2002 | 12498651 |
| phylogenetic analysis of a human isolate from the 2000 israel west nile virus epidemic. | specimens from a patient of the 2000 israel west nile virus epidemic were analyzed by reverse transcription-polymerase chain reaction. products corresponding to e, ns3, and ns5 sequences were amplified from cerebellar but not from cortical samples. phylogenetic analyses indicated a closer relationship of this isolate to 1996 romanian and 1999 russian than to 1998-99 israeli or 1999 new york isolates. | 2002 | 11996693 |
| replication and gene function in kunjin virus. | 2002 | 12082996 | |
| emergence of usutu virus, an african mosquito-borne flavivirus of the japanese encephalitis virus group, central europe. | during late summer 2001 in austria, a series of deaths in several species of birds occurred, similar to the beginning of the west nile virus (wnv) epidemic in the united states. we necropsied the dead birds and examined them by various methods; pathologic and immunohistologic investigations suggested a wnv infection. subsequently, the virus was isolated, identified, partially sequenced, and subjected to phylogenetic analysis. the isolates exhibited 97% identity to usutu virus (usuv), a mosquito- ... | 2002 | 12095429 |
| phylogenetic relationships of southern african west nile virus isolates. | phylogenetic relationships were examined for 29 southern african west nile virus (formal name west nile virus [wnv]) isolates from various sources in four countries from 1958 to 2001. in addition, sequence data were retrieved from genbank for another 23 wnv isolates and kunjin and japanese encephalitis viruses. all isolates belonged to two lineages. lineage 1 isolates were from central and north africa, europe, israel, and north america; lineage 2 isolates were from central and southern africa a ... | 2002 | 12141968 |
| kunjin virus: an australian variant of west nile? | kunjin (kun) is a flavivirus in the japanese encephalitis antigenic complex that was first isolated from culex annulirostris mosquitoes captured in northern australia in 1960. it is the etiological agent of a human disease characterized by febrile illness with rash or mild encephalitis and, occasionally, of a neurological disease in horses. kun virus shares a similar epidemiology and ecology with the closely related murray valley encephalitis (mve) virus, the major causative agent of arboviral e ... | 2001 | 11797773 |
| biogenesis of the semliki forest virus rna replication complex. | the nonstructural (ns) proteins nsp1 to -4, the components of semliki forest virus (sfv) rna polymerase, were localized in infected cells by confocal microscopy using double labeling with specific antisera against the individual ns proteins. all ns proteins were associated with large cytoplasmic vacuoles (cpv), the inner surfaces of which were covered by small invaginations, or spherules, typical of alphavirus infection. all ns proteins were localized by immuno-electron microscopy (em) to the li ... | 2001 | 11264376 |
| biophysical characterization and vector-specific antagonist activity of domain iii of the tick-borne flavivirus envelope protein. | the molecular determinants responsible for flavivirus host cell binding and tissue tropism are largely unknown, although domain iii of the envelope protein has been implicated in these functions. we examined the solution properties and antagonist activity of langat virus domain iii. our results suggest that domain iii adopts a stably folded structure that can mediate binding of tick-borne flaviviruses but not mosquito-borne flaviviruses to their target cells. three clusters of phylogenetically c ... | 2001 | 11264392 |
| molecular basis for attenuation of neurovirulence of a yellow fever virus/japanese encephalitis virus chimera vaccine (chimerivax-je). | a yellow fever virus (yfv)/japanese encephalitis virus (jev) chimera in which the structural proteins prm and e of yfv 17d are replaced with those of the jev sa14-14-2 vaccine strain is under evaluation as a candidate vaccine against japanese encephalitis. the chimera (yfv/jev sa14-14-2, or chimerivax-je) is less neurovirulent than is yfv 17d vaccine in mouse and nonhuman primate models (f. guirakhoo et al., virology 257:363-372, 1999; t. p. monath et al., vaccine 17:1869-1882, 1999). attenuatio ... | 2001 | 11134306 |
| coupling between replication and packaging of flavivirus rna: evidence derived from the use of dna-based full-length cdna clones of kunjin virus. | in order to study whether flavivirus rna packaging is dependent on rna replication, we generated two dna-based kunjin virus constructs, pkun1 and pkun1dgdd, allowing continuous production of replicating (wild-type) and nonreplicating (with a deletion of the ns5 gene rna-polymerase motif gdd) full-length kunjin virus rnas, respectively, via nuclear transcription by cellular rna polymerase ii. as expected, transfection of pkun1 plasmid dna into bhk cells resulted in the recovery of secreted infect ... | 2001 | 11312333 |
| stable expression of noncytopathic kunjin replicons simulates both ultrastructural and biochemical characteristics observed during replication of kunjin virus. | this report focuses mainly on the characterization of a vero cell line stably expressing the flavivirus kunjin (kun) replicon c20sdrep (c20sdrepvero). we showed by immunofluorescence and cryoimmunoelectron microscopy that unique flavivirus-induced membrane structures, termed convoluted membranes/paracrystalline structures, were induced in the c20sdrepvero cells. these induced cytoplasmic foci were immunolabeled with kun virus anti-ns3 antibodies and with antibodies to the cellular markers ergic5 ... | 2001 | 11145899 |
| attenuation of murray valley encephalitis virus by site-directed mutagenesis of the hinge and putative receptor-binding regions of the envelope protein. | molecular determinants of virulence in flaviviruses cluster in two regions on the three-dimensional structure of the envelope (e) protein; the base of domain ii, believed to serve as a hinge during ph-dependent conformational change in the endosome, and the lateral face of domain iii, which contains an integrin-binding motif arg-gly-asp (rgd) in mosquito-borne flaviviruses and is believed to form the receptor-binding site of the protein. in an effort to better understand the nature of attenuatio ... | 2001 | 11462041 |
| characterization of cell lines carrying self-replicating hepatitis c virus rnas. | subgenomic selectable rnas of the hepatitis c virus (hcv) have recently been shown to self-replicate to high levels in the human hepatoma cell line huh-7 (v. lohmann, f. körner, j. o. koch, u. herian, l. theilmann, and r. bartenschlager, science 285:110-113, 1999). taking advantage of this cell culture system that allows analyses of the interplay between hcv replication and the host cell, in this study we characterized two replicon-harboring cell lines that have been cultivated for more than 1 y ... | 2001 | 11152498 |
| genetic analysis of the pestivirus nonstructural coding region: defects in the ns5a unit can be complemented in trans. | the functional analysis of molecular determinants which control the replication of pestiviruses was considerably facilitated by the finding that subgenomic forms of the positive-strand rna genome of bvdv (bovine viral diarrhea virus) are capable of autonomous replication in transfected host cells. the prototype replicon, bvdv di9c, consists of the genomic 5' and 3' untranslated regions and a truncated open reading frame (orf) encoding mainly the nonstructural proteins ns3, ns4a, ns4b, ns5a, and ... | 2001 | 11483722 |
| assembly and maturation of the flavivirus kunjin virus appear to occur in the rough endoplasmic reticulum and along the secretory pathway, respectively. | the intracellular assembly site for flaviviruses in currently not known but is presumed to be located within the lumen of the rough endoplasmic reticulum (rer). building on previous studies involving immunofluorescence (if) and cryoimmunoelectron microscopy of kunjin virus (kun)-infected cells, we sought to identify the steps involved in the assembly and maturation of kun. thus, using antibodies directed against envelope protein e in if analysis, we found the accumulation of e within regions coi ... | 2001 | 11602720 |
| mutagenesis of the dengue virus type 2 ns3 protein within and outside helicase motifs: effects on enzyme activity and virus replication. | the protein ns3 of dengue virus type 2 (den-2) is the second largest nonstructural protein specified by the virus and is known to possess multiple enzymatic activities, including a serine proteinase located in the n-terminal region and an ntpase-helicase in the remaining 70% of the protein. the latter region has seven conserved helicase motifs found in all members of the family flaviviridae. den-2 ns3 lacking the proteinase region was synthesized as a fusion protein with glutathione s-transferas ... | 2001 | 11559795 |
| a case of kunjin virus encephalitis in a traveller returning from the northern territory. | 2001 | 11596722 | |
| a phylogenetic approach to following west nile virus in connecticut. | the 1999 outbreak of west nile (wn) virus in the northeastern united states was the first known natural occurrence of this flavivirus in the western hemisphere. in 1999 and 2000, 82 independent connecticut wn virus isolates were cultured from nine species of birds, five species of mosquitoes, and one striped skunk. nucleotide sequences obtained from these isolates identified 30 genetic changes, compared with wn-ny99, in a 921-nt region of the viral genome beginning at nucleotide position 205 and ... | 2001 | 11606791 |
| biological significance of glycosylation of the envelope protein of kunjin virus. | 2001 | 11797800 | |
| flock house virus rna replicates on outer mitochondrial membranes in drosophila cells. | the identification and characterization of host cell membranes essential for positive-strand rna virus replication should provide insight into the mechanisms of viral replication and potentially identify novel targets for broadly effective antiviral agents. the alphanodavirus flock house virus (fhv) is a positive-strand rna virus with one of the smallest known genomes among animal rna viruses, and it can replicate in insect, plant, mammalian, and yeast cells. to investigate the localization of f ... | 2001 | 11689648 |
| outbreak of west nile virus infection, volgograd region, russia, 1999. | from july 25 to october 1, 1999, 826 patients were admitted to volgograd region, russia, hospitals with acute aseptic meningoencephalitis, meningitis, or fever consistent with arboviral infection. of 84 cases of meningoencephalitis, 40 were fatal. fourteen brain specimens were positive in reverse transcriptase-polymerase chain reaction assays, confirming the presence of west nile/kunjin virus. | 2001 | 11266303 |
| essential role of cyclization sequences in flavivirus rna replication. | a possible role in rna replication for interactions between conserved complementary (cyclization) sequences in the 5'- and 3'-terminal regions of flavivirus rna was previously suggested but never tested in vivo. using the m-fold program for rna secondary-structure predictions, we examined for the first time the base-pairing interactions between the covalently linked 5' genomic region (first ~160 nucleotides) and the 3' untranslated region (last ~115 nucleotides) for a range of mosquito-borne fla ... | 2001 | 11413342 |
| development of dengue virus type 2 replicons capable of prolonged expression in host cells. | as part of a program to develop a dengue virus vaccine which avoids the deleterious effects of antibody dependent enhancement (ade) of infection mediated by antibodies to dengue virus structural proteins, we have begun to investigate the possibility of designing dengue vaccines based on non-structural proteins. | 2001 | 11580862 |
| host rna polymerase requirements for transcription of the human hepatitis delta virus genome. | replication of the genome of hepatitis delta virus (hdv) requires rna-directed rna synthesis using a host polymerase(s). this manuscript reviews the relevant published evidence. it also provides two new studies, both of which made use of transiently transfected huh7 cells undergoing hdv rna-directed rna synthesis. for the first study, rna transcription inhibitors were added to the transfected cells for periods of 1 to 2 days, after which assays of the effects on the accumulation of processed uni ... | 2001 | 11581384 |
| nucleic acid sequence-based amplification assays for rapid detection of west nile and st. louis encephalitis viruses. | the development and application of nucleic acid sequence-based amplification (nasba) assays for the detection of west nile (wn) and st. louis encephalitis (sle) viruses are reported. two unique detection formats were developed for the nasba assays: a postamplification detection step with a virus-specific internal capture probe and electrochemiluminescence (nasba-ecl assay) and a real-time assay with 6-carboxyfluorescein-labeled virus-specific molecular beacon probes (nasba-beacon assay). the sen ... | 2001 | 11724870 |
| hepatitis c virus nonstructural protein ns4b transforms nih3t3 cells in cooperation with the ha-ras oncogene. | although the mechanism of carcinogenesis by hepatitis c virus (hcv) is not clearly known, core and ns3p protein have been shown to form tumors in specific cell lines. in this study, on the basis of the fact that the core and ns4b proteins of kunjin virus translocate into the nucleus, we were prompted to investigate whether the hcv nonstructural protein ns4b has any function in tumor formation. first, we examined the location of the ns4b protein of hcv in transfected cells and then its oncogenic ... | 2000 | 10631105 |
| morphological features of murray valley encephalitis virus infection in the central nervous system of swiss mice. | we have examined the histological and ultrastructural features of cns infection with murray valley encephalitis (mve) virus in mice inoculated with a virulent parental strain (bh3479). light microscopic examination revealed neuronal necrosis in the olfactory bulb and hippocampus of mve-infected brains by 5 days post-infection (pi). electron microscopy of these regions showed endoplasmic reticulum membrane proliferation, and tubular and spherical structures in the cisternae of the endoplasmic ret ... | 2000 | 10718862 |
| charged residues in the transmembrane domains of hepatitis c virus glycoproteins play a major role in the processing, subcellular localization, and assembly of these envelope proteins. | for most membrane proteins, the transmembrane domain (tmd) is more than just an anchor to the membrane. the tmds of hepatitis c virus (hcv) envelope proteins e1 and e2 are extreme examples of the multifunctionality of such membrane-spanning sequences. indeed, they possess a signal sequence function in their c-terminal half, play a major role in endoplasmic reticulum localization of e1 and e2, and are potentially involved in the assembly of these envelope proteins. these multiple functions are su ... | 2000 | 10729138 |
| early diagnosis of murray valley encephalitis by reverse transcriptase-polymerase chain reaction. | a 4-year-old aboriginal boy developed encephalitis due to murray valley encephalitis virus (mve) following an earlier infection with kunjin virus (kun). the illness was severe, resulting in cerebral atrophy and profound physical and intellectual disability. the earlier kun infection complicated his serological profile and delayed antibody responses to mve. by contrast, the reverse transcriptase-polymerase chain reaction (rt-pcr) assay detected mve in serum 3 days after the onset of illness and 4 ... | 2000 | 10740807 |
| the predicted metal-binding region of the arterivirus helicase protein is involved in subgenomic mrna synthesis, genome replication, and virion biogenesis. | equine arteritis virus (eav), the prototype arterivirus, is a positive-stranded rna virus that expresses its replicase in the form of two large polyproteins of 1,727 and 3,175 amino acids. the functional replicase subunits (nonstructural proteins), which drive eav genome replication and subgenomic mrna transcription, are generated by extensive proteolytic processing. subgenomic mrna transcription involves an unusual discontinuous step and generates the mrnas for structural protein expression. pr ... | 2000 | 10799597 |
| infection of human cells by dengue virus is modulated by different cell types and viral strains. | although prior studies have investigated cellular infection by dengue virus (dv), many have used highly passaged strains. we have reassessed cellular infection by dv type 2 (dv2) using prototype and low-passage isolates representing genotypes from different geographic areas. we observed marked variation in the susceptibility to infection among cell types by different dv2 strains. hepg2 hepatoma cells were susceptible to infection by all dv2 strains assayed. although the prototype strain generate ... | 2000 | 10933688 |
| substitutions at the putative receptor-binding site of an encephalitic flavivirus alter virulence and host cell tropism and reveal a role for glycosaminoglycans in entry. | the flavivirus receptor-binding domain has been putatively assigned to a hydrophilic region (fg loop) in the envelope (e) protein. in some flaviviruses this domain harbors the integrin-binding motif arg-gly-asp (rgd). one of us has shown earlier that host cell adaptation of murray valley encephalitis virus (mve) can result in the selection of attenuated variants altered at e protein residue asp(390), which is part of an rgd motif. here, a full-length, infectious cdna clone of mve was constructed ... | 2000 | 10982329 |
| classical swine fever virus e(rns) deletion mutants: trans-complementation and potential use as nontransmissible, modified, live-attenuated marker vaccines. | an sk6 cell line (sk6c26) which constitutively expressed the glycoprotein e(rns) of classical swine fever virus (csfv) was used to rescue csfv e(rns) deletion mutants based on the infectious copy of csfv strain c. the biochemical properties of e(rns) from this cell line were indistinguishable from those of csfv e(rns). two e(rns) deletion mutants were constructed, virus flc23 and virus flc22. virus flc23 encoded only the utmost n- and c-terminal amino acids of e(rns) (deletion of 215 amino acids ... | 2000 | 10708411 |
| cis- and trans-acting elements in flavivirus rna replication. | most of the seven flavivirus nonstructural proteins (ns1 to ns5) encoded in the distal two-thirds of the rna positive-sense genome are believed to be essential components of rna replication complexes. to explore the functional relationships of these components in rna replication, we used trans-complementation analysis of full-length infectious rnas of kunjin (kun) virus with a range of lethal in-frame deletions in the nonstructural coding region, using as helper a repbhk cell line stably produci ... | 2000 | 10708442 |
| recombinant yellow fever viruses are effective therapeutic vaccines for treatment of murine experimental solid tumors and pulmonary metastases. | we have genetically engineered an attenuated yellow fever (yf) virus to carry and express foreign antigenic sequences and evaluated the potential of this type of recombinant virus to serve as a safe and effective tumor vaccine. live-attenuated yf vaccine is one of the most effective viral vaccines available today. important advantages include its ability to induce long-lasting immunity, its safety, its affordability, and its documented efficacy. in this study, recombinant live-attenuated (strain ... | 2000 | 10982366 |
| development of a primary tamarin hepatocyte culture system for gb virus-b: a surrogate model for hepatitis c virus. | gb virus-b (gbv-b) causes an acute hepatitis in tamarins characterized by increased alanine transaminase levels that quickly return to normal as the virus is cleared. phylogenetically, gbv-b is the closest relative to hepatitis c virus (hcv), and thus gbv-b infection of tamarins represents a powerful surrogate model system for the study of hcv. in this study, the course of infection of gbv-b in tamarins was followed using a real-time 5' exonuclease (taqman) reverse transcription-pcr assay to det ... | 2000 | 11090176 |
| rubella virus replication and links to teratogenicity. | rubella virus (rv) is the causative agent of the disease known more popularly as german measles. rubella is predominantly a childhood disease and is endemic throughout the world. natural infections of rubella occur only in humans and are generally mild. complications of rubella infection, most commonly polyarthralgia in adult women, do exist; occasionally more serious sequelae occur. however, the primary public health concern of rv infection is its teratogenicity. rv infection of women during th ... | 2000 | 11023958 |
| stable high-level expression of heterologous genes in vitro and in vivo by noncytopathic dna-based kunjin virus replicon vectors. | primary features of the flavivirus kunjin (kun) subgenomic replicons include continuous noncytopathic replication in host cell cytoplasm and the ability to be encapsidated into secreted virus-like particles (vlps). previously we reported preparation of rna-based kun replicon vectors and expression of heterologous genes (hg) in cell culture after rna transfection or after infection with recombinant kun vlps (a. n. varnavski and a. a. khromykh, virology 255:366-375, 1999). in this study we describ ... | 2000 | 10756054 |
| e2-p7 region of the bovine viral diarrhea virus polyprotein: processing and functional studies. | the genes encoding pestivirus e2 and ns2-3 are separated by a sequence that encodes a small hydrophobic polypeptide with an apparent molecular mass of 6 to 7 kda (p7). it has been shown that cleavage between e2 and p7 is incomplete, resulting in proteins e2-p7, e2, and p7. we found no precursor-product relationship between e2-p7 and e2, which indicates a stable nature of e2-p7. to study the function of the e2-p7 region of the polyprotein, mutations were introduced into an infectious cdna of bovi ... | 2000 | 11000219 |
| analysis of murine cd8(+) t-cell clones specific for the dengue virus ns3 protein: flavivirus cross-reactivity and influence of infecting serotype. | serotype-cross-reactive dengue virus-specific cytotoxic t lymphocytes (ctl) induced during a primary dengue virus infection are thought to play a role in the immunopathogenesis of dengue hemorrhagic fever (dhf) during a secondary dengue virus infection. although there is no animal model of dhf, we previously reported that murine dengue virus-specific ctl responses are qualitatively similar to human dengue virus-specific ctl responses. we used balb/c mice to study the specificity of the ctl respo ... | 1999 | 9847344 |
| yellow fever/japanese encephalitis chimeric viruses: construction and biological properties. | a system has been developed for generating chimeric yellow fever/japanese encephalitis (yf/je) viruses from cdna templates encoding the structural proteins prm and e of je virus within the backbone of a molecular clone of the yf17d strain. chimeric viruses incorporating the proteins of two je strains, sa14-14-2 (human vaccine strain) and je nakayama (je-n [virulent mouse brain-passaged strain]), were studied in cell culture and laboratory mice. the je envelope protein (e) retained antigenic and ... | 1999 | 10074160 |
| biological consequences of deletions within the 3'-untranslated region of flaviviruses may be due to rearrangements of rna secondary structure. | it was previously reported that deletions introduced into the 3'-untranslated region (3'-utr) of dengue type 4 (den 4) virus (men, r., bray, m., clark, d., chanock, r.m., lai, c.j., 1996. den 4 virus mutants containing deletions in the 3'-noncoding region of the rna genome: analysis of growth restriction in cell culture and altered viremia pattern and immunogenicity in rhesus monkeys. j. virol. 70, 3930-3937), tick-borne encephalitis (tbe) virus (mandl, c.w., holzmann, h., meixner, t., rauscher, ... | 1999 | 10518708 |
| markers for trans-golgi membranes and the intermediate compartment localize to induced membranes with distinct replication functions in flavivirus-infected cells. | replication of the flavivirus kunjin virus is associated with virus-induced membrane structures within the cytoplasm of infected cells; these membranes appear as packets of vesicles associated with the sites of viral rna synthesis and as convoluted membranes (cm) and paracrystalline arrays (pc) containing the components of the virus-specified protease (e. g. westaway, j. m. mackenzie, m. t. kenney, m. k. jones, and a. a. khromykh, j. virol. 71:6650-6661, 1997). to determine the cellular origins ... | 1999 | 10516064 |
| nascent flavivirus rna colocalized in situ with double-stranded rna in stable replication complexes. | incorporation of bromouridine (bru) into viral rna in kunjin virus-infected vero cells treated with actinomycin d was monitored in situ by immunofluorescence using antibodies reactive with br-rna. the results showed unequivocally that nascent viral rna was located focally in the same subcellular site as dsrna, the putative template for flavivirus rna synthesis. when cells were labeled with bru for 15 min, the estimated cycle period for rna synthesis, the nascent br-rna was not digested in permea ... | 1999 | 10329573 |
| open reading frame 1a-encoded subunits of the arterivirus replicase induce endoplasmic reticulum-derived double-membrane vesicles which carry the viral replication complex. | the replicase of equine arteritis virus (eav; family arteriviridae, order nidovirales) is expressed in the form of two polyproteins (the open reading frame 1a [orf1a] and orf1ab proteins). three viral proteases cleave these precursors into 12 nonstructural proteins, which direct both genome replication and subgenomic mrna transcription. immunofluorescence assays showed that most eav replicase subunits localize to membranes in the perinuclear region of the infected cell. using replicase-specific ... | 1999 | 9971782 |
| efficient trans-complementation of the flavivirus kunjin ns5 protein but not of the ns1 protein requires its coexpression with other components of the viral replicase. | successful trans-complementation of the defective kunjin virus (kun) rna fldgdd with a deletion of the rna polymerase motif gdd in the ns5 gene by using a bhk cell line, repbhk, that continuously produced a functionally active kun replication complex (rc) from replicon rna was recently reported (a. a. khromykh, m. t. kenney, and e. g. westaway, j. virol. 72:7270-7279, 1998). in order to identify whether this complementation of fldgdd rna was provided by the wild-type ns5 protein alone or with th ... | 1999 | 10559344 |
| isolation of homologous arbovirus cultures from heterologous mixtures using limit dilution and virus-specific enzyme immunoassays. | viral cultures were identified recently that contained both kunjin virus and the closely related flavivirus west nile. the observation that the kun virus population grew more efficiently in a mosquito cell line (c6/36) while the wn population replicated more effectively in mammalian cells (vero) allowed enrichment for either virus by culturing the mixture in the appropriate cell line. limit dilution of the enriched virus preparations was then performed by infecting microtitre cultures with seria ... | 1999 | 10598096 |
| functional analysis of cell surface-expressed hepatitis c virus e2 glycoprotein. | hepatitis c virus (hcv) glycoproteins e1 and e2, when expressed in eukaryotic cells, are retained in the endoplasmic reticulum (er). c-terminal truncation of e2 at residue 661 or 715 (position on the polyprotein) leads to secretion, consistent with deletion of a proposed hydrophobic transmembrane anchor sequence. we demonstrate cell surface expression of a chimeric glycoprotein consisting of e2 residues 384 to 661 fused to the transmembrane and cytoplasmic domains of influenza a virus hemaggluti ... | 1999 | 10400776 |
| trans-complementation analysis of the flavivirus kunjin ns5 gene reveals an essential role for translation of its n-terminal half in rna replication. | recently we described rescue of defective kunjin virus (kun) rnas with small deletions in the methyltransferase and rna polymerase motifs of the ns5 gene, using bhk cells stably expressing kun replicon rna (repbhk cells) as helper (a. a. khromykh et al., j. virol. 72:7270-7279, 1998). we have now extended our previous observations and report successful trans-complementation of defective kun rnas with most of the ns5 gene deleted or substituted with a heterologous (dengue virus) ns5 sequence. rep ... | 1999 | 10516033 |
| loss of dimerisation of the nonstructural protein ns1 of kunjin virus delays viral replication and reduces virulence in mice, but still allows secretion of ns1. | the flavivirus nonstructural protein ns1 has been implicated in viral rna replication, although its precise role has not been identified. in its native state ns1 exists as a heat labile homodimer that is thought to be required for ns1 function and secretion. however, we have recently identified a cdna clone of kun virus (flsd) that replicates efficiently in cell culture but produces and secretes ns1 in monomeric form. sequence analysis of the ns1 gene in flsd revealed a single amino acid substit ... | 1999 | 10544130 |
| genetic interaction of flavivirus nonstructural proteins ns1 and ns4a as a determinant of replicase function. | nonstructural protein 1 (ns1) of yellow fever virus (yf) is a glycoprotein localized to extracytoplasmic compartments within infected cells. we have previously shown that ns1 can be supplied in trans and is required for viral rna replication, a process thought to occur in membrane-bound cytoplasmic complexes. here we report that the ns1 gene from a related virus, dengue virus (den), is unable to function in the process of yf rna replication. this virus-specific incompatibility leads to a lack of ... | 1999 | 10233920 |
| dengue virus type 1 nonstructural glycoprotein ns1 is secreted from mammalian cells as a soluble hexamer in a glycosylation-dependent fashion. | nonstructural glycoprotein ns1, specified by dengue virus type 1 (den-1), is secreted from infected green monkey kidney (vero) cells in a major soluble form characterized by biochemical and biophysical means as a unique hexameric species. this noncovalently bound oligomer is formed by three dimeric subunits and has a molecular mass of 310 kda and a stokes radius of 64.4 a. during protein export, one of the two oligosaccharides of ns1 is processed into an endo-beta-n-acetylglucosaminidase f-resis ... | 1999 | 10364366 |
| localization of mouse hepatitis virus nonstructural proteins and rna synthesis indicates a role for late endosomes in viral replication. | the aim of the present study was to define the site of replication of the coronavirus mouse hepatitis virus (mhv). antibodies directed against several proteins derived from the gene 1 polyprotein, including the 3c-like protease (3clpro), the putative polymerase (pol), helicase, and a recently described protein (p22) derived from the c terminus of the open reading frame 1a protein (ct1a), were used to probe mhv-infected cells by indirect immunofluorescence (if) and electron microscopy (em). at ea ... | 1999 | 10438855 |
| mutagenesis of the ns2b-ns3-mediated cleavage site in the flavivirus capsid protein demonstrates a requirement for coordinated processing. | analysis of flavivirus polyprotein processing has revealed the presence of a substrate for the virus-encoded ns2b-ns3 protease at the carboxy-terminal end of the c (capsid or core) protein. cleavage at this site has been implicated in the efficient generation of the amino terminus of prm via signal peptidase cleavage. yellow fever virus has four basic residues (arg-lys-arg-arg) in the p1 through p4 positions of this cleavage site. multiple alanine substitutions were made for these residues in or ... | 1999 | 10482557 |
| mutagenesis of the ns3 protease of dengue virus type 2. | the flavivirus protease is composed of two viral proteins, ns2b and ns3. the amino-terminal portion of ns3 contains sequence and structural motifs characteristic of bacterial and cellular trypsin-like proteases. we have undertaken a mutational analysis of the region of ns3 which contains the catalytic serine, five putative substrate binding residues, and several residues that are highly conserved among flavivirus proteases and among all serine proteases. in all, 46 single-amino-acid substitution ... | 1998 | 9420267 |
| characterization of an autonomous subgenomic pestivirus rna replicon. | as an initial approach to define the requirements for the replication of bovine viral diarrhea virus (bvdv), a member of the flaviviridae family with a positive-strand rna genome, full-length genomic and subgenomic rnas were originated by in vitro transcription of diverse bvdv cdna constructs and transfected into eucaryotic host cells. rna replication was measured either directly by an rnase protection method or by monitoring the synthesis of viral protein. when full-length bvdv crna was initial ... | 1998 | 9499097 |
| phylogeny of the genus flavivirus. | we undertook a comprehensive phylogenetic study to establish the genetic relationship among the viruses of the genus flavivirus and to compare the classification based on molecular phylogeny with the existing serologic method. by using a combination of quantitative definitions (bootstrap support level and the pairwise nucleotide sequence identity), the viruses could be classified into clusters, clades, and species. our phylogenetic study revealed for the first time that from the putative ancesto ... | 1998 | 9420202 |
| rna virus vectors: where are we and where do we need to go? | 1998 | 9788984 | |
| antiapoptotic but not antiviral function of human bcl-2 assists establishment of japanese encephalitis virus persistence in cultured cells. | upon infection of japanese encephalitis virus (jev), baby hamster kidney (bhk-21) and chinese hamster ovary (cho) cells were killed by a mechanism involved in apoptosis. while readily established in a variety of cell lines, jev persistence has never been successfully instituted in bhk-21 and cho cells. since stable expression of human bcl-2 in bhk-21 cells has been shown to delay jev-induced apoptosis, in this study we investigated whether jev persistence could be established in such cells. when ... | 1998 | 9811720 |
| characterization of defective viral rna produced during persistent infection of vero cells with murray valley encephalitis virus. | defective interfering viral particles are readily produced in cell culture after a high multiplicity of infection with many animal rna viruses. due to defects that they carry in their genomes, their life cycle needs to be complemented by the helper functions provided by a parental virus which makes them both dependent on and competitive with the parental virus. in many instances, this may cause the abrogation of a lytic cycle of the parental virus, leading to a persistent infection. in this pape ... | 1998 | 9499109 |
| spontaneous and engineered deletions in the 3' noncoding region of tick-borne encephalitis virus: construction of highly attenuated mutants of a flavivirus. | the flavivirus genome is a positive-strand rna molecule containing a single long open reading frame flanked by noncoding regions (ncr) that mediate crucial processes of the viral life cycle. the 3' ncr of tick-borne encephalitis (tbe) virus can be divided into a variable region that is highly heterogeneous in length among strains of tbe virus and in certain cases includes an internal poly(a) tract and a 3'-terminal conserved core element that is believed to fold as a whole into a well-defined se ... | 1998 | 9499069 |
| signal peptidase cleavage at the flavivirus c-prm junction: dependence on the viral ns2b-3 protease for efficient processing requires determinants in c, the signal peptide, and prm. | signal peptidase cleavage at the c-prm junction in the flavivirus structural polyprotein is inefficient in the absence of the cytoplasmic viral protease, which catalyzes cleavage at the cooh terminus of the c protein. the signal peptidase cleavage occurs efficiently in circumstances where the c protein is deleted or if the viral protease complex is present. in this study, we used cdna of murray valley encephalitis virus (mve) to examine features of the structural polyprotein which allow this reg ... | 1998 | 9499070 |
| encapsidation of the flavivirus kunjin replicon rna by using a complementation system providing kunjin virus structural proteins in trans. | kunjin virus (kun) replicon rna was encapsidated by a procedure involving two consecutive electroporations of bhk-21 cells, first with kun replicon rna c20dxrep (with prme and most of c deleted) and about 24 h later with a recombinant semliki forest virus (sfv) replicon rna(s) expressing kun structural proteins. the presence of kun replicon rna in encapsidated particles was demonstrated by its amplification and expression in newly infected bhk-21 cells, detected by northern blotting with a kun-s ... | 1998 | 9621059 |
| orf1a-encoded replicase subunits are involved in the membrane association of the arterivirus replication complex. | among the functions of the replicase of equine arteritis virus (eav; family arteriviridae, order nidovirales) are important viral enzyme activities such as proteases and the putative rna polymerase and rna helicase functions. the replicase is expressed in the form of two polyproteins (open reading frame 1a [orf1a] and orf1ab), which are processed into 12 nonstructural proteins by three viral proteases. in immunofluorescence assays, the majority of these cleavage products localized to the perinuc ... | 1998 | 9658116 |
| a c-terminal motif found in the beta2-adrenergic receptor, p2y1 receptor and cystic fibrosis transmembrane conductance regulator determines binding to the na+/h+ exchanger regulatory factor family of pdz proteins. | the na+/h+ exchanger regulatory factor (nherf) binds to the tail of the beta2-adrenergic receptor and plays a role in adrenergic regulation of na+/h+ exchange. nherf contains two pdz domains, the first of which is required for its interaction with the beta2 receptor. mutagenesis studies of the beta2 receptor tail revealed that the optimal c-terminal motif for binding to the first pdz domain of nherf is d-s/t-x-l, a motif distinct from those recognized by other pdz domains. the first pdz domain o ... | 1998 | 9671706 |
| subcellular localization and some biochemical properties of the flavivirus kunjin nonstructural proteins ns2a and ns4a. | in a previous study on the replication of kunjin virus using immunoelectron microscopy (e. g. westaway, j. m. mackenzie, m. t. kenney, m. k. jones, and a. a. khromykh, 1997, j. virol. 71, 6650-6661), ns1 and ns3 were found associated with double-stranded rna (dsrna) within vesicle packets (vp) in infected vero cells, suggesting that these induced membrane structures may be the cytoplasmic sites of rna replication. ns2b and ns3 (comprising the virus-encoded protease) were colocalized within disti ... | 1998 | 9636360 |
| trans-complementation of flavivirus rna polymerase gene ns5 by using kunjin virus replicon-expressing bhk cells. | a bhk cell line persistently expressing a kunjin (kun) virus replicon rna (repbhk, similar to our recently described me/76neo bhk cell line [a. a. khromykh and e. g. westaway, j. virol. 71:1497-1505, 1997]) was used for rescue and propagation of kun viruses defective in the rna polymerase gene (ns5). a new infectious full-length kun virus cdna clone, flsdx, prepared from our previously described cdna clone pakun (a. a. khromykh and e. g. westaway, j. virol. 68:4580-4588, 1994) and possessing app ... | 1998 | 9696822 |
| transcripts from a single full-length cdna clone of hepatitis c virus are infectious when directly transfected into the liver of a chimpanzee. | we have succeeded in constructing a stable full-length cdna clone of strain h77 (genotype 1a) of hepatitis c virus (hcv). we devised a cassette vector with fixed 5' and 3' termini and constructed multiple full-length cdna clones of h77 in a single step by cloning of the entire orf, which was amplified by long reverse transcriptase-pcr, directly into this vector. the infectivity of two complete full-length cdna clones was tested by the direct intrahepatic injection of a chimpanzee with rna transc ... | 1997 | 9238047 |
| subgenomic replicons of the flavivirus kunjin: construction and applications. | several kunjin virus (kun) subgenomic replicons containing large deletions in the structural region (c-prm-e) and in the 3' untranslated region (3'utr) of the genome have been constructed. replicon rna deltame with 1,987 nucleotides deleted (from nucleotide 417 [in codon 108] in the c gene to nucleotide 2403 near the carboxy terminus of the e gene, inclusive) and replicon rna c20rep with 2,247 nucleotides deleted (from nucleotide 157 [in codon 20] in c to nucleotide 2403) replicated efficiently ... | 1997 | 8995675 |
| interaction of kunjin virus with octyl-d-glucoside extracted vero cell plasma membrane. | initial experiments using whole cells have shown that there were specific and saturable interactions between kunjin (kun) virus and receptor molecules on the vero cell surfaces. solubilisation of vero cell plasma membranes with octyl-d-glucoside (og) yielded an extract which also interacted specifically with kun virus. this was proven using electron microscopy. when the virus-og-extract complex was exposed onto vero cell monolayers, no kun virus was observed to enter into the whole cells. this w ... | 1997 | 9015287 |
| extensive nucleotide changes and deletions within the envelope glycoprotein gene of euro-african west nile viruses. | we compared the sequence of an envelope protein gene fragment from 21 temporally distinct west nile (wn) virus strains, isolated in nine african countries and in france. alignment of nucleotide sequences defined two groups of viruses which diverged by up to 29%. the first group of subtypes is composed of nine wn strains from france and africa. the austral-asian kunjin virus was classified as a wn subtype in this first group. the second group includes 12 wn strains from africa and madagascar. fou ... | 1997 | 9292017 |
| ultrastructure of kunjin virus-infected cells: colocalization of ns1 and ns3 with double-stranded rna, and of ns2b with ns3, in virus-induced membrane structures. | the subcellular location of the nonstructural proteins ns1, ns2b, and ns3 in vero cells infected with the flavivirus kunjin was investigated using indirect immunofluorescence and cryoimmunoelectron microscopy with monospecific antibodies. comparisons were also made by dual immunolabelling using antibodies to double-stranded rna (dsrna), the putative template in the flavivirus replication complex. at 8 h postinfection, the immunofluorescent patterns showed ns1, ns2b, ns3, and dsrna located in a p ... | 1997 | 9261387 |
| rna binding properties of core protein of the flavivirus kunjin. | kunjin virus (kun) c is a typical flavivirus core protein which is truncated in vivo to a mature form of 105 residues enriched in lysine and arginine. in order to study the possible association of kun c with rna in vitro, we prepared several recombinant c proteins with specific deletions, each fused at the amino-terminus to glutathione-s-transferase (gst) and expressed in e. coli. they were reacted with kun rna probes transcribed in vitro from cdna representing the 5' untranslated region (5' utr ... | 1996 | 8645104 |
| australian x disease, murray valley encephalitis and the french connection. | epidemics of a severe encephalitis occurred in eastern australia between 1917 and 1925, in which over 280 cases were reported with a fatality rate of 68%. the disease had not been described previously and was called australian x disease. the next epidemic occurred in south-east australia in the summer of 1950-51. the disease was given its name of murray valley encephalitis as this was the area from which most cases were reported. a virus was isolated by eric french in victoria, and about the sam ... | 1995 | 8545982 |
| glycosylation and antigenic variation among kunjin virus isolates. | previous studies have found kunjin (kun) virus isolates from within australia to be genetically homogenous and that the envelope protein of the type strain (mrm61c) was unglycosylated and lacked a potential glycosylation site. we investigated the extent of antigenic variation between kun virus isolates from australia and sarawak using an immunoperoxidase assay and a panel of six monoclonal antibodies. the glycosylation status of the e protein of each virus was also determined by n glycosidase f ... | 1995 | 7530394 |
| use of a flavivirus rna-dependent rna polymerase assay to investigate the antiviral activity of selected compounds. | we have developed an assay using flavivirus rna-dependent rna polymerase to test the inhibitory activity of potential antiviral agents. the effects of antiviral agents on rna synthesis were examined in this assay using extracts of vero cells infected with dengue virus type 2 or kunjin virus. several different classes of known polymerase inhibitors were tested. the synthesis of double-stranded replicative form rna was inhibited in a dose-dependent fashion in the presence of the polyoxometalate hp ... | 1994 | 7993077 |
| completion of kunjin virus rna sequence and recovery of an infectious rna transcribed from stably cloned full-length cdna. | completion of the kunjin virus (kun) rna sequence showed that it is the longest flavivirus sequence reported (11,022 bases), commencing with a 5' noncoding region of 96 bases. the 3' noncoding sequence of 624 nucleotides included a unique insertion sequence of 46 bases adjacent to the stop codon, but otherwise it had properties similar to those of rnas of closely related flaviviruses. a full-length kun cdna clone which could be stably propagated in escherichia coli dh5 alpha was constructed; sp6 ... | 1994 | 8207832 |
| synthesis of dengue virus rna in vitro: initiation and the involvement of proteins ns3 and ns5. | an assay for flavivirus rna-dependent rna polymerase activity in vitro was established using extracts of vero cells infected with dengue virus type 2 (den-2) or kunjin virus (kun). rna synthesis was initiated on a template of viral replicative form (rf) and rf was converted to the replicative intermediate (ri). the rna-dependent rna polymerase complex of den-2 utilised either den-2 or kun rf as template, and similarly the kun polymerase complex utilised either den-2 or kun rf template. in additi ... | 1993 | 8418788 |
| australian encephalitis in western australia, 1978-1991. | to review the various clinical manifestations of murray valley encephalitis (mve) or kunjin virus encephalitis in patients in western australia. | 1993 | 8386796 |
| detection of west nile virus by the polymerase chain reaction and analysis of nucleotide sequence variation. | a polymerase chain reaction (pcr) assay was developed to rapidly detect and identify west nile (wn) virus. the rna from seven isolates of wn virus from six countries and four other flaviviruses (kunjin, japanese encephalitis, st. louis encephalitis, and yellow fever viruses) was reverse-transcribed (rt) and amplified by pcr. the nucleotide sequences of the amplified products were determined by a rapid, automated dna sequencing method. the wn virus rt/pcr assay detected the target gene segment of ... | 1993 | 8470779 |
| 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 ... | 1992 | 1375278 |
| molecular and ultrastructural analysis of heavy membrane fractions associated with the replication of kunjin virus rna. | in subcellular extracts of kunjin virus-infected cells prepared by lysis and differential centrifugation, the viral rna polymerase, rna and proteins were associated mainly with cytoplasm. when the cytoplasmic extract (500 g supernate) of infected cells labelled for 3 h from 24 h post-infection was further fractionated by rapid centrifugation through a sucrose density gradient, all viral products were located only in dense or "heavy membrane" fractions, which contained three types of virus-induce ... | 1992 | 1322651 |
| 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 ... | 1992 | 1597508 |
| 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 ... | 1992 | 1349926 |
| 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 ... | 1992 | 1331144 |
| isolation of kunjin virus from a patient with a naturally acquired infection. | to describe the first isolation of kunjin virus from a patient with a natural infection. | 1992 | 1321945 |