sphingomyelinase restricts the lateral diffusion of cd4 and inhibits human immunodeficiency virus fusion.previously, we reported that treatment of cells with sphingomyelinase inhibits human immunodeficiency virus type 1 (hiv-1) entry. here, we determined by measuring fluorescence recovery after photobleaching that the lateral diffusion of cd4 decreased 4-fold following sphingomyelinase treatment, while the effective diffusion rate of ccr5 remained unchanged. notably, sphingomyelinase treatment of cells did not influence gp120 binding, hiv-1 attachment, or fluid-phase and receptor-mediated endocytos ...200717344303
hla-a2.1-restricted t cells react to serex-defined tumor antigen cml66l and are suppressed by cd4+cd25+ regulatory t cells.the question of whether t cell responses to serex-defined tumor antigens are under regulation of naturally occurring cd4+cd25+ regulatory t cells (ntreg cells) has not been answered. to address this issue, we first identified an hla-a2.1-restricted t cell antigen epitope of serex-identified tumor antigen cml66l, 66pa. the hla-a2.1/66pa peptide complex in vitro stimulated the in vivo-primed t cells as shown by increased t cell proliferation, higher secretion of the t cell cytokine interferon-gamm ...200717346430
junctophilin-mediated channel crosstalk essential for cerebellar synaptic plasticity.functional crosstalk between cell-surface and intracellular ion channels plays important roles in excitable cells and is structurally supported by junctophilins (jps) in muscle cells. here, we report a novel form of channel crosstalk in cerebellar purkinje cells (pcs). the generation of slow afterhyperpolarization (sahp) following complex spikes in pcs required ryanodine receptor (ryr)-mediated ca(2+)-induced ca(2+) release and the subsequent opening of small-conductance ca(2+)-activated k(+) (s ...200717347645
microarray analysis reveals that type i interferon strongly increases the expression of immune-response related genes in ubp43 (usp18) deficient macrophages.type i interferon (ifn) contributes significantly to innate immune responses to pathogen infections in macrophages. our previous studies demonstrate that ubp43, an isg15-specific isopeptidase, is highly expressed in macrophages and noncatalytically inhibits type i ifn signaling. to understand the effect of type i ifn and ubp43 in macrophage activation, we analyzed the expression of ifn-beta stimulated genes in wild-type and ubp43(-/-) bone marrow derived macrophages (bmms). here, we show that ub ...200717349616
differential inhibition of cellular and sindbis virus translation by brefeldin a.brefeldin a is a macrolide compound that interferes with the secretory pathway and also affects protein synthesis in mammalian cells. as a result, this antibiotic impedes the maturation of viral glycoproteins of enveloped viruses and viral genome replication in several virus species. in the present work, we show that translation of subgenomic mrna from sindbis virus, which in contrast to cellular translation is resistant to brefeldin a after prolonged treatment. the phosphorylation of eif2alpha ...200717360015
evolving the lock to fit the key to create a family of g protein-coupled receptors potently activated by an inert ligand.we evolved muscarinic receptors in yeast to generate a family of g protein-coupled receptors (gpcrs) that are activated solely by a pharmacologically inert drug-like and bioavailable compound (clozapine-n-oxide). subsequent screening in human cell lines facilitated the creation of a family of muscarinic acetylcholine gpcrs suitable for in vitro and in situ studies. we subsequently created lines of telomerase-immortalized human pulmonary artery smooth muscle cells stably expressing all five famil ...200717360345
panmicrobial oligonucleotide array for diagnosis of infectious facilitate rapid, unbiased, differential diagnosis of infectious diseases, we designed greenechippm, a panmicrobial microarray comprising 29,455 sixty-mer oligonucleotide probes for vertebrate viruses, bacteria, fungi, and parasites. methods for nucleic acid preparation, random primed pcr amplification, and labeling were optimized to allow the sensitivity required for application with nucleic acid extracted from clinical materials and cultured isolates. analysis of nasopharyngeal aspirates, b ...200717370518
insertion of egfp into the replicase gene of semliki forest virus results in a novel, genetically stable marker virus.alphavirus-based vector and replicon systems have been extensively used experimentally and are likely to be used in human and animal medicine. whilst marker genes can be inserted easily under the control of a duplicated subgenomic promoter, these constructs are often genetically unstable. here, a novel alphavirus construct is described in which an enhanced green fluorescent protein (egfp) marker gene is inserted into the virus replicase open reading frame between nsp3 and nsp4, flanked by nsp2 p ...200717374766
synergistic roles of antibody and interferon in noncytolytic clearance of sindbis virus from different regions of the central nervous system.sindbis virus (sinv) is an alphavirus that causes infection of neurons and encephalomyelitis in adult immunocompetent mice. recovery can occur without apparent neurological damage. to better define the factors facilitating noncytolytic clearance of sinv in different regions of the central nervous system (cns) and the roles of innate and adaptive immune responses at different times during infection, we have characterized sinv infection and clearance in the brain, brain stem, and spinal cords of s ...200717376910
structure of immature west nile virus.the structure of immature west nile virus particles, propagated in the presence of ammonium chloride to block virus maturation in the low-ph environment of the trans-golgi network, was determined by cryo-electron microscopy (cryo-em). the structure of these particles was similar to that of immature west nile virus particles found as a minor component of mature virus samples (naturally occurring immature particles [noips]). the structures of mature infectious flaviviruses are radically different ...200717376919
ubp43 gene expression is required for normal isg15 expression and fetal development.isg15 covalently modifies murine endometrial proteins in response to early pregnancy. isg15 can also be severed from targeted proteins by a specific protease called ubp43 (usp18). mice lacking ubp43 (null) form increased conjugated isg15 in response to interferon. the isg15 system has not been examined in chorioallantoic placenta (cp) or mesometrial (mm) components of implantation sites beyond 9.5 days post coitum (dpc). it was hypothesized that deletion of ubp43 would cause disregulation of isg ...200717381847
homer 1a uncouples metabotropic glutamate receptor 5 from postsynaptic effectors.metabotropic glutamate receptors (mglurs) and homer proteins play critical roles in neuronal functions including plasticity, nociception, epilepsy, and drug addiction. furthermore, homer proteins regulate mglur1/5 function by acting as adapters and facilitating coupling to effectors such as the inositol triphosphate receptor. however, although homer proteins and their interaction with mglurs have been the subject of intense study, direct measurements of homer-induced changes in postsynaptic mglu ...200717389377
viral vector-induced amygdala npy overexpression reverses increased alcohol intake caused by repeated deprivations in wistar rats.acute administration of neuropeptide y (npy) modulates alcohol intake in genetic and chemical models of high intake, while leaving intake unaffected during 'normal' or baseline conditions. in non-selected, normal rat lines, alcohol consumption can be increased by prolonged exposure to alcohol, and it is unclear what effect a constitutive increase in npy function will have on alcohol intake. the purpose of the present study was to examine the effects on alcohol intake of an inducible, constitutiv ...200717405766
therapy with minocycline aggravates experimental rabies in mice.minocycline is a tetracycline derivative with antiapoptotic and anti-inflammatory properties, and the drug has been shown to have beneficial effects in a variety of models of neurological disorders. the potentially neuroprotective role of minocycline was assessed in experimental in vitro and in vivo models of rabies virus infection. in this study, 5 nm minocycline did not improve the viability of embryonic mouse cortical and hippocampal neurons infected in vitro with the attenuated sad-d29 strai ...200717409147
location and role of free cysteinyl residues in the sindbis virus e1 and e2 glycoproteins.sindbis virus is a single-stranded positive-sense rna virus. it is composed of 240 copies of three structural proteins: e1, e2, and capsid. these proteins form a mature virus particle composed of two nested t=4 icosahedral shells. a complex network of disulfide bonds in the e1 and e2 glycoproteins is developed through a series of structural intermediates as virus maturation occurs (m. mulvey and d. t. brown, j. virol. 68:805-812, 1994; m. carleton et al., j. virol. 71:1558-1566, 1997). to better ...200717409163
genetic determinants of sindbis virus strain tr339 affecting midgut infection in the mosquito aedes aegypti.mosquito midgut epithelial cells (mec) play a major role in determining whether an arbovirus can successfully infect and be transmitted by mosquitoes. the sindbis virus (sinv) strain tr339 efficiently infects aedes aegypti mec but the sinv strain te/5'2j poorly infects mec. sinv determinants for mec infection have been localized to the e2 glycoprotein. the e2 amino acid sequences of tr339 and te/5'2j differ at two sites, e2-55 and e2-70. we have altered the te/5'2j virus genome by site-directed ...200717412985
a conserved region between the heptad repeats of paramyxovirus fusion proteins is critical for proper f protein folding.paramyxoviruses are a diverse family that utilizes a fusion (f) protein to enter cells via fusion of the viral lipid bilayer with a target cell membrane. although certain regions of the f protein are known to play critical roles in membrane fusion, the function of much of the protein remains unclear. sequence alignment of a set of paramyxovirus f proteins and analysis utilizing block maker identified a region of conserved amino acid sequence in a large domain between the heptad repeats of f1, de ...200717417875
synthesis of some novel heterocyclic compounds derived from diflunisal hydrazide as potential anti-infective and anti-inflammatory agents.three novel series of 2',4'-difluoro-4-hydroxybiphenyl-3-carboxylic acid derivatives namely 4-substituted-1,2,4-triazoline-3-thiones (4a-g); 2-substituted-1,3,4-thiadiazoles (5a-g) and 2-substituted-1,3,4-oxadiazoles (6a-g) have been synthesized. twenty-one of the newly synthesized compounds were tested against various bacteria, fungi, yeast species and virus. in addition, we have replaced the carboxylic acid group of diflunisal with heterocycles and the anti-inflammatory activity of heterocycle ...200717418454
transcriptional activation of interferon-stimulated genes but not of cytokine genes after primary infection of rhesus macaques with dengue virus type 1.macaques are the only animal model used to test dengue virus (denv) vaccine candidates. nevertheless, the pathogenesis of denv in macaques is not well understood. in this work, by using affymetrix oligonucleotide microarrays, we studied the broad transcriptional modifications and cytokine expression profile after infecting rhesus macaques with denv serotype 1. five days after infection, these animals produced a potent, innate antiviral immune response by inducing the transcription of signature g ...200717428947
antiviral activity of oxidized polyamines.polyamines, oxidized by serum amine oxidase, yield aminoaldehydes and hydrogen peroxide. acrolein may be formed from the aminoaldehydes by a spontaneous beta-elimination process. these oxidation products "oxidized polyamines" inhibit bacterial growth and exhibit anticancer activity. the antimicrobial activity of oxidized polyamines is not limited to bacteria; and the inactivation of bacterial viruses, plant viruses and animal viruses, was also reported. bacteriophages of the t-odd series are per ...200717429570
retrospective survey of chikungunya disease in réunion island hospital staff.réunion island (indian ocean) has been suffering from its first known chikungunya virus (chikv) epidemic since february 2005. to achieve a better understanding of the disease, a questionnaire was drawn up for hospital staff members and their household. chikv infected about one-third of the studied population, the proportion increasing with age and being higher in women. presence of a garden was associated with chikv infection. the geographical distribution of cases was concordant with insect vec ...200817433130
synaptic scaffolding molecule alpha is a scaffold to mediate n-methyl-d-aspartate receptor-dependent rhoa activation in dendrites.synaptic scaffolding molecule (s-scam) interacts with a wide variety of molecules at excitatory and inhibitory synapses. it comprises three alternative splicing variants, s-scamalpha, -beta, and -gamma. we generated mutant mice lacking specifically s-scamalpha. s-scamalpha-deficient mice breathe and feed normally but die within 24 h after birth. primary cultured hippocampal neurons from mutant mice have abnormally elongated dendritic spines. exogenously expressed s-scamalpha corrects this abnorm ...200717438139
viral translation is coupled to transcription in sindbis virus-infected cells.during the late phase of sindbis virus infection, the viral subgenomic mrna is translated efficiently in bhk cells, whereas host protein synthesis is inhibited. however, transfection of in vitro-generated sindbis virus subgenomic mrna leads to efficient translation in uninfected bhk cells, whereas it is a poor substrate in infected cells. therefore, the structure of the subgenomic mrna itself is not sufficient to confer its translatability in infected cells. in this regard, translation of the su ...200717442713
cellular and humoral immune responses to alphavirus replicon vaccines expressing cytomegalovirus pp65, ie1, and gb proteins.development of vaccines against cytomegalovirus (cmv) is an important public health priority. we used a propagation-defective, single-cycle rna replicon vector system derived from an attenuated strain of an alphavirus, venezuelan equine encephalitis virus, to produce virus-like replicon particles (vrp) expressing various combinations of pp65, ie1, or gb proteins of human cmv. protein expression in vrp-infected cells was highest with single-promoter replicons expressing pp65, ie1, a pp65/ie1 fusi ...200717442845
emerging zoonoses and vector-borne infections affecting humans in europe.the purpose of this study was to assess and describe the current spectrum of emerging zoonoses between 2000 and 2006 in european countries. a computerized search of the medline database from january 1966 to august 2006 for all zoonotic agents in european countries was performed using specific criteria for emergence. fifteen pathogens were identified as emerging in europe from 2000 to august 2006: rickettsiae spp., anaplasma phagocytophilum, borrelia burgdorferi, bartonella spp., francisella tula ...200717445320
[ockelbo disease: stinging fly transmitted polyarthritis in scandinavia]. 200717447272
rapid membrane fusion of individual virus particles with supported lipid bilayers.many enveloped viruses employ low-ph-triggered membrane fusion during cell penetration. solution-based in vitro assays in which viruses fuse with liposomes have provided much of our current biochemical understanding of low-ph-triggered viral membrane fusion. here, we extend this in vitro approach by introducing a fluorescence assay using single particle tracking to observe lipid mixing between individual virus particles (influenza or sindbis) and supported lipid bilayers. our single-particle exp ...200717449662
the opioid receptor antagonist, naloxone, protects spinal motor neurons in a murine model of alphavirus encephalomyelitis.spread of neuroadapted sindbis virus (nsv) to motor neurons (mn) of the spinal cord (sc) causes severe hind limb weakness in c57bl/6 mice and models the paralysis that can accompany alphavirus and flavivirus encephalomyelitis in humans. the fate of spinal mn dictates the severity of nsv-induced paralysis, and recent data suggest that mn damage can occur indirectly via the actions of activated microglial cells. because the opioid receptor antagonist, naloxone (nal), blocks microglial-mediated neu ...200717459376
viral alteration of cellular translational machinery increases defective ribosomal we show that cells expressing genes inserted into semliki forest virus (sfv) vectors generate a large fraction of defective ribosomal products (drips) due to frequent initiation on downstream met residues. in monopolizing the host cell translational machinery, sfv reduces levels of translation eukaryotic initiation factor 4e (eif4e), diminishes phosphorylation of ribosome subunit s6, and phosphorylates translation initiation factor eif2alpha. we show that the last event is required for sfv ...200717459927
pick1 interacts with alpha7 neuronal nicotinic acetylcholine receptors and controls their clustering.central to synaptic function are protein scaffolds associated with neurotransmitter receptors. alpha7 neuronal nicotinic acetylcholine receptors (nachrs) modulate network activity, neuronal survival and cognitive processes in the cns, but protein scaffolds that interact with these receptors are unknown. here we show that the pdz-domain containing protein pick1 binds to alpha7 nachrs and plays a role in their clustering. pick1 interacted with the alpha7 cytoplasmic loop in yeast in a pdz-dependen ...200717467288
seco-pregnane steroids target the subgenomic rna of alphavirus-like rna viruses.plants have evolved multiple mechanisms to selectively suppress pathogens by production of secondary metabolites with antimicrobial activities. therefore, direct selections for antiviral compounds from plants can be used to identify new agents with potent antiviral activity but not toxic to hosts. here, we provide evidence that a class of compounds, seco-pregnane steroid glaucogenin c and its monosugar-glycoside cynatratoside a of strobilanthes cusia and three new pantasugar-glycosides of glauco ...200717470783
novel strategy for treatment of viral central nervous system infection by using a cell-permeating inhibitor of c-jun n-terminal kinase.viral encephalitis is a major cause of morbidity and mortality worldwide, yet there is no proven efficacious therapy for most viral infections of the central nervous system (cns). many of the viruses that cause encephalitis induce apoptosis and activate c-jun n-terminal kinase (jnk) following infection. we have previously shown that reovirus infection of epithelial cell lines activates jnk-dependent apoptosis. we now show that reovirus infection resulted in activation of jnk and caspase-3 in the ...200717475657
influenza virus hemagglutinin and neuraminidase, but not the matrix protein, are required for assembly and budding of plasmid-derived virus-like particles.for influenza virus, we developed an efficient, noncytotoxic, plasmid-based virus-like particle (vlp) system to reflect authentic virus particles. this system was characterized biochemically by analysis of vlp protein composition, morphologically by electron microscopy, and functionally with a vlp infectivity assay. the vlp system was used to address the identity of the minimal set of viral proteins required for budding. combinations of viral proteins were expressed in cells, and the polypeptide ...200717475660
the alphavirus 6k protein activates endogenous ionic conductances when expressed in xenopus oocytes.the alphavirus sindbis 6k protein is involved in several functions. it contributes to the processing and membrane insertion of e1 and pe2 viral envelope glycoproteins and to virus budding. it also permeabilizes escherichia coli and mammalian cells. these viroporin-like properties have been proposed to help virus budding by modifying membrane permeabilities. we expressed sindbis virus 6k crna in xenopus oocytes to further characterize the effect of 6k on membrane conductances and permeabilization ...200717483865
poliovirus induces bax-dependent cell death mediated by c-jun nh2-terminal kinase.poliovirus (pv) is the causal agent of paralytic poliomyelitis, a disease that involves the destruction of motor neurons associated with pv replication. in pv-infected mice, motor neurons die through an apoptotic process. however, mechanisms by which pv induces cell death in neuronal cells remain unclear. here, we demonstrate that pv infection of neuronal imr5 cells induces cytochrome c release from mitochondria and loss of mitochondrial transmembrane potential, both of which are evidence of mit ...200717494073
enucleated l929 cells support invasion, differentiation, and multiplication of trypanosoma cruzi parasites.cell infection with trypanosoma cruzi, the agent of chagas' disease, begins with the uptake of infective trypomastigotes within phagosomes and their release into the cytosol, where they transform into replicating amastigotes; the latter, in turn, differentiate into cytolytically released and infective trypomastigotes. we ask here if the t. cruzi infection program can develop in enucleated host cells. monolayers of l929 cells, enucleated by centrifugation in the presence of cytochalasin b and kep ...200717502387
interaction of tia-1/tiar with west nile and dengue virus products in infected cells interferes with stress granule formation and processing body assembly.the west nile virus minus-strand 3' terminal stem loop (sl) rna was previously shown to bind specifically to cellular stress granule (sg) components, t cell intracellular antigen-1 (tia-1) and the related protein tiar. in vitro tiar binding was 10 times more efficient than tia-1. the 3'(-)sl functions as the promoter for genomic rna synthesis. colocalization of tiar and tia-1 with the viral replication complex components dsrna and ns3 was observed in the perinuclear regions of west nile virus- a ...200717502609
comparative analysis of the alphavirus-based vectors expressing rift valley fever virus glycoproteins.during the last decade, alphaviruses became widely used for expression of heterologous genetic information and development of recombinant vaccines against a variety of human and animal pathogens. in this study, we compared a number of vectors based on the genome of sindbis (sinv) and venezuelan equine encephalitis (veev) viruses for their ability to express the rift valley fever virus (rvfv) envelope glycoprotein gn and induce a protective immune response against rvfv infection. our results sugg ...200717507072
lipid rafts of primary endothelial cells are essential for kaposi's sarcoma-associated herpesvirus/human herpesvirus 8-induced phosphatidylinositol 3-kinase and rhoa-gtpases critical for microtubule dynamics and nuclear delivery of viral dna but dispensable for binding and entry.early during de novo infection of human microvascular dermal endothelial (hmvec-d) cells, kaposi's sarcoma-associated herpesvirus (kshv) (human herpesvirus 8 [hhv-8]) induces the host cell's preexisting fak, src, phosphatidylinositol 3-kinase (pi3-k), rho-gtpases, diaphanous-2 (dia-2), ezrin, protein kinase c-zeta, extracellular signal-regulated kinase 1/2 (erk1/2), and nf-kappab signal pathways that are critical for virus entry, nuclear delivery of viral dna, and initiation of viral gene expres ...200717507466
restricted tissue tropism and acquired resistance to sindbis viral vector expression in the absence of innate and adaptive immunity.our previous studies suggest that replication-defective sindbis vectors might be promising agents for specific tumor targeting and detection. however, the effects of innate and/or adaptive anti-viral immunity, in particular, the ifn-i/stat1 signaling pathway, may impact their therapeutic potential. using a bioluminescent imaging system, we demonstrate that although most normal cells are not permissively transduced by replication-defective sindbis vector, transduction of liver non-sinusoidal endo ...200717508007
virus inactivation by protein denaturants used in affinity chromatography.virus inactivation by a number of protein denaturants commonly used in gel affinity chromatography for protein elution and gel recycling has been investigated. the enveloped viruses sindbis, herpes simplex-1 and vaccinia, and the non-enveloped virus polio-1 were effectively inactivated by 0.5 m sodium hydroxide, 6 m guanidinium thiocyanate, 8 m urea and 70% ethanol. however, ph 2.6, 3 m sodium thiocyanate, 6 m guanidinium chloride and 20% ethanol, while effectively inactivating the enveloped vir ...200717517521
the neuregulin-1 receptor erbb4 controls glutamatergic synapse maturation and plasticity.neuregulin-1 (nrg1) signaling participates in numerous neurodevelopmental processes. through linkage analysis, nrg1 has been associated with schizophrenia, although its pathophysiological role is not understood. the prevailing models of schizophrenia invoke hypofunction of the glutamatergic synapse and defects in early development of hippocampal-cortical circuitry. here, we show that the erbb4 receptor, as a postsynaptic target of nrg1, plays a key role in activity-dependent maturation and plast ...200717521571
functional requirements of the yellow fever virus capsid protein.although it is known that the flavivirus capsid protein is essential for genome packaging and formation of infectious particles, the minimal requirements of the dimeric capsid protein for virus assembly/disassembly have not been characterized. by use of a trans-packaging system that involved packaging a yellow fever virus (yfv) replicon into pseudo-infectious particles by supplying the yfv structural proteins using a sindbis virus helper construct, the functional elements within the yfv capsid p ...200717526891
interferon-like virus-inhibitor induced in human leukocytes by phytohemagglutinin.phytohemagglutinin, an extract of the kidney bean, phaseolus vulgaris, induces in human leukocyte cultures an inhibitor of the cytopathic effects of sindbis virus. the physicochemical and biological properties of this virus-inhibitor are similar to those of interferon induced by newcastle disease virus, except for an instability at ph 2 and 10 and at 56 degrees c.196517533668
posttranslational n-glycosylation of the hepatitis b virus large envelope protein.the addition of n-linked glycans to proteins is normally a cotranslational process that occurs during translocation of the nascent protein to the endoplasmic reticulum. here, we report on an exception to this rule occurring on the hepatitis b virus (hbv) large l envelope protein that is a subject to co-plus posttranslational n-glycosylation.200717537250
de novo initiation of rna synthesis by the arterivirus rna-dependent rna polymerase.all plus-strand rna viruses encode an rna-dependent rna polymerase (rdrp) that functions as the catalytic subunit of the viral replication/transcription complex, directing viral rna synthesis in concert with other viral proteins and, sometimes, host proteins. rna synthesis essentially can be initiated by two different mechanisms, de novo initiation and primer-dependent initiation. most viral rdrps have been identified solely on the basis of comparative sequence analysis, and for many viruses the ...200717537850
next generation: tuberculosis vaccines that elicit protective cd8+ t cells.tuberculosis continues to cause considerable human morbidity and mortality worldwide, particularly in people coinfected with hiv. the emergence of multidrug resistance makes the medical treatment of tuberculosis even more difficult. thus, the development of a tuberculosis vaccine is a global health priority. here we review the data concerning the role of cd8+ t cells in immunity to tuberculosis and consider how cd8+ t cells can be elicited by vaccination. many immunization strategies have the po ...200717542758
novel toxicity of the unedited glur2 ampa receptor subunit dependent on surface trafficking and increased ca2+-permeability.rna editing modifies the glur2 ampa receptor subunit pore loop at the q/r site and limits receptor ca(2+) permeability. editing failure is implicated in neurodegenerative diseases, including amyotrophic lateral sclerosis. we show that channels with unedited glur2 are highly toxic in cultured hippocampal neurons. toxicity exceeds that of other ca(2+)-permeable ampa receptor types and is influenced by agonist binding site mutations, ability to desensitize, and extracellular ca(2+) levels. signific ...200717544687
neuroprotective interventions targeting detrimental host immune responses protect mice from fatal alphavirus encephalitis.systemic treatment with the tetracycline derivative, minocycline, attenuates neurologic deficits in animal models of amyotrophic lateral sclerosis, hypoxic-ischemic brain injury, and multiple sclerosis. inhibition of microglial activation within the cns is 1 mechanism proposed to underlie the beneficial effects of the drug in these systems. given the widening scope of acute viral encephalitis caused by mosquito-borne pathogens, we investigated the therapeutic effects of minocycline in a murine m ...200717549013
environment determines fidelity for an rna virus replicase.the rate of insertion and deletion mutations of the replicase of cucumber mosaic virus (cmv) was determined in planta by using a parasitic satellite rna (satrna) as a reporter. we found that the cmv replicase had different fidelity in different environments, with important implications in viral disease evolution. insertions were very rare events, irrespective of the region of the satrna genome assayed and independent of the hosts tested. on the other hand, deletion events were more frequent but ...200717553888
semliki forest virus nonstructural protein 2 is involved in suppression of the type i interferon response.the type i interferons (ifns) are potent mediators of antiviral immunity, and many viruses have developed means to block their expression or their effects. semliki forest virus (sfv) infection induces rapid and profound silencing of host cell gene expression, a process believed to be important for the inhibition of the ifn response. in sfv-infected cells, a large proportion of the nonstructural protein nsp2 is found in the nucleus, but a role for this localization has not been described. in this ...200717553895
mutations at the palmitoylation site of non-structural protein nsp1 of semliki forest virus attenuate virus replication and cause accumulation of compensatory mutations.the replicase of semliki forest virus (sfv) consists of four non-structural proteins, designated nsp1-4, and is bound to cellular membranes via an amphipathic peptide and palmitoylated cysteine residues of nsp1. it was found that mutations preventing nsp1 palmitoylation also attenuated virus replication. the replacement of these cysteines by alanines, or their deletion, abolished virus viability, possibly due to disruption of interactions between nsp1 and nsp4, which is the catalytic subunit of ...200717554031
use of sentinel chickens to study the transmission dynamics of west nile virus in a sahelian ecosystem.during the 2003 rainy season, a follow-up survey in sentinel chickens was undertaken to assess the seasonal transmission of west nile virus (wnv) in a sahelian ecosystem: the ferlo (senegal). the estimated incidence rate in chickens was 14% (95% ci 7-29), with a very low level of transmission between july and september, and a transmission peak occurring between september and october. comparing these results with the estimate obtained from a previous transversal serological study performed on hor ...200817559695
heterogeneous nuclear ribonuclear protein k interacts with sindbis virus nonstructural proteins and viral subgenomic mrna.alphaviruses are a group of arthropod-borne human and animal pathogens that can cause epidemics of significant public health and economic consequence. alphavirus rna synthesis requires four virally encoded nonstructural proteins and probably a number of cellular proteins. using comparative two-dimensional electrophoresis we were able to identify proteins enriched in cytoplasmic membrane fractions containing viral rna synthetic complexes following infection with sindbis virus. our studies demonst ...200717561226
human muscle satellite cells as targets of chikungunya virus infection.chikungunya (chik) virus is a mosquito-transmitted alphavirus that causes in humans an acute infection characterised by fever, polyarthralgia, head-ache, and myalgia. since 2005, the emergence of chik virus was associated with an unprecedented magnitude outbreak of chik disease in the indian ocean. clinically, this outbreak was characterized by invalidating poly-arthralgia, with myalgia being reported in 97.7% of cases. since the cellular targets of chik virus in humans are unknown, we studied t ...200717565380
the early protective thymus-independent antibody response to foot-and-mouth disease virus is mediated by splenic cd9+ b lymphocytes.infection of mice with cytopathic foot-and-mouth disease virus (fmdv) induces a rapid and specific thymus-independent (ti) neutralizing antibody response that promptly clears the virus. herein, it is shown that fmdv-infected dendritic cells (dcs) directly stimulate splenic innate-like cd9(+) b lymphocytes to rapidly (3 days) produce neutralizing anti-fmdv immunoglobulin m antibodies without t-lymphocyte collaboration. in contrast, neither follicular (cd9(-)) b lymphocytes from the spleen nor b l ...200717567692
coincident regulation of pkcdelta in human platelets by phosphorylation of tyr311 and tyr565 and phospholipase c signalling.pkc (protein kinase c)d plays a complex role in platelets, having effects on both positive and negative signalling functions. it is phosphorylated on tyrosine residues in response to thrombin and collagen, and it has recently been shown that tyr311 is phosphorylated in response to par (protease-activated receptor) 1 and par4 receptor activation. in the present study, we show that tyr311 and tyr565 are phosphorylated in response to thrombin, and have examined the interplay between phosphorylation ...200717570831
viruses as anticancer drugs.oncolytic viruses are being developed as anticancer drugs. they propagate selectively in tumor tissue and destroy it without causing excessive damage to normal non-cancerous tissues. when used as drugs, they must meet stringent criteria for safety and efficacy and be amenable to pharmacological study in human subjects. specificity for neoplastic tissue is the key to safety, and this goal can be achieved through a variety of ingenious virus-engineering strategies. antiviral immunity remains a sig ...200717573126
regulation of dendritic excitability by activity-dependent trafficking of the a-type k+ channel subunit kv4.2 in hippocampal neurons.voltage-gated a-type k+ channel kv4.2 subunits are highly expressed in the dendrites of hippocampal ca1 neurons. however, little is known about the subcellular distribution and trafficking of kv4.2-containing channels. here we provide evidence for activity-dependent trafficking of kv4.2 in hippocampal spines and dendrites. live imaging and electrophysiological recordings showed that kv4.2 internalization is induced rapidly upon glutamate receptor stimulation. kv4.2 internalization was clathrin m ...200717582333
synthesis of some novel thiourea derivatives obtained from 5-[(4-aminophenoxy)methyl]-4-alkyl/aryl-2,4-dihydro-3h-1,2,4-triazole-3-thiones and evaluation as antiviral/anti-hiv and anti-tuberculosis a continuation of our previous efforts on n-alkyl/aryl-n'-[4-(4-alkyl/aryl-2,4-dihydro-3h-1,2,4-triazole-3-thione-5-yl)phenyl]thioureas 1-19 and n-alkyl/aryl-n'-[4-(3-aralkylthio-4-alkyl/aryl-4h-1,2,4-triazole-5-yl)phenyl]thioureas 20-22, a series of novel 5-[(4-aminophenoxy)methyl]-4-alkyl/aryl-2,4-dihydro-3h-1,2,4-triazole-3-thiones 23-26 and several related thioureas, n-alkyl/aryl-n'-{4-[(4-alkyl/aryl-5-thioxo-4,5-dihydro-1h-1,2,4-triazol-3-yl)methoxy]phenyl}thioureas 27-42 were synthesize ...200817583388
comparison of four methods using throat swabs to confirm rubella virus infection.laboratory tests are essential for confirming sporadic cases and outbreaks of rubella. detection of rubella virus is often necessary to confirm rubella cases and to identify specimens to be used to characterize wild-type rubella viruses. the sensitivities of four methods for detecting rubella virus infection using throat swabs, which had been collected in henan and anhui provinces in china, were evaluated. the methods used were reverse transcription (rt)-pcr followed by southern hybridization us ...200717596370
characterization of reemerging chikungunya unprecedented epidemic of chikungunya virus (chikv) infection recently started in countries of the indian ocean area, causing an acute and painful syndrome with strong fever, asthenia, skin rash, polyarthritis, and lethal cases of encephalitis. the basis for chikungunya disease and the tropism of chikv remain unknown. here, we describe the replication characteristics of recent clinical chikv strains. human epithelial and endothelial cells, primary fibroblasts and, to a lesser extent, monocyte ...200717604450
role of the cytoplasmic tail domains of bunyamwera orthobunyavirus glycoproteins gn and gc in virus assembly and morphogenesis.the m rna genome segment of bunyamwera virus (bunv), the prototype of the bunyaviridae family, encodes a precursor polyprotein that is proteolytically cleaved to yield two structural proteins, gn and gc, and a nonstructural protein called nsm. gn and gc are type i integral transmembrane glycoproteins. the gn protein contains a predicted cytoplasmic tail (ct) of 78 residues, and gc has a shorter ct of 25 residues. little is known about the role of the gn and gc ct domains in the virus replication ...200717609275
alpha-beta t cells provide protection against lethal encephalitis in the murine model of veev infection.we evaluated the safety and immunogenicity of a chimeric alphavirus vaccine candidate in mice with selective immunodeficiencies. this vaccine candidate was highly attenuated in mice with deficiencies in the b and t cell compartments, as well as in mice with deficient gamma-interferon responsiveness. however, the level of protection varied among the strains tested. wild type mice were protected against lethal veev challenge. in contrast, alpha/beta (alphabeta) tcr-deficient mice developed lethal ...200717610927
a dna prime, orally delivered protein boost vaccination strategy against viral encephalitis.arboviruses of the families togaviridae and flaviviridae are widely distributed and are important causative agents of viral encephalitis, a severe and often fatal disease. the only internationally available vaccine against these diseases is expensive and laborious to manufacture and difficult to administer. therefore, new vaccines are required against these pathogens. this study investigates the use of a dna-prime, orally delivered protein boost vaccination strategy against viral encephalitis. t ...200717613719
efficient replication, and evolution of sindbis virus genomes with non-canonical 3'a/u-rich elements (nc3are) in neonatal mice.sindbis virus (sin) is a mosquito-transmitted animal rna virus. we previously reported that sin genomes lacking a canonical 19 nt 3'cse undergo novel repair processes in bhk cells to generate a library of stable atypical sin genomes with non-canonical 3'a/u-rich elements (nc3ares) adjacent to the 3' poly(a) tail [1]. to determine the stability and evolutionary pressures on the sin genomes with nc3ares to regain a 3'cse, five representative sin isolates and a wild type sin were tested in newborn ...200717616797
anopheles gambiae heat shock protein cognate 70b impedes o'nyong-nyong virus replication.phylogenetic and functional analysis was conducted on an anopheles gambiae gene, ensangg00000017398. based on phylogenetic analysis, this gene belongs to the same lineage as heat shock protein cognate 70-4 (hsc70-4) in drosophila. accordingly, we propose to name this gene heat shock protein cognate 70b (hsc70b). we previously reported that expression of hsc70b and other genes including elongation factor-1alpha (ef-1alpha) and the agglutinin attachment subunit (agglutinin) were up-regulated in o' ...200717625007
an immunogenic and protective alphavirus replicon particle-based dengue vaccine overcomes maternal antibody interference in weanling mice.a candidate pediatric dengue virus (denv) vaccine based on nonpropagating venezuelan equine encephalitis virus replicon particles (vrp) was tested for immunogenicity and protective efficacy in weanling mice in the presence and absence of potentially interfering maternal antibodies. a gene cassette encoding envelope proteins prm and e from mouse-adapted denv type 2 (denv2) strain ngc was cloned into a vee replicon vector and packaged into vrp, which programmed proper in vitro expression and proce ...200717652394
nuclear import and export of venezuelan equine encephalitis virus nonstructural protein 2.many rna viruses, which replicate predominantly in the cytoplasm, have nuclear components that contribute to their life cycle or pathogenesis. we investigated the intracellular localization of the multifunctional nonstructural protein 2 (nsp2) in mammalian cells infected with venezuelan equine encephalitis virus (vee), an important, naturally emerging zoonotic alphavirus. vee nsp2 localizes to both the cytoplasm and the nucleus of mammalian cells in the context of infection and also when express ...200717652399
a novel dual-targeted lentiviral vector leads to specific transduction of prostate cancer bone metastases in vivo after systemic administration.targeted gene transduction to organs and tissues of interest is the ultimate goal of therapeutic gene delivery. lentiviral vectors (lvs) are powerful tools for stable gene delivery but their integration into undesired cell types poses a serious safety concern for their use in the clinic. here we report the development of a new dual-targeted lv that can preferentially home to and express in prostate cancer bone metastases in vivo after systemic delivery. transductional targeting is mediated by a ...200717653099
screen for isg15-crossreactive deubiquitinases.the family of ubiquitin-like molecules (ubls) comprises several members, each of which has sequence, structural, or functional similarity to ubiquitin. isg15 is a homolog of ubiquitin in vertebrates and is strongly upregulated following induction by type i interferon. isg15 can be covalently attached to proteins, analogous to ubiquitination and with actual support of ubiquitin conjugating factors. specific proteases are able to reverse modification with ubiquitin or ubls by hydrolyzing the coval ...200717653289
the cytoplasmic tails of uukuniemi virus (bunyaviridae) g(n) and g(c) glycoproteins are important for intracellular targeting and the budding of virus-like particles.functional motifs within the cytoplasmic tails of the two glycoproteins g(n) and g(c) of uukuniemi virus (uuk) (bunyaviridae family) were identified with the help of our recently developed virus-like particle (vlp) system for uuk virus (a. k. overby, v. popov, e. p. neve, and r. f. pettersson, j. virol. 80:10428-10435, 2006). we previously reported that information necessary for the packaging of ribonucleoproteins into vlps is located within the g(n) cytoplasmic tail (a. k. overby, r. f. petters ...200717670814
west nile virus-induced neuroinflammation: glial infection and capsid protein-mediated neurovirulence.west nile virus (wnv) infection causes neurological disease at all levels of the neural axis, accompanied by neuroinflammation and neuronal loss, although the underlying mechanisms remain uncertain. given the substantial activation of neuroinflammatory pathways observed in wnv infection, we hypothesized that wnv-mediated neuroinflammation and cell death occurred through wnv infection of both glia and neurons, which was driven in part by wnv capsid protein expression. analysis of autopsied neural ...200717670819
enhanced priming of adaptive immunity by a proapoptotic mutant of mycobacterium tuberculosis.the inhibition of apoptosis of infected host cells is a well-known but poorly understood function of pathogenic mycobacteria. we show that inactivation of the seca2 gene in mycobacterium tuberculosis, which encodes a component of a virulence-associated protein secretion system, enhanced the apoptosis of infected macrophages by diminishing secretion of mycobacterial superoxide dismutase. deletion of seca2 markedly increased priming of antigen-specific cd8(+) t cells in vivo, and vaccination of mi ...200717671656
non-pathogenic sindbis virus causes hemorrhagic fever in the absence of alpha/beta and gamma interferons.the role of interferon-gamma (ifngamma) in antiviral innate immune responses during acute alphavirus infection is not well defined. we examined the contribution of ifngamma to the protection of adult mice from sindbis virus (sb)-induced disease by comparing subcutaneous infection of mice lacking receptors for either ifnalpha/beta (a129), ifngamma (g129) or both (ag129) to normal mice (wt129). while neither g129 nor wt129 mice exhibited clinical signs of disease, infection of a129 or ag129 mice w ...200717681583
identification and characterization of interferon-induced proteins that inhibit alphavirus replication.alpha/beta interferon (ifn-alpha/beta) produces antiviral effects through upregulation of many interferon-stimulated genes (isgs) whose protein products are effectors of the antiviral state. previous data from our laboratory have shown that ifn-alpha/beta can limit sindbis virus (sb) replication through protein kinase r (pkr)-dependent and pkr-independent mechanisms and that one pkr-independent mechanism inhibits translation of the infecting virus genome (k. d. ryman et al., j. virol. 79:1487-14 ...200717686841
the imidazopyrrolopyridine analogue ag110 is a novel, highly selective inhibitor of pestiviruses that targets the viral rna-dependent rna polymerase at a hot spot for inhibition of viral replication.ethyl 2-methylimidazo[1,2-a]pyrrolo[2,3-c]pyridin-8-carboxylate (ag110) was identified as a potent inhibitor of pestivirus replication. the 50% effective concentration values for inhibition of bovine viral diarrhea virus (bvdv)-induced cytopathic effect, viral rna synthesis, and production of infectious virus were 1.2 +/- 0.5 microm, 5 +/- 1 microm, and 2.3 +/- 0.3 microm, respectively. ag110 proved inactive against the hepatitis c virus and a flavivirus. ag110 inhibits bvdv replication at a tim ...200717686854
proteolytic processing of turnip yellow mosaic virus replication proteins and functional impact on infectivity.turnip yellow mosaic virus (tymv), a positive-strand rna virus belonging to the alphavirus-like supergroup, encodes its nonstructural replication proteins as a 206k precursor with domains indicative of methyltransferase (mt), proteinase (pro), ntpase/helicase (hel), and polymerase (pol) activities. subsequent processing of 206k generates a 66k protein encompassing the pol domain and uncharacterized 115k and 85k proteins. here, we demonstrate that tymv proteinase mediates an additional cleavage b ...200717686855
viral defense, carcinogenesis and isg15: novel roles for an old isg.recent studies have established that type i interferon modulates expression of large number of cellular genes. while the proteins encoded by some of these genes have a direct antiviral activity, the functions of the majority of the others have not yet been determined. one of the first identified ifn stimulated gene, encodes ubiquitin like protein isg15 that is also expressed in response to different stress stimuli. although it was shown that isg15 functions as protein modifier, it has been only ...200717689132
arenavirus entry occurs through a cholesterol-dependent, non-caveolar, clathrin-mediated endocytic mechanism.arenaviruses are important causes of viral hemorrhagic fevers in humans. arenavirus infection of cells occurs via a ph-dependent endocytic route, but detailed studies of entry pathways have not been done. we investigated the role of cell membrane cholesterol, caveolae, and clathrin coated pits in infection by lassa virus (lasv), which utilizes alpha-dystroglycan (alpha-dg) as a receptor, and pichindé virus (picv), which does not. depletion of cellular cholesterol by treatment with methyl betacyc ...200717698159
analysis of the selective advantage conferred by a c-e1 fusion protein synthesized by rubella virus di rnas.during serial passaging of rubella virus (rub) in cell culture, the dominant species of defective-interfering rna (di) generated contains an in-frame deletion between the capsid protein (c) gene and e1 glycoprotein gene resulting in production of a c-e1 fusion protein that is necessary for the maintenance of the di [tzeng, w.p., frey, t.k. (2006). c-e1 fusion protein synthesized by rubella virus di rnas maintained during serial passage. virology 356 198-207.]. a bhk cell line stably expressing t ...200717698161
averaging tens to hundreds of icosahedral particle images to resolve protein secondary structure elements using a multi-path simulated annealing optimization algorithm.accurately determining a cryoem particle's alignment parameters is crucial to high resolution single particle 3-d reconstruction. we developed multi-path simulated annealing, a monte-carlo type of optimization algorithm, for globally aligning the center and orientation of a particle simultaneously. a consistency criterion was developed to ensure the alignment parameters are correct and to remove some bad particles from a large pool of images of icosahedral particles. without using any a priori m ...200717698370
the delta2 'ionotropic' glutamate receptor functions as a non-ionotropic receptor to control cerebellar synaptic plasticity.the delta2 glutamate receptor (glurdelta2) belongs to the ionotropic glutamate receptor (iglur) family and plays a crucial role in the induction of cerebellar long-term depression (ltd), a form of synaptic plasticity underlying motor learning. nevertheless, the mechanisms by which glurdelta2 regulates cerebellar ltd have remained elusive. because a mutation occurring in lurcher mice causes continuous glurdelta2 channel activity that can be abolished by 1-naphtylacetylspermine (nasp), a channel b ...200717702810
venezuelan equine encephalitis virus infection of mosquito cells requires acidification as well as mosquito homologs of the endocytic proteins rab5 and rab7.venezuelan equine encephalitis virus (veev) is a new world alphavirus that can cause fatal encephalitis in humans. it remains a naturally emerging disease as well as a highly developed biological weapon. veev is transmitted to humans in nature by mosquito vectors. little is known about veev entry, especially in mosquito cells. here, a novel luciferase-based virus entry assay is used to show that the entry of veev into mosquito cells requires acidification. furthermore, mosquito homologs of key h ...200717707875
the atg5 atg12 conjugate associates with innate antiviral immune responses.autophagy is an essential process for physiological homeostasis, but its role in viral infection is only beginning to be elucidated. we show here that the atg5-atg12 conjugate, a key regulator of the autophagic process, plays an important role in innate antiviral immune responses. atg5-deficient mouse embryonic fibroblasts (mefs) were resistant to vesicular stomatitis virus replication, which was largely due to hyperproduction of type i interferons in response to immunostimulatory rna (isrna), s ...200717709747
production of pseudoinfectious yellow fever virus with a two-component genome.application of genetically modified, deficient-in-replication flaviviruses that are incapable of developing productive, spreading infection is a promising means of designing safe and effective vaccines. here we describe a two-component genome yellow fever virus (yfv) replication system in which each of the genomes encodes complete sets of nonstructural proteins that form the replication complex but expresses either only capsid or prm/e instead of the entire structural polyprotein. upon delivery ...200717715227
identification of novel small-molecule inhibitors of west nile virus infection.west nile virus (wnv) has spread throughout the united states and canada and now annually causes a clinical spectrum of human disease ranging from a self-limiting acute febrile illness to acute flaccid paralysis and lethal encephalitis. no therapy or vaccine is currently approved for use in humans. using high-throughput screening assays that included a luciferase expressing wnv subgenomic replicon and an ns1 capture enzyme-linked immunosorbent assay, we evaluated a chemical library of over 80,00 ...200717715228
characterization of the early events in dengue virus cell entry by biochemical assays and single-virus this study, we investigated the cell entry characteristics of dengue virus (denv) type 2 strain s1 on mosquito, bhk-15, and bs-c-1 cells. the concentration of virus particles measured by biochemical assays was found to be substantially higher than the number of infectious particles determined by infectivity assays, leading to an infectious unit-to-particle ratio of approximately 1:2,600 to 1:72,000, depending on the specific assays used. in order to explain this high ratio, we investigated th ...200717728239
aug_hairpin: prediction of a downstream secondary structure influencing the recognition of a translation start site.the translation start site plays an important role in the control of translation efficiency of eukaryotic mrnas. the recognition of the start aug codon by eukaryotic ribosomes is considered to depend on its nucleotide context. however, the fraction of eukaryotic mrnas with the start codon in a suboptimal context is relatively large. it may be expected that mrna should possess some features providing efficient translation, including the proper recognition of a translation start site. it has been ...200717760957
role of 3-o-sulfated heparan sulfate in virus-induced polykaryocyte way herpes simplex virus type-1 (hsv-1) spreads in vivo is by polykaryocytes formation. here we demonstrate that polykaryocyte production during hsv-1 spread in cultured human corneal fibroblasts (cf) required heparan sulfate (hs) and more specifically 3-o sulfated hs (3-os hs). the polykaryocyte formation heavily depended on the expression of hs on target (cf) cells but not on glycoprotein expressing effector cells. furthermore, we provide the first visual evidence of 3-os hs and hsv-1 gd c ...200717765228
ifn regulatory factor family members differentially regulate the expression of type iii ifn (ifn-lambda) genes.virus replication induces the expression of antiviral type i (ifn-alphabeta) and type iii (ifn-lambda1-3 or il-28a/b and il-29) ifn genes via tlr-dependent and -independent pathways. although type iii ifns differ genetically from type i ifns, their similar biological antiviral functions suggest that their expression is regulated in a similar fashion. structural and functional characterization of the ifn-lambda1 and ifn-lambda3 gene promoters revealed them to be similar to ifn-beta and ifn-alpha ...200717785777
role of autophagy in breast cancer.autophagy is an evolutionarily conserved process of cytoplasm and cellular organelle degradation in lysosomes. autophagy is a survival pathway required for cellular viability during starvation; however, if it proceeds to completion, autophagy can lead to cell death. in neurons, constitutive autophagy limits accumulation of polyubiquitinated proteins and prevents neuronal degeneration. therefore, autophagy has emerged as a homeostatic mechanism regulating the turnover of long-lived or damaged pro ...200717786023
interferon-like virus-inhibitor induced in human leukocytes by phytohemagglutinin.phytohemagglutinin, an extract of the kidney bean, phaseolus vulgaris, induces in human leukocyte cultures an inhibitor of the cytopathic effects of sindbis virus. the physicochemical and biological properties of this virus-inhibitor are similar to those of interferon induced by newcastle disease virus, except for an instability at ph 2 and 10 and at 56 degrees c.196517838106
arthritis and arthralgia three years after sindbis virus infection: clinical follow-up of a cohort of 49 patients.sindbis virus (sinv) emerges as large human outbreaks in northern europe every 7 years. similar to many other alphaviruses, sinv is a mosquito-borne causative agent of a rash-arthritis. previous reports suggest that in many alphavirus infections joint symptoms might persist for years. a prospective cohort of 49 patients was physically examined 3 y after verified acute sinv infection to reveal persistent joint symptoms. we carefully searched for a temporal association between the infection and cu ...200817852949
analysis of the role of autophagy in replication of herpes simplex virus in cell culture.the herpes simplex virus type 1 (hsv-1) neurovirulence gene encoding icp34.5 controls the autophagy pathway. hsv-1 strains lacking icp34.5 are attenuated in growth and pathogenesis in animal models and in primary cultured cells. while this growth defect has been attributed to the inability of an icp34.5-null virus to counteract the induction of translational arrest through the pkr antiviral pathway, the role of autophagy in the regulation of hsv-1 replication is unknown. here we show that hsv-1 ...200717855538
rubella virus-induced superinfection exclusion studied in cells with persisting replicons.for the first time, homologous superinfection exclusion was documented for rubella virus (rub) by using vero cells harbouring persisting rub replicons. infection with wild-type rub was reduced by tenfold, whereas sindbis virus infection was unaffected. replication following infection with packaged replicons and transfection with replicon transcripts was also restricted in these cells, indicating that restriction occurred after penetration and entry. translation of such 'supertransfecting' replic ...200717872530
structural and functional analyses of stem-loop 1 of the sindbis virus genome.alphavirus genome function is controlled by elements at both the 5' and 3' ends. the 5' 220 nt of the sindbis virus genome is predicted to consist of four stem-loop structures the first of which has been demonstrated to be required for efficient minus-strand rna synthesis. to understand the role of the structure of the first stem-loop (sl1) in regulating genome function, we performed enzymatic and chemical probing analyses. there were significant differences between the computer-predicted struct ...200817900652
novel vectors expressing anti-apoptotic protein bcl-2 to study cell death in semliki forest virus-infected cells.semliki forest virus (sfv, alphavirus) induce rapid shut down of host cell protein synthesis and apoptotic death of infected vertebrate cells. data on alphavirus-induced apoptosis are controversial. in this study, the anti-apoptotic bcl-2 gene was placed under the control of duplicated subgenomic promoter or different internal ribosome entry sites (ires) and expressed using a novel bicistronic sfv vector. the use of ires containing vectors resulted in high-level bcl-2 synthesis during the early ...200817904678
chimeric sindbis/eastern equine encephalitis vaccine candidates are highly attenuated and immunogenic in mice.we developed chimeric sindbis (sinv)/eastern equine encephalitis (eeev) viruses and investigated their potential for use as live virus vaccines against eeev. one vaccine candidate contained structural protein genes from a typical north american eeev strain, while the other had structural proteins from a naturally attenuated brazilian isolate. both chimeric viruses replicated efficiently in mammalian and mosquito cell cultures and were highly attenuated in mice. vaccinated mice did not develop de ...200717904699
increased immunogenicity of a dna-launched venezuelan equine encephalitis virus-based replicon dna vaccine.a novel genetic vaccine that is based on a venezuelan equine encephalitis virus (vee) replicon launched from plasmid dna is described. the plasmid encodes a vee replicon under the transcriptional control of the cytomegalovirus immediate-early promoter (vee dna). the vee dna consistently expressed 3- to 15-fold more green fluorescent protein in vitro than did a conventional dna vaccine. furthermore, transfection with the dna-launched vee replicon induced apoptosis and type i interferon production ...200717913817
Displaying items 2801 - 2900 of 5405