the distribution and prevalence of group a arbovirus neutralizing antibodies among human populations in southeast asia and the pacific islands.plaque reduction neutralization tests, using five group a arboviruses (chikungunya, ross river, getah, bebaru and sindbis), were done on sera from human populations in 44 southeast asia and pacific island localities. specificity of the plaque neutralization test was determined by examining convalescent sera from patients with known alphavirus infections. chikungunya-specific neutralizing antibodies were demonstrated in sera of persons living in south vietnam, northern malaysia, indonesia (kalima ...19751155702
the alphavirus 3'-nontranslated region: size heterogeneity and arrangement of repeated sequence elements.the 3'-nontranslated region (ntr) of representative strains of all known alphavirus species was amplified by reverse transcription-polymerase chain reaction. for 23 of them, the 3'-ntr sequence was determined. together with previously published data, this allowed an analysis of the 3'-ntr of the viruses in the genus alphavirus. the length of the 3'-ntrs varied from 77 nt for pixuna virus to 609 nt for bebaru virus. the 19-nt conserved sequence element directly adjacent to the poly(a) tract was f ...19989448694
alphavirus-specific cytotoxic t lymphocytes recognize a cross-reactive epitope from the capsid protein and can eliminate virus from persistently infected macrophages.persistent alphavirus infections in synovial and neural tissues are believed to be associated with chronic arthritis and encephalitis, respectively, and represent likely targets for cd8+ alphabeta cytotoxic t lymphocytes (ctl). here we show that the capsid protein is a dominant target for alphavirus-specific ctl in balb/c mice and that capsid-specific ctl from these mice recognize an h-2kd restricted epitope, qysggrfti. this epitope lies in the highly conserved region of the capsid protein, and ...19989573286
evolutionary relationships and systematics of the alphaviruses.partial e1 envelope glycoprotein gene sequences and complete structural polyprotein sequences were used to compare divergence and construct phylogenetic trees for the genus alphavirus. tree topologies indicated that the mosquito-borne alphaviruses could have arisen in either the old or the new world, with at least two transoceanic introductions to account for their current distribution. the time frame for alphavirus diversification could not be estimated because maximum-likelihood analyses indic ...200111581380
ross river virus transmission, infection, and disease: a cross-disciplinary review.ross river virus (rrv) is a fascinating, important arbovirus that is endemic and enzootic in australia and papua new guinea and was epidemic in the south pacific in 1979 and 1980. infection with rrv may cause disease in humans, typically presenting as peripheral polyarthralgia or arthritis, sometimes with fever and rash. rrv disease notifications in australia average 5,000 per year. the first well-described outbreak occurred in 1928. during world war ii there were more outbreaks, and the name ep ...200111585790
phylogenetic analysis of buggy creek virus: evidence for multiple clades in the western great plains, united states of america.we present the first detailed phylogenetic analysis of buggy creek virus (bcrv), a poorly known alphavirus with transmission cycles involving a cimicid swallow bug (oeciacus vicarius) vector and cliff swallows (petrochelidon pyrrhonota) and house sparrows (passer domesticus) as the principal avian hosts. nucleotide sequences of a 2,075-bp viral envelope glycoprotein-coding region, covering the entire pe2 gene, were determined for 33 bcrv isolates taken from swallow bugs at cliff swallow colonies ...200616936062
the study transplacental chikungunya virus antibody kinetics, thailand.antibodies to chikungunya virus were detected by hemagglutination-inhibition assay in 33.6% of 2,000 infants' cord sera at delivery. follow-up of 24 seropositive infants showed that the half-life of antibody persistence was 35.5 days. chikungunya virus infection is common in thailand, and routine use of diagnostic assays is needed.200617283634
discovery of frameshifting in alphavirus 6k resolves a 20-year enigma.the genus alphavirus includes several potentially lethal human viruses. additionally, species such as sindbis virus and semliki forest virus are important vectors for gene therapy, vaccination and cancer research, and important models for virion assembly and structural analyses. the genome encodes nine known proteins, including the small '6k' protein. 6k appears to be involved in envelope protein processing, membrane permeabilization, virion assembly and virus budding. in protein gels, 6k migrat ...200818822126
replication cycle of chikungunya: a re-emerging arbovirus.arboviruses (or arthropod-borne viruses), represent a threat for the new century. the 2005-2006 year unprecedented epidemics of chikungunya virus (chikv) in the french reunion island in the indian ocean, followed by several outbreaks in other parts of the world such as india, have attracted the attention of clinicians, scientists, and state authorities about the risks linked to this re-emerging mosquito-borne virus. chikv, which belongs to the alphaviruses genus, was not previously regarded as a ...200919732931
Genome scale phylogeny of the Alphavirus genus suggests a marine origin.The genus Alphavirus comprises a diverse group of viruses, including some that cause severe disease. Using full-length sequences of all known alphaviruses, we produced a robust and comprehensive phylogeny of the Alphavirus genus, presenting a more complete evolutionary history of these viruses compared to previous studies based on partial sequences. Our phylogeny suggests the origin of the alphaviruses occurred in the southern oceans and spread equally through the Old and New World. Since lice a ...201122190718
sindbis and middelburg old world alphaviruses associated with neurologic disease in horses, south africa.old world alphaviruses were identified in 52 of 623 horses with febrile or neurologic disease in south africa. five of 8 sindbis virus infections were mild; 2 of 3 fatal cases involved co-infections. of 44 middelburg virus infections, 28 caused neurologic disease; 12 were fatal. middelburg virus likely has zoonotic potential.026583836
broadly neutralizing alphavirus antibodies bind an epitope on e2 and inhibit entry and egress.we screened a panel of mouse and human monoclonal antibodies (mabs) against chikungunya virus and identified several with inhibitory activity against multiple alphaviruses. passive transfer of broadly neutralizing mabs protected mice against infection by chikungunya, mayaro, and o'nyong'nyong alphaviruses. using alanine-scanning mutagenesis, loss-of-function recombinant proteins and viruses, and multiple functional assays, we determined that broadly neutralizing mabs block multiple steps in the ...201526553503
evolutionary genetics and vector adaptation of recombinant viruses of the western equine encephalitis antigenic complex provides new insights into alphavirus diversity and host switching.western equine encephalitis virus (weev), highlands j virus (hjv), and fort morgan virus (fmv) are the sole representatives of the wee antigenic complex of the genus alphavirus, family togaviridae, that are endemic to north america. all three viruses have their ancestry in a recombination event involving eastern equine encephalitis virus (eeev) and a sindbis (sin)-like virus that gave rise to a chimeric alphavirus that subsequently diversified into the present-day weev, hjv, and fmv. here, we pr ...201425463613
in- silico exploration of thirty alphavirus genomes for analysis of the simple sequence repeats.the compilation of simple sequence repeats (ssrs) in viruses and its analysis with reference to incidence, distribution and variation would be instrumental in understanding the functional and evolutionary aspects of repeat sequences. present study encompasses the analysis of ssrs across 30 species of alphaviruses. the full length genome sequences, assessed from ncbi were used for extraction and analysis of repeat sequences using imex software. the repeats of different motif sizes (mono- to penta ...201425606453
a tyrosine-to-histidine switch at position 18 of the ross river virus e2 glycoprotein is a determinant of virus fitness in disparate hosts.arthritogenic alphaviruses are human pathogens maintained in nature through alternating replication in vertebrates and mosquitoes. using chimeric viruses, we previously reported that replacement of the pe2 coding region of the t48 strain of ross river virus (rrv-t48) with that from the attenuated dc5692 strain, which differ by 7 amino acids, resulted in an attenuated disease phenotype in a mouse model of rrv-induced rheumatic disease. here, we demonstrate that introduction of one of these amino ...201323514884
adaptive changes in alphavirus mrna translation allowed colonization of vertebrate hosts.members of the alphavirus genus are arboviruses that alternate replication in mosquitoes and vertebrate hosts. in vertebrate cells, the alphavirus resists the activation of antiviral rna-activated protein kinase (pkr) by the presence of a prominent rna structure (downstream loop [dlp]) located in viral 26s transcripts, which allows an eif2-independent translation initiation of these mrnas. this article shows that dlp structure is essential for replication of sindbis virus (sinv) in vertebrate ce ...201222761388
an rna trapping mechanism in alphavirus mrna promotes ribosome stalling and translation initiation.during translation initiation, eukaryotic initiation factor 2 (eif2) delivers the met-trna to the 40s ribosomal subunit to locate the initiation codon (augi) of mrna during the scanning process. stress-induced eif2 phosphorylation leads to a general blockade of translation initiation and represents a key antiviral pathway in mammals. however, some viral mrnas can initiate translation in the presence of phosphorylated eif2 via stable rna stem-loop structures (dlp; downstream loop) located in thei ...201626984530
development and validation of a quantitative, one-step, multiplex, real-time reverse transcriptase pcr assay for detection of dengue and chikungunya viruses.dengue virus (denv) and chikungunya virus (chikv) are important human pathogens with common transmission vectors and similar clinical presentations. patient care may be impacted by the misdiagnosis of denv and chikv in areas where both viruses cocirculate. in this study, we have developed and validated a one-step multiplex reverse transcriptase pcr (rt-pcr) to simultaneously detect, quantify, and differentiate between four denv serotypes (pan-denv) and chikungunya virus. the assay uses taqman te ...201627098955
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