Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Transgenic Aedes aegypti were engineered to express a virus-derived, inverted repeat (IR) RNA in the mosquito midgut to trigger RNA interference (RNAi) and generate resistance to dengue virus type 2 (DENV2) in the vector. Here we characterize genotypic and phenotypic stabilities of one line, Carb77, between generations G(9) and G(17). The anti-DENV2 transgene was integrated at a single site within a noncoding region of the mosquito genome. The virus resistance phenotype was strong until G(13) and suppressed replication of different DENV2 genotypes. From G(14)-G(17) the resistance phenotype to DENV2 became weaker and eventually was lost. Although the sequence of the transgene was not mutated, expression of the IR effector RNA was not detected and the Carb77 G(17) mosquitoes lost their ability to silence the DENV2 genome.
Insect Mol Biol 2009 Oct
PMID:Stability and loss of a virus resistance phenotype over time in transgenic mosquitoes harbouring an antiviral effector gene. 1975 43

An accurate molecular diagnosis for viral pathogens is highly dependent on pre-analytical procedures. The efficiencies of two viral RNA extraction methods (liquid phase partition and silica-based adsorption chromatography) and the effects of handling and storage on the stability of RNA isolated from dengue virus (DENV) were studied. Viral RNA extracted from spiked sera or clinical samples characterized with DENV infection were quantified by TaqMan real-time PCR. The presence of high serum proteins severely affected the recovery of DENV RNA by the liquid phase partition, but not the silica-based method. The recovery with Trizol liquid phase partition method was significantly improved by a concomitant addition of a co-precipitant and the reduction of sera proteins, resulting in recoveries similar to that of the silica-based methods. Repeated freeze-thaw cycles did not affect the recovery of viral RNA. While intact DENV was found to be stable in serum for up to 2 hour at 25 degrees C, recovery of viral RNA from sera stored in the lysis/binding buffer was stable for up to 5 days. These data indicate that the choice of viral RNA extraction methods, the conditions for handling, and storing of clinical sera critically affect the quantification of viral nucleic acid from clinical samples. This will impact the accuracy and reproducibility of DENV diagnosis by PCR-based assays.
J Mol Diagn 2009 Nov
PMID:Evaluation of pre-analytical variables in the quantification of dengue virus by real-time polymerase chain reaction. 1981 93

Hemorrhagic syndrome is a hallmark of severe dengue diseases. We previously suggested a mechanism of molecular mimicry in which antibodies against dengue virus (DV) nonstructural protein 1 (NS1) cross-react with platelets. In the present study, we demonstrate that protein disulfide isomerase (PDI) on the platelet surface is recognized by anti-DV NS1 antibodies. Anti-DV NS1 obtained from hyperimmunized mouse sera inhibited PDI activity and platelet aggregation, and both inhibitory effects were prevented when anti-DV NS1 antibodies were preabsorbed with PDI. Anti-PDI antibodies bound to a peptide consisting of amino acid residues 311-330 (P311-330) of NS1. This peptide was a predicted epitope analyzed by homologous sequence alignments between DV NS1 and PDI. The platelet binding activities of anti-PDI and anti-DV NS1 antibodies were both reduced by P311-330 preabsorption. Similar to the findings using anti-DV NS1, antibodies against P311-330 bound to PDI and platelets, followed by inhibition of PDI activity and platelet aggregation. Furthermore, the cross-reactivity of dengue hemorrhagic fever patient sera with platelets was reduced when patient sera were preabsorbed with PDI or P311-330. Dengue hemorrhagic fever patient sera also inhibited platelet aggregation, while PDI or P311-330 reduced this inhibitory effect. In conclusion, anti-DV NS1 antibodies cross-react with PDI on platelet surface causing inhibition of platelet aggregation, which may provide implications in dengue disease pathogenesis.
Mol Immunol 2009 Dec
PMID:Anti-dengue virus nonstructural protein 1 antibodies recognize protein disulfide isomerase on platelets and inhibit platelet aggregation. 1982 67

Dengue is an emerging tropical disease infecting tens of millions of people annually. A febrile illness with potentially severe hemorrhagic manifestations, dengue is caused by mosquito-borne viruses (DENV-1 to -4) that are maintained in endemic transmission in large urban centers of the tropics with periodic epidemic cycles at 3- to 5-year intervals. Puerto Rico (PR), a major population center in the Caribbean, has experienced increasingly severe epidemics since multiple dengue serotypes were introduced beginning in the late 1970s. We document the phylodynamics of DENV-4 between 1981 and 1998, a period of dramatic ecological expansion during which evolutionary change also occurs. The timescale of viral evolution is sufficiently short that viral transmission dynamics can be elucidated from genetic diversity data. Specifically, by combining virus sequence data with confirmed case counts in PR over these two decades, we show that the pattern of cyclic epidemics is strongly correlated with coalescent estimates of effective population size that have been estimated from sampled virus sequences using Bayesian Markov Chain Monte Carlo methods. Thus, we show that the observed epidemiologic dynamics are correlated with similar fluctuations in diversity, including severe interepidemic reductions in genetic diversity compatible with population bottlenecks that may greatly impact DENV evolutionary dynamics. Mean effective population sizes based on genetic data appear to increase prior to isolation counts, suggesting a potential bias in the latter and justifying more active surveillance of DENV activity. Our analysis explicitly integrates epidemiologic and sequence data in a joint model that could be used to further explore transmission models of infectious disease.
Mol Biol Evol 2010 Apr
PMID:Epidemic dynamics revealed in dengue evolution. 1996 86

If we understand the structural rules governing antibody (Ab)-antigen (Ag) interactions in a given virus, then we have the molecular basis to attempt to design and synthesize new epitopes to be used as vaccines or optimize the antibodies themselves for passive immunization. Comparing the binding of several different antibodies to related Ags should also further our understanding of general principles of recognition. To obtain and compare the three-dimensional structure of a large number of different complexes, however, we need a faster method than traditional experimental techniques. While biocomputational docking is fast, its results might not be accurate. Combining experimental validation with computational prediction may be a solution. As a proof of concept, here we isolated a monoclonal Ab from the blood of a human donor recovered from dengue virus infection, characterized its immunological properties, and identified its epitope on domain III of dengue virus E protein through simple and rapid NMR chemical shift mapping experiments. We then obtained the three-dimensional structure of the Ab/Ag complex by computational docking, using the NMR data to drive and validate the results. In an attempt to represent the multiple conformations available to flexible Ab loops, we docked several different starting models and present the result as an ensemble of models equally agreeing with the experimental data. The Ab was shown to bind a region accessible only in part on the viral surface, explaining why it cannot effectively neutralize the virus.
J Mol Biol 2010 Mar 12
PMID:Rapid structural characterization of human antibody-antigen complexes through experimentally validated computational docking. 2005 55

Genetically modified mosquitoes that are unable to transmit pathogens offer opportunities for controlling vector-borne diseases such as malaria and dengue. Site-specific gene recombination technologies are advantageous in the development of these insects because antipathogen effector genes can be inserted at integration sites in the genome that cause the least alteration in mosquito fitness. Here we describe Anopheles stephensi transgenic lines containing phi C31 attP'docking' sites linked to a fluorescent marker gene. Chromosomal insertion sites were determined and life-table parameters were assessed for transgenic mosquitoes of each line. No significant differences in fitness between the transgenic and nontransgenic mosquitoes were detected in this study. These transgenic lines are suitable for future site-specific integrations of antiparasite transgenes into the attP sites.
Insect Mol Biol 2010 Apr
PMID:Comparative fitness assessment of Anopheles stephensi transgenic lines receptive to site-specific integration. 2011 72

Recent data suggest that dengue immunity could be elicited via either humoral or cell-mediated routes. Directing the immune response to serotype-specific epitopes from domain (D)III of the dengue virus envelope protein (Env) may induce effective levels of neutralizing antibodies. Removing serotype-crossreactive epitopes from DIII, as well as DII, may reduce the potential for the vaccine to induce non-neutralizing antibodies associated with antibody-dependent enhancement (ADE) of infection. The use of consensus Env DIII sequences for each serotype, and perhaps even a single consensus sequence for all four serotypes of dengue virus, may direct the immune response to invariant neutralizing sequences, which might improve vaccine safety and long-term efficacy. Vaccines incorporating capsid and/or non-structural (NS) proteins may be capable of inducing tetravalent cell-mediated immunity without ADE. However, the potential of cell-mediated immunity to contribute to pathology is not well understood, and modifications of NS proteins, such as truncated NS1, may be necessary for optimal vaccine safety. This review discusses recent progress in the development of dengue vaccines.
Curr Opin Mol Ther 2010 Feb
PMID:Recent progress in dengue vaccine research and development. 2014 Aug 14

Serine protease activity of the NS3 protein of Dengue virus is an important target of antiviral agents that interfere with the viral polyprotein precursor processing catalyzed by the NS3 protease (NS3pro), which is important for the viral replication and maturation. Recent studies showed that substrate-based peptidomimetics carrying an electrophilic warhead inhibit the NS2B-NS3pro cofactor-protease complex with inhibition constants in the low micromolar concentration range when basic amino acid residues occupy P(1) and P(2) positions of the inhibitor, and an aldehyde warhead is attached to the P(1). We have used computer-assisted combinatorial techniques to design, focus using the NS2B-NS3pro receptor 3D structure, and in silico screen a virtual library of more than 9,200 peptidomimetic analogs targeted around the template inhibitor Bz-Nle-Lys-Arg-Arg-H (Bz-benzoyl) that are composed mainly of unusual amino acid residues in all positions P(1)-P(4). The most promising virtual hits were analyzed in terms of computed enzyme-inhibitor interactions and Adsorption, Distribution, Metabolism and Excretion (ADME) related physico-chemical properties. Our study can direct the interest of medicinal chemists working on a next generation of antiviral chemotherapeutics against the Dengue Fever towards the explored subset of the chemical space that is predicted to contain peptide aldehydes with NS3pro inhibition potencies in nanomolar range which display ADME-related properties comparable to the training set inhibitors.
J Comput Aided Mol Des 2010 Mar
PMID:Design, structure-based focusing and in silico screening of combinatorial library of peptidomimetic inhibitors of Dengue virus NS2B-NS3 protease. 2030 83

Dengue virus (DENV 1-4) represents a major emerging arthropod-borne pathogen. All four DENV serotypes are prevalent in the (sub) tropical regions of the world and infect 50-100 million individuals annually. Whereas the majority of DENV infections proceed asymptomatically or result in self-limited dengue fever, an increasing number of patients present more severe manifestations, such as dengue hemorrhagic fever and dengue shock syndrome. In this review we will give an overview of the infectious life cycle of DENV and will discuss the viral and host factors that are important in controlling DENV infection.
Cell Mol Life Sci 2010 Aug
PMID:Dengue virus life cycle: viral and host factors modulating infectivity. 2037 65

Flaviviruses are a highly diverse group of RNA viruses classified within the genus Flavivirus, family Flaviviridae. Most flaviviruses are arthropod-borne, requiring a mosquito or tick vector. Several flaviviruses are highly pathogenic to humans; however, their high genetic diversity and immunological relatedness makes them extremely challenging to diagnose. In this study, we developed and evaluated a broad-range Flavivirus assay designed to detect both tick- and mosquito-borne flaviviruses by using RT-PCR/electrospray ionization mass spectrometry (RT-PCR/ESI-MS) on the Ibis T5000 platform. The assay was evaluated with a panel of 13 different flaviviruses. All samples were correctly identified to the species level. To determine the limit of detection for the mosquito-borne primer sets, serial dilutions of RNA from West Nile virus (WNV) were assayed and could be detected down to an equivalent viral titer of 0.2 plaque-forming units/mL. Analysis of flaviviruses in their natural biological background included testing Aedes aegypti mosquitoes that were laboratory-infected with dengue-1 virus. The assay accurately identified the virus within infected mosquitoes, and we determined the average viral genome per mosquito to be 2.0 x 10(6). Using human blood, serum, and urine spiked with WNV and mouse blood and brain tissues from Karshi virus-infected mice, we showed that these clinical matrices did not inhibit the detection of these viruses. Finally, we used the assay to test field-collected Ixodes scapularis ticks collected from sites in New York and Connecticut. We found 16/322 (5% infection rate) ticks positive for deer tick virus, a subtype of Powassan virus. In summary, we developed a single high-throughput Flavivirus assay that could detect multiple tick- and mosquito-borne flaviviruses and thus provides a new analytical tool for their medical diagnosis and epidemiological surveillance.
Mol Cell Probes 2010 Aug
PMID:Rapid identification of vector-borne flaviviruses by mass spectrometry. 2041 52


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