TitleAbstractYear(sorted descending)
living on the edge with too many mouths to feed: why dopamine neurons die.although genes, protein aggregates, environmental toxins, and other factors associated with parkinson's disease (pd) are widely distributed in the nervous system and affect many classes of neurons, a consistent feature of pd is the exceptional and selective vulnerability of dopamine (da) neurons of the snc. what is it about these neurons, among all other neurons in the brain, that makes them so susceptible in pd? we hypothesize that a major contributory factor is the unique cellular architecture ...201223008164
pathogenic characterization of a cervical lymph node derived from a patient with kawasaki disease.kawasaki disease (kd) is the most common cause of multisystem vasculitis in childhood. although cervical lymphadenitis is one of the major symptoms in kd, lymph node biopsy is rarely performed, because kd is usually diagnosed by clinical symptoms. a cervical lymph node biopsy was taken from a girl aged 1 year and 8 months who had suspected lymphoma, but she was diagnosed with kd after the biopsy. the cervical lymph node specimen was analyzed with multivirus real-time pcr that can detect >160 vir ...201223071864
rnase l triggers autophagy in response to viral infections.autophagy is a programmed homeostatic response to diverse types of cellular stress that disposes of long-lived proteins, organelles, and invading microbes within double-membraned structures called autophagosomes. the 2',5'-oligoadenylate/rnase l system is a virus-activated host rnase pathway that disposes of or processes viral and cellular single-stranded rnas. here we report that activation of rnase l during viral infections induces autophagy. accordingly, infections with encephalomyocarditis v ...201222875977
translational repression precedes and is required for zap-mediated mrna decay.translational repression and mrna degradation are two major mechanisms for post-transcriptional regulation of gene expression. the detailed relationship between these two processes is not yet well established. zinc-finger antiviral protein (zap) inhibits the replication of certain viruses, including human immunodeficiency virus 1, by binding directly to specific viral mrnas and recruiting cellular mrna degradation machinery to degrade the target mrna. here, we report that zap also inhibits the t ...201223023399
role of bunyamwera orthobunyavirus nss protein in infection of mosquito cells.bunyamwera orthobunyavirus is both the prototype and study model of the bunyaviridae family. the viral nss protein seems to contribute to the different outcomes of infection in mammalian and mosquito cell lines. however, only limited information is available on the growth of bunyamwera virus in cultured mosquito cells other than the aedes albopictus c6/36 line.201223029584
intrahepatic infiltrating nk and cd8 t cells cause liver cell death in different phases of dengue virus infection.elevated liver enzyme level is an outstanding feature in patients with dengue. however, the pathogenic mechanism of liver injury has not been clearly demonstrated. in this study, employing a mouse model we aimed to investigate the immunopathogenic mechanism of dengue liver injury. immunocompetent c57bl/6 mice were infected intravenously with dengue virus strain 16681. infected mice had transient viremia, detectable viral capsid gene and cleaved caspase 3 in the liver. in the mean time, nk cell a ...201223050007
replication of respiratory syncytial virus is inhibited by the host defense molecule viperin.respiratory syncytial virus (rsv) is an important viral pathogen of otitis media, bronchiolitis, and pneumonia. as infection of the upper airways is a precondition for the development of these diseases, understanding rsv pathogenesis and the host response induced by rsv in this niche may enable the development of novel therapeutic strategies against this virus. we have used a microarray approach and showed that expression of the gene that encodes the antiviral protein viperin was significantly u ...201223018837
potential vaccines and post-exposure treatments for filovirus infections.viruses of the family filoviridae represent significant health risks as emerging infectious diseases as well as potentially engineered biothreats. while many research efforts have been published offering possibilities toward the mitigation of filoviral infection, there remain no sanctioned therapeutic or vaccine strategies. current progress in the development of filovirus therapeutics and vaccines is outlined herein with respect to their current level of testing, evaluation, and proximity toward ...201223170176
west nile virus (wnv) replication is independent of autophagy in mammalian cells.autophagy is a homeostatic process responsible for recycling cytosolic proteins and organelles. moreover, this pathway contributes to the cell's intrinsic innate defenses. while many viruses have evolved mechanisms to antagonize the antiviral effects of the autophagy pathway, others subvert autophagy to facilitate replication. here, we have investigated the role of autophagy in west nile virus (wnv) replication. experiments in cell lines derived from a variety of sources, including the kidney, l ...201223029249
everybody wins! poland hosts thrilling competitions of viruses, rnai and football teams.the esf-embo conference on 'antiviral rnai: from molecular biology towards applications' took place in june 2012 in pultusk, poland. it brought together scientists working at the interface of rnai and virus infections in different organisms, covering the complete range from basic mechanisms of rna silencing to rnai-based antiviral therapy.201222986551
macrophage autophagy in immunity to cryptococcus neoformans and candida albicans.autophagy is used by eukaryotes in bulk cellular material recycling and in immunity to intracellular pathogens. we evaluated the role of macrophage autophagy in the response to cryptococcus neoformans and candida albicans, two important opportunistic fungal pathogens. the autophagosome marker lc3 (microtubule-associated protein 1 light chain 3 alpha) was present in most macrophage vacuoles containing c. albicans. in contrast, lc3 was found in only a few vacuoles containing c. neoformans previous ...201222710871
intracytoplasmic trapping of influenza virus by a lipophilic derivative of aglycoristocetin.we report on a new anti-influenza virus agent, sa-19, a lipophilic glycopeptide derivative consisting of aglycoristocetin coupled to a phenylbenzyl-substituted cyclobutenedione. in madin-darby canine kidney cells infected with influenza a/h1n1, a/h3n2, or b virus, sa-19 displayed a 50% antivirally effective concentration of 0.60 μm and a selectivity index (ratio of cytotoxic versus antiviral concentration) of 112. sa-19 was 11-fold more potent than unsubstituted aglycoristocetin and was active i ...201222740402
large ribosomal protein 4 increases efficiency of viral recoding sequences.expression of retroviral replication enzymes (pol) requires a controlled translational recoding event to bypass the stop codon at the end of gag. this recoding event occurs either by direct suppression of termination via the insertion of an amino acid at the stop codon (readthrough) or by alteration of the mrna reading frame (frameshift). here we report the effects of a host protein, large ribosomal protein 4 (rpl4), on the efficiency of recoding. using a dual luciferase reporter assay, we found ...201222718819
fighting mycobacteria through isgylation. 201222940737
comprehensive proteomic analysis of nonintegrin laminin receptor interacting proteins.human nonintegrin laminin receptor is a multifunctional protein acting as an integral component of the ribosome and a cell surface receptor for laminin-1. the laminin receptor is overexpressed in several human cancers and is also the cell surface receptor for several viruses and pathogenic prion proteins, making it a pathologically significant protein. this study focused on the proteomic characterization of laminin receptor interacting proteins from mus musculus. the use of affinity chromatograp ...201222909348
west nile virus growth is independent of autophagy activation.west nile virus (wnv) is an arthropod-borne virus with a worldwide distribution that causes neurologic disease and death. autophagy is a cellular homeostatic mechanism involved in antiviral responses but can be subverted to support viral growth as well. we show that autophagy is induced by wnv infection in cell culture and in primary neuron cultures. following wnv infection, lysosomes co-localize with autophagosomes resulting in lc3b-ii turnover and autolysosomal acidification. however, activati ...201222939285
heterozygous tbk1 mutations impair tlr3 immunity and underlie herpes simplex encephalitis of childhood.childhood herpes simplex virus-1 (hsv-1) encephalitis (hse) may result from single-gene inborn errors of tlr3 immunity. tlr3-dependent induction of ifn-α/β or ifn-λ is crucial for protective immunity against primary hsv-1 infection in the central nervous system (cns). we describe here two unrelated children with hse carrying different heterozygous mutations (d50a and g159a) in tbk1, the gene encoding tank-binding kinase 1, a kinase at the crossroads of multiple ifn-inducing signaling pathways. b ...201222851595
hepatitis c virus translation preferentially depends on active rna replication.hepatitis c virus (hcv) rna initiates its replication on a detergent-resistant membrane structure derived from the endoplasmic reticulum (er) in the hcv replicon cells. by performing a pulse-chase study of bru-labeled hcv rna, we found that the newly-synthesized hcv rna traveled along the anterograde-membrane traffic and moved away from the er. presumably, the rna moved to the site of translation or virion assembly in the later steps of viral life cycle. in this study, we further addressed how h ...201222937067
overexpression of membrane proteins in mammalian cells for structural studies.the number of structures of integral membrane proteins from higher eukaryotes is steadily increasing due to a number of innovative protein engineering and crystallization strategies devised over the last few years. however, it is sobering to reflect that these structures represent only a tiny proportion of the total number of membrane proteins encoded by a mammalian genome. in addition, the structures determined to date are of the most tractable membrane proteins, i.e., those that are expressed ...201222963530
effects of larval rearing temperature on immature development and west nile virus vector competence of culex tarsalis.temperature is known to induce changes in mosquito physiology, development, ecology, and in some species, vector competence for arboviruses. since colonized mosquitoes are reared under laboratory conditions that can be significantly different from their field counterparts, laboratory vector competence experiments may not accurately reflect natural vector-virus interactions.201222967798
preparation of bioactive interferon alpha-loaded polysaccharide nanoparticles using a new approach of temperature-induced water phase/water-phase emulsion.the aim of this study was to develop a temperature-induced polyethylene glycol (peg) water phase/polysaccharide water-phase emulsion approach for preparing interferon alpha-2b (ifnα-2b)-loaded polysaccharide nanoparticles. ifnα-2b was first added to a mixture of an aqueous solution of peg and polysaccharide. the mixture solution was stirred in a magnetic stirrer at a rate of 2000 rpm for 45 seconds at 0°c ± 0.5°c. the solution was then prefrozen at different temperatures. the polysaccharide and ...201222973103
nlrs, inflammasomes, and viral infection.nlr proteins are innate immune sensors that respond to microbial infection. upon pathogen infection, some nlr proteins form large complexes, called inflammasomes, which activate caspase-1 and induce the production of active il-1β and il-18. activation of inflammasomes can also lead to an inflammatory cell death program, named pyroptosis. in this review, we will discuss the role of various nlr proteins in sensing different viral infections, as well as the strategies used by several rna and dna vi ...201222581934
activity based protein profiling to detect serine hydrolase alterations in virus infected cells.activity-based protein profiling (abpp) is a newly emerging technique that uses active site-directed probes to monitor the functional status of enzymes. serine hydrolases are one of the largest families of enzymes in mammals. more than 200 serine hydrolases have been identified, but little is known about their specific roles. serine hydrolases are involved in a variety of physiological functions, including digestion, immune response, blood coagulation, and reproduction. abpp has been used recent ...201223024641
dengue reporter viruses reveal viral dynamics in interferon receptor-deficient mice and sensitivity to interferon effectors in vitro.dengue virus (denv) is a global disease threat for which there are no approved antivirals or vaccines. establishing state-of-the-art screening systems that rely on fluorescent or luminescent reporters may accelerate the development of anti-denv therapeutics. however, relatively few reporter denv platforms exist. here, we show that denv can be genetically engineered to express a green fluorescent protein or firefly luciferase. reporter viruses are infectious in vitro and in vivo and are sensitive ...201222908290
translational regulation of anopheles gambiae mrnas in the midgut during plasmodium falciparum infection.malaria is caused by plasmodium parasites, which are transmitted via the bites of infected anopheline mosquitoes. midgut invasion is a major bottleneck for plasmodium development inside the mosquito vectors. malaria parasites in the midgut are surrounded by a hostile environment rich in digestive enzymes, while a rapidly responding immune system recognizes plasmodium ookinetes and recruits killing factors from the midgut and surrounding tissues, dramatically reducing the population of invading o ...201222857387
retinoblastoma protein induction by hiv viremia or ccr5 in monocytes exposed to hiv-1 mediates protection from activation-induced apoptosis: ex vivo and in vitro study.we have previously described an antiapoptotic steady-state gene expression profile in circulating human monocytes from asymptomatic viremic hiv(+) donors, but the mechanism associated with this apoptosis resistance remains to be fully elucidated. here, we show that rb1 activation is a dominant feature of apoptosis resistance in monocytes exposed to hiv-1 in vivo (as measured ex vivo) and in vitro. monocytes from asymptomatic viremic hiv(+) individuals show a positive correlation between levels o ...201222701041
identification of a novel antiviral inhibitor of the flavivirus guanylyltransferase enzyme.arthropod-borne flavivirus infection causes serious morbidity and mortality worldwide, but there are currently no effective antiflaviviral chemotherapeutics available for human use. therefore, it is critical that new therapeutics against virus-specific targets be developed. to identify new compounds that may be used as broadly active flavivirus therapeutics, we have performed a high-throughput screening of 235,456 commercially available compounds for small-molecule inhibitors of the dengue virus ...201222674988
identification of novel host cell binding partners of oas1b, the protein conferring resistance to flavivirus-induced disease in mice.oas1b was previously identified as the product of the flv(r) allele that confers flavivirus-specific resistance to virus-induced disease in mice by an uncharacterized, rnase l-independent mechanism. to gain insights about the mechanism by which oas1b specifically reduces the efficiency of flavivirus replication, cellular protein interaction partners were identified and their involvement in the oas1b-mediated flavivirus resistance mechanism was analyzed. initial difficulties in getting the two-hy ...201222623793
a single mutation in the glycophorin a binding site of hepatitis a virus enhances virus clearance from the blood and results in a lower fitness variant.hepatitis a virus (hav) has previously been reported to bind to human red blood cells through interaction with glycophorin a. residue k221 of vp1 and the surrounding vp3 residues are involved in such an interaction. this capsid region is specifically recognized by the monoclonal antibody h7c27. a monoclonal antibody-resistant mutant with the mutation g1217d has been isolated. in the present study, the g1217d mutant was characterized physically and biologically in comparison with the parental hm1 ...201222593170
tracking expression and subcellular localization of rna and protein species using high-throughput single cell imaging flow cytometry.we report a high-throughput application of multispectral imaging flow cytometry (mifc) for analyzing the expression and localization of both rna and protein molecules in a heterogeneous population of cells. the approach was developed using polyadenylated nuclear (pan) rna, an abundant, noncoding rna expressed by kaposi's sarcoma-associated herpesvirus (kshv) during the lytic phase of infection. high levels of pan rna are, in part, dependent on its interaction with poly(a)-binding protein c1 (pab ...201222745225
a graph theory method for determination of cryo-em image focuses.accurate determination of micrograph focuses is essential for averaging multiple images to reach high-resolution 3-d reconstructions in electron cryo-microscopy (cryo-em). current methods use iterative fitting of focus-dependent simulated power spectra to the power spectra of experimental images, with the fitting performed independently for different images. here we have developed a novel graph theory based method in which the rotational average focus and individual angular sector focuses of all ...201222842112
matching biochemical and functional efficacies confirm zip as a potent competitive inhibitor of pkmζ in neurons.pkmζ is an autonomously active, atypical protein kinase c (apkc) isoform that is both necessary and sufficient for maintaining long-term potentiation (ltp) and long-term memory. the myristoylated ζ-pseudosubstrate peptide, zip, potently inhibits pkmζ biochemically in vitro, within cultured cells, and within neurons in hippocampal slices, and reverses ltp maintenance and erases long-term memory storage. a recent study (wu-zhang et al., 2012), however, suggested zip was not effective on a pkmζ fus ...201222846225
a novel coding-region rna element modulates infectious dengue virus particle production in both mammalian and mosquito cells and regulates viral replication in aedes aegypti mosquitoes.dengue virus (denv) is an enveloped flavivirus with a positive-sense rna genome transmitted by aedes mosquitoes, causing the most important arthropod-borne viral disease affecting humans. relatively few cis-acting rna regulatory elements have been described in the denv coding-region. here, by introducing silent mutations into a denv-2 infectious clone, we identify the conserved capsid-coding region 1 (ccr1), an rna sequence element that regulates viral replication in mammalian cells and to a gre ...201222840606
interaction of endogenous tau protein with synaptic proteins is regulated by n-methyl-d-aspartate receptor-dependent tau phosphorylation.amyloid-β and tau protein are the two most prominent factors in the pathology of alzheimer disease. recent studies indicate that phosphorylated tau might affect synaptic function. we now show that endogenous tau is found at postsynaptic sites where it interacts with the psd95-nmda receptor complex. nmda receptor activation leads to a selective phosphorylation of specific sites in tau, regulating the interaction of tau with fyn and the psd95-nmda receptor complex. based on our results, we propose ...201222833681
neurogranin targets calmodulin and lowers the threshold for the induction of long-term potentiation.calcium entry and the subsequent activation of camkii trigger synaptic plasticity in many brain regions. the induction of long-term potentiation (ltp) in the ca1 region of the hippocampus requires a relatively high amount of calcium-calmodulin. this requirement is usually explained, based on in vitro and theoretical studies, by the low affinity of camkii for calmodulin. an untested hypothesis, however, is that calmodulin is not randomly distributed within the spine and its targeting within the s ...201222848456
targeted gene transfer of different genes to presynaptic and postsynaptic neocortical neurons connected by a glutamatergic synapse.genetic approaches to analyzing neuronal circuits and learning would benefit from a technology to first deliver a specific gene into presynaptic neurons, and then deliver a different gene into an identified subset of their postsynaptic neurons, connected by a specific synapse type. here, we describe targeted gene transfer across a neocortical glutamatergic synapse, using as the model the projection from rat postrhinal to perirhinal cortex. the first gene transfer, into the presynaptic neurons in ...201222820303
loss of stress response as a consequence of viral infection: implications for disease and therapy.herein, we propose that viral infection can induce a deficient cell stress response and thereby impairs stress tolerance and makes tissues vulnerable to damage. having a valid paradigm to address the pathological impacts of viral infections could lead to effective new therapies for diseases that have previously been unresponsive to intervention. host response to viral infections can also lead to autoimmune diseases like type 1 diabetes. in the case of newcastle disease virus, the effects of vira ...201222797944
identifying host factors that regulate viral infection. 201222807672
regulation of the autophagic bcl-2/beclin 1 interaction.autophagy is an intracellular degradation process responsible for the delivery of cellular material to the lysosomes. one of the key mechanisms for control of autophagy is the modulation of the interaction between the autophagic protein beclin 1 and the members of the anti-apoptotic bcl-2 family (e.g., bcl-2, bcl-xl and mcl-1). this binding is regulated by a variety of proteins and compounds that are able to enhance or inhibit the bcl-2/beclin 1 interaction in order to repress or activate autoph ...201224710477
antiviral activity of a small molecule deubiquitinase inhibitor occurs via induction of the unfolded protein response.ubiquitin (ub) is a vital regulatory component in various cellular processes, including cellular responses to viral infection. as obligate intracellular pathogens, viruses have the capacity to manipulate the ubiquitin (ub) cycle to their advantage by encoding ub-modifying proteins including deubiquitinases (dubs). however, how cellular dubs modulate specific viral infections, such as norovirus, is poorly understood. to examine the role of dubs during norovirus infection, we used wp1130, a small ...201222792064
extended jak activation and delayed stat1 dephosphorylation contribute to the distinct signaling profile of cns neurons exposed to interferon-gamma.although interferon-gamma (ifn-γ) plays a critical role in the noncytolytic elimination of many neurotropic viral infections, the signaling response to this cytokine has not been extensively characterized in primary cns neurons. we previously demonstrated that the ifn-γ response at the signaling and gene expression levels is temporally extended in primary mouse hippocampal neurons, as compared to the transient response of primary mouse embryonic fibroblasts (mef). we hypothesize that the protrac ...201222769061
autophagy and immunity - insights from human herpesviruses.the herpesviruses are a family of double-stranded dna viruses that infect a wide variety of organisms. having co-evolved with their hosts over millennia, herpesviruses have developed a large repertoire of mechanisms to manipulate normal cellular processes for their own benefit. consequently, studies on these viruses have made important contributions to our understanding of fundamental biological processes. here we describe recent research on the human herpesviruses that has contributed to our un ...201222783253
engineered hepatitis b virus surface antigen l protein particles for in vivo active targeting of splenic dendritic cells.dendritic cells (dcs) are key regulators of adaptive t-cell responses. by capturing exogenous antigens and presenting antigen-derived peptides via major histocompatibility complex molecules to naïve t cells, dcs induce antigen-specific immune responses in vivo. in order to induce effective host immune responses, active delivery of exogenous antigens to dcs is considered important for future vaccine development. we recently generated bionanocapsules (bncs) consisting of hepatitis b virus surface ...201222848163
structure of the surface layer of the methanogenic archaean methanosarcina acetivorans.archaea have a self-assembling proteinaceous surface (s-) layer as the primary and outermost boundary of their cell envelopes. the s-layer maintains structural rigidity, protects the organism from adverse environmental elements, and yet provides access to all essential nutrients. we have determined the crystal structure of one of the two "homologous" tandem polypeptide repeats that comprise the methanosarcina acetivorans s-layer protein and propose a high-resolution model for a microbial s-layer ...201222753492
how do viruses interact with stress-associated rna granules? 201222761570
overexpression of serum response factor in astrocytes improves neuronal plasticity in a model of early alcohol exposure.neuronal plasticity deficits underlie many of the cognitive problems seen in fetal alcohol spectrum disorders (fasd). we have developed a ferret model showing that early alcohol exposure leads to a persistent disruption in ocular dominance (od) plasticity. recently, we showed that this deficit could be reversed by overexpression of serum response factor (srf) in the primary visual cortex during the period of monocular deprivation (md). surprisingly, this restoration was observed throughout the e ...201222742904
viral flice inhibitory protein of rhesus monkey rhadinovirus inhibits apoptosis by enhancing autophagosome formation.rhesus monkey rhadinovirus (rrv) is a gamma-2 herpesvirus closely related to human herpesvirus 8 (hhv8). rrv encodes viral flice inhibitory protein (vflip), which has death effector domains. little is known about rrv vflip. this study intended to examine its function in apoptosis. here we found that rrv vflip inhibits apoptosis induced by tumor necrosis factor-α (tnf-α) and cycloheximide. in hela cells with vflip expression, the cleavage of poly [adp-ribose] polymerase 1 (parp-1) and activities ...201222745754
disrupted cortical function underlies behavior dysfunction due to social isolation.stressful events during early childhood can have a profound lifelong influence on emotional and cognitive behaviors. however, the mechanisms by which stress affects neonatal brain circuit formation are poorly understood. here, we show that neonatal social isolation disrupts molecular, cellular, and circuit developmental processes, leading to behavioral dysfunction. neonatal isolation prevented long-term potentiation and experience-dependent synaptic trafficking of α-amino-3-hydroxy-5-methylisoxa ...201222706303
variability in detection and quantification of interferon β-1b-induced neutralizing antibodies.interferon-beta (ifnb) therapy for multiple sclerosis can lead to the induction of neutralizing antibodies (nabs) against ifnb. various methods are used for detection and quantification of nabs.201222703536
θ-defensins: cyclic peptides with endless potential.θ-defensins, the only cyclic peptides of animal origin, have been isolated from the leukocytes of rhesus macaques and baboons. their biogenesis is unusual because each peptide is an 18-residue chimera formed by the head-to-tail splicing of nonapeptides derived from two separate precursors. θ-defensins have multiple arginines and a ladder-like tridisulfide array spanning their two antiparallel β-strands. human θ-defensin genes contain a premature stop codon that prevents effective translation of ...201222700960
multiple approaches to investigate the transport and activity-dependent release of bdnf and their application in neurogenetic disorders.studies utilizing genetic and pharmacological manipulations in rodent models and neuronal cultures have revealed myriad roles of brain-derived neurotrophic factor (bdnf). currently, this knowledge of bdnf function is being translated into improvement strategies for several debilitating neurological disorders in which bdnf abnormalities play a prominent role. common among the bdnf-related disorders are irregular trafficking and release of mature bdnf (mbdnf) and/or its prodomain predecessor, prob ...201222720171
covalent protein modification with isg15 via a conserved cysteine in the hinge region.the ubiquitin-like protein isg15 (interferon-stimulated gene of 15 kda) is strongly induced by type i interferons and displays antiviral activity. as other ubiquitin-like proteins (ubls), isg15 is post-translationally conjugated to substrate proteins by an isopeptide bond between the c-terminal glycine of isg15 and the side chains of lysine residues in the substrates (isgylation). isg15 consists of two ubiquitin-like domains that are separated by a hinge region. in many orthologs, this region co ...201222693631
evidence for a genetic and physical interaction between nonstructural proteins ns1 and ns4b that modulates replication of west nile virus.flavivirus ns1 is a nonstructural glycoprotein that is expressed on the cell surface and secreted into the extracellular space. despite its transit through the secretory pathway, ns1 is an essential gene linked to early viral rna replication. how this occurs has remained a mystery given the disparate localization of ns1 and the viral rna replication complex, as the latter is present on the cytosolic face of the endoplasmic reticulum (er). we recently identified an n-terminal di-amino acid motif ...201222553322
autophagic clearance of sin nombre hantavirus glycoprotein gn promotes virus replication in cells.hantavirus glycoprotein precursor (gpc) is posttranslationally cleaved into two glycoproteins, gn and gc. cells transfected with plasmids expressing either gpc or both gn and gc revealed that gn is posttranslationally degraded. treatment of cells with the autophagy inhibitors 3-methyladenine, ly-294002, or wortmanin rescued gn degradation, suggesting that gn is degraded by the host autophagy machinery. confocal microscopic imaging showed that gn is targeted to autophagosomes for degradation by a ...201222553339
epitope insertion at the n-terminal molecular switch of the rabbit hemorrhagic disease virus t = 3 capsid protein leads to larger t = 4 capsids.viruses need only one or a few structural capsid proteins to build an infectious particle. this is possible through the extensive use of symmetry and the conformational polymorphism of the structural proteins. using virus-like particles (vlp) from rabbit hemorrhagic disease virus (rhdv) as a model, we addressed the basis of calicivirus capsid assembly and their application in vaccine design. the rhdv capsid is based on a t=3 lattice containing 180 identical subunits (vp1). we determined the stru ...201222491457
effects of manipulating apoptosis on sindbis virus infection of aedes aegypti mosquitoes.improved control of vector-borne diseases requires an understanding of the molecular factors that determine vector competence. apoptosis has been shown to play a role in defense against viruses in insects and mammals. although some observations suggest a correlation between apoptosis and resistance to arboviruses in mosquitoes, there is no direct evidence tying apoptosis to arbovirus vector competence. to determine whether apoptosis can influence arbovirus replication in mosquitoes, we manipulat ...201222438551
green tea polyphenol egcg sensing motif on the 67-kda laminin receptor.we previously identified the 67-kda laminin receptor (67lr) as the cell-surface receptor conferring the major green tea polyphenol (-)-epigallocatechin-3-o-gallate (egcg) responsiveness to cancer cells. however, the underlying mechanism for interaction between egcg and 67lr remains unclear. in this study, we investigated the possible role of egcg-67lr interaction responsible for its bioactivities.201222666419
inhibition and avoidance of mrna degradation by rna viruses.the cellular mrna decay machinery plays a major role in regulating the quality and quantity of gene expression in cells. this machinery involves multiple enzymes and pathways that converge to promote the exonucleolytic decay of mrnas. the transcripts made by rna viruses are susceptible to degradation by this machinery and, in fact, can be actively targeted. thus, to maintain gene expression and replication, rna viruses have evolved a number of strategies to avoid and/or inactivate aspects of the ...201222626865
the small hydrophobic protein of the human respiratory syncytial virus forms pentameric ion channels.the small hydrophobic (sh) protein is encoded by the human respiratory syncytial virus. its absence leads to viral attenuation in the context of whole organisms, and it prevents apoptosis in infected cells. herein, we have examined the structure of sh protein in detergent micelles and in lipid bilayers, by solution nmr and attenuated total reflection-fourier transform infrared spectroscopy, respectively. we found that sh protein has a single α-helical transmembrane domain and forms homopentamers ...201222621926
the contribution of rodent models to the pathological assessment of flaviviral infections of the central nervous system.members of the genus flavivirus are responsible for a spectrum of important neurological syndromes in humans and animals. rodent models have been used extensively to model flavivirus neurological disease, to discover host-pathogen interactions that influence disease outcome, and as surrogates to determine the efficacy and safety of vaccines and therapeutics. in this review, we discuss the current understanding of flavivirus neuroinvasive disease and outline the host, viral and experimental facto ...201222592957
homeostatic synaptic scaling is regulated by protein sumoylation.homeostatic scaling allows neurons to alter synaptic transmission to compensate for changes in network activity. here, we show that suppression of network activity with tetrodotoxin, which increases surface expression of ampa receptors (ampars), dramatically reduces levels of the desumoylating (where sumo is small ubiquitin-like modifier) enzyme senp1, leading to a consequent increase in protein sumoylation. overexpression of the catalytic domain of senp1 prevents this scaling effect, and we ide ...201222582390
cross-protective immunity against o'nyong-nyong virus afforded by a novel recombinant chikungunya vaccine.emerging mosquito-borne alphavirus infections caused by chikungunya virus (chikv) or o'nyong-nyong virus (onnv) are responsible for sporadic and sometimes explosive urban outbreaks. currently, there is no licensed vaccine against either virus. we have developed a highly attenuated recombinant chikv candidate vaccine (chikv/ires) that in preclinical studies was demonstrated to be safe, immunogenic and efficacious. in this study we investigated the potential of this vaccine to induce cross-protect ...201222583812
chikungunya virus-induced autophagy delays caspase-dependent cell death.autophagy is an important survival pathway and can participate in the host response to infection. studying chikungunya virus (chikv), the causative agent of a major epidemic in india, southeast asia, and southern europe, we reveal a novel mechanism by which autophagy limits cell death and mortality after infection. we use biochemical studies and single cell multispectral assays to demonstrate that direct infection triggers both apoptosis and autophagy. chikv-induced autophagy is mediated by the ...201222508836
complexity of the microglial activation pathways that drive innate host responses during lethal alphavirus encephalitis in mice.microglia express multiple tlrs (toll-like receptors) and provide important host defence against viruses that invade the cns (central nervous system). although prior studies show these cells become activated during experimental alphavirus encephalitis in mice to generate cytokines and chemokines that influence virus replication, tissue inflammation and neuronal survival, the specific prrs (pattern recognition receptors) and signalling intermediates controlling microglial activation in this setti ...201222471445
temperature-sensitive mutants and revertants in the coronavirus nonstructural protein 5 protease (3clpro) define residues involved in long-distance communication and regulation of protease activity.positive-strand rna virus genomes are translated into polyproteins that are processed by viral proteases to yield functional intermediate and mature proteins. coronaviruses (covs) carry genes that encode an nsp5 protease (also known as 3clpro or mpro) responsible for 11 maturation cleavages. the nsp5 structure contains two chymotrypsin-like domains (d1 and d2) and a unique domain (d3), and forms functional dimers. however, little is known of interactions or communication across the structure of ...201222345451
genetic divergence of rotavirus nonstructural protein 4 results in distinct serogroup-specific viroporin activity and intracellular punctate structure morphologies.nonstructural protein 4 (nsp4) viroporin activity is critical for the replication and assembly of serogroup a rotavirus (rva); however, the dramatic primary sequence divergence of nsp4s across serogroups raises the possibility that viroporin activity is not a common feature among rvs. we tested for nsp4 viroporin activity from divergent strains, including rva (ec and ty-1), rvb (idir), and rvc (cowden). canonical viroporin motifs were identified in rva, rvb, and rvc nsp4s, but the arrangement of ...201222357281
translational control of the activation of transcription factor nf-κb and production of type i interferon by phosphorylation of the translation factor eif4e.type i interferon is an integral component of the antiviral response, and its production is tightly controlled at the levels of transcription and translation. the eukaryotic translation-initiation factor eif4e is a rate-limiting factor whose activity is regulated by phosphorylation of ser209. here we found that mice and fibroblasts in which eif4e cannot be phosphorylated were less susceptible to virus infection. more production of type i interferon, resulting from less translation of nfkbia mrna ...201222544393
a novel small molecule inhibitor of influenza a viruses that targets polymerase function and indirectly induces interferon.influenza viruses continue to pose a major public health threat worldwide and options for antiviral therapy are limited by the emergence of drug-resistant virus strains. the antiviral cytokine, interferon (ifn) is an essential mediator of the innate immune response and influenza viruses, like many viruses, have evolved strategies to evade this response, resulting in increased replication and enhanced pathogenicity. a cell-based assay that monitors ifn production was developed and applied in a hi ...201222577360
avian influenza rapidly induces antiviral genes in duck lung and intestine.ducks are the natural reservoir of influenza a and survive infection by most strains. to characterize the duck immune response to influenza, we sought to identify innate immune genes expressed early in an infection. we used suppressive subtractive hybridization (ssh) to construct 3 libraries enriched in differentially expressed genes from lung rna of a duck infected with highly pathogenic avian influenza virus a/vietnam/1203/04 (h5n1), or lung and intestine rna of a duck infected with low pathog ...201222534314
specific targeting of human interleukin (il)-13 receptor α2-positive cells with lentiviral vectors displaying il-13.the ability to selectively and efficiently target transgene delivery to specific cell types in vitro and in vivo remains one of the formidable challenges in gene therapy. lentiviral vectors have several advantages that make them attractive as gene delivery vehicles and their tropism can be altered through pseudotyping, allowing transgene delivery to specific populations of cells. the human interleukin-13 receptor α2 (il-13rα2) is uniquely overexpressed in many different human tumors, making it a ...201222612657
antibody-directed lentiviral gene transduction for live-cell monitoring and selection of human ips and hes cells.the identification of stem cells within a mixed population of cells is a major hurdle for stem cell biology--in particular, in the identification of induced pluripotent stem (ips) cells during the reprogramming process. based on the selective expression of stem cell surface markers, a method to specifically infect stem cells through antibody-conjugated lentiviral particles has been developed that can deliver both visual markers for live-cell imaging as well as selectable markers to enrich for ip ...201222536330
the n-end rule pathway.the n-end rule pathway is a proteolytic system in which n-terminal residues of short-lived proteins are recognized by recognition components (n-recognins) as essential components of degrons, called n-degrons. known n-recognins in eukaryotes mediate protein ubiquitylation and selective proteolysis by the 26s proteasome. substrates of n-recognins can be generated when normally embedded destabilizing residues are exposed at the n terminus by proteolytic cleavage. n-degrons can also be generated thr ...201222524314
usp18 promotes conventional cd11b+ dendritic cell development.dendritic cells (dcs) represent the key cells linking innate and adaptive immune responses. it is critical to understand the molecular factors regulating dc differentiation. usp18 is an ifn-inducible member of the ubiquitin-specific protease family, which deconjugates ubiquitin-like modifier isg15 from target proteins and competitively inhibits ifn-α/β-induced jak/stat activation. this study demonstrates that the frequency of conventional cd11b(+) dcs in the spleen of usp18(-/-) mice was signifi ...201222491252
histone h3 lysine 9 di-methylation as an epigenetic signature of the interferon response.effective antiviral immunity depends on the ability of infected cells or cells triggered with virus-derived nucleic acids to produce type i interferon (ifn), which activates transcription of numerous antiviral genes. however, disproportionately strong or chronic ifn expression is a common cause of inflammatory and autoimmune diseases. we describe an epigenetic mechanism that determines cell type-specific differences in ifn and ifn-stimulated gene (isg) expression in response to exogenous signals ...201222412156
theranostic potential of oncolytic vaccinia virus.biological cancer therapies, such as oncolytic, or replication-selective viruses have advantages over traditional therapeutics as they can employ multiple different mechanisms to target and destroy cancers (including direct cell lysis, immune activation and vascular collapse). this has led to their rapid recent clinical development. however this also makes their pre-clinical and clinical study complex, as many parameters may affect their therapeutic potential and so defining reason for treatment ...201222509200
autophagy and mechanisms of effective immunity.macroautophagy (autophagy) is a cellular pathway facilitating several critical functions. first, autophagy is a major pathway of degradation. it enables elimination of microbes that have invaded intracellular compartments. in addition, it promotes degradation of damaged cellular content, thereby acting to limit inflammatory signals. second, autophagy is a major trafficking pathway, shuttling content between the cytosol and the lysosomal compartment. given these two key roles, autophagy can have ...201222566941
modulation of gsk-3β activity in venezuelan equine encephalitis virus infection.alphaviruses, including venezuelan equine encephalitis virus (veev), cause disease in both equine and humans that exhibit overt encephalitis in a significant percentage of cases. features of the host immune response and tissue-specific responses may contribute to fatal outcomes as well as the development of encephalitis. it has previously been shown that veev infection of mice induces transcription of pro-inflammatory cytokines genes (e.g., ifn-γ, il-6, il-12, inos and tnf-α) within 6 h. gsk-3β ...201222496857
novel inhibitors of neurotropic alphavirus replication that improve host survival in a mouse model of acute viral encephalitis.arboviral encephalitis is a potentially devastating human disease with no approved therapies that target virus replication. we previously discovered a novel class of thieno[3,2-b]pyrrole-based inhibitors active against neurotropic alphaviruses such as western equine encephalitis virus (weev) in cultured cells. in this report, we describe initial development of these novel antiviral compounds, including bioisosteric replacement of the 4h-thieno[3,2-b]pyrrole core with indole to improve metabolic ...201222428985
the immunology of neurodegeneration.while immune responses in neurodegeneration were regarded as little more than a curiosity a decade ago, they are now increasingly moving toward center stage. factors driving this movement include the recognition that most of the relevant immune molecules are produced within the brain, that microglia are proficient immune cells shaping neuronal circuitry and fate, and that systemic immune responses affect brain function. we will review this complex field from the perspective of neurons, extra-neu ...201222466657
nonstructural protein 2 of porcine reproductive and respiratory syndrome virus inhibits the antiviral function of interferon-stimulated gene 15.type i interferon (alpha/beta interferon [ifn-α/β]) stimulates the expression of interferon-stimulated gene 15 (isg15), which encodes a ubiquitin-like protein, isg15. free isg15 and isg15 conjugates function in diverse cellular pathways, particularly regulation of antiviral innate immune responses. in this study, we demonstrate that isg15 overexpression inhibits porcine reproductive and respiratory syndrome virus (prrsv) replication in cell culture and that the antiviral activity of interferon i ...201222258253
sindbis virus infectivity improves during the course of infection in both mammalian and mosquito cells.alphaviruses are enveloped, single-stranded positive sense rna viruses that are transmitted by an arthropod vector to a wide host range, including avian and mammalian species. arthropods and vertebrates have different cellular environments and this may cause the different cellular pathologies that are observed between the invertebrate vector and vertebrate hosts in both whole organisms and cultured cell lines. in this report, we used sindbis virus and examined mosquito and mammalian cell lines f ...201222484152
atm kinase is activated by sindbis viral vector infection.sindbis virus is a prototypic member of the alphavirus genus, togaviridae family. sindbis replication results in cellular cytotoxicity, a feature that has been exploited by our laboratory for treatment of in vivo tumors. understanding the interactions between sindbis vectors and the host cell can lead to better virus production and increased efficacy of gene therapy vectors. here we present studies investigating a possible cellular response to genotoxic effects of sindbis vector infection. the a ...201222475743
virus recognition by toll-7 activates antiviral autophagy in drosophila.innate immunity is highly conserved and relies on pattern recognition receptors (prrs) such as toll-like receptors (identified through their homology to drosophila toll) for pathogen recognition. although drosophila toll is vital for immune recognition and defense, roles for the other eight drosophila tolls in immunity have remained elusive. here we have shown that toll-7 is a prr both in vitro and in adult flies; loss of toll-7 led to increased vesicular stomatitis virus (vsv) replication and m ...201222464169
dengue virus infection of the aedes aegypti salivary gland and chemosensory apparatus induces genes that modulate infection and blood-feeding behavior.the female aedes aegypti salivary gland plays a pivotal role in bloodmeal acquisition and reproduction, and thereby dengue virus (denv) transmission. it produces numerous immune factors, as well as immune-modulatory, vasodilatory, and anti-coagulant molecules that facilitate blood-feeding. to assess the impact of denv infection on salivary gland physiology and function, we performed a comparative genome-wide microarray analysis of the naïve and denv infection-responsive a. aegypti salivary gland ...201222479185
sindbis virus induces the production of a novel class of endogenous sirnas in aedes aegypti mosquitoes.small rna regulatory pathways are used to control the activity of transposons, regulate gene expression and resist infecting viruses. we examined the biogenesis of mrna-derived endogenous short-interfering rnas (endo-sirnas) in the disease vector mosquito aedes aegypti. under standard conditions, mrna-derived endo-sirnas were produced from the bidirectional transcription of tail-tail overlapping gene pairs. upon infection with the alphavirus, sindbis virus (sinv), another class of mrna-derived e ...201222458920
a proteome map of primary cultured rat schwann cells.schwann cells (scs) are the principal glial cells of the peripheral nervous system with a wide range of biological functions. scs play a key role in peripheral nerve regeneration and are involved in several hereditary peripheral neuropathies. the objective of this study was to gain new insight into the whole protein composition of scs.201222443529
aggrephagy: selective disposal of protein aggregates by macroautophagy.protein aggregation is a continuous process in our cells. some proteins aggregate in a regulated manner required for different vital functional processes in the cells whereas other protein aggregates result from misfolding caused by various stressors. the decision to form an aggregate is largely made by chaperones and chaperone-assisted proteins. proteins that are damaged beyond repair are degraded either by the proteasome or by the lysosome via autophagy. the aggregates can be degraded by the p ...201222518139
dengue virus infection perturbs lipid homeostasis in infected mosquito cells.dengue virus causes ∼50-100 million infections per year and thus is considered one of the most aggressive arthropod-borne human pathogen worldwide. during its replication, dengue virus induces dramatic alterations in the intracellular membranes of infected cells. this phenomenon is observed both in human and vector-derived cells. using high-resolution mass spectrometry of mosquito cells, we show that this membrane remodeling is directly linked to a unique lipid repertoire induced by dengue virus ...201222457619
two-photon scanning microscopy of in vivo sensory responses of cortical neurons genetically encoded with a fluorescent voltage sensor in rat.a fluorescent voltage sensor protein "flare" was created from a kv1.4 potassium channel with yfp situated to report voltage-induced conformational changes in vivo. the rna virus sindbis introduced flare into neurons in the binocular region of visual cortex in rat. injection sites were selected based on intrinsic optical imaging. expression of flare occurred in the cell bodies and dendritic processes. neurons imaged in vivo using two-photon scanning microscopy typically revealed the soma best, di ...201222461770
neuromuscular manifestations of west nile virus infection.the most common neuromuscular manifestation of west nile virus (wnv) infection is a poliomyelitis syndrome with asymmetric paralysis variably involving one (monoparesis) to four limbs (quadriparesis), with or without brainstem involvement and respiratory failure. this syndrome of acute flaccid paralysis may occur without overt fever or meningoencephalitis. although involvement of anterior horn cells in the spinal cord and motor neurons in the brainstem are the major sites of pathology responsibl ...201222461779
transmission dynamics of an insect-specific flavivirus in a naturally infected culex pipiens laboratory colony and effects of co-infection on vector competence for west nile virus.we established a laboratory colony of culex pipiens mosquitoes from eggs collected in colorado and discovered that mosquitoes in the colony are naturally infected with culex flavivirus (cxfv), an insect-specific flavivirus. in this study we examined transmission dynamics of cxfv and effects of persistent cxfv infection on vector competence for west nile virus (wnv). we found that vertical transmission is the primary mechanism for persistence of cxfv in cx. pipiens, with venereal transmission pot ...201222425062
anopheles gambiae antiviral immune response to systemic o'nyong-nyong infection.mosquito-borne viral diseases cause significant burden in much of the developing world. although host-virus interactions have been studied extensively in the vertebrate host, little is known about mosquito responses to viral infection. in contrast to mosquitoes of the aedes and culex genera, anopheles gambiae, the principal vector of human malaria, naturally transmits very few arboviruses, the most important of which is o'nyong-nyong virus (onnv). here we have investigated the a. gambiae immune ...201222428080
synthesis and biological evaluation of a series of thieno-expanded tricyclic purine 2'-deoxy nucleoside analogues.introducing structural diversity into the nucleoside scaffold for use as potential chemotherapeutics has long been considered an important approach to drug design. in that regard, we have designed and synthesized a number of innovative 2'-deoxy expanded nucleosides where a heteroaromatic thiophene spacer ring has been inserted in between the imidazole and pyrimidine ring systems of the natural purine scaffold. the synthetic efforts towards realizing the expanded 2'-deoxy-guanosine and -adenosine ...201222464686
cellular pharmacology of protein kinase mζ (pkmζ) contrasts with its in vitro profile: implications for pkmζ as a mediator of memory.a number of recent studies have used pharmacological inhibitors to establish a role for protein kinase mζ (pkmζ) in synaptic plasticity and memory. these studies use zeta inhibitory peptide (zip) and chelerythrine as inhibitors of pkmζ to block long term potentiation and memory; staurosporine is used as a negative control to show that a nonspecific kinase inhibitor does not block long term potentiation and memory. here, we show that neither zip nor chelerythrine inhibits pkmζ in cultured cells o ...201222378786
lateral diffusion and exocytosis of membrane proteins in cultured neurons assessed using fluorescence recovery and fluorescence-loss photobleaching.membrane proteins such as receptors and ion channels undergo active trafficking in neurons, which are highly polarised and morphologically complex. this directed trafficking is of fundamental importance to deliver, maintain or remove synaptic proteins. super-ecliptic phluorin (sep) is a ph-sensitive derivative of egfp that has been extensively used for live cell imaging of plasma membrane proteins(1-2). at low ph, protonation of sep decreases photon absorption and eliminates fluorescence emissio ...201222395448
virus maturation.we examine virus maturation of selected nonenveloped and enveloped single-stranded rna viruses, retroviruses, bacteriophages, and herpesviruses. processes associated with maturation in the rna viruses range from subtle (nodaviruses and picornaviruses) to dramatic (tetraviruses and togaviruses). the elaborate assembly and maturation pathway of hiv is discussed in contrast to the less sophisticated but highly efficient processes associated with togaviruses. bacteriophage assembly and maturation ar ...201222404678
the role of bcl-2 family proteins in therapy responses of malignant astrocytic gliomas: bcl2l12 and beyond.glioblastoma (gbm) is a highly aggressive and lethal brain cancer with a median survival of less than two years after diagnosis. hallmarks of gbm tumors include soaring proliferative indices, high levels of angiogenesis, diffuse invasion into normal brain parenchyma, resistance toward therapy-induced apoptosis, and pseudopallisading necrosis. despite the recent advances in neurosurgery, radiation therapy, and the development of targeted chemotherapeutic regimes, gbm remains one of the deadliest ...201222431925
crystallography, evolution, and the structure of undergraduate education in mathematics and physics was a good grounding for graduate studies in crystallographic studies of small organic molecules. as a postdoctoral fellow in minnesota, i learned how to program an early electronic computer for crystallographic calculations. i then joined max perutz, excited to use my skills in the determination of the first protein structures. the results were even more fascinating than the development of techniques and provided inspiration for starting my ...201222318719
protein phosphatase 1 subunit ppp1r15a/gadd34 regulates cytokine production in polyinosinic:polycytidylic acid-stimulated dendritic response to inflammatory stimulation, dendritic cells (dcs) have a remarkable pattern of differentiation that exhibits specific mechanisms to control the immune response. here we show that in response to polyriboinosinic:polyribocytidylic acid (pi:c), dcs mount a specific integrated stress response during which the transcription factor atf4 and the growth arrest and dna damage-inducible protein 34 (gadd34/ppp1r15a), a phosphatase 1 (pp1) cofactor, are expressed. in agreement with increased ga ...201222315398
a tlr4 agonist synergizes with dendritic cell-directed lentiviral vectors for inducing antigen-specific immune responses.tlr4 agonists can be used as adjuvants to trigger innate immune responses of antigen-presenting cells (apcs) such as dendritic cells (dcs) to enhance vaccine-specific immunity. adjuvant effects of tlr4 agonists are mediated by downstream signaling controlled by both myd88 and trif adapter proteins. in this study, we investigated the adjuvanting capacity of glucopyranosyl lipid a (gla), a chemically synthesized tlr4 agonist, to boost antigen-specific immunity elicited by dc-directed lentiviral ve ...201222314134
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