Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
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| west nile viral infection of equids. | west nile virus (wnv) is a flavivirus transmitted between certain species of birds and mosquito vectors. tangential infections of equids and subsequent equine epizootics have occurred historically. although the attack rate has been estimated to be below 10%, mortality rates can approach 50% in horses that present clinical disease. symptoms are most commonly presenting in the form of encephalitis with ataxia as well as limb weakness, recumbency and muscle fasciculation. the most effective strateg ... | 2013 | 24035480 |
| natural exposure of horses to mosquito-borne flaviviruses in south-east queensland, australia. | in 2011 an unprecedented epidemic of equine encephalitis occurred in south-eastern (se) australia following heavy rainfall and severe flooding in the preceding 2-4 months. less than 6% of the documented cases occurred in queensland, prompting the question of pre-existing immunity in queensland horses. a small-scale serological survey was conducted on horses residing in one of the severely flood-affected areas of se-queensland. using a flavivirus-specific blocking-elisa we found that 63% (39/62) ... | 2013 | 24048209 |
| west nile virus genome with glycosylated envelope protein and deletion of alpha helices 1, 2, and 4 in the capsid protein is noninfectious and efficiently secretes subviral particles. | flavivirus genomes with deletions in the capsid (c) gene are attractive vaccine candidates, as they secrete highly immunogenic subviral particles (svps) without generating infectious virus. here, we report that cytomegalovirus promoter-driven cdna of west nile virus kunjin (kunv) containing a glycosylation motif in the envelope (e) gene and a combined deletion of alpha helices 1, 2, and 4 in c produces significantly more svps than kunv cdnas with nonglycosylated e and various other deletions in ... | 2013 | 24049184 |
| characterization of the mouse neuroinvasiveness of selected european strains of west nile virus. | west nile virus (wnv) has caused outbreaks and sporadic infections in central, eastern and mediterranean europe for over 45 years. most strains responsible for the european and mediterranean basin outbreaks are classified as lineage 1. in recent years, wnv strains belonging to lineage 1 and 2 have been causing outbreaks of neuroinvasive disease in humans in countries such as italy, hungary and greece, while mass mortality among birds was not reported. this study characterizes three european stra ... | 2013 | 24058590 |
| vaccines in development against west nile virus. | west nile encephalitis emerged in 1999 in the united states, then rapidly spread through the north american continent causing severe disease in human and horses. since then, outbreaks appeared in europe, and in 2012, the united states experienced a new severe outbreak reporting a total of 5,387 cases of west nile virus (wnv) disease in humans, including 243 deaths. so far, no human vaccine is available to control new wnv outbreaks and to avoid worldwide spreading. in this review, we discuss the ... | 2013 | 24084235 |
| low seroprevalence of murray valley encephalitis and kunjin viruses in an opportunistic serosurvey, victoria 2011. | to assess evidence of recent and past exposure to murray valley encephalitis virus (mvev) and west nile clade kunjin virus (kunv) in residents of the murray valley, victoria, during a period of demonstrated activity of both viruses in early 2011. | 2013 | 24090325 |
| west nile virus in the transfusion setting with a special focus on italian preventive measures adopted in 2008-2012 and their impact on blood safety. | 2013 | 24120610 | |
| s-adenosyl-homocysteine is a weakly bound inhibitor for a flaviviral methyltransferase. | the methyltransferase enzyme (mtase), which catalyzes the transfer of a methyl group from s-adenosyl-methionine (adomet) to viral rna, and generates s-adenosyl-homocysteine (adohcy) as a by-product, is essential for the life cycle of many significant human pathogen flaviviruses. here we investigated inhibition of the flavivirus mtase by several adohcy-derivatives. unexpectedly we found that adohcy itself barely inhibits the flavivirus mtase activities, even at high concentrations. adohcy was als ... | 2013 | 24130807 |
| molecular epidemiology and evolution of west nile virus in north america. | west nile virus (wnv) was introduced to new york in 1999 and rapidly spread throughout north america and into parts of central and south america. displacement of the original new york (ny99) genotype by the north america/west nile 2002 (na/wn02) genotype occurred in 2002 with subsequent identification of a novel genotype in 2003 in isolates collected from the southwestern unites states region (sw/wn03 genotype). both genotypes co-circulate to date. subsequent wnv surveillance studies have confir ... | 2013 | 24135819 |
| comparison of the live attenuated yellow fever vaccine 17d-204 strain to its virulent parental strain asibi by deep sequencing. | the first comparison of a live rna viral vaccine strain to its wild-type parental strain by deep sequencing is presented using as a model the yellow fever virus (yfv) live vaccine strain 17d-204 and its wild-type parental strain, asibi. | 2013 | 24141982 |
| european surveillance for west nile virus in mosquito populations. | a wide range of arthropod-borne viruses threaten both human and animal health either through their presence in europe or through risk of introduction. prominent among these is west nile virus (wnv), primarily an avian virus, which has caused multiple outbreaks associated with human and equine mortality. endemic outbreaks of west nile fever have been reported in italy, greece, france, romania, hungary, russia and spain, with further spread expected. most outbreaks in western europe have been due ... | 2013 | 24157510 |
| west nile virus: a re-emerging pathogen revisited. | west nile virus (wnv), a flavivirus of the flaviviridae family, is maintained in nature in an enzootic transmission cycle between avian hosts and ornithophilic mosquito vectors, although the virus occasionally infects other vertebrates. wnv causes sporadic disease outbreaks in horses and humans, which may result in febrile illness, meningitis, encephalitis and flaccid paralysis. until recently, its medical and veterinary health concern was relatively low; however, the number, frequency and sever ... | 0 | 24175211 |
| west nile virus. | 2013 | 24179475 | |
| dengue virus infection: current concepts in immune mechanisms and lessons from murine models. | dengue viruses (denv), a group of four serologically distinct but related flaviviruses, are responsible for one of the most important emerging viral diseases. this mosquito-borne disease has a great impact in tropical and subtropical areas of the world in terms of illness, mortality and economic costs, mainly due to the lack of approved vaccine or antiviral drugs. infections with one of the four serotypes of denv (denv-1-4) result in symptoms ranging from an acute, self-limiting febrile illness, ... | 0 | 24182427 |
| non-structural protein-1 is required for west nile virus replication complex formation and viral rna synthesis. | flavivirus ns1 is a non-structural glycoprotein that is expressed on the cell surface and secreted into the extracellular space, where it acts as an antagonist of complement pathway activation. despite its transit through the secretory pathway and intracellular localization in the lumen of the endoplasmic reticulum and golgi vesicles, ns1 is as an essential gene for flavivirus replication. how ns1 modulates infection remains uncertain given that the viral rna replication complex localizes to the ... | 2013 | 24245822 |
| exploring the spatio-temporal dynamics of reservoir hosts, vectors, and human hosts of west nile virus: a review of the recent literature. | over the last two decades west nile virus (wnv) has been responsible for significant disease outbreaks in humans and animals in many parts of the world. its extremely rapid global diffusion argues for a better understanding of its geographic extent. the purpose of this inquiry was to explore spatio-temporal patterns of wnv using geospatial technologies to study populations of the reservoir hosts, vectors, and human hosts, in addition to the spatio-temporal interactions among these populations. r ... | 2013 | 24284356 |
| the changing epidemiology of kunjin virus in australia. | west nile virus (wnv) is a mosquito-borne virus responsible for outbreaks of viral encephalitis in humans and horses, with particularly virulent strains causing recent outbreaks of disease in eastern europe, the middle east and north america. a strain of wnv, kunjin (wnvkun), is endemic in northern australia and infection with this virus is generally asymptomatic. however in early 2011, an unprecedented outbreak of encephalitis in horses occurred in south-eastern australia, resulting in mortalit ... | 2013 | 24287851 |
| the west nile virus assembly process evades the conserved antiviral mechanism of the interferon-induced mxa protein. | flaviviruses have evolved means to evade host innate immune responses. recent evidence suggests this is due to prevention of interferon production and signaling in flavivirus-infected cells. here we show that the interferon-induced mxa protein can sequester the west nile virus strain kunjin virus (wnvkun) capsid protein in cytoplasmic tubular structures in an expression-replication system. this sequestering resulted in reduced titers of secreted wnvkun particles. we show by electron microscopy, ... | 2014 | 24314641 |
| enhanced arbovirus surveillance with deep sequencing: identification of novel rhabdoviruses and bunyaviruses in australian mosquitoes. | viral metagenomics characterizes known and identifies unknown viruses based on sequence similarities to any previously sequenced viral genomes. a metagenomics approach was used to identify virus sequences in australian mosquitoes causing cytopathic effects in inoculated mammalian cell cultures. sequence comparisons revealed strains of liao ning virus (reovirus, seadornavirus), previously detected only in china, livestock-infecting stretch lagoon virus (reovirus, orbivirus), two novel dimarhabdov ... | 2013 | 24314645 |
| west nile virus state of the art report of malwest project. | during the last three years greece is experiencing the emergence of west nile virus (wnv) epidemics. within this framework, an integrated surveillance and control programme (malwest project) with thirteen associate partners was launched aiming to investigate the disease and suggest appropriate interventions. one out of seven work packages of the project is dedicated to the state of the art report for wnv. three expert working groups on humans, animals and mosquitoes were established. medical dat ... | 2013 | 24317379 |
| west nile virus in the united states - a historical perspective. | prior to 1999, west nile virus (wnv) was a bit player in the screenplay of global vector-borne viral diseases. first discovered in the west nile district of uganda in 1937, this culex sp.-transmitted virus was known for causing small human febrile outbreaks in africa and the middle east. prior to 1995, the last major human wnv outbreak was in the 1950s in israel. the epidemiology and ecology of wnv began to change in the mid-1990s when an epidemic of human encephalitis occurred in romania. the i ... | 2013 | 24335779 |
| cytoplasmic viruses: rage against the (cellular rna decay) machine. | 2013 | 24339774 | |
| increased pathogenicity of west nile virus (wnv) by glycosylation of envelope protein and seroprevalence of wnv in wild birds in far eastern russia. | in this review, we discuss the possibility that the glycosylation of west nile (wn) virus e-protein may be associated with enhanced pathogenicity and higher replication of wn virus. the results indicate that e-protein glycosylation allows the virus to multiply in a heat-stable manner and therefore, has a critical role in enhanced viremic levels and virulence of wn virus in young-chick infection model. the effect of the glycosylation of the e protein on the pathogenicity of wn virus in young chic ... | 2013 | 24351738 |
| vector-virus interactions and transmission dynamics of west nile virus. | west nile virus (wnv; flavivirus; flaviviridae) is the cause of the most widespread arthropod-borne viral disease in the world and the largest outbreak of neuroinvasive disease ever observed. mosquito-borne outbreaks are influenced by intrinsic (e.g., vector and viral genetics, vector and host competence, vector life-history traits) and extrinsic (e.g., temperature, rainfall, human land use) factors that affect virus activity and mosquito biology in complex ways. the concept of vectorial capacit ... | 2013 | 24351794 |
| applications of a sugar-based surveillance system to track arboviruses in wild mosquito populations. | effective arbovirus surveillance is essential to ensure the implementation of control strategies, such as mosquito suppression, vaccination, or dissemination of public warnings. traditional strategies employed for arbovirus surveillance, such as detection of virus or virus-specific antibodies in sentinel animals, or detection of virus in hematophagous arthropods, have limitations as an early-warning system. a system was recently developed that involves collecting mosquitoes in co2-baited traps, ... | 2014 | 24359415 |
| comparison of the neuropathology induced by two west nile virus strains. | some strains of west nile virus (wnv) are neuroinvasive and may induce fatal encephalitis/meningitis in a variety of animal species including humans. whether, however, there is a strain-specific signature in the brain is as yet unknown. here we investigated the neuropathogenesis induced by two phylogenetically distant wnv strains of lineage 1, wnv(is98) and wnv(kun35 911). while four-week old c57bl/6j mice were susceptible to both strains and succumbed rapidly after intraperitoneal inoculation, ... | 2013 | 24367664 |
| zoonotic encephalitides caused by arboviruses: transmission and epidemiology of alphaviruses and flaviviruses. | in this review, we mainly focus on zoonotic encephalitides caused by arthropod-borne viruses (arboviruses) of the families flaviviridae (genus flavivirus) and togaviridae (genus alphavirus) that are important in both humans and domestic animals. specifically, we will focus on alphaviruses (eastern equine encephalitis virus, western equine encephalitis virus, venezuelan equine encephalitis virus) and flaviviruses (japanese encephalitis virus and west nile virus). most of these viruses were origin ... | 2013 | 24427764 |
| effect of dengue-2 virus infection on protein expression in the salivary glands of aedes aegypti mosquitoes. | dengue virus (denv) is the most important mosquito-transmitted flavivirus that is transmitted throughout the tropical and subtropical regions of the world. the primary mosquito vector of denv in urban locations is aedes aegypti. key to understanding the transmission of denv is the relationship between pathogen and vector. accordingly, we report our preliminary characterization of the differentially expressed proteins from ae. aegypti mosquitoes after denv infection. we investigated the virus-vec ... | 2014 | 24445208 |
| surveillance for arboviral zoonoses in new zealand birds. | given the significant burden that emerging infectious diseases place on global economies and public health, the monitoring and mitigation of, and early response to, potential infectious diseases are of the highest priority. the objective of this study was to survey for known and other potential arboviral zoonoses in multiple bird species at four locations in new zealand. | 2013 | 24478919 |
| estimating the burden of japanese encephalitis virus and other encephalitides in countries of the mekong region. | diverse aetiologies of viral and bacterial encephalitis are widely recognized as significant yet neglected public health issues in the mekong region. a robust analysis of the corresponding health burden is lacking. we retrieved 75 articles on encephalitis in the region published in english or in french from 1965 through 2011. review of available data demonstrated that they are sparse and often derived from hospital-based studies with significant recruitment bias. almost half (35 of 75) of articl ... | 2014 | 24498443 |
| mechanisms underlying the inhibition of interferon signaling by viruses. | a hallmark of the antiviral response is the induction of interferons. first discovered in 1957 by issac and lindeman, interferons are noted for their ability to interfere with viral replication. interferons act via autocrine and paracrine pathways to induce an antiviral state in infected cells and in neighboring cells containing interferon receptors. interferons are the frontline defenders against viral infection and their primary function is to locally restrict viral propagation. viruses have e ... | 2014 | 24504013 |
| ultrastructural characterization and three-dimensional architecture of replication sites in dengue virus-infected mosquito cells. | during dengue virus infection of host cells, intracellular membranes are rearranged into distinct subcellular structures such as double-membrane vesicles, convoluted membranes, and tubular structures. recent electron tomographic studies have provided a detailed three-dimensional architecture of the double-membrane vesicles, representing the sites of dengue virus replication, but temporal and spatial evidence linking membrane morphogenesis with viral rna synthesis is lacking. integrating techniqu ... | 2014 | 24522909 |
| vector competence of culex neavei and culex quinquefasciatus (diptera: culicidae) from senegal for lineages 1, 2, koutango and a putative new lineage of west nile virus. | west nile virus (wn virus) is one of the most widespread arbovirus and exhibits a great genetic diversity with 8 lineages, at least 4 (1, 2, koutango, and putative new) are present in africa. in west africa, culex neavei and culex quinquefasciatus are considered as potential vectors for wn virus transmission in sylvatic or urban context. we analyzed the vector competence of these culex species from senegal for african lineages and envelope proteins sequences of viral strains used. we showed that ... | 2014 | 24567319 |
| ebola virus vaccines: an overview of current approaches. | ebola hemorrhagic fever is one of the most fatal viral diseases worldwide affecting humans and nonhuman primates. although infections only occur frequently in central africa, the virus has the potential to spread globally and is classified as a category a pathogen that could be misused as a bioterrorism agent. as of today there is no vaccine or treatment licensed to counteract ebola virus infections. dna, subunit and several viral vector approaches, replicating and non-replicating, have been tes ... | 2014 | 24575870 |
| inhibition of hsp70 reduces porcine reproductive and respiratory syndrome virus replication in vitro. | successful viral infection requires the involvement of host cellular factors in their life cycle. heat shock protein 70 (hsp70) can be recruited by numerous viruses to promote the folding, maturation, or assembly of viral proteins. we have previously shown that hsp70 is significantly elevated in porcine reproductive and respiratory syndrome virus (prrsv)-infected lungs, suggesting hsp70 may play a potential role during prrsv infection. in this study, we tried to investigate the role of hsp70 dur ... | 2014 | 24625230 |
| use of envelope domain iii protein for detection and differentiation of flaviviruses in the free state province, south africa. | the presence of the mosquito-borne flavivirus species west nile virus (wnv) and wesselsbron virus (wessv) in southern africa is well established; however, their true prevalence remains unknown. to date, the presence of tick-borne flaviviruses has not been confirmed in this region. serological assays using reagents that can be handled in a biosafety level 2 or lower facility were developed and evaluated for the detection and differentiation of tick- and mosquito-borne flaviviruses in the free sta ... | 2014 | 24689894 |
| flavivirus detection and differentiation by a microsphere array assay. | flaviviruses of the japanese encephalitis virus (jev) serocomplex include major human and animal pathogens that have a propensity to spread and emerge in new geographic areas. different genotypes or genetic lineages have been defined for many of these viruses, and they are distributed worldwide. tools enabling rapid detection of new or emerging flaviviruses and differentiation of important subgroups have widespread application for arbovirus diagnosis and surveillance, and are crucial for detecti ... | 2014 | 24690622 |
| rna structures that resist degradation by xrn1 produce a pathogenic dengue virus rna. | dengue virus is a growing global health threat. dengue and other flaviviruses commandeer the host cell's rna degradation machinery to generate the small flaviviral rna (sfrna), a noncoding rna that induces cytopathicity and pathogenesis. host cell exonuclease xrn1 likely loads on the 5' end of viral genomic rna and degrades processively through ∼10 kb of rna, halting near the 3' end of the viral rna. the surviving rna is the sfrna. we interrogated the architecture of the complete dengue 2 sfrna, ... | 2014 | 24692447 |
| evaluation of a mouse model for the west nile virus group for the purpose of determining viral pathotypes. | west nile virus (wnv; family flaviviridae; genus flavivirus) group members are an important cause of viral meningoencephalitis in some areas of the world. they exhibit marked variation in pathogenicity, with some viral lineages (such as those from north america) causing high prevalence of severe neurological disease, whilst others (such as australian kunjin virus) rarely cause disease. the aim of this study was to characterize wnv disease in a mouse model and to elucidate the pathogenetic featur ... | 2014 | 24694397 |
| the nairovirus nairobi sheep disease virus/ganjam virus induces the translocation of protein disulphide isomerase-like oxidoreductases from the endoplasmic reticulum to the cell surface and the extracellular space. | nairobi sheep disease virus (nsdv) of the genus nairovirus causes a haemorrhagic gastroenteritis in sheep and goats with mortality up to 90%; the virus is found in east and central africa, and in india, where the virus is called ganjam virus. nsdv is closely related to the human pathogen crimean-congo haemorrhagic fever virus, which also causes a haemorrhagic disease. as with other nairoviruses, replication of nsdv takes place in the cytoplasm and the new virus particles bud into the golgi appar ... | 2014 | 24714576 |
| current developments in understanding of west nile virus central nervous system disease. | west nile virus (wnv) is the most important cause of epidemic encephalitis in the united states. we review articles published in the last 18 months related to the epidemiology, immunology, clinical features, and treatment of this disease. | 0 | 24722324 |
| a novel t-cell receptor mimic defines dendritic cells that present an immunodominant west nile virus epitope in mice. | we used a newly generated t-cell receptor mimic monoclonal antibody (tcrm mab) that recognizes a known nonself immunodominant peptide epitope from west nile virus (wnv) ns4b protein to investigate epitope presentation after virus infection in c57bl/6 mice. previous studies suggested that peptides of different length, either ssvwnattai (10-mer) or ssvwnatta (9-mer) in complex with class i mhc antigen h-2d(b) , were immunodominant after wnv infection. our data establish that both peptides are pres ... | 2014 | 24723377 |
| the role of viral persistence in flavivirus biology. | in nature, vector-borne flaviviruses are persistently cycled between either the tick or mosquito vector and small mammals such as rodents, skunks, and swine. these viruses account for considerable human morbidity and mortality worldwide. increasing and substantial evidence of viral persistence in humans, which includes the isolation of rna by rt-pcr and infectious virus by culture, continues to be reported. viral persistence can also be established in vitro in various human, animal, arachnid, an ... | 2014 | 24737600 |
| experimental infection of rhesus macaques and common marmosets with a european strain of west nile virus. | west nile virus (wnv) is a mosquito-borne flavivirus that infects humans and other mammals. in some cases wnv causes severe neurological disease. during recent years, outbreaks of wnv are increasing in worldwide distribution and novel genetic variants of the virus have been detected. although a substantial amount of data exists on wnv infections in rodent models, little is known about early events during wnv infection in primates, including humans. to gain a deeper understanding of this process, ... | 2014 | 24743302 |
| development of nucleic acid vaccines: use of self-amplifying rna in lipid nanoparticles. | self-amplifying rna or rna replicon is a form of nucleic acid-based vaccine derived from either positive-strand or negative-strand rna viruses. the gene sequences encoding structural proteins in these rna viruses are replaced by mrna encoding antigens of interest as well as by rna polymerase for replication and transcription. this kind of vaccine has been successfully assayed with many different antigens as vaccines candidates, and has been shown to be potent in several animal species, including ... | 2014 | 24748793 |
| a review of the epidemiological and clinical aspects of west nile virus. | the resurgence of west nile virus (wnv) in north america and europe in recent years has raised the concerns of local authorities and highlighted that mosquito-borne disease is not restricted to tropical regions of the world. wnv is maintained in enzootic cycles involving, primarily, culex spp. mosquitoes and avian hosts, with epizootic spread to mammals, including horses and humans. human infection results in symptomatic illness in approximately one-fifth of cases and neuroinvasive disease in le ... | 2014 | 24748813 |
| dicer-2-dependent activation of culex vago occurs via the traf-rel2 signaling pathway. | despite their importance as vectors of human and livestock diseases, relatively little is known about innate antiviral immune pathways in mosquitoes and other insects. previous work has shown that culex vago (cxvago), which is induced and secreted from west nile virus (wnv)-infected mosquito cells, acts as a functional homolog of interferon, by activating jak-stat pathway and limiting virus replication in neighbouring cells. here we describe the dicer-2-dependent pathway leading to wnv-induced c ... | 2014 | 24762775 |
| expression of mosquito microrna aae-mir-2940-5p is downregulated in response to west nile virus infection to restrict viral replication. | west nile virus (wnv) is an enveloped virus with a single-stranded positive-sense rna genome from the flaviviridae family. wnv is spread by mosquitoes and able to infect humans, causing encephalitis and meningitis that can be fatal; it therefore presents a significant risk for human health. in insects, innate response to rna virus infection mostly relies on rna interference and jak/sat pathways; however, some evidence indicates that it can also involve micrornas (mirnas). mirnas are small noncod ... | 2014 | 24829359 |
| quantitative proteomic analysis of host-virus interactions reveals a role for golgi brefeldin a resistance factor 1 (gbf1) in dengue infection. | dengue virus is considered to be the most important mosquito-borne virus worldwide and poses formidable economic and health care burdens on many tropical and subtropical countries. dengue infection induces drastic rearrangement of host endoplasmic reticulum membranes into complex membranous structures housing replication complexes; the contribution(s) of host proteins and pathways to this process is poorly understood but is likely to be mediated by protein-protein interactions. we have developed ... | 2014 | 24855065 |
| abrogation of tlr3 inhibition by discrete amino acid changes in the c-terminal half of the west nile virus ns1 protein. | west nile virus (wnv) is a mosquito-transmitted pathogen, which causes significant disease in humans. the innate immune system is a first-line defense against invading microorganism and many flaviviruses, including wnv, have evolved multifunctional proteins, which actively suppress its activation and antiviral actions. the wnv non-structural protein 1 (ns1) inhibits signal transduction originating from toll-like receptor 3 (tlr3) and also critically contributes to virus genome replication. in th ... | 2014 | 24889229 |
| aedes albopictus (diptera: culicidae) as a potential vector of endemic and exotic arboviruses in australia. | in 2005, established populations of aedes albopictus (skuse) were discovered in the torres strait, the region that separates papua new guinea from northern australia. this increased the potential for this species to be introduced to mainland australia. because it is an arbovirus vector elsewhere, we undertook laboratory-based infection and transmission experiments to determine the potential for ae. albopictus from the torres strait to become infected with and transmit the four major australian e ... | 2014 | 24897860 |
| substitution of ns5 n-terminal domain of dengue virus type 2 rna with type 4 domain caused impaired replication and emergence of adaptive mutants with enhanced fitness. | flavivirus ns3 and ns5 are required in viral replication and 5'-capping. ns3 has ns2b-dependent protease, rna helicase, and 5'-rna triphosphatase activities. ns5 has 5'-rna methyltransferase (mt)/guanylyltransferase (gt) activities within the n-terminal 270 amino acids and the rna-dependent rna polymerase (pol) activity within amino acids 271-900. a chimeric ns5 containing the d4mt/d4gt and the d2pol domains in the context of wild-type (wt) d2 rna was constructed. rnas synthesized in vitro were ... | 2014 | 24904061 |
| infection with non-lethal west nile virus eg101 strain induces immunity that protects mice against the lethal west nile virus ny99 strain. | herein we demonstrate that infection of mice with west nile virus (wnv) eg101 provides protective immunity against lethal challenge with wnv ny99. our data demonstrated that wnv eg101 is largely non-virulent in adult mice when compared to wnv ny99. by day 6 after infection, wnv-specific igm and igg antibodies, and neutralizing antibodies were detected in the serum of all wnv eg101 infected mice. plaque reduction neutralization test data demonstrated that serum from wnv eg101 infected mice neutra ... | 2014 | 24915459 |
| the west nile virus-like flavivirus koutango is highly virulent in mice due to delayed viral clearance and the induction of a poor neutralizing antibody response. | the mosquito-borne west nile virus (wnv) is responsible for outbreaks of viral encephalitis in humans, horses, and birds, with particularly virulent strains causing recent outbreaks of disease in eastern europe, the middle east, north america, and australia. previous studies have phylogenetically separated wnv strains into two main genetic lineages (i and ii) containing virulent strains associated with neurological disease. several wnv-like strains clustering outside these lineages have been ide ... | 2014 | 24942584 |
| rna virus reverse genetics and vaccine design. | rna viruses are capable of rapid spread and severe or potentially lethal disease in both animals and humans. the development of reverse genetics systems for manipulation and study of rna virus genomes has provided platforms for designing and optimizing viral mutants for vaccine development. here, we review the impact of rna virus reverse genetics systems on past and current efforts to design effective and safe viral therapeutics and vaccines. | 2014 | 24967693 |
| host competence and helicase activity differences exhibited by west nile viral variants expressing ns3-249 amino acid polymorphisms. | a single helicase amino acid substitution, ns3-t249p, has been shown to increase viremia magnitude/mortality in american crows (amcrs) following west nile virus (wnv) infection. lineage/intra-lineage geographic variants exhibit consistent amino acid polymorphisms at this locus; however, the majority of wnv isolates associated with recent outbreaks reported worldwide have a proline at the ns3-249 residue. in order to evaluate the impact of ns3-249 variants on avian and mammalian virulence, multip ... | 2014 | 24971589 |
| g3bp1, g3bp2 and caprin1 are required for translation of interferon stimulated mrnas and are targeted by a dengue virus non-coding rna. | viral rna-host protein interactions are critical for replication of flaviviruses, a genus of positive-strand rna viruses comprising major vector-borne human pathogens including dengue viruses (denv). we examined three conserved host rna-binding proteins (rbps) g3bp1, g3bp2 and caprin1 in dengue virus (denv-2) infection and found them to be novel regulators of the interferon (ifn) response against denv-2. the three rbps were required for the accumulation of the protein products of several interfe ... | 2014 | 24992036 |
| in vitro and in vivo characterization of a west nile virus mad78 infectious clone. | the viral determinants governing the varied neuropathogenicity of different west nile virus (wnv) strains are poorly understood. here, we generated an infectious clone (wnv-mad(ic)) of the non-pathogenic strain wnv-mad78 and compared its replication to that of parental wnv-mad78 and a wnv-mad78 infectious clone (wnv-mad(tx-utrs)) containing the 5' and 3' untranslated regions (utrs) of the pathogenic strain wnv-tx. all three viruses replicated at similar rates and caused similar lethality in mice ... | 2014 | 25023336 |
| interferon regulatory factor 5-dependent immune responses in the draining lymph node protect against west nile virus infection. | upon activation of toll-like and rig-i-like receptor signaling pathways, the transcription factor irf5 translocates to the nucleus and induces antiviral immune programs. the recent discovery of a homozygous mutation in the immunoregulatory gene guanine exchange factor dedicator of cytokinesis 2 (dock2mu/mu) in several irf5-/- mouse colonies has complicated interpretation of immune functions previously ascribed to irf5. to define the antiviral functions of irf5 in vivo, we infected backcrossed ir ... | 2014 | 25031348 |
| characterization of the mode of action of a potent dengue virus capsid inhibitor. | dengue viruses (dv) represent a significant global health burden, with up to 400 million infections every year and around 500,000 infected individuals developing life-threatening disease. in spite of attempts to develop vaccine candidates and antiviral drugs, there is a lack of approved therapeutics for the treatment of dv infection. we have previously reported the identification of st-148, a small-molecule inhibitor exhibiting broad and potent antiviral activity against dv in vitro and in vivo ... | 2014 | 25056895 |
| phylogenetic analysis of west nile virus genome, iran. | 0 | 25061976 | |
| evidence of experimental vertical transmission of emerging novel ecsa genotype of chikungunya virus in aedes aegypti. | chikungunya virus (chikv) has emerged as one of the most important arboviruses of public health significance in the past decade. the virus is mainly maintained through human-mosquito-human cycle. other routes of transmission and the mechanism of maintenance of the virus in nature are not clearly known. vertical transmission may be a mechanism of sustaining the virus during inter-epidemic periods. laboratory experiments were conducted to determine whether aedes aegypti, a principal vector, is cap ... | 2014 | 25080107 |
| japanese b encephalitis: an overview of the disease and use of chimerivax-je as a preventative vaccine. | the japanese encephalitis virus (jev) is endemic in many countries in southern asia and the western pacific rim, with new spread to previously unrecognized countries. it is an important cause of childhood neurological disease associated with permanent neurological sequelae and death. fortunately, je is a vaccine-preventable disease. the chimerivax™-je (sanofi pasteur, lyon, france) is a live-attenuated chimeric vaccine derived from the live-attenuated yellow fever virus, yf17d, which expresses t ... | 2013 | 25134477 |
| modulation of α-enolase post-translational modifications by dengue virus: increased secretion of the basic isoforms in infected hepatic cells. | hepatic cells are major sites of dengue virus (denv) replication and liver injury constitutes a characteristic of severe forms of dengue. the role of hepatic cells in dengue pathogenesis is not well established, but since hepatocytes are the major source of plasma proteins, changes in protein secretion by these cells during infection might contribute to disease progression. previously, we showed that denv infection alters the secretion pattern of hepatic hepg2 cells, with α-enolase appearing as ... | 2014 | 25171719 |
| phylogenetic analysis of poly and non structural protein in japanese encephalitis virus with other related viral families. | japanese encephalitis (je) causes inflammation of brain. the mortality rate due to je is 30% while 10 -15 % of patients make full recovery. the disease spreads through infected mosquito bites breeding in rice fields and feeds on pigs, birds, and ducks. | 0 | 25205875 |
| monomeric nature of dengue virus ns3 helicase and thermodynamic analysis of the interaction with single-stranded rna. | dengue virus nonstructural protein 3 (ns3) is a multifunctional protein formed by a superfamily-2 rna helicase linked to a protease domain. in this work, we report results from in vitro experiments designed to determine the oligomeric state of dengue virus ns3 helicase (ns3h) and to characterize fundamental properties of the interaction with single-stranded (ss)rna. pulsed field gradient-nmr spectroscopy was used to determine the effective hydrodynamic radius of ns3h, which was constant over a w ... | 2014 | 25223789 |
| linking pig-tailed macaque major histocompatibility complex class i haplotypes and cytotoxic t lymphocyte escape mutations in simian immunodeficiency virus infection. | the influence of major histocompatibility complex class i (mhc-i) alleles on human immunodeficiency virus (hiv) diversity in humans has been well characterized at the population level. mhc-i alleles likely affect viral diversity in the simian immunodeficiency virus (siv)-infected pig-tailed macaque (macaca nemestrina) model, but this is poorly characterized. we studied the evolution of siv in pig-tailed macaques with a range of mhc-i haplotypes. siv(mac251) genomes were amplified from the plasma ... | 2014 | 25275134 |
| epidemiology of west nile disease in europe and in the mediterranean basin from 2009 to 2013. | west nile virus (wnv) transmission has been confirmed in the last four years in europe and in the mediterranean basin. an increasing concern towards west nile disease (wnd) has been observed due to the high number of human and animal cases reported in these areas confirming the importance of this zoonosis. a new epidemiological scenario is currently emerging: although new introductions of the virus from abroad are always possible, confirming the epidemiological role played by migratory birds, th ... | 2014 | 25302311 |
| the bioactive lipid 4-hydroxyphenyl retinamide inhibits flavivirus replication. | dengue virus (denv), a member of the flaviviridae family, is a mosquito-borne pathogen and the cause of dengue fever. the increasing prevalence of denv worldwide heightens the need for an effective vaccine and specific antivirals. due to the dependence of denv upon the lipid biosynthetic machinery of the host cell, lipid signaling and metabolism present unique opportunities for inhibiting viral replication. we screened a library of bioactive lipids and modulators of lipid metabolism and identifi ... | 2014 | 25313218 |
| two distinct sets of ns2a molecules are responsible for dengue virus rna synthesis and virion assembly. | flavivirus nonstructural protein 2a (ns2a) plays important roles in both viral rna synthesis and virion assembly. the molecular details of how the ns2a protein modulates the two distinct events have not been defined. to address this question, we have performed a systematic mutagenesis of ns2a using dengue virus (denv) serotype 2 (denv-2) as a model. we identified two sets of ns2a mutations with distinct defects during a viral infection cycle. one set of ns2a mutations (d125a and g200a) selective ... | 2014 | 25392211 |
| development, characterization and application of monoclonal antibodies against brazilian dengue virus isolates. | dengue is the most prevalent human arboviral disease. the morbidity related to dengue infection supports the need for an early, quick and effective diagnostic test. brazil is a hotspot for dengue, but no serological diagnostic test has been produced using brazilian dengue virus isolates. this study aims to improve the development of immunodiagnostic methods for dengue virus (denv) detection through the production and characterization of 22 monoclonal antibodies (mabs) against brazilian isolates ... | 2014 | 25412181 |
| putative new west nile virus lineage in uranotaenia unguiculata mosquitoes, austria, 2013. | west nile virus (wnv) is becoming more widespread and markedly effecting public health. we sequenced the complete polyprotein gene of a divergent wnv strain newly detected in a pool of uranotaenia unguiculata mosquitoes in austria. phylogenetic analyses suggest that the new strain constitutes a ninth wnv lineage or a sublineage of wnv lineage 4. | 0 | 25418009 |
| evidence of west nile virus infection in nepal. | acute febrile illness is common among those seeking medical care and is frequently treated empirically with the underlying illness remaining undiagnosed in resource-poor countries. a febrile illness study was conducted 2009-2010 to identify known and unknown pathogens circulating in nepal. | 2014 | 25427544 |
| whole genome phylogenetic investigation of a west nile virus strain isolated from a tick sampled from livestock in north eastern kenya. | west nile virus (wnv) has a wide geographical distribution and has been associated to cause neurological disease in humans and horses. mosquitoes are the traditional vectors for wnv; however, the virus has also been isolated from tick species in north africa and europe which could be a means of introduction and spread of the virus over long distances through migratory birds. although wnv has been isolated in mosquitoes in kenya, paucity of genetic and pathogenicity data exists. we previously rep ... | 2014 | 25430727 |
| sequential conformational rearrangements in flavivirus membrane fusion. | the west nile virus (wnv) envelope protein, e, promotes membrane fusion during viral cell entry by undergoing a low-ph triggered conformational reorganization. we have examined the mechanism of wnv fusion and sought evidence for potential intermediates during the conformational transition by following hemifusion of wnv virus-like particles (vlps) in a single particle format. we have introduced specific mutations into e, to relate their influence on fusion kinetics to structural features of the p ... | 2014 | 25479384 |
| role of enhanced vector transmission of a new west nile virus strain in an outbreak of equine disease in australia in 2011. | in 2011, a variant of west nile virus kunjin strain (wnvkun) caused an unprecedented epidemic of neurological disease in horses in southeast australia, resulting in almost 1,000 cases and a 9% fatality rate. we investigated whether increased fitness of the virus in the primary vector, culex annulirostris, and another potential vector, culex australicus, contributed to the widespread nature of the outbreak. | 2014 | 25499981 |
| oxidative stress influences positive strand rna virus genome synthesis and capping. | flaviviruses are 5' capped positive-stranded rna viruses that replicate their genomes within endoplasmic reticulum-derived vesicles. flaviviruses are well known to induce oxidative stress late in infection but it is unknown if oxidative stress plays a positive role in the viral rna replication cycle. we therefore examined how oxidation affects flavivirus rna replication. we found that antioxidant treatment reduced virus production, reduced the viral positive-to-negative strand rna ratio, and res ... | 2014 | 25514423 |
| seroprevalence screening for the west nile virus in malaysia's orang asli population. | west nile virus (wnv) infection is an emerging zoonotic disease caused by an rna virus of the genus flavivirus. wnv is preserved in the environment through cyclic transmission, with mosquitoes, particularly culex species, serving as a vector, birds as an amplifying host and humans and other mammals as dead-end hosts. to date, no studies have been carried out to determine the prevalence of the wnv antibody in malaysia. the aim of this study was to screen for the seroprevalence of the wnv in malay ... | 2014 | 25515627 |
| safety and immunogenicity of a delta inulin-adjuvanted inactivated japanese encephalitis virus vaccine in pregnant mares and foals. | in 2011, following severe flooding in eastern australia, an unprecedented epidemic of equine encephalitis occurred in south-eastern australia, caused by murray valley encephalitis virus (mvev) and a new variant strain of kunjin virus, a subtype of west nile virus (wnvkun). this prompted us to assess whether a delta inulin-adjuvanted, inactivated cell culture-derived japanese encephalitis virus (jev) vaccine (je-advax™) could be used in horses, including pregnant mares and foals, to not only indu ... | 2014 | 25516480 |
| molecular and immunological characterization of a dna-launched yellow fever virus 17d infectious clone. | yellow fever virus (yfv)-17d is an empirically developed, highly effective live-attenuated vaccine that has been administered to human beings for almost a century. yfv-17d has stood as a paradigm for a successful viral vaccine, and has been exploited as a potential virus vector for the development of recombinant vaccines against other diseases. in this study, a dna-launched yfv-17d construct (pbelobac-flyf) was explored as a new modality to the standard vaccine to combine the commendable feature ... | 2014 | 25516543 |
| emergence of west nile virus lineage 2 in europe: a review on the introduction and spread of a mosquito-borne disease. | west nile virus (wnv) is transmitted by mosquitoes and causes fever and encephalitis in humans, equines, and occasionally wild birds. the virus was first isolated in sub-saharan africa where it is endemic. wnv lineage 1 has been responsible for repeated disease outbreaks in the countries of the mediterranean basin over the past 50 years. this lineage was also introduced into north america in 1999 causing widespread human, equine, and avian mortality. wnv lineage 2, the first wnv lineage to be is ... | 2014 | 25538937 |
| sero-prevalence and cross-reactivity of chikungunya virus specific anti-e2ep3 antibodies in arbovirus-infected patients. | chikungunya virus (chikv) and clinically-related arboviruses cause large epidemics with serious economic and social impact. as clinical symptoms of chikv infections are similar to several flavivirus infections, good detection methods to identify chikv infection are desired for improved treatment and clinical management. the strength of anti-e2ep3 antibody responses was explored in a longitudinal study on 38 chikv-infected patients. we compared their anti-e2ep3 responses with those of patients in ... | 2015 | 25568956 |
| rice stripe virus affects the viability of its vector offspring by changing developmental gene expression in embryos. | plant viruses may affect the viability and development process of their herbivore vectors. small brown planthopper (sbph) is main vector of rice stripe virus (rsv), which causes serious rice stripe disease. here, we reported the effects of rsv on sbph offspring by crossing experiments between viruliferous and non-viruliferous strains. the life parameters of offspring from different cross combinations were compared. the hatchability of f1 progeny from viruliferous parents decreased significantly, ... | 2015 | 25601039 |
| unzippers, resolvers and sensors: a structural and functional biochemistry tale of rna helicases. | the centrality of rna within the biological world is an irrefutable fact that currently attracts increasing attention from the scientific community. the panoply of functional rnas requires the existence of specific biological caretakers, rna helicases, devoted to maintain the proper folding of those molecules, resolving unstable structures. however, evolution has taken advantage of the specific position and characteristics of rna helicases to develop new functions for these proteins, which are a ... | 2015 | 25622248 |
| scanning mutagenesis studies reveal a potential intramolecular interaction within the c-terminal half of dengue virus ns2a involved in viral rna replication and virus assembly and secretion. | the ns2a protein of dengue virus (denv) has eight predicted transmembrane segments (ptmss; ptms1 to ptms8). ns2a has been shown to participate in rna replication, virion assembly, and the host antiviral response. however, the role of the amino acid residues within the ptms regions of ns2a during the virus life cycle is poorly understood. in the study described here, we explored the function of denv ns2a by introducing a series of double or triple alanine substitutions into the c-terminal half (p ... | 2015 | 25653435 |
| plant-made vaccines against west nile virus are potent, safe, and economically feasible. | the threat of west nile virus (wnv) epidemics with increasingly severe neuroinvasive infections demands the development and licensing of effective vaccines. to date, vaccine candidates based on inactivated, live-attenuated, or chimeric virus, and viral dna and wnv protein subunits have been developed. some have been approved for veterinary use or are under clinical investigation, yet no vaccine has been licensed for human use. reaching the milestone of a commercialized human vaccine, however, ma ... | 2015 | 25676782 |
| climate change impacts on west nile virus transmission in a global context. | west nile virus (wnv), the most widely distributed virus of the encephalitic flaviviruses, is a vector-borne pathogen of global importance. the transmission cycle exists in rural and urban areas where the virus infects birds, humans, horses and other mammals. multiple factors impact the transmission and distribution of wnv, related to the dynamics and interactions between pathogen, vector, vertebrate hosts and environment. hence, among other drivers, weather conditions have direct and indirect i ... | 0 | 25688020 |
| a basic cluster in the n terminus of yellow fever virus ns2a contributes to infectious particle production. | the flavivirus ns2a protein is involved in the assembly of infectious particles. to further understand its role in this process, a charged-to-alanine scanning analysis was performed on ns2a encoded by an infectious cdna clone of yellow fever virus (yfv). fifteen mutants containing single, double, or triple charged-to-alanine changes were tested. five of them did not produce infectious particles, whereas efficient rna replication was detectable for two of the five ns2a mutants (r22a-k23a-r24a and ... | 2015 | 25694595 |
| the involvement of microtubules and actin during the infection of japanese encephalitis virus in neuroblastoma cell line, imr32. | the role of the cytoskeleton, actin, and microtubules were examined during the process of japanese encephalitis (jev) infection in a human neuroblastoma cell line, imr32. cytochalasin d and nocodazole were used to depolymerise the cellular actin and microtubules, respectively, in order to study the effect of jev infection in the cell. this study shows that depolymerisation of the actin cytoskeleton at early process of infection inhibits jev infection in the cell; however infection was not inhibi ... | 2015 | 25705678 |
| a case of murray valley encephalitis in a 2-year-old australian stock horse in south-east queensland. | this report summarises the findings from a case of naturally-occurring murray valley encephalitis in a 2-year-old filly presenting with acute onset of depression and weakness. serum samples tested at the onset of clinical signs were negative for hendra and kunjin virus antibodies, but positive for murray valley encephalitis virus (mvev) using igm-capture elisa (1 : 300 dilution). a virus neutralisation assay performed 4 weeks later confirmed a titre of 1 : 160. sera collected in the weeks preced ... | 2015 | 25708787 |
| new insights into flavivirus evolution, taxonomy and biogeographic history, extended by analysis of canonical and alternative coding sequences. | to generate the most diverse phylogenetic dataset for the flaviviruses to date, we determined the genomic sequences and phylogenetic relationships of 14 flaviviruses, of which 10 are primarily associated with culex spp. mosquitoes. we analyze these data, in conjunction with a comprehensive collection of flavivirus genomes, to characterize flavivirus evolutionary and biogeographic history in unprecedented detail and breadth. based on the presumed introduction of yellow fever virus into the americ ... | 2015 | 25719412 |
| physico-chemical requirements and kinetics of membrane fusion of flavivirus-like particles. | flaviviruses deliver their rna genome into the host-cell cytoplasm by fusing their lipid envelope with a cellular membrane. expression of the flavivirus pre-membrane and envelope glycoprotein genes in the absence of other viral genes results in the spontaneous assembly and secretion of virus-like particles (vlps) with membrane fusion activity. here, we examined the physico-chemical requirements for membrane fusion of vlps from west nile and japanese encephalitis viruses. in a bulk fusion assay, ... | 2015 | 25740960 |
| west nile disease epidemiology in north-west africa: bibliographical review. | west nile fever (wnf) or west nile disease (wnd) is a mosquito-borne viral disease that can affect birds, humans and horses. west nile virus (wnv) is a member of the genus flavivirus in the family flaviviridae. wnv is maintained in a mosquito-bird-mosquito transmission cycle, whereas humans and horses are considered dead-end hosts. in human and horses, symptoms range from unapparent infection to mild febrile illness, meningitis, encephalitis or death. wnv has a wide geographical range that inclu ... | 2016 | 25753775 |
| conserved amino acids within the n-terminus of the west nile virus ns4a protein contribute to virus replication, protein stability and membrane proliferation. | the west nile virus strain kunjin virus (wnvkun) ns4a protein is a multifunctional protein involved in many aspects of the virus life-cycle and is a major component of the wnvkun replication complex (rc). previously we identified a conserved region in the c-terminus of ns4a regulating proteolytic processing and rc assembly, and now investigate key conserved residues in the n-terminus of ns4a and their contribution to wnvkun replication. mutation of p13 completely ablated replication, whereas, mu ... | 2015 | 25771497 |
| japanese encephalitis virus nonstructural protein ns5 interacts with mitochondrial trifunctional protein and impairs fatty acid β-oxidation. | infection with japanese encephalitis virus (jev) can induce the expression of pro-inflammatory cytokines and cause acute encephalitis in humans. β-oxidation breaks down fatty acids for atp production in mitochondria, and impaired β-oxidation can induce pro-inflammatory cytokine expression. to address the role of fatty-acid β-oxidation in jev infection, we measured the oxygen consumption rate of mock- and jev-infected cells cultured with or without long chain fatty acid (lcfa) palmitate. cells wi ... | 2015 | 25816318 |
| senataxin suppresses the antiviral transcriptional response and controls viral biogenesis. | the human helicase senataxin (setx) has been linked to the neurodegenerative diseases amyotrophic lateral sclerosis (als4) and ataxia with oculomotor apraxia (aoa2). here we identified a role for setx in controlling the antiviral response. cells that had undergone depletion of setx and setx-deficient cells derived from patients with aoa2 had higher expression of antiviral mediators in response to infection than did wild-type cells. mechanistically, we propose a model whereby setx attenuates the ... | 2015 | 25822250 |
| viral membrane fusion. | membrane fusion is an essential step when enveloped viruses enter cells. lipid bilayer fusion requires catalysis to overcome a high kinetic barrier; viral fusion proteins are the agents that fulfill this catalytic function. despite a variety of molecular architectures, these proteins facilitate fusion by essentially the same generic mechanism. stimulated by a signal associated with arrival at the cell to be infected (e.g., receptor or co-receptor binding, proton binding in an endosome), they und ... | 2015 | 25866377 |
| the global ecology and epidemiology of west nile virus. | since its initial isolation in uganda in 1937 through the present, west nile virus (wnv) has become an important cause of human and animal disease worldwide. wnv, an enveloped virus of the genus flavivirus, is naturally maintained in an enzootic cycle between birds and mosquitoes, with occasional epizootic spillover causing disease in humans and horses. the mosquito vectors for wnv are widely distributed worldwide, and the known geographic range of wnv transmission and disease has continued to i ... | 2015 | 25866777 |
| vector borne infections in italy: results of the integrated surveillance system for west nile disease in 2013. | the epidemiology of west nile disease (wnd) is influenced by multiple ecological factors and, therefore, integrated surveillance systems are needed for early detecting the infection and activating consequent control actions. as different animal species have different importance in the maintenance and in the spread of the infection, a multispecies surveillance approach is required. an integrated and comprehensive surveillance system is in place in italy aiming at early detecting the virus introdu ... | 2015 | 25874224 |
| the i22v and l72s substitutions in west nile virus prm protein promote enhanced prm/e heterodimerisation and nucleocapsid incorporation. | amino acid substitutions i22v and l72s in the prm protein of west nile virus kunjin strain (wnvkun) were previously shown to enhance virus secretion and virulence, but a mechanism by which this occurred was not determined. | 2015 | 25946997 |