Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| contribution of disulfide bridging to epitope expression of the dengue type 2 virus envelope glycoprotein. | the individual contributions of each of the six conserved disulfide (ss) bonds in the dengue 2 virus envelope (e) glycoprotein (strain 16681) to epitope expression was determined by measuring the reactivities of a panel of well-defined monoclonal antibodies (mabs) with llc-mk(2) cells that had been transiently transformed with plasmid vectors expressing e proteins that were mutant in their ss bonds. three domain i (di) epitopes (c1, c3, and c4) were affected by elimination of any ss bond and wer ... | 2004 | 14963174 |
| cysteine mediated multimerization of a recombinant dengue e fragment fused to the p64k protein following immobilized metal ion affinity chromatography. | a fragment of the envelope protein of dengue 2 virus encoding the amino acid (aa) 286-426 was fused to the p64k protein from neisseria meningitidis. the hybrid gene (pd5) was expressed in escherichia coli. the influence of using immobilized metal ion affinity chromatography (imac) in the purification process of pd5 was examined. after the elution, pd5 protein formed aggregates of high molecular weight depending on disulfide-bonds. the study of different conditions affecting the redox potential i ... | 2004 | 15003248 |
| the non-structural 3 (ns3) protein of dengue virus type 2 interacts with human nuclear receptor binding protein and is associated with alterations in membrane structure. | flaviviral infections produce a distinct array of virus-induced intracellular membrane alterations that are associated with the flaviviral replication machinery. currently, it is still unknown which flaviviral protein(s) is/are responsible for this induction. using yeast two-hybrid and co-immunoprecipitation analyses, we demonstrated that the ns3 protein of dengue virus type 2 interacted specifically with nuclear receptor binding protein (nrbp), a host cellular protein that influences traffickin ... | 2004 | 15084397 |
| conformational changes of the flavivirus e glycoprotein. | dengue virus, a member of the flaviviridae family, has a surface composed of 180 copies each of the envelope (e) glycoprotein and the membrane (m) protein. the crystal structure of an n-terminal fragment of e has been determined and compared with a previously described structure. the primary difference between these structures is a 10 degrees rotation about a hinge relating the fusion domain dii to domains di and diii. these two rigid body components were used for independent fitting of e into t ... | 2004 | 15341726 |
| epitope determinants of a chimpanzee fab antibody that efficiently cross-neutralizes dengue type 1 and type 2 viruses map to inside and in close proximity to fusion loop of the dengue type 2 virus envelope glycoprotein. | the epitope determinants of chimpanzee fab antibody 1a5, which have been shown to be broadly reactive to flaviviruses and efficient for cross-neutralization of dengue virus type 1 and type 2 (denv-1 and denv-2), were studied by analysis of denv-2 antigenic variants. sequence analysis showed that one antigenic variant contained a gly-to-val substitution at position 106 within the flavivirus-conserved fusion peptide loop of the envelope protein (e), and another variant contained a his-to-gln subst ... | 2004 | 15542644 |
| wild terrestrial rainforest mammals as potential reservoirs for flaviviruses (yellow fever, dengue 2 and st louis encephalitis viruses) in french guiana. | a serological survey for yellow fever virus (yfv), dengue 2 virus (denv-2), and st louis encephalitis virus (slev) was undertaken using a seroneutralization technique in 27 wild forest mammal species (574 individuals) in french guiana. evidence of yellow fever infection was observed in 10 species, with high prevalence recorded in howler monkey (18%) and agouti (20%). antibodies against denv-2 and slev were found sporadically in various species. this potential host diversity and the range of pote ... | 2004 | 15138077 |
| analysis of recombinant dengue virus polypeptides for dengue diagnosis and evaluation of the humoral immune response. | dengue is a serious cause of morbidity and mortality in tropical areas worldwide. we cloned and expressed recombinant polypeptides spanning the entire genome of a brazilian dengue virus type 2 (denv-2) strain in contiguous segments to generate antigens for dengue diagnosis and evaluation of the human humoral immune response. when analyzed by western blot and an enzyme-linked immunosorbent assay (elisa) using human sera, the most reactive polypeptide (pd2-3(e)) was located in the n-terminal porti ... | 2004 | 15306702 |
| a 7-deaza-adenosine analog is a potent and selective inhibitor of hepatitis c virus replication with excellent pharmacokinetic properties. | improved treatments for chronic hepatitis c virus (hcv) infection are needed due to the suboptimal response rates and deleterious side effects associated with current treatment options. the triphosphates of 2'-c-methyl-adenosine and 2'-c-methyl-guanosine were previously shown to be potent inhibitors of the hcv rna-dependent rna polymerase (rdrp) that is responsible for the replication of viral rna in cells. here we demonstrate that the inclusion of a 7-deaza modification in a series of purine nu ... | 2004 | 15388457 |
| histidine 39 in the dengue virus type 2 m protein has an important role in virus assembly. | the mature flavivirus particle comprises a nucleocapsid core surrounded by a lipid bilayer containing the membrane (m) (derived from the precursor prm) and envelope (e) proteins. the formation of intracellular prm/e heterodimers occurs rapidly after translation and is believed to be important for the assembly and secretion of immature virus particles. in this study, the role of the his residue at position 39 in the m protein (m39) of dengue virus type 2 (denv-2) in the virus life cycle was inves ... | 2004 | 15557235 |
| cytokine production in brain of mice experimentally infected with dengue virus. | dengue virus encephalopathy was experimentally induced in newborn mice by i.p. inoculation of dengue 2 virus. at 6 and 9 days post-infection, motor incoordination and posterior limb paralysis were observed with focal necrosis, apoptotic cells, perivascular inflammatory cuffing and astrocytosis, mainly in the cortex and hippocampus. expression of dengue virus genome and mrna encoding for tnf-alpha, il-1alpha, il-2, il-6, il-1beta, il-12 p40, ifnalpha, and ifnbeta; in addition host survival and in ... | 2004 | 15106828 |
| dengue virus type 2 in cuba, 1997: conservation of e gene sequence in isolates obtained at different times during the epidemic. | it was recently reported that disease severity increased during the 1997 cuban dengue 2 virus epidemic and it was suggested that this might be explained by the appearance of neutralization resistant escape mutants. we investigated these observations and ideas by sequencing 20 dengue 2 virus isolates obtained during the early (low case fatality rate) and the late (high case fatality rate) phases of the outbreak. our results showed total conservation of the e gene sequence for these isolates sugge ... | 2004 | 15578237 |
| determination of the disulfide bond arrangement of dengue virus ns1 protein. | the 12 half-cystines of ns1 proteins are absolutely conserved among flaviviruses, suggesting their importance to the structure and function of these proteins. in the present study, peptides from recombinant dengue-2 virus ns1 were produced by tryptic digestion in 100% h(2)(16)o, peptic digestion in 50% h(2)(18)o, thermolytic digestion in 50% h(2)(18)o, or combinations of these digestion conditions. peptides were separated by size exclusion and/or reverse phase high performance liquid chromatogra ... | 2004 | 14981082 |
| identification of a 48kda tubulin or tubulin-like c6/36 mosquito cells protein that binds dengue virus 2 using mass spectrometry. | binding of dengue virus 2 (denv-2) to c6/36 mosquito cells protein was investigated. a 48 kda denv-2-binding c6/36 cells protein (d2bp) was detected in a virus overlay protein-binding assay. the binding occurred only to the c6/36 cells cytosolic protein fraction and it was inhibited by free d2bp. d2bp was shown to bind to denv-2 e in the far-western-binding studies and using mass spectrometry (ms) and ms/ms, peptide masses of the d2bp that matched to beta-tubulin and alpha-tubulin chains were id ... | 2004 | 15207695 |
| identification of the homotypic interaction domain of the core protein of dengue virus type 2. | dengue virus causes dengue haemorrhagic fever or dengue shock syndrome with a high mortality rate. the genome of dengue virus is a positive-sense, single-stranded rna encoding three structural and seven non-structural proteins. the core protein is one of the three structural proteins and is the building block of the nucleocapsid of dengue virus. the core protein of dengue virus type 2 (den2) is composed of 100 aa with four alpha-helix domains. an internal hydrophobic domain located at aa 44-60 w ... | 2004 | 15269372 |
| fusion pcr generated japanese encephalitis virus/dengue 4 virus chimera exhibits lack of neuroinvasiveness, attenuated neurovirulence, and a dual-flavi immune response in mice. | the first flavivirus chimera encoding dengue 4 virus (d4) prm and e structural proteins in a japanese encephalitis virus (jev) backbone was successfully generated using the long-pcr based cdna-fragment stitching (lpcrcfs) technique, demonstrating the technique's applicability for rapid preparation of flavivirus chimeras. the jev/d4 chimera multiplied at levels equal to jev and d4 in the mosquito cell line c6/36, while in a mouse neuronal cell line (n2a) jev replicated efficiently, but jev/d4 and ... | 2004 | 15302944 |
| structure of the dengue virus envelope protein after membrane fusion. | dengue virus enters a host cell when the viral envelope glycoprotein, e, binds to a receptor and responds by conformational rearrangement to the reduced ph of an endosome. the conformational change induces fusion of viral and host-cell membranes. a three-dimensional structure of the soluble e ectodomain (se) in its trimeric, postfusion state reveals striking differences from the dimeric, prefusion form. the elongated trimer bears three 'fusion loops' at one end, to insert into the host-cell memb ... | 2004 | 14737159 |
| identification of residues in the dengue virus type 2 ns2b cofactor that are critical for ns3 protease activation. | proteolytic processing of the dengue virus polyprotein is mediated by host cell proteases and the virus-encoded ns2b-ns3 two-component protease. the ns3 protease represents an attractive target for the development of antiviral inhibitors. the three-dimensional structure of the ns3 protease domain has been determined, but the structural determinants necessary for activation of the enzyme by the ns2b cofactor have been characterized only to a limited extent. to test a possible functional role of t ... | 2004 | 15564480 |
| therapeutic effects of dengue 2 virus capsid protein and staphylococcal nuclease fusion protein on dengue-infected cell cultures. | dengue infection poses a serious public health problem in most tropical and subtropical areas. no effective antiviral drugs or vaccines are currently available against dengue infection. to explore the feasibility of using capsid-targeted viral inactivation (ctvi) as an antiviral strategy against dengue infection, we constructed a plasmid expressing a fusion protein consisting of staphylococcal nuclease (sn) fused to dengue 2 virus capsid protein (d2c), and investigated its effects on the product ... | 2004 | 15592886 |
| deglycosylation of the ns1 protein of dengue 2 virus, strain 16681: construction and characterization of mutant viruses. | the dengue 2 virus (denv-2) ns1 glycoprotein contains two potential sites for n-linked glycosylation at asn-130 and asn-207. ns1 produced in infected cells is glycosylated at both of these sites. we used site-directed mutagenesis of a denv-2, strain 16681, full length infectious clone to create mutant viruses lacking the asn-130, asn-207 or both of these ns1 glycosylation sites in order to investigate the effects of deglycosylation. ablation of both ns1 glycosylation sites resulted in unstable v ... | 2004 | 15592895 |
| dengue virus inoculation to human skin explants: an effective approach to assess in situ the early infection and the effects on cutaneous dendritic cells. | although dengue virus (dv) enters through skin while mosquitoes feed, early contacts remain unexplored regarding the cutaneous viral fate and in situ immune responses. we addressed this by exposing healthy, non-cadaveric, freshly obtained human skin explants to a human dv2 isolate. we demonstrated negative-strand dv-rna and non-structural protein-1, both suggestive of viral replication in skin. although control, mock-infected and dv-infected explants showed less (mhc-cii(+)/cd1a(+)/langerin+) la ... | 2005 | 16191104 |
| circulating human antibodies against dengue ns1 protein: potential of recombinant d2v-ns1 proteins in diagnostic tests. | the dengue virus (dv) causes one of the most important arthropod-borne human viral diseases throughout the tropical and subtropical countries. however, the morbidity and mortality of dv infections could be reduced with an early hospitalization care and a rapid risk identification of developing the dengue haemorrhagic fever (dhf). the nonstructural glycoprotein 1 (ns1) has been pointed as a reagent for immune-assay diagnostic test optimization. to evaluate this potential, recombinant dv2-ns1 prot ... | 2005 | 15780810 |
| suckling mice were used to detect infectious dengue-2 viruses by intracerebral injection of the full-length rna transcript. | in this study we established a mouse brain injection system to detect infectious dengue-2 virus produced from the full-length rna transcripts. | 2005 | 15812190 |
| competitive inhibition of the dengue virus ns3 serine protease by synthetic peptides representing polyprotein cleavage sites. | the ns3 serine protease of dengue virus is required for the maturation of the viral polyprotein and consequently represents a promising target for the development of antiviral inhibitors. however, the substrate specificity of this enzyme has been characterized only to a limited extent. in this study, we have investigated product inhibition of the ns3 protease by synthetic peptides derived from the p6-p1 and the p1'-p5' regions of the natural polyprotein substrate. n-terminal cleavage site peptid ... | 2005 | 15823576 |
| effect of temperature and insecticide stresses on aedes aegypti larvae and their influence on the susceptibility of mosquitoes to dengue-2 virus. | two major factors, higher temperatures and the application of insecticides, can drastically alter the genetic structure of a vector mosquito population. due to these two stresses, the majority of the population gets wiped out, but the ones that withstand the stress and survive are likely to pass on survivability, and have an altered physiology. our study shows that exposures to higher temperatures and ddt during the larval stage affects their susceptibility as adult mosquitoes to the den-2 virus ... | 2005 | 16438138 |
| dengue virus inhibits alpha interferon signaling by reducing stat2 expression. | alpha/beta interferon (ifn-alpha/beta) is a key mediator of innate antiviral responses but has little effect on the established replication of dengue viruses, which are mosquito-borne flaviviruses of immense global health importance. understanding how the ifn system is inhibited in dengue virus-infected cells would provide critical insights into disease pathogenesis. in a recent study analyzing the ability of individual dengue virus-encoded proteins to antagonize the ifn response, nonstructural ... | 2005 | 15827155 |
| characterization of dengue-2 virus binding to surfaces of mammalian and insect cells. | the binding of dengue type 2 (den-2) virus to mammalian (llc-mk(2) and vero) and mosquito (c6/36 and ap61) cell surfaces was investigated by a virus-binding assay using purified (3)h-labeled den-2 virus. the den-2 virus binding to all four cell types was specific and saturable, indicating the presence of a single class of receptors (ranging from 3.7 x 10(3) to 3.5 x 10(4) receptors/cell) with a high affinity for den-2 virus (k(d) ranging from 98 to 171 pm). treatment of cell surfaces with certai ... | 2005 | 15827273 |
| induction of protective antibodies against dengue virus by tetravalent dna immunization of mice with domain iii of the envelope protein. | dengue fever is a growing public health concern around the world and despite vaccine development efforts, there are currently no effective dengue vaccines. in the present study we report the induction of protective antibodies against dengue virus by dna immunization with domain iii (diii) region of the envelope protein (e) in a mouse model. the diii region of all four dengue virus serotypes were cloned separately into pcdna 3 plasmid. protein expression was tested in cos-7 cells. each plasmid, o ... | 2005 | 15837370 |
| emergence of dengue virus type-3 in northern india. | during the last few decades dengue has reemerged in several parts of southeast asia, including india. a major outbreak of dengue infection occurred in northern india during october to december 2003. to determine the etiology, we carried out serological, virological and molecular investigations of this outbreak. a total of 76 dengue suspected patient blood samples were collected from gwalior, madhya pradesh and delhi, india. serological investigations carried out using an in-house dipstick elisa ... | 2005 | 15916043 |
| an evaluation of dengue type-2 inactivated, recombinant subunit, and live-attenuated vaccine candidates in the rhesus macaque model. | the safety, immunogenicity, and protective efficacy of two non-replicating antigen-based vaccines and one live-attenuated virus (lav) vaccine for dengue type-2 (dengue-2) virus were evaluated in the rhesus macaque model. the non-replicating vaccines consisted of whole, purified inactivated virus (piv) and a recombinant subunit protein containing the amino-(n)-terminal 80% of envelope protein (r80e), each formulated with one of five different adjuvants. each formulation was administered to three ... | 2005 | 16005749 |
| the modeled structure of the rna dependent rna polymerase of gbv-c virus suggests a role for motif e in flaviviridae rna polymerases. | the flaviviridae virus family includes major human and animal pathogens. the rna dependent rna polymerase (rdrp) plays a central role in the replication process, and thus is a validated target for antiviral drugs. despite the increasing structural and enzymatic characterization of viral rdrps, detailed molecular replication mechanisms remain unclear. the hepatitis c virus (hcv) is a major human pathogen difficult to study in cultured cells. the bovine viral diarrhea virus (bvdv) is often used as ... | 2005 | 16225688 |
| s-phase-dependent enhancement of dengue virus 2 replication in mosquito cells, but not in human cells. | dengue virus (den) is the most prevalent cause of arthropod-borne viral illness in humans. we determined the influence of cellular growth state on den type 2 (den2) replication in mosquito and human cells, based on the hypothesis that manipulation of cellular growth state will facilitate identification of viral and cellular determinants of productive infection. comparison of density-arrested and cycling c6/36 aedes albopictus cells infected with a low-passage den2 isolate revealed that cycling c ... | 2005 | 16227245 |
| genetic characterization of yokose virus, a flavivirus isolated from the bat in japan. | yokose virus (strain oita-36) was isolated from the bat in japan in 1971. in the present study, we determined complete nucleotide sequences of yokose virus using rt-pcr and race techniques. yokose virus genome consists of 10,857 nucleotides in length (accession no. ab114858), containing a single open reading frame (3425 amino acids) encoding 11 viral proteins. we deduced the boundaries of each protein in the polyprotein sequence according to the protein cleavage sites of other flaviviruses. the ... | 2005 | 15661139 |
| invasion and maintenance of dengue virus type 2 and type 4 in the americas. | dengue virus type 4 (denv-4) was first reported in the americas in 1981, where it caused epidemics of dengue fever throughout the region. in the same year, the region's first epidemic of dengue hemorrhagic fever was reported, caused by an asian strain of dengue virus type 2 (denv-2) that was distinct from the american subtype circulating previously. despite the importance of these epidemics, little is known about the rates or determinants of viral spread among island and mainland populations or ... | 2005 | 16282468 |
| inhibition of alpha/beta interferon signaling by the ns4b protein of flaviviruses. | flaviviruses are insect-borne, positive-strand rna viruses that have been disseminated worldwide. their genome is translated into a polyprotein, which is subsequently cleaved by a combination of viral and host proteases to produce three structural proteins and seven nonstructural proteins. the nonstructural protein ns4b of dengue 2 virus partially blocks activation of stat1 and interferon-stimulated response element (isre) promoters in cells stimulated with interferon (ifn). we have found that t ... | 2005 | 15956546 |
| dengue virus nonstructural protein ns5 induces interleukin-8 transcription and secretion. | elevated circulating levels of chemokines have been reported in patients with dengue fever and are proposed to contribute to the pathogenesis of dengue disease. to establish in vitro models for chemokine induction by dengue 2 virus (den2v), we studied a variety of human cell lines and primary cells. den2v infection of hepg2 and primary dendritic cells induced the production of interleukin-8 (il-8), rantes, mip-1alpha, and mip-1beta, whereas only il-8 and rantes were induced following dengue viru ... | 2005 | 16103156 |
| potential role of sylvatic and domestic african mosquito species in dengue emergence. | dengue virus 2 (denv-2) strains that circulate in sylvatic habitats of senegal and other parts of west africa are believed to represent ancestral forms that evolved into endemic/epidemic strains that now circulate widely in urban areas of the tropics. previous studies suggested that the evolution of the endemic/epidemic strains was mediated by adaptation to the peridomestic mosquito vectors aedes aegypti and ae. albopictus. we conducted experimental infections using sylvatic and peridomestic sen ... | 2005 | 16103619 |
| recombinant non-structural 1 (ns1) protein of dengue-2 virus interacts with human stat3beta protein. | a combination of yeast two-hybrid library screening, co-immunoprecipitation and immunofluorescence microscopy demonstrated that dengue-2 virus non-structural 1 (ns1) protein can interact with an n-terminally truncated form of human stat3beta (deltan40-stat3beta) protein. the ns1 protein interacted with the activated stat3beta protein in vesicle-like structures in the cell cytoplasm. in addition, transfection of dendritic cells with plasmid expressing ns1 protein also resulted in significant indu ... | 2005 | 15878791 |
| effect of mosquito midgut trypsin activity on dengue-2 virus infection and dissemination in aedes aegypti. | the effect of mosquito midgut trypsins in dengue serotype 2 flavivirus (denv-2) infectivity to aedes aegypti was studied. addition of soybean trypsin inhibitor (sti) in a denv-2 infectious blood meal resulted in a 91-97% decrease in midgut denv-2 rna copies (qrt-pcr analysis). sti treatment also resulted in slower denv-2 replication in the midgut, less denv-2 e protein expression, and decreased dissemination to the thorax and the head. a second uninfected blood meal, 7 days after the sti-treated ... | 2005 | 15891140 |
| association mapping of segregating sites in the early trypsin gene and susceptibility to dengue-2 virus in the mosquito aedes aegypti. | evidence suggests that midgut trypsins in aedes aegypti condition the mosquito's ability to become infected with the dengue-2 flavivirus (den2). the activity of early trypsin protein peaks approximately 3 h after blood feeding and then drops within a few hours. we use association mapping to test the hypothesis that segregating sites in early trypsin condition midgut susceptibility to den2 virus. a total of 1642 females from throughout mexico and the southern us were fed an artificial blood meal ... | 2005 | 15894193 |
| antibody responses to asian and american genotypes of dengue 2 virus in immunized mice. | the possibility of a correlation between dengue virus genotype groups and disease severity is currently under discussion. the objective of this investigation was to identify any immunogenic difference between the american and asian dengue 2 virus genotypes through the study of antibody development (virus-binding immunoglobulin g and neutralizing antibodies) in mice. differences in the neutralization pattern between the strains studied were observed, suggesting the presence of slight antigenic va ... | 2005 | 15699435 |
| epidemiology of dengue and dengue hemorrhagic fever in a cohort of adults living in bandung, west java, indonesia. | a prospective study of dengue fever (df) and dengue hemorrhagic fever (dhf) was conducted in a cohort of adult volunteers from two textile factories located in west java, indonesia. volunteers in the cohort were bled every three months and were actively followed for the occurrence of dengue (den) disease. the first two years of the study showed an incidence of symptomatic den disease of 18 cases per 1,000 person-years and an estimated asymptomatic/ mild infection rate of 56 cases per 1,000 perso ... | 2005 | 15728868 |
| quantitative trait loci that control dengue-2 virus dissemination in the mosquito aedes aegypti. | the mosquito aedes aegypti is the most important vector of yellow fever and dengue fever flaviviruses. ae. aegypti eradication campaigns have not been sustainable and there are no effective vaccines for dengue viruses. alternative control strategies may depend upon identification of mosquito genes that condition flavivirus susceptibility and may ultimately provide clues for interrupting transmission. quantitative trait loci affecting the ability of ae. aegypti to develop a dengue-2 infection in ... | 2005 | 15781707 |
| selection of d2s3, an aedes aegypti (diptera: culicidae) strain with high oral susceptibility to dengue 2 virus and d2meb, a strain with a midgut barrier to dengue 2 escape. | family-based phenotypic selection was used to breed two genetic strains of aedes aegypti l. that differ in susceptibility to infection with dengue serotype 2 virus (den-2) strain jam1409. a dengue 2 susceptible on 3 chromosomes (d2s3) strain was bred from ae. aegypti aegypti and ae. aegyptiformosus p1 parents to have a high midgut infection rate (mir) and a high disseminated infection rate (dir). a dengue 2 midgut escape barrier (d2meb) strain was bred from d2s3 and houston p1 parents to have a ... | 2005 | 15799518 |
| ultrastructural studies on dengue virus type 2 infection of cultured human monocytes. | early interaction of dengue virus and monocyte/macrophages could be an important feature for virus dissemination after its initial entry via the mosquito vector. since ultrastructural analysis of this interaction has not been reported, dengue type 2 (den2) virus-infected human monocyte cultures were studied at 1, 2, 4 and 6 hours after infection. | 2005 | 15801983 |
| production and characterization of a monoclonal antibody specific for ns3 protease and the atpase region of dengue-2 virus. | dengue is considered a reemerging disease of worldwide distribution. the dengue virus non-structural protein 3 (ns3) is known to possess atpase, helicase, and protease activities that are a constitutive part of the replication complex of dengue virus. in this report, we discuss the cloning, expressing, and purifying of the dengue-2 ns3 protein, to immunize mice and then generate monoclonal antibodies (mabs). our results show the production of mabs specific to ns3 protein of dengue-2 virus, which ... | 2005 | 15943564 |
| dengue virus type 2 antagonizes ifn-alpha but not ifn-gamma antiviral effect via down-regulating tyk2-stat signaling in the human dendritic cell. | the immunopathogenesis mechanism of dengue virus (dv) infection remains elusive. we previously showed that the target of dv in humans is dendritic cells (dcs), the primary sentinels of immune system. we also observed that despite the significant amount of ifn-alpha induced; dv particles remain massively produced from infected dcs. it suggests that dv may antagonize the antiviral effect of ifn-alpha. recent work in animal studies demonstrated the differential critical roles of antiviral cytokines ... | 2005 | 15944325 |
| liver injury and viremia in mice infected with dengue-2 virus. | the goal of this study was to test the feasibility of balb/c mice as an experimental model in the study of dengue disease. balb/c mice were intraperitoneal infected with denv-2 obtained from a human patient. histopathological analysis of infected animals revealed liver injury with viral antigens detection. in initial stages, the most prominent lesions were vacuolization and diffuse steatosis in hepatocytes. serum levels of alt and ast increased progressively, reaching the highest values 7 days p ... | 2005 | 15961136 |
| structure of the dengue virus helicase/nucleoside triphosphatase catalytic domain at a resolution of 2.4 a. | dengue fever is an important emerging public health concern, with several million viral infections occurring annually, for which no effective therapy currently exists. the ns3 protein from dengue virus is a multifunctional protein of 69 kda, endowed with protease, helicase, and nucleoside 5'-triphosphatase (ntpase) activities. thus, ns3 plays an important role in viral replication and represents a very interesting target for the development of specific antiviral inhibitors. we present the struct ... | 2005 | 16051821 |
| [capsid-targeted viral inactivation for dengue virus infection]. | to explore the feasibility of capsid-targeted viral inactivation for dengue virus infection, a newly-discovered antiviral strategy, a mammalian cell line stably expressing staphylococcal nuclease fused to the capsid protein of dengue 2 virus was established and the effects on the production of infectious virus particles were examined. the results presented evidence that the enzymatically active staphylococcal nuclease fused to capsid protein could be incorporated into the nascent virions during ... | 2005 | 15847175 |
| modulation of the nucleoside triphosphatase/rna helicase and 5'-rna triphosphatase activities of dengue virus type 2 nonstructural protein 3 (ns3) by interaction with ns5, the rna-dependent rna polymerase. | dengue virus type 2 (den2), a member of the flaviviridae family, is a re-emerging human pathogen of global significance. den2 nonstructural protein 3 (ns3) has a serine protease domain (ns3-pro) and requires the hydrophilic domain of ns2b (ns2bh) for activation. ns3 is also an rna-stimulated nucleoside triphosphatase (ntpase)/rna helicase and a 5'-rna triphosphatase (rtpase). in this study the first biochemical and kinetic properties of full-length ns3 (ns3fl)-associated ntpase, rtpase, and rna ... | 2005 | 15917225 |
| comparative analysis of immunoglobulin m (igm) capture enzyme-linked immunosorbent assay using virus-like particles or virus-infected mouse brain antigens to detect igm antibody in sera from patients with evident flaviviral infections. | the use of immunoglobulin m (igm) antibody-capture enzyme-linked immunosorbent assay (mac-elisa) serves as a valuable tool for the diagnosis of acute flaviviral infections, since igm antibody titers are detectable early, peak at about 2 weeks postinfection, and subsequently decline to lower levels over the next few months. traditionally, virus-infected tissue culture or suckling mouse brain (smb) has been the source of viral antigens used in the assay. in an effort to provide a reliable source o ... | 2005 | 16000440 |
| evaluation of chemical and antiviral properties of essential oils from south american plants. | the essential oils of seven aromatic plants from córdoba, san luis and san juan provinces (argentina) were isolated by steam distillation and analysed by a gas chromatography/mass spectrometry technique. the oils were screened for cytotoxicity and in vitro inhibitory activity against herpes simplex virus type 1 (hsv-1), dengue virus type 2 (denv-2) and junin virus (junv) by a virucidal test. the oils showed a variable virucidal action according to the virus. the better relationship between cytot ... | 2005 | 16130522 |
| individual donor nucleic acid amplification testing for detection of west nile virus. | we have developed an economical, high-throughput nucleic acid amplification test (nat) for blood-borne viruses, suitable for use in the screening of plasma samples from individual blood donors. this assay system includes a semiautomated procedure, using 96-well glass fiber plates for the extraction of viral nucleic acids from plasma and "universal beacon" technology which permits the detection of all genotypes of highly variable viruses (e.g., human immunodeficiency virus and hepatitis c virus). ... | 2005 | 16207971 |
| miniature rt-pcr system for diagnosis of rna-based viruses. | this paper presents an innovative portable chip-based rt-pcr system for amplification of specific nucleic acid and detection of rna-based viruses. the miniature rt-pcr chip is fabricated using mems (micro-electro-mechanical-system) techniques, and comprises a micro temperature control module and a pdms (polydimethylsiloxane)-based microfluidic control module. the heating and sensing elements of temperature control module are both made of platinum and are located within the reaction chambers in o ... | 2005 | 16221971 |
| [study on dengue virus infection of human dendritic cells]. | to study dengue virus (dv) infection of human dendritic cells (dc). monocyte isolated from healthy human peripheral blood were incubated in medium with gm-csf and il-4 for more than 7 days. dcs were then collected and identified by transmission electron microscope, immunohistochemistry and lymphocytes stimulatory ability. dengue virus type ii (dv-2) were infected with human dendritic cells(dc) in vitro, culture supernatants and cells were collected by different time postinfection (6h, 12h, 24h, ... | 2005 | 16245879 |
| attenuation and immunogenicity of recombinant yellow fever 17d-dengue type 2 virus for rhesus monkeys. | a chimeric yellow fever (yf)-dengue serotype 2 (dengue 2) virus was constructed by replacing the premembrane and envelope genes of the yf 17d virus with those from dengue 2 virus strains of southeast asian genotype. the virus grew to high titers in vero cells and, after passage 2, was used for immunogenicity and attenuation studies in rhesus monkeys. subcutaneous immunization of naive rhesus monkeys with the 17d-d2 chimeric virus induced a neutralizing antibody response associated with the prote ... | 2005 | 16302098 |
| dna priming e and ns1 constructs--homologous proteins boosting immunization strategy to improve immune response against dengue in mice. | dna priming-protein boosting is a strategy used to establish strong immunity to a specific pathogen by the use of two different antigens through sequential delivery systems. in this work, two recombinant plasmids were used, one encoding for the dengue virus e protein, which is know to induce neutralizing antibodies (pcdna 3.1/e), and the other encoding for the dengue virus nonstructural protein 1 (pcdna 3.1/ns1), as a source of b- and t-cell epitopes possibly involved in protective immunity. we ... | 2005 | 16359237 |
| non-structural proteins of dengue 2 virus offer limited protection to interferon-deficient mice after dengue 2 virus challenge. | chimeric (d2/wn) viruses containing the pre-membrane (prm) and envelope (e) proteins of west nile virus (wn virus) and the capsid (c) and non-structural proteins of dengue 2 (den2) virus were used to evaluate the protective immunity elicited by either the flaviviral e protein or non-structural proteins. ag129 interferon-deficient mice, previously shown to be protected against lethal den1 or den2 viral infection after vaccination with a wild-type or candidate vaccine strain of den1 or den2 virus, ... | 2006 | 16432020 |
| subcellular localization and membrane topology of the dengue virus type 2 non-structural protein 4b. | dengue virus (dv) is a member of the family flaviviridae. these positive strand rna viruses encode a polyprotein that is processed in case of dv into 10 proteins. although for most of these proteins distinct functions have been defined, this is less clear for the highly hydrophobic non-structural protein (ns) 4b. despite its possible role as an antagonist of the interferon-induced antiviral response, this protein may play an additional more direct role for viral replication. in this study we det ... | 2006 | 16436383 |
| probing the substrate specificity of the dengue virus type 2 ns3 serine protease by using internally quenched fluorescent peptides. | the ns3 (dengue virus non-structural protein 3) serine protease of dengue virus is an essential component for virus maturation, thus representing an attractive target for the development of antiviral drugs directed at the inhibition of polyprotein processing. in the present study, we have investigated determinants of substrate specificity of the dengue virus ns3 protease by using internally quenched fluorogenic peptides containing abz (o-aminobenzoic acid; synonymous to anthranilic acid) and 3-n ... | 2006 | 16489931 |
| structure and age of genetic diversity of dengue virus type 2 in thailand. | dengue virus type 2 (denv-2) is a common viral infection and an important health concern in south-east asia. to determine the molecular evolution of denv-2 in thailand, 105 isolates of the e (envelope) gene and 10 complete genomes sampled over a 27 year period were sequenced. phylogenetic analysis of these data revealed that three genotypes of denv-2 have circulated in thailand, although, since 1991, only viruses assigned to asian genotype i have been sampled from the population. a broader analy ... | 2006 | 16528037 |
| enhancement of recombinant soluble dengue virus 2 envelope domain iii protein production in escherichia coli trxb and gor double mutant. | the dengue virus is currently the most important flavivirus causing human diseases in the tropical and subtropical regions of the world. the envelope protein domain iii of dengue virus type 2 (d2eiii), which induces protective and neutralizing antibodies, was expressed as an n-terminal fusion to a hexa-histidine tag in escherichia coli. the expression of recombinant d2eiii of 103 amino acids in the soluble form can be achieved using suitable host strains, such as origami, at a low induction temp ... | 2006 | 17116581 |
| virus-like particles production in green plants. | viruses-like particles (vlps), assembled from capsid structural subunits of several different viruses, have found a number of biomedical applications such as vaccines and novel delivery systems for nucleic acids and small molecules. production of recombinant proteins in different plant systems has been intensely investigated and improved upon in the last two decades. plant-derived antibodies, vaccines, and microbicides have received great attention and shown immense promise. in the case of mucos ... | 2006 | 16997715 |
| synthesis and pharmacokinetics of valopicitabine (nm283), an efficient prodrug of the potent anti-hcv agent 2'-c-methylcytidine. | in our search for new therapeutic agents against chronic hepatitis c, a ribonucleoside analogue, 2'-c-methylcytidine, was discovered to be a potent and selective inhibitor in cell culture of a number of rna viruses, including the pestivirus bovine viral diarrhea virus, a surrogate model for hepatitis c virus (hcv), and three flaviviruses, namely, yellow fever virus, west nile virus, and dengue-2 virus. however, pharmacokinetic studies revealed that 2'-c-methylcytidine suffers from a low oral bio ... | 2006 | 17064080 |
| characterization of antibody responses to combinations of a dengue virus type 2 dna vaccine and two dengue virus type 2 protein vaccines in rhesus macaques. | we evaluated three nonreplicating dengue virus type 2 (denv-2) vaccines: (i) a dna vaccine containing the prm-e gene region (d), (ii) a recombinant subunit protein vaccine containing the b domain (i.e., domain iii) of the e protein as a fusion with the escherichia coli maltose-binding protein (r), and (iii) a purified inactivated virus vaccine (p). groups of four rhesus macaques each were primed once and boosted twice using seven different vaccination regimens. after primary vaccination, enzyme- ... | 2006 | 16973561 |
| dna vaccine against the non-structural 1 protein (ns1) of dengue 2 virus. | dengue is one of the most important mosquito-borne viral disease causing dengue fever and/or dengue shock syndrome/haemorrhagic fever. in some reports, the non-structural protein 1 (ns1) has been identified as a promising antigen for the development of vaccines against dengue virus (denv). apparently, it can elicit a protective antibody response with complement-fixing activities. in order to investigate the potential of a dna vaccine based on the ns1 protein against denv, we used the plasmid pct ... | 2006 | 16140430 |
| evaluation of an enzyme immunoassay for detection of dengue virus ns1 antigen in human serum. | we evaluated a one-step sandwich-format microplate enzyme immunoassay for detecting dengue virus ns1 antigen (ag) in human serum by use of platelia dengue ns1 ag kits (bio-rad laboratories, marnes la coquette, france). we collected 299 serum samples from patients with dengue disease and 50 serum samples from patients not infected with dengue virus. for the 239 serum samples from patients with acute infections testing positive by reverse transcription-pcr and/or virus isolation for one of the fou ... | 2006 | 16988003 |
| cryptic properties of a cluster of dominant flavivirus cross-reactive antigenic sites. | a number of flaviviruses are important human pathogens, including yellow fever, dengue, west nile, japanese encephalitis, and tick-borne encephalitis (tbe) viruses. infection with or immunization against any of these viruses induces a subset of antibodies that are broadly flavivirus cross-reactive but do not exhibit significant cross-neutralization. nevertheless, these antibodies can efficiently bind to the major envelope protein (e), which is the main target of neutralizing and protective antib ... | 2006 | 16973559 |
| an unusual transitory increase of lupus anticoagulant in dengue virus infection complicated with cerebral ischaemia. | dengue is a common mosquito-transmitted viral disease prevalent at many undeveloped and developing countries. although, neurological complication and hemostatic disturbance are common in dengue virus infection, cerebral ischaemia is barely mentioned. a 61-year-old woman experienced an acute onset of right hemiparesis in her early course of dengue virus type ii infection. extensive laboratory investigation revealed an increase of lupus anticoagulant activity and a prolonged activated partial thro ... | 2006 | 16045995 |
| infectious clone construction of dengue virus type 2, strain jamaican 1409, and characterization of a conditional e6 mutation. | a full-length infectious cdna clone (ic) was constructed from the genome of the dengue virus type 2 (denv-2) jamaica83 1409 strain, pbac1409ic, by using a bacterial artifical chromosome plasmid system. infectious virus was generated and characterized for growth in cell culture and for infection in aedes aegypti mosquitoes. during construction, an isoleucine to methionine (ile-->met) change was found at position 6 in the envelope glycoprotein sequence between low- and high-passage denv-2 1409 str ... | 2006 | 16847122 |
| differential dengue cross-reactive and neutralizing antibody responses in balb/c and swiss albino mice induced by immunization with flaviviral vaccines and by infection with homotypic dengue-2 virus strains. | we investigated whether cross-reactive and/or cross-protective antibodies against dengue virus could be generated in 6-week-old balb/c mice by immunization with currently approved flaviviral vaccines, i.e., japanese encephalitis (je) biken and yellow fever (yf) 17d. cross-reactivity with dengue antigens was apparent in at least one-third each of je-vaccinated mouse sera and of je/yf-vaccinated mouse sera by dengue enzyme immunoassay, but was not detected in sera of mice immunized with yf vaccine ... | 2006 | 16553548 |
| determining genetic stabilities of chimeric dengue vaccine candidates based on dengue 2 pdk-53 virus by sequencing and quantitative taqmama. | the genetic stabilities of the three attenuation loci of the candidate dengue 2 (d2) pdk-53 vaccine virus were evaluated for the pdk-53 virus and pdk-53-vectored chimeric d2/1, d2/3, and d2/4 viruses following 10 sequential passages in vero cells. sequencing revealed that the dominant ns1-53-asp and the ns3-250-val attenuation loci were extremely stable, whereas reversion occurred at the 5'ncr-57-u locus in 10 of the 18 viral lineages tested. a more sensitive and quantitative assay, the taqman m ... | 2006 | 16087248 |
| tetravalent neutralizing antibody response against four dengue serotypes by a single chimeric dengue envelope antigen. | we employed dna shuffling and screening technologies to develop a single recombinant dengue envelope (e) antigen capable of inducing neutralizing antibodies against all four antigenically distinct dengue serotypes. by dna shuffling of codon-optimized dengue 1-4 e genes, we created a panel of novel chimeric clones expressing c-terminal truncated e antigens that combined epitopes from all four dengue serotypes. dna vaccines encoding these novel chimeras induced multivalent t cell and neutralizing ... | 2006 | 16125280 |
| antiviral action of nitric oxide on dengue virus type 2 replication. | recently, nitric oxide (no) has been shown to suppress dengue virus (denv) rna and protein accumulation in infected cells. in this report, the potential target of the inhibitory effect of no was studied at the molecular level. the no donor, s-nitroso-n-acetylpenicillamine (snap), showed an inhibitory effect on rna accumulation at around 8-14 h post-infection, which corresponded to the step of viral rna synthesis in the denv life cycle. the activity of the viral replicase isolated from snap-treat ... | 2006 | 16963759 |
| protection against dengue type 2 virus induced in mice immunized with a dna plasmid encoding the non-structural 1 (ns1) gene fused to the tissue plasminogen activator signal sequence. | dengue is one of the most important arboviral diseases in humans, and although efforts over the last decades have dealt with the development of a vaccine, this vaccine is not available yet. in order to evaluate the potential of a dna vaccine based on the non-structural 1 (ns1) protein against dengue virus (denv), we constructed the pctpans1 plasmid which contains the secretory signal sequence derived from human tissue plasminogen activator (t-pa) fused to the full length of the denv-2 ns1 gene. ... | 2006 | 16122850 |
| cell type-specific mechanisms of interleukin-8 induction by dengue virus and differential response to drug treatment. | in vitro infection with dengue virus induces interleukin (il)-8 secretion, which increases endothelial cell permeability; this has been proposed as a mechanism for plasma leakage in dengue hemorrhagic fever. we studied the mechanisms of il-8 induction, using luciferase reporter constructs, and the effect of pharmacological inhibitors of either il-8 secretion or nuclear factor- kappa b (nf-kappa b) activation on il-8 induction by dengue 2 virus (den2v) infection. il-8 induction by den2v infection ... | 2006 | 16544247 |
| morphological studies in a model for dengue-2 virus infection in mice. | one of the main difficulties in studying dengue virus infection in humans and in developing a vaccine is the absence of a suitable animal model which develops the full spectrum of dengue fever, dengue haemorrhagic fever, and dengue shock syndrome. it is our proposal to present morphological aspects of an animal model which shows many similarities with the dengue infection in humans. balb/c mice were intraperitoneally infected with non-neuroadapted dengue virus serotype 2 (denv-2). histopathologi ... | 2006 | 17293987 |
| concurrent infection with dengue virus type-2 and denv-3 in a patient from ceará, brazil. | dengue outbreaks have occurred in several regions in brazil and cocirculating dengue virus type 1 (denv-1), denv-2, and denv-3 have been frequently observed. dual infection by denv-2 and denv-3 was identified by type-specific indirect immunofluorescence assay and confirmed by reverse transcription polymerase chain reaction in a patient in ceará with a mild disease. this is the first documented case of simultaneous infection with denv-2 and denv-3 in brazil. sequencing confirmed denv-2 and denv-3 ... | 2006 | 17293990 |
| identification and characterization of carbohydrate molecules in mammalian cells recognized by dengue virus type 2. | the interaction between cell surface receptors and the envelope glycoprotein (egp) on the viral membrane surface is the initial step of dengue virus infection. to understand the host range, tissue tropism, and virulence of this pathogen, it is critical to elucidate the molecular mechanisms of the interaction of egp with receptor molecules. here, using a tlc/virus-binding assay, we isolated and characterized a carbohydrate molecule on mammalian cell surfaces that is recognized by dengue virus typ ... | 2006 | 16567427 |
| secreted expression and purification of dengue 2 virus full-length nonstructural glycoprotein ns1 in pichia pastoris. | the dengue 2 virus (den-2) rna (ngc strain) was used as a substrate to produce dna clones of the full-length ns1 genes via reverse transcriptase synthesis of cdna followed by polymerase chain reaction amplification of the ns1 region. products were cloned into ppiczalphab vector for sequencing and into pichia pastoris for expression. a recombinant protein with a molecular size of approximately 80 kda was secreted into the supernatant from the yeast cells when induced with methanol. the expressed ... | 2006 | 16791415 |
| dengue in the americas and southeast asia: do they differ? | the populations of southeast asia (se asia) and tropical america are similar, and all four dengue viruses of asian origin are endemic in both regions. yet, during comparable 5-year periods, se asia experienced 1.16 million cases of dengue hemorrhagic fever (dhf), principally in children, whereas in the americas there were 2.8 million dengue fever (df) cases, principally in adults, and only 65,000 dhf cases. this review aims to explain these regional differences. in se asia, world war ii amplifie ... | 2006 | 17341332 |
| a chimeric tetravalent dengue dna vaccine elicits neutralizing antibody to all four virus serotypes in rhesus macaques. | dna shuffling and screening technologies were used to produce chimeric dna constructs expressing antigens that shared epitopes from all four dengue serotypes. three shuffled constructs (sa, sb and sc) were evaluated in the rhesus macaque model. constructs sa and sc expressed pre-membrane and envelope genes, whereas construct sb expressed only the ectodomain of envelope protein. five of six, and four of six animals vaccinated with sa and sc, respectively, developed antibodies that neutralized all ... | 2006 | 16814355 |
| induction of neutralizing antibodies and t cell responses by dengue virus type 2 envelope domain iii encoded by plasmid and adenoviral vectors. | dengue is a re-emerging public health problem in many developing nations. there is neither a specific antiviral therapy to treat nor a licensed vaccine to prevent dengue infections. in recent years, the carboxy-terminal region of the major dengue virion envelope (e) protein, known as domain iii, has emerged as a significant sub-unit vaccine candidate. in this study, we created a recombinant adenovirus capable of expressing the e domain iii (ediii) of dengue virus type 2 (den-2) and tested it in ... | 2006 | 16860446 |
| an integrated microfluidic chip for dna/rna amplification, electrophoresis separation and on-line optical detection. | this study presents an integrated microfluidic chip capable of performing dna/rna (deoxyribonucleic acid/ribonucleic acid) amplification, electrokinetic sample injection and separation, and on-line optical detection of nucleic acid products in an automatic mode. in the proposed device, dna/rna samples are first replicated using a micromachine-based pcr module or reverse transcription pcr (rt-pcr) module and then transported by a pneumatic micropump to a sample reservoir. the samples are subseque ... | 2006 | 16865670 |
| preliminary characterization of (nucleoside-2'-o-)-methyltransferase crystals from meaban and yokose flaviviruses. | viral methyltranferases (mtase) are involved in the third step of the mrna-capping process, transferring a methyl group from s-adenosyl-l-methionine (sam) to the capped mrna. mtases are classified into two groups: (guanine-n7)-methyltransferases (n7mtases), which add a methyl group onto the n7 atom of guanine, and (nucleoside-2'-o-)-methyltransferases (2'omtases), which add a methyl group to a ribose hydroxyl. the mtases of two flaviviruses, meaban and yokose viruses, have been overexpressed, pu ... | 2006 | 16880552 |
| macrophage and dengue virus: friend or foe? | the cells of monocyte-macrophage (mphi) lineage play important roles both in innate and adaptive immune responses. they are the first line of defence in body and their job is to phagocytose a foreign invader, the pathogen, digest it and remove it. mphi help body in mounting the antigenspecific immune response by presenting the digested pathogen antigen in conjunction with major histocompatibility complex (mhc) class ii molecules to recruit b and t lymphocytes response. usually mphi succeed in th ... | 2006 | 16926454 |
| role of rna helicases in hiv-1 replication. | viruses are replication competent genomes which are relatively gene-poor. even the largest viruses (i.e. herpesviruses) encode only slightly >200 open reading frames (orfs). however, because viruses replicate obligatorily inside cells, and considering that evolution may be driven by a principle of economy of scale, it is reasonable to surmise that many viruses have evolved the ability to co-opt cell-encoded proteins to provide needed surrogate functions. an in silico survey of viral sequence dat ... | 2006 | 16935887 |
| slower rates of clearance of viral load and virus-containing immune complexes in patients with dengue hemorrhagic fever. | although previous studies have revealed the contribution of an initial high level of dengue virus replication to the severe and potentially life-threatening diseases dengue hemorrhagic fever (dhf) and dengue shock syndrome, the involvement of dengue virus in the immunopathological processes during the transition from fever to defervescence, which is a critical stage in determining the progression to dhf, has not been appreciated. previously, we reported that dengue virus can be detected in the i ... | 2006 | 16983615 |
| molecular evolution of dengue 2 virus in puerto rico: positive selection in the viral envelope accompanies clade reintroduction. | dengue virus is a circumtropical, mosquito-borne flavivirus that infects 50-100 million people each year and is expanding in both range and prevalence. of the four co-circulating viral serotypes (denv-1 to denv-4) that cause mild to severe febrile disease, denv-2 has been implicated in the onset of dengue haemorrhagic fever (dhf) in the americas in the early 1980s. to identify patterns of genetic change since denv-2's reintroduction into the region, molecular evolution in denv-2 from puerto rico ... | 2006 | 16528038 |
| parvovirus b19 empty capsids as antigen carriers for presentation of antigenic determinants of dengue 2 virus. | for the production of dengue-vaccine candidates, empty capsids, or virus-like particles (vlps), of parvovirus b19 that carry dengue 2-specific epitopes were employed as antigen carriers. two epitopes (comprising amino acids 352-368 and 386-397) of domain biii of the envelope glycoprotein were chosen to produce recombinant b19 vlps for immunization of balb/c mice. serum samples from immunized mice revealed that recombinant b19 vlps elicited strong humoral immune responses. in summary, this b19 vl ... | 2006 | 16941345 |
| differential enhancement of dengue virus immune complex infectivity mediated by signaling-competent and signaling-incompetent human fcgamma ria (cd64) or fcgammariia (cd32). | fcgamma receptor (fcgammar)-mediated entry of infectious dengue virus immune complexes into monocytes/macrophages is hypothesized to be a key event in the pathogenesis of complicated dengue fever. fcgammaria (cd64) and fcgammariia (cd32), which predominate on the surface of such dengue virus-permissive cells, were compared for their influence on the infectivity of dengue 2 virus immune complexes formed with human dengue virus antibodies. a signaling immunoreceptor tyrosine-based activation motif ... | 2006 | 17005690 |
| chimeric japanese encephalitis virus/dengue 2 virus infectious clone: biological properties, immunogenicity and protection against dengue encephalitis in mice. | a molecular clone of japanese encephalitis virus (je virus) was derived from the je virus nakayama strain and used to produce infectious je virus in cell culture. the engineered je virus resembled the parental je virus in cell-culture properties and was related closely to other je virus strains based on nucleotide sequence analysis. the je virus clone was used as a genetic background for construction of a chimeric virus containing the structural proteins prm and e of dengue virus, serotype 2. th ... | 2006 | 17030845 |
| the pathogenicity of mosquito densovirus (c6/36dnv) and its interaction with dengue virus type ii in aedes albopictus. | when aedes albopictus larvae were infected with c6/36 densovirus (c6/36dnv), the mortality reached 97.46% within 21 days for those larvae infected at the first day after hatching, and 14.17% for control. a real-time quantitative polymerase chain reaction (qpcr) was used to trace the dynamic change of the quantity of c6/36dnv genomes in the larvae and the adults, and to study the interaction of c6/36dnv with dengue virus type ii(den-ii) in mosquitoes. it showed that c6/36dnv could persist in the ... | 2006 | 17172379 |
| inhibitory potential of quercus lusitanica extract on dengue virus type 2 replication. | this study reports the in vitro inhibitory potential of crude extract of quercus lusitanica (q. lusitanica) seeds on the replication of dengue virus type 2 (den-2). in vitro antiviral activity of q. lusitanica extract, assessed in c6/36 cells (cloned cells of aedes albopictus larvae) employing a virus inhibition assay, showed dose-dependent inhibition. the q. lusitanica extract at its maximum non-toxic concentration of 0.25 mg/ml completely inhibited 10-1,000 tcid50 of virus, as indicated by the ... | 2006 | 17547068 |
| microarray and real-time rt-pcr analyses of a novel set of differentially expressed human genes in ecv304 endothelial-like cells infected with dengue virus type 2. | the cellular and molecular pathways of dengue infection have not been as intensively studied compared to the host immunological responses. changes in mrna expression levels of ecv304 human endothelial-like cells following infection with the virulent new guinea c strain of dengue virus type 2 were analyzed by a microarray system comprising 7600 oligonucleotide cdnas. after normalization against the uninfected control using two independent software programs, 111 genes exhibited at least a 1.5-fold ... | 2006 | 16112753 |
| capsid-targeted viral inactivation can destroy dengue 2 virus from within in vitro. | capsid-targeted viral inactivation (ctvi) has emerged as a conceptually powerful antiviral strategy that exploits viral structural proteins to target a destructive enzyme specifically into progeny virions. we have recently demonstrated the principle of ctvi against dengue virus infection and observed a modest therapeutic effect in vitro (arch virol 2005, 150: 659-669). here we tested a prophylactic model of ctvi, in which mammalian cells stably expressing the dengue 2 virus capsid protein fused ... | 2006 | 16155726 |
| inhibitory activity of cyclohexenyl chalcone derivatives and flavonoids of fingerroot, boesenbergia rotunda (l.), towards dengue-2 virus ns3 protease. | boesenbergia rotunda (l.) cyclohexenyl chalcone derivatives, 4-hydroxypanduratin a and panduratin a, showed good competitive inhibitory activities towards dengue 2 virus ns3 protease with the ki values of 21 and 25 microm, respectively, whilst those of pinostrobin and cardamonin were observed to be non-competitive. nmr and gcms spectroscopic data formed the basis of assignment of structures of the six compounds isolated. | 2006 | 16621533 |
| [construction and identification of genomic cdna subclones of dengue 2 virus ngc strain]. | to construct the cdna subclones spanning the entire genome of dengue 2 virus ngc strain for further construction of full-length infectious viral cdna clone. | 2006 | 16624755 |
| enhanced immune response by amphotericin b following ns1 protein prime-oral recombinant salmonella vaccine boost vaccination protects mice from dengue virus challenge. | a recombinant vaccine strain sl3261/plt105 of attenuated aroa salmonella enterica serovar typhimurium sl3261 strain expressing a secreted dengue virus type 2 non-structural ns1 and yersinia pestis f1 (caf1) fusion protein, rns1:caf1, was generated. immunological evaluation was performed by prime-boost vaccine regimen. oral immunization of mice with 1 x 10(9)cfu of sl3261/plt105 only induced low levels of ns1-specific antibody response and protective immunity following dengue virus challenge. the ... | 2006 | 16759760 |
| engineering rna interference-based resistance to dengue virus type 2 in genetically modified aedes aegypti. | mosquitoes (aedes aegypti) were genetically modified to exhibit impaired vector competence for dengue type 2 viruses (denv-2). we exploited the natural antiviral rna interference (rnai) pathway in the mosquito midgut by constructing an effector gene that expresses an inverted-repeat (ir) rna derived from the premembrane protein coding region of the denv-2 rna genome. the a. aegypti carboxypeptidase a promoter was used to express the ir rna in midgut epithelial cells after ingestion of a bloodmea ... | 2006 | 16537508 |