| immunogenicity and specificity of norovirus consensus gii.4 virus-like particles in monovalent and bivalent vaccine formulations. | noroviruses, a major cause of acute gastroenteritis worldwide, present antigenic diversity that must be considered for the development of an effective vaccine. in this study, we explored approaches to increase the broad reactivity of virus-like particle (vlp) norovirus vaccine candidates. the immunogenicity of a gii.4 "consensus" vlp that was engineered from sequences of three genetically distinct naturally occurring gii.4 strains was examined for its ability to induce cross-reactive immune resp ... | 2012 | 22469864 |
| dna microarray for detection of gastrointestinal viruses. | gastroenteritis is a clinical illness of humans and other animals that is characterized by vomiting and diarrhea and caused by a variety of pathogens, including viruses. an increasing number of viral species have been associated with gastroenteritis or have been found in stool samples as new molecular tools have been developed. in this work, a dna microarray capable in theory of parallel detection of more than 100 viral species was developed and tested. initial validation was done with 10 differ ... | 2014 | 25355758 |
| 5' and 3' untranslated regions strongly enhance performance of geminiviral replicons in nicotiana benthamiana leaves. | we previously reported a recombinant protein production system based on a geminivirus replicon that yields high levels of vaccine antigens and monoclonal antibodies in plants. the bean yellow dwarf virus (beydv) replicon generates massive amounts of dna copies, which engage the plant transcription machinery. however, we noticed a disparity between transcript level and protein production, suggesting that mrnas could be more efficiently utilized. in this study, we systematically evaluated genetic ... | 2016 | 26941764 |
| antimicrobial activity of bismuth subsalicylate on clostridium difficile, escherichia coli o157:h7, norovirus, and other common enteric pathogens. | previous studies have shown bismuth subsalicylate (bss) has antimicrobial properties, but few studies have addressed the mechanism of action. furthermore, following bss ingestion other bismuth salts form throughout the gastrointestinal tract including bismuth oxychloride (biocl) that also act upon enteric pathogens. to further understand the antimicrobial activity of bismuth in infectious diarrhea, the antimicrobial effect of bss and biocl on clostridium difficile, salmonella, shigella, shiga to ... | 2015 | 25901890 |
| propidium monoazide reverse transcriptase pcr and rt-qpcr for detecting infectious enterovirus and norovirus. | presently there is no established cell line or small animal model that allows for the detection of infectious human norovirus. current methods based on rt-pcr and rt-qpcr detect both infectious and non-infectious virus and thus the conclusions that may be drawn regarding the public health significance of positive findings are limited. in this study, pma rt-pcr and rt-qpcr assays were evaluated for selective detection of infectious poliovirus, murine norovirus (mnv-1), and norwalk virus. viruses ... | 2015 | 25796356 |
| broad-spectrum antivirals against 3c or 3c-like proteases of picornaviruses, noroviruses, and coronaviruses. | phylogenetic analysis has demonstrated that some positive-sense rna viruses can be classified into the picornavirus-like supercluster, which includes picornaviruses, caliciviruses, and coronaviruses. these viruses possess 3c or 3c-like proteases (3cpro or 3clpro, respectively), which contain a typical chymotrypsin-like fold and a catalytic triad (or dyad) with a cys residue as a nucleophile. the conserved key sites of 3cpro or 3clpro may serve as attractive targets for the design of broad-spectr ... | 2012 | 22915796 |
| helium beam shadowing for high spatial resolution patterning of antibodies on microstructured diagnostic surfaces. | we have developed a technique for the high-resolution, self-aligning, and high-throughput patterning of antibody binding functionality on surfaces by selectively changing the reactivity of protein-coated surfaces in specific regions of a workpiece with a beam of energetic helium particles. the exposed areas are passivated with bovine serum albumin (bsa) and no longer bind the antigen. we demonstrate that patterns can be formed (1) by using a stencil mask with etched openings that forms a pattern ... | 2013 | 24706125 |
| persistence of norwalk virus, male-specific coliphage, and escherichia coli on stainless steel coupons and in phosphate-buffered saline. | human noroviruses (novs) are a leading cause of acute gastroenteritis and are frequently transmitted by contaminated food, water, hands, and environmental surfaces. little is known about their environmental stability and/or which alternative microorganisms can serve as effective surrogates. to examine whether escherichia coli and male-specific coliphage ms2 can be appropriate surrogates for novs, approximately 6.8 log genomic equivalent copies of norwalk virus (nv), and 6.0 to 6.5 log pfu or cfu ... | 2012 | 23212011 |
| secretory pathway antagonism by calicivirus homologues of norwalk virus nonstructural protein p22 is restricted to noroviruses. | our previous report that the norwalk virus nonstructural protein p22 is an antagonist of the cellular secretory pathway suggests a new aspect of norovirus/host interaction. to explore conservation of function of this highly divergent calicivirus protein, we examined the effects of p22 homologues from four human and two murine noroviruses, and feline calicivirus on the secretory pathway. | 2012 | 22943503 |
| vomiting as a symptom and transmission risk in norovirus illness: evidence from human challenge studies. | in the us, noroviruses are estimated to cause 21 million cases annually with economic losses reaching $2 billion. outbreak investigations frequently implicate vomiting as a major transmission risk. however, little is known about the characteristics of vomiting as a symptom or the amount of virus present in emesis. | 2016 | 27116105 |
| the viral polymerase inhibitor 2'-c-methylcytidine inhibits norwalk virus replication and protects against norovirus-induced diarrhea and mortality in a mouse model. | human noroviruses are a major cause of food-borne illness, accountable for 50% of all-etiologies outbreaks of acute gastroenteritis (in both developing and developed countries). there is no vaccine or antiviral drug for the prophylaxis or treatment of norovirus-induced gastroenteritis. we recently reported the inhibitory effect of 2'-c-methylcytidine (2cmc), a hepatitis c virus polymerase inhibitor, on the in vitro replication of murine norovirus (mnv). here we evaluated the inhibitory effect of ... | 2013 | 23986582 |
| design, synthesis, and bioevaluation of viral 3c and 3c-like protease inhibitors. | a class of tripeptidyl transition state inhibitors containing a p1 glutamine surrogate, a p2 leucine, and a p3 arylalanines, was found to potently inhibit norwalk virus replication in enzyme and cell based assays. an array of warheads, including aldehyde, α-ketoamide, bisulfite adduct, and α-hydroxyphosphonate transition state mimic, was also investigated. tripeptidyls 2 and 6 possess antiviral activities against noroviruses, human rhinovirus, severe acute respiratory syndrome coronavirus, and c ... | 2013 | 24125888 |
| small molecule deubiquitinase inhibitors promote macrophage anti-infective capacity. | the global spread of anti-microbial resistance requires urgent attention, and diverse alternative strategies have been suggested to address this public health concern. host-directed immunomodulatory therapies represent one approach that could reduce selection for resistant bacterial strains. recently, the small molecule deubiquitinase inhibitor wp1130 was reported as a potential anti-infective drug against important human food-borne pathogens, notably listeria monocytogenes and noroviruses. util ... | 2014 | 25093325 |
| tulane virus as a potential surrogate to mimic norovirus behavior in oysters. | oyster contamination by noroviruses is an important health and economic problem. the present study aimed to compare the behaviors of norwalk virus (the prototype genogroup i norovirus) and two culturable viruses: tulane virus and mengovirus. after bioaccumulation, tissue distributions were quite similar for norwalk virus and tulane virus, with the majority of viral particles detected in digestive tissues, while mengovirus was detected in large amounts in the gills and mantle as well as in digest ... | 2015 | 26025893 |
| immunogenicity of newcastle disease virus vectors expressing norwalk virus capsid protein in the presence or absence of vp2 protein. | noroviruses are the most common cause of acute gastroenteritis in humans. development of an effective vaccine is required for reducing their outbreaks. in order to develop a gi norovirus vaccine, newcastle disease virus vectors, rlasota and modified rbc, were used to express vp1 protein of norwalk virus. co-expression of vp1 and vp2 proteins by newcastle disease virus vectors resulted in enhanced expression of norwalk virus vp1 protein and self-assembly of vp1 protein into virus-like particles. ... | 2015 | 26099695 |
| the enterovirus protease inhibitor rupintrivir exerts cross-genotypic anti-norovirus activity and clears cells from the norovirus replicon. | potent and safe inhibitors of norovirus replication are needed for the treatment and prophylaxis of norovirus infections. we here report that the in vitro anti-norovirus activity of the protease inhibitor rupintrivir is extended to murine noroviruses and that rupintrivir clears human cells from their norwalk replicon after only two passages of antiviral pressure. in addition, we demonstrate that rupintrivir inhibits the human norovirus (genogroup ii [gii]) protease and further explain the inhibi ... | 2014 | 24890597 |
| epidemiology of norovirus gastroenteritis outbreaks in two primary schools in a city in eastern china. | we describe the epidemiology of 2 outbreaks of norovirus (gii) gastroenteritis in elementary schools in a city in eastern china using data from field investigations, pathogen testing, and face-to-face interviews. the transmission shows a point source type. in a case-control study, we identified airborne and person-to-person transmission as the source of the outbreaks. | 2013 | 23663855 |
| predicting susceptibility to norovirus gii.4 by use of a challenge model involving humans. | gii.4 is the predominant norovirus genotype worldwide. challenge models involving humans have shown the association of human histo-blood group antigens (hbgas) and susceptibility to infection with norwalk virus (gi.1 norovirus), but the association of hbgas and infection with other noroviruses is based on results of epidemiological studies. we performed the first gii.4 challenge study involving humans and prospectively evaluated the relationship between hbgas and norovirus infection and associat ... | 2012 | 22927452 |
| incorporating social contact data in spatio-temporal models for infectious disease spread. | summaryroutine public health surveillance of notifiable infectious diseases gives rise to weekly counts of reported cases-possibly stratified by region and/or age group. we investigate how an age-structured social contact matrix can be incorporated into a spatio-temporal endemic-epidemic model for infectious disease counts. to illustrate the approach, we analyze the spread of norovirus gastroenteritis over six age groups within the 12 districts of berlin, 2011-2015, using contact data from the p ... | 2016 | 28025182 |
| the norovirus ns3 protein is a dynamic lipid- and microtubule-associated protein involved in viral rna replication. | norovirus (nov) infections are a significant health burden to society, yet the lack of reliable tissue culture systems has hampered the development of appropriate antiviral therapies. here we show that the nov ns3 protein, derived from murine nov (mnv), is intimately associated with the mnv replication complex and the viral replication intermediate double-stranded rna (dsrna). we observed that when expressed individually, mnv ns3 and ns3 encoded by human norwalk virus (nv) induced the formation ... | 2017 | 27881660 |
| replication of human norovirus rna in mammalian cells reveals lack of interferon response. | human noroviruses (hunovs), named after the prototype strain norwalk virus (nv), are a leading cause of acute gastroenteritis outbreaks worldwide. studies on the related murine norovirus (mnv) have demonstrated the importance of an interferon (ifn) response in host control of virus replication, but this remains unclear for hunovs. despite the lack of an efficient cell culture infection system, transfection of stool-isolated nv rna into mammalian cells leads to viral rna replication and virus pro ... | 2016 | 27466422 |
| frequent use of the iga isotype in human b cells encoding potent norovirus-specific monoclonal antibodies that block hbga binding. | noroviruses (nov) are the most common cause of non-bacterial acute gastroenteritis and cause local outbreaks of illness, especially in confined situations. despite being identified four decades ago, the correlates of protection against norovirus gastroenteritis are still being elucidated. recent studies have shown an association of protection with nov-specific serum histo-blood group antigen-blocking antibody and with serum iga in patients vaccinated with nov vlps. here, we describe the isolatio ... | 2016 | 27355511 |
| natural norovirus infections in rhesus macaques. | using a recently developed real-time reverse transcription pcr, i retested 500 fecal samples from rhesus macaques collected in 2008. previous conventional reverse transcription pcr testing identified 1 isolate of gii norovirus; retesting found gi, gii, and possible giv noroviruses in the samples, indicating the natural circulation of noroviruses in nonhuman primate colonies. | 2016 | 27314565 |
| mapping and modeling of a strain-specific epitope in the norwalk virus capsid inner shell. | noroviruses are diverse positive-strand rna viruses associated with acute gastroenteritis. cross-reactive epitopes have been mapped primarily to conserved sequences in the capsid vp1 shell (s) domain, and strain-specific epitopes to the highly variable protruding (p) domain. in this work, we investigated a strain-specific linear epitope defined by mab nv10 that was raised against prototype (genogroup i.1) strain norwalk virus (nv). using peptide scanning and mutagenesis, the epitope was mapped t ... | 2016 | 26971245 |
| stability of norwalk virus capsid protein interfaces evaluated by in silico nanoindentation. | norwalk virus causes severe gastroenteritis for which there is currently no specific anti-viral therapy. a stage of the infection process is uncoating of the protein capsid to expose the viral genome and allow for viral replication. a mechanical characterization of the norwalk virus may provide important information relating to the mechanism of uncoating. the mechanical strength of the norwalk virus has previously been investigated using atomic force microscopy (afm) nanoindentation experiments. ... | 2015 | 26284238 |
| serum immunoglobulin a cross-strain blockade of human noroviruses. | background. human noroviruses are the leading cause of acute viral gastroenteritis, justifying vaccine development despite a limited understanding of strain immunity. after genogroup i (gi).1 norovirus infection and immunization, blockade antibody titers to multiple virus-like particles (vlps) increase, suggesting that gi cross-protection may occur. methods. immunoglobulin (ig)a was purified from sera collected from gi.1-infected participants, and potential neutralization activity was measured ... | 2015 | 26180833 |
| application of salivary antibody immunoassays for the detection of incident infections with norwalk virus in a group of volunteers. | norovirus infection is the most common cause of acute gastroenteritis in developed countries. developing an assay based on a non-invasive biomarker for detecting incident norovirus infections could improve disease surveillance and epidemiological investigations. this project involved analysis of iga and igg norovirus-specific antibody responses in saliva samples from a norwalk virus (genogroup i, genotype 1 norovirus) challenge study involving infected and symptomatic, and non-infected asymptoma ... | 2015 | 25985985 |
| mucosal and cellular immune responses to norwalk virus. | noroviruses are a leading cause of acute gastroenteritis worldwide. mucosal and cellular immune responses remain poorly understood, with most studies of noroviruses having focused on serological responses to infection. | 2015 | 25635121 |
| crystal structures of gi.8 boxer virus p dimers in complex with hbgas, a novel evolutionary path selected by the lewis epitope. | human noroviruses (hunovs) recognize histo-blood group antigens (hbgas) as attachment factors, in which genogroup (g) i and gii hunovs use distinct binding interfaces. the genetic and evolutionary relationships of gii hunovs under selection by the host hbgas have been well elucidated via a number of structural studies; however, such relationships among gi novs remain less clear due to the fact that the structures of hbga-binding interfaces of only three gi novs with similar binding profiles are ... | 2015 | 25547362 |
| experimental human infection with norwalk virus elicits a surrogate neutralizing antibody response with cross-genogroup activity. | the human noroviruses (novs) are genetically diverse, rapidly evolving rna viruses and are the major cause of epidemic gastroenteritis of humans. serum antibodies that block the interaction of novs and nov viruslike particles (vlps) with host attachment factors are considered surrogate neutralizing antibodies in the absence of cell culture and small-animal replication models for the human novs. a serological assay for nov-blocking antibodies was used to assess the breadth of the heterotypic anti ... | 2015 | 25540269 |
| norovirus dose-response: are currently available data informative enough to determine how susceptible humans are to infection from a single virus? | two forms of single-hit infection dose-response models have previously been developed to assess available data from human feeding trials and estimate the norovirus dose-response relationship. the mechanistic interpretations of these models include strong assumptions that warrant reconsideration: the first study includes an implicit assumption that there is no immunity to norwalk virus among the specific study population, while the recent second study includes assumptions that such immunity could ... | 2015 | 25522208 |
| immunomagnetic separation combined with rt-qpcr for determining the efficacy of disinfectants against human noroviruses. | little is known about the effectiveness of disinfectants against human noroviruses (nov) partially because human nov cannot be routinely cultured in laboratory. the objective of this study was to develop a nov monoclonal antibody-conjugated immunomagnetic separation (ims) procedure combined with real-time reverse transcription polymerase chain reaction (rt-qpcr) assays to study the in vitro efficacy of disinfectants against human nov. monoclonal antibodies against norwalk virus (nv, gi.1) and no ... | 2016 | 25270388 |
| two human challenge studies confirm high infectivity of norwalk virus. | | 2015 | 25121553 |
| two human challenge studies confirm high infectivity of norwalk virus. | | 2014 | 25013128 |
| development of a gaussia luciferase-based human norovirus protease reporter system: cell type-specific profile of norwalk virus protease precursors and evaluation of inhibitors. | norwalk virus (nv) is the prototype strain of human noroviruses (hunovs), a group of positive-strand rna viruses in the caliciviridae family and the leading cause of epidemic gastroenteritis worldwide. investigation of hunov replication and development of antiviral therapeutics in cell culture remain challenging tasks. here, we present norogluc, a hunov protease reporter system based on a fusion of nv p41 protein with a naturally secreted gaussia luciferase (gluc), linked by the p41/p22 cleavage ... | 2014 | 25008934 |
| disease course and viral shedding in experimental norwalk virus and snow mountain virus infection. | norovirus is the most common cause of acute infectious gastroenteritis, causing approximately 21 million cases annually in the usa. the virus is highly contagious and resistant to decontamination, making outbreaks difficult to control. to facilitate the development of better control methods, this study characterized the viral shedding patterns in stools from subjects experimentally infected with genogroup i or ii norovirus. viral stool titers were determined by quantitative real-time rt-pcr for ... | 2014 | 24531909 |
| seroepidemiology of norovirus-associated travelers' diarrhea. | noroviruses (novs) are the most common cause of epidemic gastroenteritis, responsible for at least 50% of all gastroenteritis outbreaks worldwide and were recently identified as a leading cause of travelers' diarrhea (td) in us and european travelers to mexico, guatemala, and india. | 2016 | 24383649 |
| tlr7 and 9 agonists are highly effective mucosal adjuvants for norovirus virus-like particle vaccines. | virus-like particles (vlps) are an active area of vaccine research, development and commercialization. mucosal administration of vlps provides an attractive avenue for delivery of vaccines with the potential to produce robust immune responses. nasal and oral delivery routes are particularly intriguing due to differential activation of mucosa-associated lymphoid tissues. we compared both intranasal and oral administration of vlps with a panel of toll-like receptor (tlr) agonists (tlr3, 5, 7, 7/8, ... | 2014 | 24280723 |
| determination of the 50% human infectious dose for norwalk virus. | noroviruses are the most common cause of gastroenteritis in the united states. an understanding of the infectious dose of these viruses is important for risk assessment studies. | 2014 | 24253285 |
| laboratory evidence of norwalk virus contamination on the hands of infected individuals. | human norovirus (nov) outbreak investigations suggest that the hands of infected individuals play an important role in nov transmission. however, there is no experimental evidence documenting the likelihood and degree of nov contamination on hands. as part of a clinical trial designed to evaluate the efficacy of high-pressure processing for norwalk virus (nv) inactivation in oysters, 159 hand rinse samples were collected from 6 infected and 6 uninfected subjects. nv was concentrated from the sam ... | 2013 | 24123733 |
| structural and inhibitor studies of norovirus 3c-like proteases. | noroviruses have a single-stranded, positive sense 7-8kb rna genome, which encodes a polyprotein precursor processed by a virus-encoded 3c-like cysteine protease (3clpro) to generate mature non-structural proteins. because processing of the polyprotein is essential for virus replication, norovirus 3clpro has been targeted for the discovery of anti-norovirus small molecule therapeutics. thus, we performed functional, structural and inhibition studies of norovirus 3clpro with fluorescence resonanc ... | 2013 | 24055466 |
| expression and assembly of norwalk virus-like particles in plants using a viral rna silencing suppressor gene. | binary vector-based transient expression of heterologous proteins in plants is a very attractive strategy due to the short time required for proceeding from planning to expression. however, this expression system is limited by comparatively lower yields due to strong post-transcriptional gene silencing (ptgs) in the host plants. the aim of this study was to optimize a procedure for expression of norovirus virus-like particles (vlps) in plants using a binary vector with co-expression of a ptgs su ... | 2013 | 23925532 |
| unusual self-assembly properties of norovirus newbury2 virus-like particles. | in the caliciviridae family of nonenveloped, positive-stranded rna viruses, noroviruses are major causes of human and animal gastroenteritis worldwide. the norovirus t=3 icosahedral capsid is made of 180 copies of the vp1 protein, as exemplified in the crystal structure of the virus-like particle (vlp) of the human norwalk virus (nv). it was previously shown that the ca 40-nm recombinant nv vlp can be disassembled and reassembled in vitro. here we report on the disassembly and self-assembly prop ... | 2013 | 23871846 |
| development of norwalk virus-specific monoclonal antibodies with therapeutic potential for the treatment of norwalk virus gastroenteritis. | passive immunoprophylaxis or immunotherapy with norovirus-neutralizing monoclonal antibodies (mabs) could be a useful treatment for high-risk populations, including infants and young children, the elderly, and certain patients who are debilitated or immunocompromised. in order to obtain antinorovirus mabs with therapeutic potential, we stimulated a strong adaptive immune response in chimpanzees to the prototype norovirus strain norwalk virus (nv) (genogroup i.1). a combinatorial phage fab displa ... | 2013 | 23785216 |
| infectivity of gi and gii noroviruses established from oyster related outbreaks. | noroviruses (novs) are the major cause of acute epidemic gastroenteritis in industrialized countries. outbreak strains are predominantly genogroup ii (gii) nov, but genogroup i (gi) strains are regularly found in oyster related outbreaks. the prototype norwalk virus (gi), has been shown to have high infectivity in a human challenge study. whether other novs are equally infectious via natural exposure remains to be established. human susceptibility to nov is partly determined by the secretor stat ... | 2013 | 23746803 |
| lack of norovirus replication and histo-blood group antigen expression in 3-dimensional intestinal epithelial cells. | noroviruses (novs) are a leading cause of gastroenteritis worldwide. an in vitro model for nov replication remains elusive, making study of the virus difficult. a previous study, which used a 3-dimensional (3-d) intestinal model derived from int-407 cells reported nov replication and extensive cytopathic effects (cpe). using the same 3-d model, but with highly purified norwalk virus (nv), we attempted to replicate this study. our results showed no evidence of nv replication by real-time pcr of v ... | 2013 | 23622517 |
| substrate recognition by norovirus polymerase: microsecond molecular dynamics study. | molecular dynamics simulations of complexes between norwalk virus rna dependent rna polymerase and its natural ctp and 2dctp (both containing the o5'-c5'-c4'-o4' sequence of atoms bridging the triphosphate and sugar moiety) or modified coctp (c5'-o5'-c4'-o4'), cocctp (c5'-o5'-c4'-c4'') substrates were produced by means of cuda programmable graphical processing units and the acemd software package. it enabled us to gain microsecond md trajectories clearly showing that similar nucleoside triphosph ... | 2013 | 23619980 |
| identification and characterization of a peptide affinity reagent for detection of noroviruses in clinical samples. | norovirus (nov) is the most common agent of nonbacterial epidemic gastroenteritis and is estimated to cause 21 million cases of the disease in the united states annually. the antigen enzyme-linked immunosorbent assays (elisas) currently available for nov diagnosis detect only certain strains and are approved for use in the united states only in epidemics where nov is suspected. there is a clear need for simpler, more rapid, and more reliable diagnostic tools for the detection of nov. in this stu ... | 2013 | 23554202 |
| genetic susceptibility to norovirus gii.3 and gii.4 infections in chinese pediatric diarrheal disease. | noroviruses (novs) are a leading cause of viral diarrhea in young children. secretor status has been confirmed to be linked with norwalk virus (nov gi.1) infection but there is limited information about whether secretor genotypes are associated with pediatric nov epidemic strains in vivo. | 2014 | 25037042 |
| antibody responses to norovirus genogroup gi.1 and gii.4 proteases in volunteers administered norwalk virus. | an assay was developed to detect antibodies against two norovirus proteases among participants in a norwalk virus (gi.1) challenge study. prechallenge seroprevalence was lower against the protease from the homologous gi.1 virus than against protease from a heterologous gii.4 strain. seroresponses were detected for 14 of 19 (74%) infected persons. | 2012 | 23035177 |
| antiviral activity of gold/copper sulfide core/shell nanoparticles against human norovirus virus-like particles. | human norovirus is a leading cause of acute gastroenteritis worldwide in a plethora of residential and commercial settings, including restaurants, schools, and hospitals. methods for easily detecting the virus and for treating and preventing infection are critical to stopping norovirus outbreaks, and inactivation via nanoparticles (nps) is a more universal and attractive alternative to other physical and chemical approaches. using norovirus gi.1 (norwalk) virus-like particles (vlps) as a model v ... | 2015 | 26474396 |
| epidemiology and evolution of rotaviruses and noroviruses from an archival who global study in children (1976-79) with implications for vaccine design. | prompted by the discovery of new gastrointestinal viruses, the nih, niaid and who investigated the etiology of acute diarrhea that occurred from 1976-1979 in a global cohort of infants and young children. rotaviruses were found to be major pathogens worldwide, whereas the norwalk virus could not be detected using a radioimmunoassay. the aim of this study is to re-evaluate the role and diversity of rotaviruses and noroviruses in the original cohort using more sensitive current technologies. stool ... | 2013 | 23536875 |
| cryo-em structure of a novel calicivirus, tulane virus. | tulane virus (tv) is a newly isolated cultivatable calicivirus that infects juvenile rhesus macaques. here we report a 6.3 å resolution cryo-electron microscopy structure of the tv virion. the tv virion is about 400 å in diameter and consists of a t = 3 icosahedral protein capsid enclosing the rna genome. 180 copies of the major capsid protein vp1 (∼57 kda) are organized into two types of dimers a/b and c/c and form a thin, smooth shell studded with 90 dimeric protrusions. the overall capsid org ... | 2013 | 23533651 |
| structural basis of substrate specificity and protease inhibition in norwalk virus. | norwalk virus (nv), the prototype human calicivirus, is the leading cause of nonbacterial acute gastroenteritis. the nv protease cleaves the polyprotein encoded by open reading frame 1 of the viral genome at five nonhomologous sites, releasing six nonstructural proteins that are essential for viral replication. the structural details of how nv protease recognizes multiple substrates are unclear. in our x-ray structure of an nv protease construct, we observed that the c-terminal tail, representin ... | 2013 | 23365454 |
| structural and dynamics characterization of norovirus protease. | norovirus protease is an essential enzyme for proteolytic maturation of norovirus nonstructural proteins and has been implicated as a potential target for antiviral drug development. although x-ray structural studies of the protease give us wealth of structural information including interactions of the protease with its substrate and dimeric overall structure, the role of protein dynamics in the substrate recognition and the biological relevance of the protease dimer remain unclear. here we dete ... | 2013 | 23319456 |
| substrate specificity of tulane virus protease. | tulane virus (tv) is a cultivable calicivirus isolated from rhesus monkeys. in this study, we characterized the substrate specificity of tv protease in trans using recombinant proteases and tv polyprotein fragments containing the predicted proteolytic cleavage sites. cleavage products have been obtained from 4 of the 5 fragments containing (573)q-s(574) between the helicase and 3a-like protein, (712)e-a(713) between the 3a-like protein and vpg, (802)e-g(803) between vpg and the protease, and (97 ... | 2013 | 23141588 |
| in silico 3d structure analysis accelerates the solution of a real viral structure and antibodies docking mechanism. | norwalk virus (nov) is responsible for most outbreaks of non-bacterial gastroenteritis. nov is genetically diverse and show antigenically variable. recently, we produced a monoclonal antibody called 5b-18 that reacts broadly with nov genogroup ii (gii). we suspected the 5b-18 binds to a conformational epitope on 3d structure of virion. x-ray crystallography showed us that 5b-18 binds to nov at the p domain, which protrudes from the capsid surface of the virion. however, there seems to be no spac ... | 2012 | 23133439 |
| antiviral activity of nucleoside analogues against norovirus. | norovirus (nov) is the leading cause of epidemic gastroenteritis worldwide. the lack of a cell culture has significantly hampered the development of effective therapies against human nov. clinically approved nucleoside and non-nucleoside analogues have been used successfully against rna viruses. | 2012 | 22910194 |
| intranasal vaccination with murabutide enhances humoral and mucosal immune responses to a virus-like particle vaccine. | murabutide (mb) is a synthetic immunomodulator recognized by the nucleotide-binding oligomerization domain-containing protein 2 (nod2) receptor on mammalian cells. mb has previously been approved for testing in multiple human clinical trials to determine its value as an antiviral therapeutic, and as an adjuvant for injected vaccines. we have found a new use for this immunomodulator; it functions as a mucosal adjuvant that enhances immunogenicity of virus-like particles (vlp) administered intrana ... | 2012 | 22855691 |
| intranasal vaccination with an adjuvanted norwalk virus-like particle vaccine elicits antigen-specific b memory responses in human adult volunteers. | noroviruses are the most frequent cause of acute gastroenteritis in humans of all ages. no vaccines are currently available. an intranasally delivered norwalk (nv) virus-like particle (vlp) vaccine was recently shown to be well tolerated, immunogenic and to protect against infection in phase 1 studies. here, we examined b memory (b(m)) responses in volunteers who received the highest dosage levels of the nv-vlp vaccine (50 μg and 100 μg). we measured the frequency of nv-specific igg and iga-secr ... | 2012 | 22710446 |
| persistence and transferability of noroviruses on and between common surfaces and foods. | human noroviruses (hunov) are the leading cause of foodborne disease, and poor personal hygiene practices of infected workers are the most common mode of contamination. the purpose of this study was to characterize the persistence and transferability of representative noroviruses norwalk virus (nv), snow mountain virus (smv), and murine norovirus 1 (mnv-1) on and between solid surfaces and foods. changes in virus concentration on artificially inoculated solid surfaces (stainless steel, ceramic, ... | 2012 | 22564943 |