Mitchell, M.; Nam, H; Carter, A; McCall, A; Rence, C; Bennett, A; Gurda, B; McKenna, R; Porter, M; et. al.
Adeno-associated virus (AAV) serotype 9, which is under development for gene-delivery applications, shows significantly enhanced capsid-associated transduction efficiency in muscle compared with other AAV serotypes. With the aim of characterizing the structural determinants of this property, the purification, crystallization and preliminary X-ray crystallographic analyses of the AAV9 viral capsid are reported. The crystals diffracted X-rays to 2.8 A resolution using synchrotron radiation and belonged to the trigonal space group P32, with unit-cell parameters a = b = 251.0, c = 640.0 A. There are three complete viral capsids in the crystal unit cell. The orientation and position of the asymmetric unit capsid have been determined by molecular-replacement methods and structure determination is in progress.
Gong, Yi; Mu, Dakai; Prabhakar, Shilpa; Moser, Ann; Musolino, Patricia; Ren, JiaQian; Breakefield, Xandra O; Maguire, Casey A; Eichler, Florian S
X-linked adrenoleukodystrophy (X-ALD) is a devastating neurological disorder caused by mutations in the ABCD1 gene that encodes a peroxisomal ATP-binding cassette transporter (ABCD1) responsible for transport of CoA-activated very long-chain fatty acids (VLCFA) into the peroxisome for degradation. We used recombinant adenoassociated virus serotype 9 (rAAV9) vector for delivery of the human ABCD1 gene (ABCD1) to mouse central nervous system (CNS). In vitro, efficient delivery of ABCD1 gene was achieved in primary mixed brain glial cells from Abcd1-/- mice as well as X-ALD patient fibroblasts. Importantly, human ABCD1 localized to the peroxisome, and AAV-ABCD1 transduction showed a dose-dependent effect in reducing VLCFA. In vivo, AAV9-ABCD1 was delivered to Abcd1-/- mouse CNS by either stereotactic intracerebroventricular (ICV) or intravenous (IV) injections. Astrocytes, microglia and neurons were the major target cell types following ICV injection, while IV injection also delivered to microvascular endothelial cells and oligodendrocytes. IV injection also yielded high transduction of the adrenal gland. Importantly, IV injection of AAV9-ABCD1 reduced VLCFA in mouse brain and spinal cord. We conclude that AAV9-mediated ABCD1 gene transfer is able to reach target cells in the nervous system and adrenal gland as well as reduce VLCFA in culture and a mouse model of X-ALD.
DiMattia, Michael A.; Nam, Hyun-Joo; Van Vliet, Kim; Mitchell, Matthew; Bennett, Antonette; Gurda, Brittney L.; McKenna, Robert; Olson, Norman H.; Sinkovits, Robert S.; Potter, Mark; Byrne, Barry J.; Aslanidi, George; Zolotukhin, Sergei; Muzyczka, Nicholas; Baker, Timothy S.
Adeno-associated virus serotype 9 (AAV9) has enhanced capsid-associated tropism for cardiac muscle and the ability to cross the blood-brain barrier compared to other AAV serotypes. To help identify the structural features facilitating these properties, we have used cryo-electron microscopy (cryo-EM) and three-dimensional image reconstruction (cryo-reconstruction) and X-ray crystallography to determine the structure of the AAV9 capsid at 9.7- and 2.8-Å resolutions, respectively. The AAV9 capsi...
Daniel J. Schuster
Full Text Available Adeno-associated virus serotype 9 (AAV9-mediated gene transfer has been reported in central nervous system (CNS and peripheral tissues. The current study compared the pattern of expression of Green Fluorescent Protein (GFP across the mouse CNS and selected peripheral tissues after intrathecal (i.t. or intravenous (i.v. delivery of equivalent doses of single-stranded AAV9 vector. After i.t. delivery, GFP immunoreactivity (-ir was observed in spinal neurons, primary afferent fibers and corresponding primary sensory neurons at all spinal levels. Robust transduction was seen in small and large dorsal root ganglion (DRG neurons as well as trigeminal and vagal primary afferent neurons. Transduction efficiency in sensory ganglia was substantially lower in i.v. treated mice. In brain, i.v. delivery yielded GFP-immunoreactivity (-ir primarily in spinal trigeminal tract, pituitary, and scattered isolated neurons and astrocytes. In contrast, after i.t. delivery, GFP-ir was widespread throughout CNS, with greater intensity and more abundant neuropil-like staining at six weeks compared to three weeks. Brain regions with prominent GFP-ir included cranial nerve nuclei, ventral pons, cerebellar cortex, hippocampus, pituitary, choroid plexus, and selected nuclei of midbrain, thalamus and hypothalamus. In cortex, GFP-ir was associated with blood vessels, and was seen in both neurons and astrocytes. In the periphery, GFP-ir in colon and ileum was present in the enteric nervous system in both i.v. and i.t. treated mice. Liver and adrenal cortex, but not adrenal medulla, also showed abundant GFP-ir after both routes of delivery. In summary, i.t. delivery yielded higher transduction efficiency in sensory neurons and the CNS. The observation of comparable gene transfer to peripheral tissues using the two routes indicates that a component of i.t. delivered vector is redistributed from the subarachnoid space to the systemic circulation.
Bell, Christie L; Gurda, Brittney L; Van Vliet, Kim; Agbandje-McKenna, Mavis; Wilson, James M
Adeno-associated virus serotype 9 (AAV9) vectors show promise for gene therapy of a variety of diseases due to their ability to transduce multiple tissues, including heart, skeletal muscle, and the alveolar epithelium of the lung. In addition, AAV9 is unique compared to other AAV serotypes in that it is capable of surpassing the blood-brain barrier and transducing neurons in the brain and spinal cord. It has recently been shown that AAV9 uses galactose as a receptor to transduce many different cell types in vitro, as well as cells of the mouse airway in vivo. In this study, we sought to identify the specific amino acids of the AAV9 capsid necessary for binding to galactose. By site-directed mutagenesis and cell binding assays, plus computational ligand docking studies, we discovered five amino acids, including N470, D271, N272, Y446, and W503, which are required for galactose binding that form a pocket at the base of the protrusions around the icosahedral 3-fold axes of symmetry. The importance of these amino acids for tissue tropism was also confirmed by in vivo studies in the mouse lung. Identifying the interactions necessary for AAV9 binding to galactose may lead to advances in vector engineering.
DiMattia, Michael A; Nam, Hyun-Joo; Van Vliet, Kim; Mitchell, Matthew; Bennett, Antonette; Gurda, Brittney L; McKenna, Robert; Olson, Norman H; Sinkovits, Robert S; Potter, Mark; Byrne, Barry J; Aslanidi, George; Zolotukhin, Sergei; Muzyczka, Nicholas; Baker, Timothy S; Agbandje-McKenna, Mavis
Adeno-associated virus serotype 9 (AAV9) has enhanced capsid-associated tropism for cardiac muscle and the ability to cross the blood-brain barrier compared to other AAV serotypes. To help identify the structural features facilitating these properties, we have used cryo-electron microscopy (cryo-EM) and three-dimensional image reconstruction (cryo-reconstruction) and X-ray crystallography to determine the structure of the AAV9 capsid at 9.7- and 2.8-Å resolutions, respectively. The AAV9 capsid exhibits the surface topology conserved in all AAVs: depressions at each icosahedral two-fold symmetry axis and surrounding each five-fold axis, three separate protrusions surrounding each three-fold axis, and a channel at each five-fold axis. The AAV9 viral protein (VP) has a conserved core structure, consisting of an eight-stranded, β-barrel motif and the αA helix, which are present in all parvovirus structures. The AAV9 VP differs in nine variable surface regions (VR-I to -IX) compared to AAV4, but at only three (VR-I, VR-II, and VR-IV) compared to AAV2 and AAV8. VR-I differences modify the raised region of the capsid surface between the two-fold and five-fold depressions. The VR-IV difference produces smaller three-fold protrusions in AAV9 that are less "pointed" than AAV2 and AAV8. Significantly, residues in the AAV9 VRs have been identified as important determinants of cellular tropism and transduction and dictate its antigenic diversity from AAV2. Hence, the AAV9 VRs likely confer the unique infection phenotypes of this serotype.
Tijana Knezevic, PhD
Full Text Available Mutations in Bcl-2–associated athanogene 3 (BAG3 were associated with skeletal muscle dysfunction and dilated cardiomyopathy. Retro-orbital injection of an adeno-associated virus serotype 9 expressing BAG3 (rAAV9-BAG3 significantly (p < 0.0001 improved left ventricular ejection fraction, fractional shortening, and stroke volume 9 days post-injection in mice with cardiac dysfunction secondary to a myocardial infarction. Furthermore, myocytes isolated from mice 3 weeks after injection showed improved cell shortening, enhanced systolic [Ca2+]i and increased [Ca2+]i transient amplitudes, and increased maximal L-type Ca2+ current amplitude. These results suggest that BAG3 gene therapy may provide a novel therapeutic option for the treatment of heart failure.
Bish, Lawrence T; Morine, Kevin; Sleeper, Meg M; Sanmiguel, Julio; Wu, Di; Gao, Guangping; Wilson, James M; Sweeney, H Lee
Heart disease is the leading cause of morbidity and mortality. Cardiac gene transfer may serve as a novel therapeutic approach. This investigation was undertaken to compare cardiac tropisms of adeno-associated virus (AAV) serotypes 1, 6, 7, 8, and 9. Neonatal mice were injected with 2.5 x 10(11) genome copies (GC) of AAV serotype 1, 6, 7, 8, or 9 expressing LacZ under the control of the constitutive chicken beta-actin promoter with cytomegalovirus enhancer promoter via intrapericardial injection and monitored for up to 1 year. Adult rats were injected with 5 x 10(11) GC of the AAV vectors via direct cardiac injection and monitored for 1 month. Cardiac distribution of LacZ expression was assessed by X-Gal histochemistry, and beta-galactosidase activity was quantified in a chemiluminescence assay. Cardiac functional data and biodistribution data were also collected in the rat. AAV9 provided global cardiac gene transfer stable for up to 1 year that was superior to other serotypes. LacZ expression was relatively cardiac specific, and cardiac function was unaffected by gene transfer. AAV9 provides high-level, stable expression in the mouse and rat heart and may provide a simple alternative to the creation of cardiac-specific transgenic mice. AAV9 should be used in rodent cardiac studies and may be the vector of choice for clinical trials of cardiac gene transfer.
Kohlbrenner, Erik; Weber, Thomas
Vectors based on adeno-associated virus serotype 9 (AAV9) efficiently transduce cardiomyocytes in both rodents and large animal models upon either systemic or regional vector delivery. In this chapter, we describe the most widely used production and purification method of AAV9. This production approach does not depend on the use of a helpervirus but instead on transient transfection of HEK293T cells with a plasmid containing the recombinant AAV genome and a second plasmid encoding the AAV9 capsid proteins, the AAV Rep proteins and the adenoviral helper functions. The recombinant AAV is then purified by iodixanol density gradient centrifugation. This chapter also describes in detail the characterization and quality control methods required for assuring high quality vector preparations, which is of particular importance for experiments in large animal models.
Enomoto, Mitsuhiro; Hirai, Takashi; Kaburagi, Hidetoshi; Yokota, Takanori
RNA interference is a powerful tool used to induce loss-of-function phenotypes through post-transcriptional gene silencing. Small interfering RNA (siRNA) molecules have been used to target the central nervous system (CNS) and are expected to have clinical utility against refractory neurodegenerative diseases. However, siRNA is characterized by low transduction efficiency, insufficient inhibition of gene expression, and short duration of therapeutic effects, and is thus not ideal for treatment of neural tissues and diseases. To address these problems, viral delivery of short-hairpin RNA (shRNA) expression cassettes that support more efficient and long-lasting transduction into target tissues is expected to be a promising delivery tool. Various types of gene therapy vectors have been developed, such as adenovirus, adeno-associated virus (AAV), herpes simplex virus and lentivirus; however, AAV is particularly advantageous because of its relative lack of immunogenicity and lack of chromosomal integration. In human clinical trials, recombinant AAV vectors are relatively safe and well-tolerated. In particular, serotype 9 of AAV (AAV9) vectors show the highest tropism for neural tissue and can cross the blood-brain barrier, and we have shown that intrathecal delivery of AAV9 yields relatively high gene transduction into dorsal root ganglia or spinal cord. This chapter describes how to successfully use AAV vectors encoding shRNA in vivo, particularly for RNA interference in the central and peripheral nervous system.
Friis, Martin Barfred; Rasmussen, Thomas Bruun; Belsham, Graham
Modulation of translation initiation efficiency on classical swine fever virus (CSFV) RNA can be achieved by targeted mutations within the internal ribosome entry site (IRES). In this study, cDNAs corresponding to the wild type (wt) or mutant forms of the IRES of CSFV strain Paderborn were...... in vitro and electroporated into porcine PK15 cells. Rescued mutant viruses were obtained from RNAs that contained mutations within domain IIIf which retained more than 75% of wt translation efficiency. Sequencing of cDNA generated from these rescued viruses verified the maintenance of the introduced...... changes within the IRES. The growth characteristics of each rescued mutant virus were compared to that of the wt virus. It was shown that viable mutant viruses with reduced translation initiation efficiency can be designed and generated and that viruses containing mutations within domain IIIf of the IRES...
Accurate detection of viruses in plants and animals is critical for agriculture production and human health. Deep sequencing and assembly of virus-derived siRNAs has proven to be a highly efficient approach for virus discovery. However, to date no computational tools specifically designed for both k...
Terrier, O; Essere, B; Yver, M; Barthélémy, M; Bouscambert-Duchamp, M; Kurtz, P; VanMechelen, D; Morfin, F; Billaud, G; Ferraris, O; Lina, B; Rosa-Calatrava, M; Moules, V
Respiratory infections caused by viruses are major causes of upper and lower respiratory tract infections. They account for an important mortality and morbidity worldwide. Amongst these viruses, influenza viruses and paramyxoviruses are major pathogens. Their transmission is mainly airborne, by direct transmission through droplets from infected cases. In the context of an influenza pandemic, as well as for the reduction of nosocomial infections, systems that can reduce or control virus transmission will reduce the burden of this disease. It may also be part of the strategy for pandemic mitigation. A new system based on physical decontamination of surface and air has been developed. This process generates cold oxygen plasma (COP) by subjecting air to high-energy deep-UV light. To test its efficiency, we have developed an experimental device to assess for the decontamination of nebulized respiratory viruses. High titer suspensions of influenza virus type A, human parainfluenza virus type 3 and RSV have been tested. Different experimental conditions have been evaluated against these viruses. The use of COP with an internal device allowed the best results against all viruses tested. We recorded a reduction of 6.5, 3.8 and 4 log(10) TCID50/mL of the titre of the hPIV-3, RSV and influenza virus A (H5N2) suspensions. The COP technology is an efficient and innovative strategy to control airborne virus dissemination. It could successfully control nosocomial diffusion of respiratory viruses in hospital setting, and could be useful for the reduction of influenza transmission in the various consultation settings implemented for the management of cases during a pandemic.
Varadi, K; Michelfelder, S; Korff, T; Hecker, M; Trepel, M; Katus, H A; Kleinschmidt, J A; Müller, O J
We have demonstrated the potential of random peptide libraries displayed on adeno-associated virus (AAV)2 to select for AAV2 vectors with improved efficiency for cell type-directed gene transfer. AAV9, however, may have advantages over AAV2 because of a lower prevalence of neutralizing antibodies in humans and more efficient gene transfer in vivo. Here we provide evidence that random peptide libraries can be displayed on AAV9 and can be utilized to select for AAV9 capsids redirected to the cell type of interest. We generated an AAV9 peptide display library, which ensures that the displayed peptides correspond to the packaged genomes and performed four consecutive selection rounds on human coronary artery endothelial cells in vitro. This screening yielded AAV9 library capsids with distinct peptide motifs enabling up to 40-fold improved transduction efficiencies compared with wild-type (wt) AAV9 vectors. Incorporating sequences selected from AAV9 libraries into AAV2 capsids could not increase transduction as efficiently as in the AAV9 context. To analyze the potential on endothelial cells in the intact natural vascular context, human umbilical veins were incubated with the selected AAV in situ and endothelial cells were isolated. Fluorescence-activated cell sorting analysis revealed a 200-fold improved transduction efficiency compared with wt AAV9 vectors. Furthermore, AAV9 vectors with targeting sequences selected from AAV9 libraries revealed an increased transduction efficiency in the presence of human intravenous immunoglobulins, suggesting a reduced immunogenicity. We conclude that our novel AAV9 peptide library is functional and can be used to select for vectors for future preclinical and clinical gene transfer applications.
Khattak, Shahryar; Sandoval-Guzmán, Tatiana; Stanke, Nicole; Protze, Stephanie; Tanaka, Elly M; Lindemann, Dirk
Molecular studies of appendage regeneration have been hindered by the lack of a stable and efficient means of transferring exogenous genes. We therefore sought an efficient integrating virus system that could be used to study limb and tail regeneration in salamanders. We show that replication-deficient foamy virus (FV) vectors efficiently transduce cells in two different regeneration models in cell culture and in vivo. Injection of EGFP-expressing FV but not lentivirus vector particles into regenerating limbs and tail resulted in widespread expression that persisted throughout regeneration and reamputation pointing to the utility of FV for analyzing adult phenotypes in non-mammalian models. Furthermore, tissue specific transgene expression is achieved using FV vectors during limb regeneration. FV vectors are efficient mean of transferring genes into axolotl limb/tail and infection persists throughout regeneration and reamputation. This is a nontoxic method of delivering genes into axolotls in vivo/ in vitro and can potentially be applied to other salamander species.
Friis, Martin Barfred; Rasmussen, Thomas Bruun; Belsham, Graham J.
Modulation of translation initiation efficiency on classical swine fever virus (CSFV) RNA can be achieved by targeted mutations within the internal ribosome entry site (IRES). In this study, the nucleotides 47 to 427, including the IRES region of the wt CSFV strain Paderborn, were amplified...... and inserted, under T7 promoter control, into mono- and dicistronic plasmids containing the reporter genes rLuc and fLuc. Mutant fragments of the IRES sequence were generated by overlap PCR and inserted into the reporter plasmids. To evaluate IRES functionality, translation of the rLUC was placed under...... viruses were obtained after one cell culture passage from constructs with more than 75 % translation efficiency compared to the wildtype IRES. cDNA was generated from these clones and sequenced to verify the maintenance of the changes in the IRES. These results show that full-length viable mutant viruses...
Ajorloo, Mehdi; Bamdad, Taravat; Gholami, Ali Reza; Azadmanesh, Keyhan
Rabies is an acute viral disease that causes encephalomyelitis in mammals and human. The only way to prevent this disease is through vaccination before or after exposure. The aim of this study is to evaluate the efficiency of the Pasteur virus (PV) minigenome, using PV strain. Enhanced Green Fluorescent Protein (EGFP) sequence was placed between the designed necessary elements (Hammerhead, HDV ribozyme, 3' Leader, and 5' Trailer sequences), which resemble the rabies virus PV strain (PV2061) genome and anti-genome. These constructs were placed between T7 polymerase promoter and T7 polymerase terminator sequences. The accuracy of the minigenome was confirmed by the expression of EGFP using the helper virus in T7-BHK cell line. The viral necessary elements of positive and negative sense strands were evaluated for the ability of EGFP expression in the presence of the helper virus. While the positive strand showed background results, no EGFP background was observed in the negative strand application. Establishment of minigenome system does not require advanced biosafety levels. Furthermore, using minigenome system eliminates many potential confounding factors that may be present in coding regions of the genome. Use of the minigenome system is easier and more feasible than the full genome rescue of the virus. This study successfully shows the efficiency of the constructed rabies virus minigenome in expression of inserted gene.
Huo, Yan; Chen, Liying; Su, Lei; Wu, Yao; Chen, Xiaoying; Fang, Rongxiang; Zhang, Lili
Rice stripe virus (RSV), the causative agent of rice stripe disease, is transmitted by Laodelphax striatellus in a persistent-propagative manner. Efficient virus acquisition is primary for studies of virus transmission and virus-insect vector interactions. However, under greenhouse conditions, less than 30% of the L. striatellus population, on average, become viruliferous during feeding on RSV-infected plants. Here, we explored a method for efficient RSV acquisition by feeding the insects with a virus-containing artificial diet. Virus particles were partially purified from frozen infected rice leaves. A series of RSV concentrations in a 5% sucrose solution were tested in the feed of L. striatellus nymphs. The percentage of infected insects increased along with the increasing viral concentration, and the highest infection percentage 96% was achieved using a 1200ngμL(-1) crude RSV suspension after 48h feeding. RSV particles acquired in this manner were able to spread to L. striatellus salivary glands. This improved method of obtaining viruliferous insects should assist the study of RSV transmission mechanisms in L. striatellus. Copyright © 2016 Elsevier B.V. All rights reserved.
Meng, Lan-Huan; Wang, Rui-Heng; Zhu, Ben-Zhong; Zhu, Hong-Liang; Luo, Yun-Bo; Fu, Da-Qi
Solanum rostratum is a “super weed” that grows fast, is widespread, and produces the toxin solanine, which is harmful to both humans and other animals. To our knowledge, no study has focused on its molecular biology owing to the lack of available transgenic methods and sequence information for S. rostratum. Virus-induced gene silencing (VIGS) is a powerful tool for the study of gene function in plants; therefore, in the present study, we aimed to establish tobacco rattle virus (TRV)-derived VIGS in S. rostratum. The genes for phytoene desaturase (PDS) and Chlorophyll H subunit (ChlH) of magnesium protoporphyrin chelatase were cloned from S. rostratum and used as reporters of gene silencing. It was shown that high-efficiency VIGS can be achieved in the leaves, flowers, and fruit of S. rostratum. Moreover, based on our comparison of three different types of infection methods, true leaf infection was found to be more efficient than cotyledon and sprout infiltration in long-term VIGS in multiple plant organs. In conclusion, the VIGS technology and tomato genomic sequences can be used in the future to study gene function in S. rostratum. PMID:27258320
Full Text Available Solanum rostratum is a "super weed" that grows fast, is widespread, and produces the toxin solanine, which is harmful to both humans and other animals. To our knowledge, no study has focused on its molecular biology owing to the lack of available transgenic methods and sequence information for S. rostratum. Virus-induced gene silencing (VIGS is a powerful tool for the study of gene function in plants; therefore, in the present study, we aimed to establish tobacco rattle virus (TRV-derived VIGS in S. rostratum. The genes for phytoene desaturase (PDS and Chlorophyll H subunit (ChlH of magnesium protoporphyrin chelatase were cloned from S. rostratum and used as reporters of gene silencing. It was shown that high-efficiency VIGS can be achieved in the leaves, flowers, and fruit of S. rostratum. Moreover, based on our comparison of three different types of infection methods, true leaf infection was found to be more efficient than cotyledon and sprout infiltration in long-term VIGS in multiple plant organs. In conclusion, the VIGS technology and tomato genomic sequences can be used in the future to study gene function in S. rostratum.
Valli, M B; Carloni, G; Manzin, A; Nasorri, F; Ponzetto, A; Clementi, M
The susceptibility of Vero cells and derivative cell clones to hepatitis C virus (HCV) infection was assayed by qualitative and quantitative polymerase chain reaction (PCR)-based methods. Cell extracts from Vero cells inoculated with HCV were tested for the presence of both positive and negative strands of HCV RNA; in parallel, cell-free HCV genomes were assayed in culture supernatant fluids. Quantitation of genomic HCV RNA molecules in infected cells by competitive reverse transcription PCR (cRT-PCR) indicated that HCV replication was more efficient in a derivative clone (named clone 10) than in parental Vero cells or other clones under study. Analysis of HCV-binding to cell receptors, performed by cRT-PCR quantitation of viral particles adsorbed to the cell surface, demonstrated a 10-fold higher virus-binding level of clone 10 than that of parental Vero cells. The results shown here indicate that the Vero clone 10 may constitute an efficient model system for analysing early events in HCV infection as well as a source of virus for diagnostic and biotechnological applications.
Schultz, Anna Charlotte; Perelle, Sylvie; Di Pasquale, Simona
Enteric viruses, including norovirus (NoV) and hepatitis A virus (HAV), have emerged as a major cause of waterborne outbreaks worldwide. Due to their low infectious doses and low concentrations in water samples, an efficient and rapid virus concentration method is required for routine control. Th...
Lin, Fang-Jing; Bosquée, Emilie; Liu, Ying-Jie; Chen, Ju-Lian; Yong, Liu; Francis, Frédéric
Aphids cause serious damages to crops not only by tacking sap but also by transmitting numerous viruses. To develop biological control, the aphid alarm pheromone, namely E-β-farnesene (EβF), has been demonstrated to be efficient to repel aphids and as attract beneficials, making it a potential tool to control aphid pests. Considering aphids also as virus vectors, changes of their behavior could also interfere with the virus acquisition and transmission process. Here, a combination of two aphid species and two potato virus models were selected to test the influence of EβF release on aphid and virus dispersion under laboratory conditions. EβF release was found to significantly decrease the population of Myzus persicae and Macrosiphum euphorbiae around the infochemical releaser but simultaneously also increasing the dispersal of Potato Virus Y (PVY). At the opposite, no significant difference for Potato Leaf Roll Virus (PLRV) transmission efficiency was observed with similar aphid alarm pheromone releases for none of the aphid species. These results provide some support to carefully consider infochemical releasers not only for push-pull strategy and pest control but also to include viral disease in a the plant protection to aphids as they are also efficient virus vectors. Impact of aphid kinds and transmission mechanisms will be discussed according to the large variation found between persistent and non persistent potato viruses and interactions with aphids and related infochemicals. Copyright © 2016 Elsevier B.V. All rights reserved.
Thomsen, Allan Randrup; Nansen, A; Christensen, Jan Pravsgaard
+ cells and B cells. Our results reveal that the primary activation, clonal expansion, and differentiation of CD8+ T cells does not require expression of CD40L. However, lack of expression results in rapid impairment of CTL responsiveness and failure to permanently control virus replication. This happens...... not only in mice infected with the rapidly spreading virus strain but also at a late stage in mice infected with the strain of more limited potential for spreading. In the latter mice, virus replication is initially controlled very efficiently, but high levels of virus can be detected in the blood...... were infected with one of two strains of lymphocytic choriomeningitis virus differing markedly in their capacity to spread in the host. Infection with lymphocytic choriomeningitis virus is initially controlled primarily by CD8+ effector cells, whereas long-term immune surveillance also depends upon CD4...
West Nile virus (WNV) is an emergent pathogen in the Americas, first reported in New York during 1999, and has since spread across the United States (USA), Central and South America causing neurological disease in humans, horses and some bird species, including domestic geese. No WNV vaccines are li...
Full Text Available The development of oncolytic viruses has led to an emerging new class of cancer therapeutics. Although the safety profile has been encouraging, the transition of oncolytic viruses to the clinical setting has been a slow process due to modifications. Therefore, a new generation of more potent oncolytic viruses needs to be exploited, following our better understanding of the complex interactions between the tumor, its microenvironment, the virus, and the host immune response. The conventional method for creation of tumor-targeted oncolytic viruses is based on homologous recombination. However, the creation of new mutant oncolytic viruses with large genomes remains a challenge due to the multi-step process and low efficiency of homologous recombination. The CRISPR-associated endonuclease Cas9 has hugely advanced the potential to edit the genomes of various organisms due to the ability of Cas9 to target a specific genomic site by a single guide RNA. In this review, we discuss the CRISPR-Cas9 system as an efficient viral editing method for the creation of new oncolytic viruses, as well as its potential future applications in the development of oncolytic viruses. Further, this review discusses the potential of off-target effects as well as CRISPR-Cas9 as a tool for basic research into viral biology.
Elderfield, Ruth A; Parker, Lauren; Stilwell, Peter; Roberts, Kim L; Schepelmann, Silke; Barclay, Wendy S
Ferrets have become the model animal of choice for influenza pathology and transmission experiments as they are permissive and susceptible to human influenza A viruses. However, inoculation of ferrets with mumps virus (MuV) did not lead to successful infections. We evaluated the use of highly differentiated ferret tracheal epithelium cell cultures, FTE, for predicting the potential of ferrets to support respiratory viral infections. FTE cultures supported productive replication of human influenza A and B viruses but not of MuV, whereas analogous cells generated from human airways supported replication of all three viruses. We propose that in vitro strategies using these cultures might serve as a method of triaging viruses and potentially reducing the use of ferrets in viral studies.
of in vitro transcripts in Huh7.5 cells, production of infectious viruses was delayed. However, in subsequent viral passages efficient spread of infection and HCV RNA titers as high as for J6/JFH were obtained. Infectivity titers were at all time points analyzed comparable to J6/JFH control virus. Sequence...... analysis of recovered 5a/2a recombinants from 2 serial passages and subsequent reverse genetic studies revealed adaptive mutations in p7, NS2 and/or NS3. Infectivity of the 5a/2a viruses was CD81 and SR-BI dependant, and the recombinant viruses could be neutralized by chronic phase sera from patients...... infected with genotype 5a. Conclusion: The developed 5a/2a viruses provide a robust in vitro tool for research in HCV genotype 5, including vaccine studies and functional analyses of an increasingly important genotype in South Africa and Europe...
Avazova, Dildora; Kurbanov, Fuat; Tanaka, Yasuhito; Sugiyama, Masaya; Radchenko, Ivan; Ruziev, Dilmurod; Musabaev, Erkin; Mizokami, Masashi
A national program of universal vaccination for the prevention of chronic hepatitis B virus (HBV) infection was launched in Uzbekistan since 1998. To evaluate the 6 years' outcome of the program, 567 children were enrolled in the study. Among those enrolled, 333 had immunized with adw2 type based Engerix-B (Glaxo Smith Kline Beechem, Rixensart, Belgium) and 48 with adr type based Hepavax-Gene (Green Cross Vaccine Corporation, Korea). A cohort of 186 children born before the immunization program, was also included in the study. When 45 vaccinated children were compared to age/sex-matched 45 unvaccinated children, the sero-prevalence of HBsAg was 0 versus 11% (P = 0.56), and of anti-HBc was 0% versus 44% (P Uzbekistan irrespective of the vaccine formulation used, because the horizontal transmission pattern predominates currently in this endemic region. (Copyright) 2007 Wiley-Liss, Inc.
Marzio, Giuseppe; Vink, Monique; Verhoef, Koen; de Ronde, Anthony; Berkhout, Ben
Transcription represents a crucial step in the life cycle of human immunodeficiency virus (HIV) and is highly regulated. Here we show that the strength of the viral long terminal repeat (LTR) promoter is optimized for efficient replication. Artificially increasing the rate of LTR-driven
Potato virus Y (PVY) strains are transmitted by different aphid species in a non-persistent, non-circulative manner. Green peach aphid (GPA, Myzus persicae Sulzer; Aphididae, Macrosiphini) is the most efficient vector in laboratory studies, but potato aphid (PA, Macrosiphum euphorbiae Thomas; Aphidi...
Hata, Akihiko; Katayama, Hiroyuki; Kojima, Keisuke; Sano, Shoichi; Kasuga, Ikuro; Kitajima, Masaaki; Furumai, Hiroaki
Rainfall events can introduce large amount of microbial contaminants including human enteric viruses into surface water by intermittent discharges from combined sewer overflows (CSOs). The present study aimed to investigate the effect of rainfall events on viral loads in surface waters impacted by CSO and the reliability of molecular methods for detection of enteric viruses. The reliability of virus detection in the samples was assessed by using process controls for virus concentration, nucleic acid extraction and reverse transcription (RT)-quantitative PCR (qPCR) steps, which allowed accurate estimation of virus detection efficiencies. Recovery efficiencies of poliovirus in river water samples collected during rainfall events (10%). The log10-transformed virus concentration efficiency was negatively correlated with suspended solid concentration (r(2)=0.86) that increased significantly during rainfall events. Efficiencies of DNA extraction and qPCR steps determined with adenovirus type 5 and a primer sharing control, respectively, were lower in dry weather. However, no clear relationship was observed between organic water quality parameters and efficiencies of these two steps. Observed concentrations of indigenous enteric adenoviruses, GII-noroviruses, enteroviruses, and Aichi viruses increased during rainfall events even though the virus concentration efficiency was presumed to be lower than in dry weather. The present study highlights the importance of using appropriate process controls to evaluate accurately the concentration of water borne enteric viruses in natural waters impacted by wastewater discharge, stormwater, and CSOs. © 2013.
Lund, Anders Henrik; Duch, M; Lovmand, J
Two Akv murine leukemia virus-based retroviral vectors with primer binding sites matching tRNA(Gln-1) and tRNA(Lys-3) were constructed. The transduction efficiency of these mutated vectors was found to be comparable to that of a vector carrying the wild-type primer binding site matching t......RNA(Pro). Polymerase chain reaction amplification and sequence analysis of transduced proviruses confirmed the transfer of vectors with mutated primer binding sites and further showed that tRNA(Gln-2) may act efficiently in conjunction with the tRNA(Gln-1) primer binding site. We conclude that murine leukemia virus...... can replicate by using various tRNA molecules as primers and propose primer binding site-tRNA primer interactions to be of major importance for tRNA primer selection. However, efficient primer selection does not require perfect Watson-Crick base pairing at all 18 positions of the primer binding site....
Full Text Available Duck Tembusu virus (DTMUV is a recently emerging pathogenic flavivirus that has resulted in a huge economic loss in the duck industry. However, no vaccine is currently available to control this pathogen. Consequently, a practical strategy to construct a vaccine against this pathogen should be determined. In this study, duck enteritis virus (DEV was examined as a candidate vaccine vector to deliver the envelope (E of DTMUV. A modified mini-F vector was inserted into the SORF3 and US2 gene junctions of the attenuated DEV vaccine strain C-KCE genome to generate an infectious bacterial artificial chromosome (BAC of C-KCE (vBAC-C-KCE. The envelope (E gene of DTMUV was inserted into the C-KCE genome through the mating-assisted genetically integrated cloning (MAGIC strategy, resulting in the recombinant vector, pBAC-C-KCE-E. A bivalent vaccine C-KCE-E was generated by eliminating the BAC backbone. Immunofluorescence and western blot analysis results indicated that the E proteins were vigorously expressed in C-KCE-E-infected chicken embryo fibroblasts (CEFs. Duck experiments demonstrated that the insertion of the E gene did not alter the protective efficacy of C-KCE. Moreover, C-KCE-E-immunized ducks induced neutralization antibodies against DTMUV. These results demonstrated, for the first time, that recombinant C-KCE-E can serve as a potential bivalent vaccine against DEV and DTMUV.
Full Text Available After endocytic uptake, influenza viruses transit early endosomal compartments and eventually reach late endosomes. There, the viral glycoprotein hemagglutinin (HA triggers fusion between endosomal and viral membrane, a critical step that leads to release of the viral segmented genome destined to reach the cell nucleus. Endosomal maturation is a complex process involving acidification of the endosomal lumen as well as endosome motility along microtubules. While the pH drop is clearly critical for the conformational change and membrane fusion activity of HA, the effect of intracellular transport dynamics on the progress of infection remains largely unclear. In this study, we developed a comprehensive mathematical model accounting for the first steps of influenza virus infection. We calibrated our model with experimental data and challenged its predictions using recombinant viruses with altered pH sensitivity of HA. We identified the time point of virus-endosome fusion and thereby the diffusion distance of the released viral genome to the nucleus as a critical bottleneck for efficient virus infection. Further, we concluded and supported experimentally that the viral RNA is subjected to cytosolic degradation strongly limiting the probability of a successful genome import into the nucleus.
Full Text Available The presence of enteric viruses in biosolids can be underestimated due to the inefficient methods (mainly molecular methods used to recover the viruses from these matrices. Therefore, the goal of this study was to evaluate the different methods used to recover adenoviruses (AdV, rotavirus species A (RVA, norovirus genogroup II (NoV GII and the hepatitis A virus (HAV from biosolid samples at a large urban wastewater treatment plant in Brazil after they had been treated by mesophilic anaerobic digestion. Quantitative polymerase chain reaction (PCR was used for spiking experiments to compare the detection limits of feasible methods, such as beef extract elution and ultracentrifugation. Tests were performed to detect the inhibition levels and the bacteriophage PP7 was used as an internal control. The results showed that the inhibitors affected the efficiency of the PCR reaction and that beef extract elution is a suitable method for detecting enteric viruses, mainly AdV from biosolid samples. All of the viral groups were detected in the biosolid samples: AdV (90%, RVA, NoV GII (45% and HAV (18%, indicating the viruses' resistance to the anaerobic treatment process. This is the first study in Brazil to detect the presence of RVA, AdV, NoV GII and HAV in anaerobically digested sludge, highlighting the importance of adequate waste management.
Full Text Available The presence of high molecular weight double-stranded RNA (dsRNA within plant cells is an indicator of infection with RNA viruses as these possess genomic or replicative dsRNA. DECS (dsRNA isolation, exhaustive amplification, cloning, and sequencing analysis has been shown to be capable of detecting unknown viruses. We postulated that a combination of DECS analysis and next-generation sequencing (NGS would improve detection efficiency and usability of the technique. Here, we describe a model case in which we efficiently detected the presumed genome sequence of Blueberry shoestring virus (BSSV, a member of the genus Sobemovirus, which has not so far been reported. dsRNAs were isolated from BSSV-infected blueberry plants using the dsRNA-binding protein, reverse-transcribed, amplified, and sequenced using NGS. A contig of 4,020 nucleotides (nt that shared similarities with sequences from other Sobemovirus species was obtained as a candidate of the BSSV genomic sequence. Reverse transcription (RT-PCR primer sets based on sequences from this contig enabled the detection of BSSV in all BSSV-infected plants tested but not in healthy controls. A recombinant protein encoded by the putative coat protein gene was bound by the BSSV-antibody, indicating that the candidate sequence was that of BSSV itself. Our results suggest that a combination of DECS analysis and NGS, designated here as “DECS-C,” is a powerful method for detecting novel plant viruses.
Yehia A. Osman; Waled M. El-Senousy; Adel A. El-Morsi; Mohammed K. Rashed
The fecal bacteria have been taken as the gold standard for water industry. However, the spread of viral gastroenteritis due to drinking water have given a momentum to a recent push by microbiologists to consider viruses as important pollution indicator as fecal bacteria. Therefore, we designed a study to evaluate the efficiency of two types of water purification systems: the traditional water treatment plant and two types compact units. Both systems produced drinking waters free of bacteria,...
Benjamin D Dalziel
Full Text Available Host-range shifts in influenza virus are a major risk factor for pandemics. A key question in the study of emerging zoonoses is how the evolution of transmission efficiency interacts with heterogeneity in contact patterns in the new host species, as this interplay influences disease dynamics and prospects for control. Here we use a synergistic mixture of models and data to tease apart the evolutionary and demographic processes controlling a host-range shift in equine H3N8-derived canine influenza virus (CIV. CIV has experienced 15 years of continuous transfer among dogs in the United States, but maintains a patchy distribution, characterized by sporadic short-lived outbreaks coupled with endemic hotspots in large animal shelters. We show that CIV has a high reproductive potential in these facilities (mean R(0 = 3.9 and that these hotspots act as refugia from the sparsely connected majority of the dog population. Intriguingly, CIV has evolved a transmission efficiency that closely matches the minimum required to persist in these refugia, leaving it poised on the extinction/invasion threshold of the host contact network. Corresponding phylogenetic analyses show strong geographic clustering in three US regions, and that the effective reproductive number of the virus (R(e in the general dog population is close to 1.0. Our results highlight the critical role of host contact structure in CIV dynamics, and show how host contact networks could shape the evolution of pathogen transmission efficiency. Importantly, efficient control measures could eradicate the virus, in turn minimizing the risk of future sustained transmission among companion dogs that could represent a potential new axis to the human-animal interface for influenza.
Dalziel, Benjamin D.; Huang, Kai; Geoghegan, Jemma L.; Arinaminpathy, Nimalan; Dubovi, Edward J.; Grenfell, Bryan T.; Ellner, Stephen P.; Holmes, Edward C.; Parrish, Colin R.
Host-range shifts in influenza virus are a major risk factor for pandemics. A key question in the study of emerging zoonoses is how the evolution of transmission efficiency interacts with heterogeneity in contact patterns in the new host species, as this interplay influences disease dynamics and prospects for control. Here we use a synergistic mixture of models and data to tease apart the evolutionary and demographic processes controlling a host-range shift in equine H3N8-derived canine influenza virus (CIV). CIV has experienced 15 years of continuous transfer among dogs in the United States, but maintains a patchy distribution, characterized by sporadic short-lived outbreaks coupled with endemic hotspots in large animal shelters. We show that CIV has a high reproductive potential in these facilities (mean R0 = 3.9) and that these hotspots act as refugia from the sparsely connected majority of the dog population. Intriguingly, CIV has evolved a transmission efficiency that closely matches the minimum required to persist in these refugia, leaving it poised on the extinction/invasion threshold of the host contact network. Corresponding phylogenetic analyses show strong geographic clustering in three US regions, and that the effective reproductive number of the virus (Re) in the general dog population is close to 1.0. Our results highlight the critical role of host contact structure in CIV dynamics, and show how host contact networks could shape the evolution of pathogen transmission efficiency. Importantly, efficient control measures could eradicate the virus, in turn minimizing the risk of future sustained transmission among companion dogs that could represent a potential new axis to the human-animal interface for influenza. PMID:25340642
Yang, Xiao Xi; Li, Chun Mei; Huang, Cheng Zhi
Interactions between nanoparticles and viruses have attracted increasing attention due to the antiviral activity of nanoparticles and the resulting possibility to be employed as biomedical interventions. In this contribution, we developed a very simple route to prepare uniform and stable silver nanoparticles (AgNPs) with antiviral properties by using curcumin, which is a member of the ginger family isolated from rhizomes of the perennial herb Curcuma longa and has a wide range of biological activities like antioxidant, antifungal, antibacterial and anti-inflammatory effects, and acts as reducing and capping agents in this synthetic route. The tissue culture infectious dose (TCID50) assay showed that the curcumin modified silver nanoparticles (cAgNPs) have a highly efficient inhibition effect against respiratory syncytial virus (RSV) infection, giving a decrease of viral titers about two orders of magnitude at the concentration of cAgNPs under which no toxicity was found to the host cells. Mechanism investigations showed that cAgNPs could prevent RSV from infecting the host cells by inactivating the virus directly, indicating that cAgNPs are a novel promising efficient virucide for RSV.Interactions between nanoparticles and viruses have attracted increasing attention due to the antiviral activity of nanoparticles and the resulting possibility to be employed as biomedical interventions. In this contribution, we developed a very simple route to prepare uniform and stable silver nanoparticles (AgNPs) with antiviral properties by using curcumin, which is a member of the ginger family isolated from rhizomes of the perennial herb Curcuma longa and has a wide range of biological activities like antioxidant, antifungal, antibacterial and anti-inflammatory effects, and acts as reducing and capping agents in this synthetic route. The tissue culture infectious dose (TCID50) assay showed that the curcumin modified silver nanoparticles (cAgNPs) have a highly efficient inhibition
Cheng, Henrique; Wolfe, Stephanie H; Valencia, Valery; Qian, Keping; Shen, Leping; Phillips, M Ian; Chang, Lung-Ji; Zhang, Y Clare
Efficient delivery of therapeutic proteins into the pancreas represents a major obstacle to gene therapy of pancreatic disorders. The current study compared the efficiency of recombinant lentivirus and adeno-associated virus (AAV) serotypes 1, 2, 5, 8 vectors delivered by intrapancreatic injection for gene transfer in vivo. Our results indicate that lentivirus and AAV 1, 2, 8 are capable of transducing pancreas with the order of efficiency AAV8 >AAV1 > AAV2 >/= lentivirus, whereas AAV5 was ineffective. AAV8 resulted in an efficient, persistent (150 days) and dose-dependent transduction in exocrine acinar cells and endocrine islet cells. Pancreatic ducts and blood vessels were also transduced. Extrapancreatic transduction was restricted to liver. Leukocyte infiltration was not observed in pancreas and blood glucose levels were not altered. Thus, AAV8 represents a safe and effective vehicle for therapeutic gene transfer to pancreas in vivo.
Chad R Irwin
Full Text Available Myxoma virus (MYXV is one of many animal viruses that exhibit oncolytic properties in transformed human cells. Compared to orthopoxviruses like vaccinia (VACV, MYXV spreads inefficiently, which could compromise its use in treating tumors and their associated metastases. The VACV F11 protein promotes virus exit and rapid spread by inhibiting Rho signalling, which results in a disruption of cortical actin. We have previously shown that although MYXV lacks an F11 homolog, the F11L gene can be introduced into MYXV promoting the spread of this Leporipoxvirus in natural host cells. Here we show that the F11-encoding (F11L(+ MYXV strain replicates to higher levels in a number of human cancer cells. We also show that F11L(+ MYXV induces better tumor control and prolonged survival of mice bearing MDA-MB-231 cancer cells. Furthermore, we show that this virus also spreads more efficiently from the site of growth in one injected tumor, to a second untreated tumor. While we focused mostly on the use of a modified MYXV we were able to show that the effects of F11 on MYXV growth in cancer cells could be mimicked through the use of pharmacological inhibition or siRNA-mediated silencing of key regulators of cortical actin (RhoA, RhoC, mDia1, or LIMK2. These data suggest that it may be possible to increase the oncolytic efficacy of wild-type MYXV using chemical inhibitors of RhoA/C or their downstream targets. Furthermore, since all viruses must overcome barriers to exit posed by structures like cortical actin, these findings suggest that the oncolytic activity of other viruses may be enhanced through similar strategies.
Irwin, Chad R.; Favis, Nicole A.; Agopsowicz, Kate C.; Hitt, Mary M.; Evans, David H.
Myxoma virus (MYXV) is one of many animal viruses that exhibit oncolytic properties in transformed human cells. Compared to orthopoxviruses like vaccinia (VACV), MYXV spreads inefficiently, which could compromise its use in treating tumors and their associated metastases. The VACV F11 protein promotes virus exit and rapid spread by inhibiting Rho signalling, which results in a disruption of cortical actin. We have previously shown that although MYXV lacks an F11 homolog, the F11L gene can be introduced into MYXV promoting the spread of this Leporipoxvirus in natural host cells. Here we show that the F11-encoding (F11L+) MYXV strain replicates to higher levels in a number of human cancer cells. We also show that F11L+ MYXV induces better tumor control and prolonged survival of mice bearing MDA-MB-231 cancer cells. Furthermore, we show that this virus also spreads more efficiently from the site of growth in one injected tumor, to a second untreated tumor. While we focused mostly on the use of a modified MYXV we were able to show that the effects of F11 on MYXV growth in cancer cells could be mimicked through the use of pharmacological inhibition or siRNA-mediated silencing of key regulators of cortical actin (RhoA, RhoC, mDia1, or LIMK2). These data suggest that it may be possible to increase the oncolytic efficacy of wild-type MYXV using chemical inhibitors of RhoA/C or their downstream targets. Furthermore, since all viruses must overcome barriers to exit posed by structures like cortical actin, these findings suggest that the oncolytic activity of other viruses may be enhanced through similar strategies. PMID:24391902
Irwin, Chad R; Favis, Nicole A; Agopsowicz, Kate C; Hitt, Mary M; Evans, David H
Myxoma virus (MYXV) is one of many animal viruses that exhibit oncolytic properties in transformed human cells. Compared to orthopoxviruses like vaccinia (VACV), MYXV spreads inefficiently, which could compromise its use in treating tumors and their associated metastases. The VACV F11 protein promotes virus exit and rapid spread by inhibiting Rho signalling, which results in a disruption of cortical actin. We have previously shown that although MYXV lacks an F11 homolog, the F11L gene can be introduced into MYXV promoting the spread of this Leporipoxvirus in natural host cells. Here we show that the F11-encoding (F11L(+)) MYXV strain replicates to higher levels in a number of human cancer cells. We also show that F11L(+) MYXV induces better tumor control and prolonged survival of mice bearing MDA-MB-231 cancer cells. Furthermore, we show that this virus also spreads more efficiently from the site of growth in one injected tumor, to a second untreated tumor. While we focused mostly on the use of a modified MYXV we were able to show that the effects of F11 on MYXV growth in cancer cells could be mimicked through the use of pharmacological inhibition or siRNA-mediated silencing of key regulators of cortical actin (RhoA, RhoC, mDia1, or LIMK2). These data suggest that it may be possible to increase the oncolytic efficacy of wild-type MYXV using chemical inhibitors of RhoA/C or their downstream targets. Furthermore, since all viruses must overcome barriers to exit posed by structures like cortical actin, these findings suggest that the oncolytic activity of other viruses may be enhanced through similar strategies.
Guo, Jin-Chao; Tang, Yan-Dong; Zhao, Kuan; Wang, Tong-Yun; Liu, Ji-Ting; Gao, Jia-Cong; Chang, Xiao-Bo; Cui, Hong-Yu; Tian, Zhi-Jun; Cai, Xue-Hui; An, Tong-Qing
Bacterial artificial chromosomes (BACs) are powerful tools for the manipulation of the large genomes of DNA viruses, such as herpesviruses. However, the methods currently used to construct the recombinant viruses, an important intermediate link in the generation of BACs, involve the laborious process of multiple plaque purifications. Moreover, some fastidious viruses may be lost or damaged during these processes, making it impossible to generate BACs from these large-genome DNA viruses. Here, we introduce the CRISPR/Cas9 as a site-specific gene knock-in instrument that promotes the homologs recombination of a linearized transfer vector and the Pseudorabies virus genome through double incisions. The efficiency of recombination is as high as 86%. To our knowledge, this is the highest efficiency ever reported for Pseudorabies virus recombination. We also demonstrate that the positions and distances of the CRISPR/Cas9 single guide RNAs from the homology arms correlate with the efficiency of homologous recombination. Our work show a simple and fast cloning method of BACs with large genome inserted by greatly enhancing the HR efficiencies through CRISPR/Cas9-mediated homology-directed repair mechanism, and this method could be of helpful for manipulating large DNA viruses, and will provide a successful model for insertion of large DNA fragments into other viruses.
Wang, Qiaochun; Cuellar, Wilmer J; Rajamäki, Minna-Liisa; Hirata, Yukimasa; Valkonen, Jari P T
Accumulation of viruses in vegetatively propagated plants causes heavy yield losses. Therefore, supply of virus-free planting materials is pivotal to sustainable crop production. In previous studies, Raspberry bushy dwarf virus (RBDV) was difficult to eradicate from raspberry (Rubus idaeus) using the conventional means of meristem tip culture. As shown in the present study, it was probably because this pollen-transmitted virus efficiently invades leaf primordia and all meristematic tissues except the least differentiated cells of the apical dome. Subjecting plants to thermotherapy prior to meristem tip culture heavily reduced viral RNA2, RNA3 and the coat protein in the shoot tips, but no virus-free plants were obtained. Therefore, a novel method including thermotherapy followed by cryotherapy was developed for efficient virus eradication. Heat treatment caused subcellular alterations such as enlargement of vacuoles in the more developed, virus-infected cells, which were largely eliminated following subsequent cryotherapy. Using this protocol, 20-36% of the treated shoot tips survived, 30-40% regenerated and up to 35% of the regenerated plants were virus-free, as tested by ELISA and reverse transcription loop-mediated isothermal amplification. Novel cellular and molecular insights into RBDV-host interactions and the factors influencing virus eradication were obtained, including invasion of shoot tips and meristematic tissues by RBDV, enhanced viral RNA degradation and increased sensitivity to freezing caused by thermotherapy, and subcellular changes and subsequent death of cells caused by cryotherapy. This novel procedure should be helpful with many virus-host combinations in which virus eradication by conventional means has proven difficult.
Lennefors, Britt-Louise; van Roggen, Petra M; Yndgaard, Flemming; Savenkov, Eugene I; Valkonen, Jari P T
Rhizomania caused by Beet necrotic yellow vein virus (BNYVV) is one of the most devastating sugar beet diseases. Sugar beet plants engineered to express a 0.4 kb inverted repeat construct based on the BNYVV replicase gene accumulated the transgene mRNA to similar levels in leaves and roots, whereas accumulation of the transgene-homologous siRNA was more pronounced in roots. The roots expressed high levels of resistance to BNYVV transmitted by the vector, Polymyxa betae. Resistance to BNYVV was not decreased following co-infection of the plants with Beet soil borne virus and Beet virus Q that share the same vector with BNYVV. Similarly, co-infection with the aphid-transmitted Beet mild yellowing virus, Beet yellows virus (BYV), or with all of the aforementioned viruses did not affect the resistance to BNYVV, while they accumulated in roots. These viruses are common in most of the sugar beet growing areas in Europe and world wide. However, there was a competitive interaction between BYV and BMYV in sugar beet leaves, as infection with BYV decreased the titres of BMYV. Other interactions between the viruses studied were not observed. The results suggest that the engineered resistance to BNYVV expressed in the sugar beets of this study is efficient in roots and not readily compromised following infection of the plants with heterologous viruses.
Dong, Zhan-Qi; Chen, Ting-Ting; Zhang, Jun; Hu, Nan; Cao, Ming-Ya; Dong, Fei-Fan; Jiang, Ya-Ming; Chen, Peng; Lu, Cheng; Pan, Min-Hui
Although current antiviral strategies can inhibit baculovirus infection and decrease viral DNA replication to a certain extent, novel tools are required for specific and accurate elimination of baculovirus genomes from infected insects. Using the newly developed clustered regularly interspaced short palindromic repeats/associated protein 9 nuclease (CRISPR/Cas9) technology, we disrupted a viral genome in infected insect cells in vitro as a defense against viral infection. We optimized the CRISPR/Cas9 system to edit foreign and viral genome in insect cells. Using Bombyx mori nucleopolyhedrovirus (BmNPV) as a model, we found that the CRISPR/Cas9 system was capable of cleaving the replication key factor ie-1 in BmNPV thus effectively inhibiting virus proliferation. Furthermore, we constructed a virus-inducible CRISPR/Cas9 editing system, which minimized the probability of off-target effects and was rapidly activated after viral infection. This is the first report describing the application of the CRISPR/Cas9 system in insect antiviral research. Establishment of a highly efficient virus-inducible CRISPR/Cas9 system in insect cells provides insights to produce virus-resistant transgenic strains for future. Copyright © 2016 Elsevier B.V. All rights reserved.
Mishchenko, Ivan; Nechitailo, Galina S.; Dunich, Alina; Mishchenko, Anatoliy; Boiko, Anatolii
organization, and physiological balances. Using microgravity simulated in the clinostats, it is possible to investigate the effects of this factor on the relationships in the system “virus - host plant”. This problem remains important as its solution allows to discover a wider set of techniques allowing to obtain plants free from viral infections. The possibility of the WSMV (wheat steak mosaic virus) elimination in wheat plants under the influence of simulated microgravity has been demonstrated in our works. The study of this phenomenon allowed to admit that the freeing of plants from viral infection under the impact of simulated microgravity occurs in the process of induced resistance formation. In our further research activities, we used potato plants for which the elimination of viral infections is of exceptional importance. Viruses transmitted mechanically have to use a vascular system to move all over the plant and, finally, into the tubers. The factors limiting this movability will at certain moments of plant growth favor the elimination of virus in certain parts of the plant. Introduction of tissues from such parts into in vitro cultures allows to regenerate virus-free plants. Epy efficiency of tissue culture in combination with clonal micro multiplication in vitro allows to obtain up to 1 mln plants from a single one in half a year. Such a productivity of a new technology allowed to prognosticate the potato production in vitro in the world on the level of 212 mln plantlets per year. But today, according to some estimates the in vitro potato production may be achieved with lower expenditures on plant remediation and freeing of the cultivars from viral infection. Therefore the purpose of work was to probe possibilities of receiving virus free seminal material of potato at the terms of clinorotation and set of its economic efficiency. Researches of simulated microgravity influence conducted on the potato varieties Sineglazka, Crimean, Agave, Linda, Bellaroza
Kosel, Janez; Gutiérrez-Aguirre, Ion; Rački, Nejc; Dreo, Tanja; Ravnikar, Maja; Dular, Matevž
The aim of this study was to accurately quantify the impact of hydrodynamic cavitation on the infectivity of bacteriophage MS2, a norovirus surrogate, and to develop a small scale reactor for testing the effect of hydrodynamic cavitation on human enteric viruses, which cannot be easily prepared in large quantities. For this purpose, 3 mL scale and 1 L scale reactors were constructed and tested. Both devices were efficient in generating hydrodynamic cavitation and in reducing the infectivity of MS2 virus. Furthermore, they reached more than 4 logs reductions of viral infectivity, thus confirming the scalability of hydrodynamic cavitation for this particular application. As for the mechanism of page inactivation, we suspect that cavitation generated OH - radicals formed an advanced oxidation process, which could have damaged the host's recognition receptors located on the surface of the bacteriophage. Additional damage could arise from the high shear forces inside the cavity. Moreover, the effectiveness of the cavitation was higher for suspensions containing low initial viral titers that are in similar concentration to the ones found in real water samples. According to this, cavitation generators could prove to be a useful tool for treating virus-contaminated wastewaters in the future. Copyright © 2017 Elsevier Ltd. All rights reserved.
Full Text Available Abstract To search for cellular genes up-regulated by vaccinia virus (VV infection, differential display-reverse transcription-polymerase chain reaction (ddRT-PCR assays were used to examine the expression of mRNAs from mock-infected and VV-infected HeLa cells. Two mitochondrial genes for proteins that are part of the electron transport chain that generates ATP, ND4 and CO II, were up-regulated after VV infection. Up-regulation of ND4 level by VV infection was confirmed by Western blotting analysis. Up-regulation of ND4 was reduced by the MAPK inhibitor, apigenin, which has been demonstrated elsewhere to inhibit VV replication. The induction of ND4 expression occurred after viral DNA replication since ara C, an inhibitor of poxviral DNA replication, could block this induction. ATP production was increased in the host cells after VV infection. Moreover, 4.5 μM oligomycin, an inhibitor of ATP production, reduced the ATP level 13 hr after virus infection to that of mock-infected cells and inhibited viral protein expression and virus production, suggesting that increased ATP production is required for efficient VV production. Our results further suggest that induction of ND4 expression is through a Bcl-2 independent pathway.
Zheng, Nuoyan; Pérez, José de Jesús; Zhang, Zhonghui; Domínguez, Elvira; Garcia, Juan Antonio; Xie, Qi
Site-specific proteases are the most popular kind of enzymes for removing the fusion tags from fused target proteins. Nuclear inclusion protein a (NIa) proteases obtained from the family Potyviridae have become promising due to their high activities and stringencies of sequences recognition. NIa proteases from tobacco etch virus (TEV) and tomato vein mottling virus (TVMV) have been shown to process recombinant proteins successfully in vitro. In this report, recombinant PPV (plum pox virus) NIa protease was employed to process fusion proteins with artificial cleavage site in vitro. Characteristics such as catalytic ability and affecting factors (salt, temperature, protease inhibitors, detergents, and denaturing reagents) were investigated. Recombinant PPV NIa protease expressed and purified from Escherichia coli demonstrated efficient and specific processing of recombinant GFP and SARS-CoV nucleocapsid protein, with site F (N V V V H Q black triangle down A) for PPV NIa protease artificially inserted between the fusion tags and the target proteins. Its catalytic capability is similar to those of TVMV and TEV NIa protease. Recombinant PPV NIa protease reached its maximal proteolytic activity at approximately 30 degrees C. Salt concentration and only one of the tested protease inhibitors had minor influences on the proteolytic activity of PPV NIa protease. Recombinant PPV NIa protease was resistant to self-lysis for at least five days.
Kojima, Shohei; Honda, Tomoyuki; Matsumoto, Yusuke; Tomonaga, Keizo
Recently developed vector systems based on Borna disease virus (BDV) hold promise as platforms for efficient and stable gene delivery to the central nervous system (CNS). However, because it currently takes several weeks to rescue recombinant BDV (rBDV), an improved rescue procedure would enhance the utility of this system. Heat stress reportedly enhances the rescue efficiency of other recombinant viruses. Here, heat stress was demonstrated to increase the amount of BDV genome in persistently BDV-infected cells without obvious cytotoxicity. Further analyses suggested that the effect of heat stress on BDV infection is not caused by an increase in the activity of BDV polymerase. More cells in which BDV replication occurs were obtained in the initial phase of rBDV rescue by using heat stress than when it was not used. Thus, heat stress is a useful improvement on the published rescue procedure for rBDV. The present findings may accelerate the practical use of BDV vector systems in basic science and the clinic and thus enable broader adoption of this viral vector, which is uniquely suited for gene delivery to the CNS. © 2014 The Societies and Wiley Publishing Asia Pty Ltd.
Watanabe, Yohei; Ibrahim, Madiha S; Hagiwara, Katsuro; Okamoto, Minoru; Kamitani, Wataru; Yanai, Hideyuki; Ohtaki, Naohiro; Hayashi, Yohei; Taniyama, Hiroyuki; Ikuta, Kazuyoshi; Tomonaga, Keizo
To investigate the biological characteristics of field isolates of Borna disease virus (BDV), as well as to understand BDV infections outside endemic countries, we isolated the virus from brain samples of a heifer with Borna disease in Japan. We demonstrate that the brain lysate contained replication products of BDV and induced viral propagation in rat glioma cells, suggesting that a replication-competent BDV existed in the bovine brain. This field strain of BDV, named Bo/04w, showed efficient viral release and transmissibility and also displayed a distinct pattern of expression of viral phosphoprotein (P) during infection, as compared with laboratory-adapted BDV strains. Interestingly, we found the level of P to be significantly low in cells infected with Bo/04w, and the transcription of this isolate to be more efficient than that of laboratory strain of BDV. These results indicated that the field isolate may regulate the expression of P at an optimal level in infected cells. We also confirmed that Bo/04w maintains biological significance in neonatal gerbil brain. Sequencing revealed that despite the biological differences, the field isolate is closely related genetically to the laboratory strains of BDV. We discuss here the sequence similarities between BDV isolates from endemic and nonendemic countries.
Merezak, C; Pierreux, Christophe; Adam, E.; Lemaigre, Frédéric; Rousseau, Guy; Calomme, C; Van Lint, C; Christophe, D; Kerkhofs, P.; Burny, A.; Kettmann, R.; Willems, L.
Repression of viral expression is a major strategy developed by retroviruses to escape from the host immune response. The absence of viral proteins (or derived peptides) at the surface of an infected cell does not permit the establishment of an efficient immune attack. Such a strategy appears to have been adopted by animal oncoviruses such as bovine leukemia virus (BLV) and human T-cell leukemia virus (HTLV). In BLV-infected animals, only a small fraction of the infected lymphocytes (between ...
Zheng, Yan; Hu, Yuan
Hepatitis A virus (HAV) can cause serious liver disease and even death. HAV outbreaks are associated with the consumption of raw or minimally processed produce, making it a major public health concern. Infections have occurred despite the fact that effective HAV vaccine has been available. Development of a rapid and sensitive HAV detection method is necessary for an investigation of an HAV outbreak. Detection of HAV is complicated by the lack of a reliable culture method. In addition, due to the low infectious dose of HAV, these methods must be very sensitive. Current methods rely on efficient sample preparation and concentration steps followed by sensitive molecular detection techniques. Using green onions which was involved in most recent HAV outbreaks as a representative produce, a method of capturing virus particles was developed using carboxyl-derivatized magnetic beads in this study. Carboxyl beads, like antibody-coated beads or cationic beads, detect HAV at a level as low as 100 pfu/25g of green onions. RNA from virus concentrated in this manner can be released by heat-shock (98°C 5min) for molecular detection without sacrificing sensitivity. Bypassing the RNA extraction procedure saves time and removes multiple manipulation steps, which makes large scale HAV screening possible. In addition, the inclusion of beef extract and pectinase rather than NP40 in the elution buffer improved the HAV liberation from the food matrix over current methods by nearly 10 fold. The method proposed in this study provides a promising tool to improve food risk assessment and protect public health. Published by Elsevier B.V.
Lindbo John A
Full Text Available Abstract Background Plants are increasingly being examined as alternative recombinant protein expression systems. Recombinant protein expression levels in plants from Tobacco mosaic virus (TMV-based vectors are much higher than those possible from plant promoters. However the common TMV expression vectors are costly, and at times technically challenging, to work with. Therefore it was a goal to develop TMV expression vectors that express high levels of recombinant protein and are easier, more reliable, and more cost-effective to use. Results We have constructed a Cauliflower mosaic virus (CaMV 35S promoter-driven TMV expression vector that can be delivered as a T-DNA to plant cells by Agrobacterium tumefaciens. Co-introduction (by agroinfiltration of this T-DNA along with a 35S promoter driven gene for the RNA silencing suppressor P19, from Tomato bushy stunt virus (TBSV resulted in essentially complete infection of the infiltrated plant tissue with the TMV vector by 4 days post infiltration (DPI. The TMV vector produced between 600 and 1200 micrograms of recombinant protein per gram of infiltrated tissue by 6 DPI. Similar levels of recombinant protein were detected in systemically infected plant tissue 10–14 DPI. These expression levels were 10 to 25 times higher than the most efficient 35S promoter driven transient expression systems described to date. Conclusion These modifications to the TMV-based expression vector system have made TMV vectors an easier, more reliable and more cost-effective way to produce recombinant proteins in plants. These improvements should facilitate the production of recombinant proteins in plants for both research and product development purposes. The vector should be especially useful in high-throughput experiments.
Chung, Chueh-Yao; Liu, Ching-Hsuan; Wang, Guey-Horng; Jassey, Alagie; Li, Chia-Lin; Chen, Lei; Yen, Ming-Hong; Lin, Chun-Ching; Lin, Liang-Tzung
Without a vaccine, hepatitis C virus (HCV) remains a significant threat, putting 170-300 million carriers worldwide at risk of cirrhosis and hepatocellular carcinoma. Although the direct-acting antivirals targeting HCV replication have revolutionized the treatment of hepatitis C, several obstacles persist, including resistance development, potential side-effects, and the prohibitive cost that limits their availability. Furthermore, treatment of HCV re-infection in liver transplantation remains a significant challenge. Developing novel antivirals that target viral entry could help expand the scope of HCV therapeutics and treatment strategies. Herein, we report (4R,6S)-2-dihydromenisdaurilide (DHMD), a natural butenolide, as an efficient inhibitor of HCV entry. Specifically, DHMD potently inhibited HCV infection at non-cytotoxic concentration. Examination on the viral life cycle demonstrated that DHMD selectively targeted the early steps of infection while leaving viral replication/translation and assembly/release unaffected. Furthermore, DHMD did not induce an antiviral interferon response. Mechanistic dissection of HCV entry revealed that DHMD could inactivate cell-free virus, abrogate viral attachment, and inhibit viral entry/fusion, with the most pronounced effect observed against the viral adsorption phase as validated using ELISA and confocal microscopy. Due to its potency, DHMD may be of value for further development as an entry inhibitor against HCV, particularly for application in transplant setting.
Sundaresha, S; Sreevathsa, Rohini; Balol, Gurupada B; Keshavareddy, G; Rangaswamy, K T; Udayakumar, M
A rapid and efficient sap inoculation method for tobacco streak virus (TSV) was developed in sunflower. Sap from TSV-infected sunflower plants was freshly extracted in phosphate buffer and diluted serially from 10(-1) to 10(-8). Two-day old seedlings of sunflower were injured at the meristem and immersed in the sap for 10 min, maintained at 20 °C for 2-3 days and shifted to greenhouse. The surviving seedlings in the respective sap dilution were scored for symptoms of sunflower necrosis disease (SND). SND symptoms were seen in 80 % of the seedlings inoculated with a sap dilution of 10(-5). ELISA and RT-PCR analysis of coat protein and movement protein of TSV confirmed SND symptoms. The methodology was also found to be reproducible when the sap from the infected plants was inoculated onto healthy plants. The main aim of the study was to develop a primary screening strategy for the selection of transgenics developed for SND resistance. This methodology can also be extended for the analysis of resistance against other viruses.
Full Text Available Annexin A2 (ANXA2 is a protein implicated in diverse cellular functions, including exocytosis, DNA synthesis and cell proliferation. It was recently proposed to be involved in RNA metabolism because it was shown to associate with some cellular mRNA. Here, we identified ANXA2 as a RNA binding protein (RBP that binds IBV (Infectious Bronchitis Virus pseudoknot RNA. We first confirmed the binding of ANXA2 to IBV pseudoknot RNA by ultraviolet crosslinking and showed its binding to RNA pseudoknot with ANXA2 protein in vitro and in the cells. Since the RNA pseudoknot located in the frameshifting region of IBV was used as bait for cellular RBPs, we tested whether ANXA2 could regulate the frameshfting of IBV pseudoknot RNA by dual luciferase assay. Overexpression of ANXA2 significantly reduced the frameshifting efficiency from IBV pseudoknot RNA and knockdown of the protein strikingly increased the frameshifting efficiency. The results suggest that ANXA2 is a cellular RBP that can modulate the frameshifting efficiency of viral RNA, enabling it to act as an anti-viral cellular protein, and hinting at roles in RNA metabolism for other cellular mRNAs.
Sakai, Makoto; Fujimoto, Naohiro; Ishii, Katsunori; Nakamura, Hiroyuki; Kaneda, Yasufumi; Awazu, Kunio
Photodynamic therapy (PDT) is a photochemical modality approved for cancer treatment. PDT has demonstrated efficacy in early stage lung cancer and esophageal cancer. The accumulation of photosensitizers in cancer cells is necessary to enhance the therapeutic benefits of PDT; however, photosensitizers have low uptake efficiency. To overcome this limitation, a drug delivery system, such as the hemagglutinating virus of Japan envelope (HVJ-E) vector, is required. In this study, the combination of PDT and HVJ-E was investigated for enhancing the efficacy of PDT. The photosensitizers that were evaluated included 5-aminolaevulinic acid (5-ALA), protoporphyrin IX (PPIX), and HVJ-PPIX. The uptake of the photosensitizers as increased twenty-fold with the addition of HVJ-E. The cytotoxicity of conventional 5-ALA was enhanced by the addition of HVJ-E vector. In conclusion, HVJ-E vector improved the uptake of photosensitizers and the PDT effect.
Masamizu, Yoshito; Okada, Takashi; Ishibashi, Hidetoshi; Takeda, Shin'ichi; Yuasa, Shigeki; Nakahara, Kiyoshi
Although the adeno-associated virus (AAV) vector is a promising tool for gene transfer into neurons, especially for therapeutic purposes, neurotropism in primate brains is not fully elucidated for specific AAV serotypes. Here, we injected AAV serotype 8 (AAV8) vector carrying the enhanced green fluorescent protein (EGFP) gene under a ubiquitous promoter into the cerebral cortex, striatum and substantia nigra of common marmosets. Robust neuronal EGFP expression was observed at all injected sites. Cell typing with immunohistochemistry confirmed efficient AAV8-mediated gene transfer into the pyramidal neurons in the cortex, calbindin-positive medium spiny neurons in the striatum and dopaminergic neurons in the substantia nigra. The results indicate a preferential tropism of AAV8 for subsets of neurons, but not for glia, in monkey brains.
Zhang, Yanfang; Du, Ruikun; Huang, Shaomei; Zhang, Tao; Liu, Jinliang; Zhu, Bibo; Wang, Hualin; Deng, Fei; Cao, Shengbo
The cDNA fragment of JEV prME gene was cloned into the baculovirus shuttle vector (bacmid) to construct a recombinant baculovirus vector, defined as AcBac-prME. Then the recombinant baculovirus Ac-prME was obtained by transfecting Sf9 cells with AcBac-prME. Western blot analysis and immunofluorescence results indicated that both prM and E proteins were efficiently expressed in Sf9 cells. Electron microscopy suggested that prME was assembled into JEV-VLPs. To further evaluate the potential of JEV-VLPs as vaccine, the mice were immunized with JEV-VLPs and then challenged with lethal JEV. The results of mice survival and pathological changes demonstrated that the JEV-VLPs performed complete protection against JEV-P3 strain and relieved pathological changes in the mice brain significant. This study suggest that JEV-VLPs would be a potential vaccine for Japanese encephalitis virus.
Thrane, Susan; Janitzek, Christoph M; Matondo, Sungwa
BACKGROUND: Virus-like particles (VLPs) represent a significant advance in the development of subunit vaccines, combining high safety and efficacy. Their particulate nature and dense repetitive subunit organization makes them ideal scaffolds for display of vaccine antigens. Traditional approaches...... vaccine antigens fused to SpyCatcher or SpyTag resulted in formation of antigen-VLP complexes with coupling efficiencies (% occupancy of total VLP binding sites) ranging from 22-88 %. In mice, spy-VLP vaccines presenting the malaria proteins Pfs25 or VAR2CSA markedly increased antibody titer, affinity......, longevity and functional efficacy compared to corresponding vaccines employing monomeric proteins. The spy-VLP vaccines also effectively broke B cell self-tolerance and induced potent and durable antibody responses upon vaccination with cancer or allergy-associated self-antigens (PD-L1, CTLA-4 and IL-5...
Masud, H M Abdullah Al; Watanabe, Takahiro; Yoshida, Masahiro; Sato, Yoshitaka; Goshima, Fumi; Kimura, Hiroshi; Murata, Takayuki
Epstein-Barr virus (EBV), a member of human gammaherpesvirus, infects mainly B cells. EBV has two alternative life cycles, latent and lytic, and is reactivated occasionally from the latent stage to the lytic cycle. To combat EBV-associated disorders, understanding the molecular mechanisms of the EBV lytic replication cycle is also important. Here, we focused on an EBV lytic gene, BKRF4. Using our anti-BKRF4 antibody, we revealed that the BKRF4 gene product is expressed during the lytic cycle with late kinetics. To characterize the role of BKRF4, we constructed BKRF4-knockout mutants using the bacterial artificial chromosome (BAC) and CRISPR/Cas9 systems. While disruption of the BKRF4 gene had almost no effect on viral protein expression and DNA synthesis, it significantly decreased progeny virion levels in HEK293 and Akata cells. Furthermore, we show that BKRF4 is involved not only in production of progeny virions but also in increasing the infectivity of the virus particles. Immunoprecipitation assays revealed that BKRF4 interacted with a virion protein, BGLF2. We showed that the C-terminal region of BKRF4 was critical for this interaction and for efficient progeny production. Immunofluorescence analysis revealed that BKRF4 partially colocalized with BGLF2 in the nucleus and perinuclear region. Finally, we showed that BKRF4 is a phosphorylated, possible tegument protein and that the EBV protein kinase BGLF4 may be important for this phosphorylation. Taken together, our data suggest that BKRF4 is involved in the production of infectious virions.IMPORTANCE While the latent genes of EBV have been studied extensively, the lytic genes are less well characterized. This study focused on one such lytic gene, BKRF4, which is conserved only among gammaherpesviruses (ORF45 of Kaposi's sarcoma-associated herpesvirus or murine herpesvirus-68). After preparing the BKRF4 knockout virus using B95-8 EBV-BAC, we demonstrated that the BKRF4 gene was involved in infectious progeny
Kondo, Yoshitaka; Miyata, Keizo; Kato, Fuminori
This unit describes a novel method for antibody delivery into living cells using HVJ (hemagglutinating virus of Japan) envelope, an inactivated Sendai virus particle. (c) 2010 by John Wiley & Sons, Inc.
Temple, Rachel M; Zhu, Junjia; Budgeon, Lynn; Christensen, Neil David; Meyers, Craig; Sample, Clare E
Epstein-Barr virus is a ubiquitous human herpesvirus associated with epithelial and lymphoid tumors. EBV is transmitted between human hosts in saliva and must cross the oral mucosal epithelium before infecting B lymphocytes, where it establishes a life-long infection. The latter process is well understood because it can be studied in vitro, but our knowledge of infection of epithelial cells has been limited by the inability to infect epithelial cells readily in vitro or to generate cell lines from EBV-infected epithelial tumors. Because epithelium exists as a stratified tissue in vivo, organotypic cultures may serve as a better model of EBV in epithelium than monolayer cultures. Here, we demonstrate that EBV is able to infect organotypic cultures of epithelial cells to establish a predominantly productive infection in the suprabasal layers of stratified epithelium, similar to that seen with Kaposi's-associated herpesvirus. These cells did express latency-associated proteins in addition to productive-cycle proteins, but a population of cells that exclusively expressed latency-associated viral proteins could not be detected; however, an inability to infect the basal layer would be unlike other herpesviruses examined in organotypic cultures. Furthermore, infection did not induce cellular proliferation, as it does in B cells, but instead resulted in cytopathic effects more commonly associated with productive viral replication. These data suggest that infection of epithelial cells is an integral part of viral spread, which typically does not result in the immortalization or enhanced growth of infected epithelial cells but rather in efficient production of virus.
Full Text Available To investigate the exact effects of different origins of Newcastle disease virus (NDV hemagglutinin-neuraminidase (HN protein to the biological characteristics of the virus, we systematically studied the correlation between the HN protein and NDV virulence by exchanging the HN of velogenic or lentogenic NDV strains with the HN from other strains of different virulence. The results revealed that the rSG10 or rLaSota derivatives bearing the HN gene of other viruses exhibited decreased or increased hemadsorption (HAd, neuraminidase and fusion promotion activities. In vitro and in vivo tests further showed that changes in replication level, tissue tropism and virulence of the chimeric viruses were also consistent with these biological activities. These findings demonstrated that the balance among three biological activities caused variation in replication and pathogenicity of the virus, which was closely related to the origin of the HN protein. Our study highlights the importance of the HN glycoprotein in modulating the virulence of NDV and contributes to a more complete understanding of the virulence of NDV.
Kruijsen, Debby; Einarsdottir, Helga K; Schijf, Marcel A; Coenjaerts, Frank E; van der Schoot, Ellen C; Vidarsson, Gestur; van Bleek, Grada M
Infants are protected from a severe respiratory syncytial virus (RSV) infection in the first months of life by maternal antibodies or by prophylactically administered neutralizing antibodies. Efforts are under way to produce RSV-specific antibodies with increased neutralizing capacity compared to the currently licensed palivizumab. While clearly beneficial during primary infections, preexisting antibodies might affect the onset of adaptive immune responses and the ability to resist subsequent RSV infections. Therefore, we addressed the question of how virus neutralizing antibodies influence the priming of subsequent adaptive immune responses. To test a possible role of the neonatal Fc receptor (FcRn) in this process, we compared the responses in C57BL/6 wild-type (WT) and FcRn(-/-) mice. We observed substantial virus-specific T-cell priming and B-cell responses in mice primed with RSV IgG immune complexes resulting in predominantly Th1-type CD4(+) T-cell and IgG2c antibody responses upon live-virus challenge. RSV-specific CD8(+) T cells were primed as well. Activation of these adaptive immune responses was independent of FcRn. Thus, neutralizing antibodies that localize to the airways and prevent infection-related routes of antigen processing can still facilitate antigen presentation of neutralized virus particles and initiate adaptive immune responses against RSV.
Jian, You-Ru; Chang, Sui-Yuan; Lin, Pin-Yi; Yang, Yao-Hsu; Chuang, Ya-Hui
Allergic asthma is a globally respiratory inflammatory disease. Influenza virus is a respiratory pathogen that causes yearly epidemics and results in high rates of morbidity and mortality. Patients with allergic asthma had a more severe symptom and a higher mortality when they were infected with influenza virus. Hence, influenza vaccination is recommended for patients with asthma. We evaluated the efficacy and effects of influenza vaccination on allergic asthma in a mouse model. Ovalbumin-immunized mice were inoculated with inactivated influenza virus A/Puerto Rico/8/34 (PR8) as vaccines and morbidity or mortality and allergic asthma features of these mice were analyzed. Mice inoculated with inactivated PR8 induced high levels of anti-PR8 IgG2a and upregulation of Toll-like receptor (TLR) 7. Vaccinated allergic mice were healthy when they were challenged with live influenza virus while none of non-vaccinated allergic mice survived. Furthermore, inactivated influenza virus vaccine induced neither extra airway inflammation nor asthma features such as IgE, airway hyper-reactivity, and eosinophilia in allergic mice. Particularly, decreased frequency of immune cell infiltrated airways and Th2 cytokines IL-4 and IL-6 production in the bronchoalveolar lavage fluid were noted in vaccinated allergic mice. These results suggested that inactivated influenza virus vaccine is efficient to protect allergic mice from further influenza infection, and it does not exacerbate but reduces IL-4 and IL-6 of allergic asthma. Influenza vaccination is essential and efficient for allergic subjects to protect influenza virus infection. © 2013 John Wiley & Sons Ltd.
Van de Perre, P; Jacobs, D; Sprecher-Goldberger, S
Using a mechanical model, we studied human immunodeficiency virus (HIV) leakage through six different trademark condoms. The presence of the recovered virus was determined after passage to MT-2 cells and to cultured mitogen-stimulated normal human peripheral blood mononuclear cells (PMC). Only the natural membrane condom showed virus leakage after inside pressure. In addition, the kinetics of virus inactivation at 37 degrees C were followed inside and outside the condom. The virus was partially inactivated after 10 min at 37 degrees C inside the condom, but the degree of inactivation seemed higher in some of the trademark condoms.
Burgers, Wendy A; Ginbot, Zekarias; Shen, Yen-Ju; Chege, Gerald K; Soares, Andreia P; Müller, Tracey L; Bunjun, Rubina; Kiravu, Agano; Munyanduki, Henry; Douglass, Nicola; Williamson, Anna-Lise
Poxvirus vectors represent promising human immunodeficiency virus (HIV) vaccine candidates and were a component of the only successful HIV vaccine efficacy trial to date. We tested the immunogenicity of a novel recombinant capripoxvirus vector, lumpy skin disease virus (LSDV), in combination with modified vaccinia Ankara (MVA), both expressing genes from HIV-1. Here, we demonstrated that the combination regimen was immunogenic in rhesus macaques, inducing high-magnitude, broad and balanced CD4(+) and CD8(+) T-cell responses, and transient activation of the immune response. These studies support further development of LSDV as a vaccine vector. © 2014 The Authors.
Hulseberg, Christine E; Fénéant, Lucie; Szymańska, Katarzyna M; White, Judith M
Lassa virus (LASV) is an arenavirus whose entry into host cells is mediated by a glycoprotein complex (GPC) comprised of a receptor binding subunit, GP1, a fusogenic transmembrane subunit, GP2, and a stable signal peptide. After receptor-mediated internalization, arenaviruses converge in the endocytic pathway, where they are thought to undergo low-pH-triggered, GPC-mediated fusion with a late endosome membrane. A unique feature of LASV entry is a pH-dependent switch from a primary cell surface receptor (α-dystroglycan) to an endosomal receptor, lysosomal-associated membrane protein (Lamp1). Despite evidence that the interaction between LASV GP1 and Lamp1 is critical, the function of Lamp1 in promoting LASV infection remains poorly characterized. Here we used wild-type (WT) and Lamp1 knockout (KO) cells to show that Lamp1 increases the efficiency of, but is not absolutely required for, LASV entry and infection. We then used cell-cell and pseudovirus-cell surface fusion assays to demonstrate that LASV GPC-mediated fusion occurs at a significantly higher pH when Lamp1 is present compared to when Lamp1 is missing. Correspondingly, we found that LASV entry occurs through less acidic endosomes in WT (Lamp1-positive) versus Lamp1 KO cells. We propose that, by elevating the pH threshold for fusion, Lamp1 allows LASV particles to exit the endocytic pathway before they encounter an increasingly acidic and harsh proteolytic environment, which could inactivate a significant percentage of incoming viruses. In this manner Lamp1 increases the overall efficiency of LASV entry and infection. IMPORTANCE Lassa virus is the most clinically important member of the Arenaviridae , a family that includes six additional biosafety level 4 (BSL4) hemorrhagic fever viruses. The lack of specific antiviral therapies for Lassa fever drives an urgent need to identify druggable targets, and interventions that block infection at the entry stage are particularly attractive. Lassa virus is only the
Shiang, Yen-Chun; Ou, Chung-Mao; Chen, Shih-Ju; Ou, Ting-Yu; Lin, Han-Jia; Huang, Chih-Ching; Chang, Huan-Tsung
We have developed aptamer (Apt)-conjugated gold nanoparticles (Apt-Au NPs, 13 nm in diameter) as highly effective inhibitors for human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT). Two Apts, RT1t49 (Aptpol) and ODN 93 (AptRH), which recognize the polymerase and RNase H regions of HIV-1 RT, are used to conjugate Au NPs to prepare Aptpol-Au NPs and AptRH-Au NPs, respectively. In addition to DNA sequence, the surface density of the aptamers on Au NPs (nApt-Au NPs; n is the number of aptamer molecules on each Au NP) and the linker length number (Tm; m is the base number of the deoxythymidine linker) between the aptamer and Au NPs play important roles in determining their inhibition activity. A HIV-lentiviral vector-based antiviral assay has been applied to determine the inhibitory effect of aptamers or Apt-Au NPs on the early stages of their replication cycle. The nuclease-stable G-quadruplex structure of 40AptRH-T45-Au NPs shows inhibitory efficiency in the retroviral replication cycle with a decreasing infectivity (40.2%).We have developed aptamer (Apt)-conjugated gold nanoparticles (Apt-Au NPs, 13 nm in diameter) as highly effective inhibitors for human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT). Two Apts, RT1t49 (Aptpol) and ODN 93 (AptRH), which recognize the polymerase and RNase H regions of HIV-1 RT, are used to conjugate Au NPs to prepare Aptpol-Au NPs and AptRH-Au NPs, respectively. In addition to DNA sequence, the surface density of the aptamers on Au NPs (nApt-Au NPs; n is the number of aptamer molecules on each Au NP) and the linker length number (Tm; m is the base number of the deoxythymidine linker) between the aptamer and Au NPs play important roles in determining their inhibition activity. A HIV-lentiviral vector-based antiviral assay has been applied to determine the inhibitory effect of aptamers or Apt-Au NPs on the early stages of their replication cycle. The nuclease-stable G-quadruplex structure of 40AptRH-T45
Li, Yi-Ping; Ramirez, Santseharay; Mikkelsen, Lotte
UNLABELLED: The first discovered and sequenced hepatitis C virus (HCV) genome and the first in vivo infectious HCV clones originated from the HCV prototype strains HCV-1 and H77, respectively, both widely used in research of this important human pathogen. In the present study, we developed...... efficiently after transfection and subsequent infection of naive Huh7.5 cells, reaching titers of 10(3.5) and 10(4.4) FFU/ml, respectively. IMPORTANCE: Hepatitis C virus (HCV) was discovered in 1989 with the cloning of the prototype strain HCV-1 genome. In 1997, two molecular clones of H77, the other HCV...
Logan, Nicola; McMonagle, Elizabeth; Drew, Angharad A; Takahashi, Emi; McDonald, Michael; Baron, Michael D; Gilbert, Martin; Cleaveland, Sarah; Haydon, Daniel T; Hosie, Margaret J; Willett, Brian J
Morbillivirus neutralising antibodies are traditionally measured using either plaque reduction neutralisation tests (PRNTs) or live virus microneutralisation tests (micro-NTs). While both test formats provide a reliable assessment of the strength and specificity of the humoral response, they are restricted by the limited number of viral strains that can be studied and often present significant biological safety concerns to the operator. In this study, we describe the adaptation of a replication-defective vesicular stomatitis virus (VSVΔG) based pseudotyping system for the measurement of morbillivirus neutralising antibodies. By expressing the haemagglutinin (H) and fusion (F) proteins of canine distemper virus (CDV) on VSVΔG pseudotypes bearing a luciferase marker gene, neutralising antibody titres could be measured rapidly and with high sensitivity. Further, by exchanging the glycoprotein expression construct, responses against distinct viral strains or species may be measured. Using this technique, we demonstrate cross neutralisation between CDV and peste des petits ruminants virus (PPRV). As an example of the value of the technique, we demonstrate that UK dogs vary in the breadth of immunity induced by CDV vaccination; in some dogs the neutralising response is CDV-specific while, in others, the neutralising response extends to the ruminant morbillivirus PPRV. This technique will facilitate a comprehensive comparison of cross-neutralisation to be conducted across the morbilliviruses. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.
Kruijsen, Debby; Einarsdottir, Helga K.; Schijf, Marcel A.; Coenjaerts, Frank E.; van der Schoot, Ellen C.; Vidarsson, Gestur; van Bleek, Grada M.
Infants are protected from a severe respiratory syncytial virus (RSV) infection in the first months of life by maternal antibodies or by prophylactically administered neutralizing antibodies. Efforts are under way to produce RSV-specific antibodies with increased neutralizing capacity compared to
Zemb, O; Urios, L; Coetsier, C; Lebaron, P
To isolate viruses of specific heterotrophic bacterial strains from marine environments using a host addition/virus amplification protocol (HAVAP) for use in phage/host systems. Bacteria-free seawater samples containing natural viruses assemblages were inoculated with a single laboratory grown bacterial host of interest in a nutrient-enriched [peptone, Fe(III) and yeast extract] seawater suspension. These conditions enhanced the replication of only those virus(s) capable of infecting the host bacterium. After incubation, free viruses were recovered at concentrations ranging 10(5)-10(10) infectious virus particles per ml of seawater. Using this approach, 15 viruses were isolated and represented 12 unique phage/host systems. Two of the hosts tested were infected by more than one virus. Isolation of high concentrations of specific viruses is possible even if their initial concentrations in native waters are low. This approach allows the recovery of phage/host systems that may not be numerically dominant. This host enrichment protocol for virus detection and isolation is well-suited for aquatic viral ecology studies that require phage/host systems.
Dobrowsky, Terrence M.; Rabi, S. Alireza; Nedellec, Rebecca; Daniels, Brian R.; Mullins, James I.; Mosier, Donald E.; Siliciano, Robert F.; Wirtz, Denis
In about half of patients infected with HIV-1 subtype B, viral populations shift from utilizing the transmembrane protein CCR5 to CXCR4, as well as or instead of CCR5, during late stage progression of the disease. How the relative adhesion efficiency and fusion competency of the viral Env proteins relate to infection during this transition is not well understood. Using a virus-cell fusion assay and live-cell single-molecule force spectroscopy, we compare the entry competency of viral clones to tensile strengths of the individual Env-receptor bonds of Env proteins obtained from a HIV-1 infected patient prior to and during coreceptor switching. The results suggest that the genetic determinants of viral entry were predominantly enriched in the C3, HR1 and CD regions rather than V3. Env proteins can better mediate entry into cells after coreceptor switch; this effective entry capacity does not correlate with the bond strengths between viral Env and cellular receptors.
Li, Yi-Ping; Ramirez, Santseharay; Jensen, Sanne B
Chronic infection with hepatitis C virus (HCV) is an important cause of end stage liver disease worldwide. In the United States, most HCV-related disease is associated with genotype 1 infection, which remains difficult to treat. Drug and vaccine development was hampered by inability to culture...... patient isolates representing HCV genotypes 1-7 and subtypes; only a recombinant 2a genome (strain JFH1) spontaneously replicated in vitro. Recently, we identified three mutations F1464L/A1672S/D2979G (LSG) in the nonstructural (NS) proteins, essential for development of full-length HCV 2a (J6) and 2b (J8......) culture systems in Huh7.5 cells. Here, we developed a highly efficient genotype 1a (strain TN) full-length culture system. We initially found that the LSG substitutions conferred viability to an intergenotypic recombinant composed of TN 5' untranslated region (5'UTR)-NS5A and JFH1 NS5B-3'UTR; recovered...
Lohman, Gregory J. S.; Zhang, Yinhua; Zhelkovsky, Alexander M.; Cantor, Eric J.; Evans, Thomas C.
Single-stranded DNA molecules (ssDNA) annealed to an RNA splint are notoriously poor substrates for DNA ligases. Herein we report the unexpectedly efficient ligation of RNA-splinted DNA by Chlorella virus DNA ligase (PBCV-1 DNA ligase). PBCV-1 DNA ligase ligated ssDNA splinted by RNA with kcat ≈ 8 x 10−3 s−1 and KM DNA ligase produced only 5′-adenylylated DNA with a 20-fold lower kcat and a KM ≈ 300 nM. The rate of ligation increased with addition of Mn2+, but was strongly inhibited by concentrations of NaCl >100 mM. Abortive adenylylation was suppressed at low ATP concentrations (8, leading to increased product yields. The ligation reaction was rapid for a broad range of substrate sequences, but was relatively slower for substrates with a 5′-phosphorylated dC or dG residue on the 3′ side of the ligation junction. Nevertheless, PBCV-1 DNA ligase ligated all sequences tested with 10-fold less enzyme and 15-fold shorter incubation times than required when using T4 DNA ligase. Furthermore, this ligase was used in a ligation-based detection assay system to show increased sensitivity over T4 DNA ligase in the specific detection of a target mRNA. PMID:24203707
Lai, Huafang; Engle, Michael; Fuchs, Anja; Keller, Thomas; Johnson, Syd; Gorlatov, Sergey; Diamond, Michael S; Chen, Qiang
Over the past decade, West Nile virus (WNV) has spread to all 48 of the lower United States as well as to parts of Canada, Mexico, the Caribbean, and South America, with outbreaks of neuroinvasive disease occurring annually. At present, no therapeutic or vaccine is available for human use. Epidemics of WNV and other emerging infectious disease threats demand cost-efficient and scalable production technologies that can rapidly transfer effective therapeutics into the clinical setting. We have previously reported that Hu-E16, a humanized anti-WNV mAb, binds to a highly conserved epitope on the envelope protein, blocks viral fusion, and shows promising postexposure therapeutic activity. Herein, we generated a plant-derived Hu-E16 mAb that can be rapidly scaled up for commercial production. Plant Hu-E16 was expressed at high levels within 8 days of infiltration in Nicotiana benthamiana plants and retained high-affinity binding and potent neutralizing activity in vitro against WNV. A single dose of plant Hu-E16 protected mice against WNV-induced mortality even 4 days after infection at rates that were indistinguishable from mammalian-cell-produced Hu-E16. This study demonstrates the efficacy of a plant-produced mAb against a potentially lethal infection several days after exposure in an animal challenge model and provides a proof of principle for the development of plant-derived mAbs as therapy against emerging infectious diseases.
Aldabe, R; Feduchi, E; Novoa, I; Carrasco, L
Poliovirus protease 2A cleaves p220, a component of initiation factor eIF-4F. Polyclonal antibodies that recognize p220 and the cleaved products from different species have been raised. Transfection of several cell lines with poliovirus 2Apro cloned in different plasmids leads to efficient cleavage of p220 upon infection with VT7, a recombinant vaccinia virus that expresses the T7 RNA polymerase. Under these conditions vaccinia virus protein synthesis is severely inhibited, while expression of poliovirus protein 2C from a similar plasmid has no effect. These results show by the first time the effects of p220 cleavage on vaccinia virus translation in the infected cells.
López, Carolina B.; Yount, Jacob S.; Hermesh, Tamar; Moran, Thomas M.
Adaptive immunity in response to virus infection involves the generation of Th1 cells, cytotoxic T cells, and antibodies. This type of immune response is crucial for the clearance of virus infection and for long-term protection against reinfection. Type I interferons (IFNs), the primary innate cytokines that control virus growth and spreading, can influence various aspects of adaptive immunity. The development of antiviral immunity depends on many viral and cellular factors, and the extent to...
Yamada, Kentaro; Noguchi, Kazuko; Nishizono, Akira
Most street rabies viruses have two N-glycosylation sites in their glycoproteins (G proteins), i.e., at Asn(37) and Asn(319), but Asn(37) is usually not core-glycosylated in an efficient manner. Previously, we reported the possible roles of single additional N-glycosylations at Asn(194) or Asn(247) in the cell adaptation and reduced pathogenicity of a street rabies virus, which suggest that N-glycosylation is closely related to the evolution of rabies viruses. In this study, we characterized two novel N-glycosylation-modified variants, N5C#7 and N5C#8, which were cloned using the limiting dilution method after serial passaging of the street rabies virus strain 1088 in mouse neuroblastoma-derived NA cells. N5C#7 had an L38R mutation in the G protein, which led to efficient core glycosylation at Asn(37). On the other hand, N5C#8 had a D146N mutation in the G protein, which led to an additional N-glycosylation at position 146. Both variants replicated highly efficiently in NA cells compared with the parental strain. Like the parental strain, both variants caused lethal infections in adult mice after intracerebral inoculation. However, N5C#7 exhibited reduced pathogenicity after intramuscular inoculation, whereas N5C#8 displayed the same level of pathogenicity as the parental strain. In summary, the efficient core glycosylation at position 37 was related to cell adaptation and the reduced pathogenicity of the street rabies virus. By contrast, despite of being related to cell adaptation, the additional N-glycosylation at position 146 did not affect the pathogenicity, which is consistent with a report that street rabies virus strains with N-glycosylation sites at positions 37, 146, and 319 have been isolated from rabid animals. Thus, the results of the present study provide additional evidence that supports the relationship between G protein N-glycosylation and rabies virus evolution. Copyright © 2013 Elsevier B.V. All rights reserved.
Kleine Büning, Maximiliane; Meyer, Denise; Austermann-Busch, Sophia; Roman-Sosa, Gleyder; Rümenapf, Tillmann; Becher, Paul
RNA recombination is a major driving force for the evolution of RNA viruses and is significantly implicated in the adaptation of viruses to new hosts, changes of virulence, as well as in the emergence of new viruses including drug-resistant and escape mutants. However, the molecular details of recombination in animal RNA viruses are only poorly understood. In order to determine whether viral RNA recombination depends on translation of viral proteins, a nonreplicative recombination system was established which is based on cotransfection of cells with synthetic bovine viral diarrhea virus (family Flaviviridae) RNA genome fragments either lacking the internal ribosome entry site required for cap-independent translation or lacking almost the complete polyprotein coding region. The emergence of a number of recombinant viruses demonstrated that IRES-mediated translation of viral proteins is dispensable for efficient recombination and suggests that RNA recombination can occur in the absence of viral proteins. Analyses of 58 independently emerged viruses led to the detection of recombinant genomes with duplications, deletions and insertions in the 5' terminal region of the open reading frame, leading to enlarged core fusion proteins detectable by Western blot analysis. This demonstrates a remarkable flexibility of the pestivirus core protein. Further experiments with capped and uncapped genome fragments containing a luciferase gene for monitoring the level of protein translation revealed that even a ∼1,000-fold enhancement of translation of viral proteins did not increase the frequency of RNA recombination. Taken together, this study highlights that nonreplicative RNA recombination does not require translation of viral proteins. © The Author(s) 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.
Jin, Y L; Chen, L M; Le, Y; Li, Y L; Hong, Y H; Jia, K T; Yi, M S
A cell line ZBE3 isolated from a continuous cell culture derived from zebrafish Danio rerio blastomeres by clonal growth was characterized. ZBE3 cells had been subcultured for >120 passages since the initial primary culture of the blastomeres. The ZBE3 cells grow stably at temperature from 20 to 32° C with an optimum temperature of 28° C in ESM2 or ESM4 medium with 15% foetal bovine serum (FBS). The optimum FBS concentration for ZBE3 cell growth ranged from 15 to 20%. Cytogenetical analysis indicated that the modal chromosome number of ZBE3 cells was 50, the same as the diploid chromosome number of D. rerio. Significant cytopathic effect was observed in ZBE3 cells after infection with redspotted grouper nervous necrosis virus, Singapore grouper iridovirus and grass carp reovirus, and the viral replication in the cells was confirmed by real-time quantitative PCR and transmission electron microscopy, indicating the susceptibility of ZBE3 cells to the three fish viruses. After transfected with pEGFP-N3 plasmid, ZBE3 cells showed a transfection efficiency of about 40% which was indicated by the percentage of cells expressing green fluorescence protein. The stable growth, susceptibility to fish viruses as well as high transfection efficiency make ZBE3 cells be a useful tool in transgenic manipulation, fish virus-host cell interaction and immune response in fish. © 2017 The Fisheries Society of the British Isles.
Wu, Hong-Xia; Wang, Hua-Lei; Guo, Xiao-Feng; Yang, Yu-Jiao; Ma, Jin-Zhu; Wang, Tie-Cheng; Gao, Yu-Wei; Zhao, Yong-Kun; Yang, Song-Tao; Xia, Xian-Zhu
To investigate the potential of adeno-associated viruses serotype 2 (AAV2)-mediated RNA interference (RNAi) as an antiviral agent against rabies, recombinant AAV2 vectors expressing siRNA targeting the nucleoprotein (N) gene of rabies virus (RABV) (rAAV-N796) were constructed and evaluated. When NA cells pretreated with rAAV-N796 were challenged with RABV, there was a 37.8 ± 3.4% to 55.1 ± 5.3% reduction in RABV virus titer. When cells pre-challenged with RABV were treated with rAAV-N796, there was a 4.4 ± 1.4 to 28.8 ± 3.2% reduction in RABV virus titer. Relative quantification of RABV transcripts using real-time PCR and Western blot revealed that the knockdown of RABV-N gene transcripts was based on the rAAV-N796 inoculation titer. When any NA cells were treated with rAAV-N796 before or after challenged with RABV, significant reduction in virus titer was observed in both administrations. Mice treated intracerebrally with rAAV-N796 exhibited 50 ± 5.3 and 62.5 ± 4.7% protection when challenged intracerebrally or intramuscally, respectively, with lethal RABV. When mice treated intramuscularly with rAAV-N796 were challenged intramuscularly with lethal RABV, they exhibited 37.5 ± 3.7% protection. When mice were intracerebrally and intramuscularly with rAAV-N796 24 hr after exposure to RABV infection, they exhibited 25 ± 4.1% protection The N gene mRNA levels in the brains of challenged mice with three different administrations were reduced (55, 68, 32 and 25%, respectively). These results indicated that AAV2 vector-mediated siRNA delivery in vitro in NA cells inhibited RABV multiplication, inhibited RABV multiplication in vivo in the mice brain and imparted partial protection against lethal rabies. So, it may have a potential to be used as an alternative antiviral approach against rabies.
Bastone, P.; Romen, F.; Liu, W.; Wirtz, R.; Koch, U.; Josephson, N.; Langbein, S.; Löchelt, M.
As serious side effects affected recent virus-mediated gene transfer studies, novel vectors with improved safety profiles are urgently needed. In the present study, replication-deficient retroviral vectors based on feline foamy virus (FFV) were constructed and analyzed. The novel FFV vectors are
Maize rough dwarf disease (MRDD) caused by Rice black-streaked dwarf virus (RBSDV) is the most important viral disease of maize in China. Although deploying disease resistant hybrids would be the most effective way to control the disease, development of resistant hybrids has been limited by virus t...
Hercík, Kamil; Kozák, Jaroslav; Šála, Michal; Dejmek, Milan; Hřebabecký, Hubert; Zborníková, Eva; Smola, Miroslav; Růžek, Daniel; Nencka, Radim; Bouřa, Evžen
Roč. 137, Jan (2017), s. 131-133 ISSN 0166-3542 R&D Projects: GA ČR GA15-09310S Institutional support: RVO:61388963 ; RVO:60077344 Keywords : hepatitis C virus * borne encephalitis virus * crystal structure Subject RIV: CC - Organic Chemistry Impact factor: 4.271, year: 2016
Kritzman, A.; Gera, A.; Raccah, B.; Lent, van J.W.M.; Peters, D.
The route of tomato spotted wilt virus (TSWV) in the body of its vectors, Frankliniella occidentalis and Thrips tabaci (Thysanoptera: Thripidae) was studied during their development. First instar larvae were allowed, immediately upon hatching, to acquire virus from mechanically infected Datura
Tian, Ji; Pei, Haixia; Zhang, Shuai; Chen, Jiwei; Chen, Wen; Yang, Ruoyun; Meng, Yonglu; You, Jie; Gao, Junping; Ma, Nan
Virus-induced gene silencing (VIGS) is a useful tool for functional characterization of genes in plants. Unfortunately, the efficiency of infection by Tobacco rattle virus (TRV) is relatively low for some non-Solanaceae plants, which are economically important, such as rose (Rosa sp.). Here, to generate an easy traceable TRV vector, a green fluorescent protein (GFP) gene was tagged to the 3' terminus of the coat protein gene in the original TRV2 vector, and the silencing efficiency of the modified TRV-GFP vector was tested in several plants, including Nicotiana benthamiana, Arabidopsis thaliana, rose, strawberry (Fragaria ananassa), and chrysanthemum (Dendranthema grandiflorum). The results showed that the efficiency of infection by TRV-GFP was equal to that of the original TRV vector in each tested plant. Spread of the modified TRV virus was easy to monitor by using fluorescent microscopy and a hand-held UV lamp. When TRV-GFP was used to silence the endogenous phytoene desaturase (PDS) gene in rose cuttings and seedlings, the typical photobleached phenotype was observed in 75-80% plants which were identified as GFP positive by UV lamp. In addition, the abundance of GFP protein, which represented the concentration of TRV virus, was proved to correlate negatively with the level of the PDS gene, suggesting that GFP could be used as an indicator of the degree of silencing of a target gene. Taken together, this work provides a visualizable and efficient tool to predict positive gene silencing plants, which is valuable for research into gene function in plants, especially for non-Solanaceae plants.
Tian, Ji; Pei, Haixia; Ma, Nan
Virus-induced gene silencing (VIGS) is a useful tool for functional characterization of genes in plants. Unfortunately, the efficiency of infection by Tobacco rattle virus (TRV) is relatively low for some non-Solanaceae plants, which are economically important, such as rose (Rosa sp.). Here, to generate an easy traceable TRV vector, a green fluorescent protein (GFP) gene was tagged to the 3’ terminus of the coat protein gene in the original TRV2 vector, and the silencing efficiency of the modified TRV–GFP vector was tested in several plants, including Nicotiana benthamiana, Arabidopsis thaliana, rose, strawberry (Fragaria ananassa), and chrysanthemum (Dendranthema grandiflorum). The results showed that the efficiency of infection by TRV–GFP was equal to that of the original TRV vector in each tested plant. Spread of the modified TRV virus was easy to monitor by using fluorescent microscopy and a hand-held UV lamp. When TRV–GFP was used to silence the endogenous phytoene desaturase (PDS) gene in rose cuttings and seedlings, the typical photobleached phenotype was observed in 75–80% plants which were identified as GFP positive by UV lamp. In addition, the abundance of GFP protein, which represented the concentration of TRV virus, was proved to correlate negatively with the level of the PDS gene, suggesting that GFP could be used as an indicator of the degree of silencing of a target gene. Taken together, this work provides a visualizable and efficient tool to predict positive gene silencing plants, which is valuable for research into gene function in plants, especially for non-Solanaceae plants. PMID:24218330
Full Text Available The current method for creation of vaccinia virus (VACV vectors involves using a selection and purification marker, however inclusion of a gene without therapeutic value in the resulting vector is not desirable for clinical use. The Cre-LoxP system has been used to make marker-free Poxviruses, but the efficiency was very low. To obtain a marker-free VACV vector, we developed marker gene excision systems to modify the thymidine kinase (TK region and N1L regions using Cre-Loxp and Flp-FRET systems respectively. CRISPR-Cas9 system significantly resulted in a high efficiency (â¼90% in generation of marker gene-positive TK-mutant VACV vector. The marker gene (RFP could be excised from the recombinant virus using Cre recombinase. To make a marker-free VV vector with double gene deletions targeting the TK and N1L gene, we constructed a donor repair vector targeting the N1L gene, which can carry a therapeutic gene and the marker (RFP that could be excised from the recombinant virus using Flp recombinase. The marker-free system developed here can be used to efficiently construct VACV vectors armed with any therapeutic genes in the TK region or N1L region without marker genes. Our marker-free system platform has significant potential for development of new marker-free VACV vectors for clinical application.
Huang, F; Ahmad, W; Duan, M; Liu, Z; Guan, Z; Zhang, M; Qiao, B; Li, Y; Song, Y; Song, Y; Chen, Y; Amjad Ali, M
Rabies remains an enigmatic and widely discussed global infectious disease and causes an increasing number of deaths. The currently used highly effective prophylactic and post exposure (p.e.) vaccination depends solely upon inexpensive, effective and safe vaccines to counteract the spread of the disease. In this study, the potential of an attenuated Chinese rabies vaccine (SRV9) strain in prophylactic and p.e. vaccination against the street strain of rabies virus (RV) was evaluated in mice. Prophylactic vaccination consisting of one intramuscular (i.m.) dose of SRV9 protected 100% of mice from intracerebral (i.c.) challenge with a lethal dose of the street virus. The latter was detected in the brain of mice at day 6 post challenge by RT-PCR. Post exposure vaccination was performed at days 1, 2, 3, 4, 5 and 6 post infection (p.i.) with either SRV9 or inactivated rabies vaccine. The survival rates after i.m. inoculation of SRV9 at the indicated days were 70%, 50%, 30%, 20%, 10%, and 0%, respectively; the corresponding survival rates for the inactivated rabies vaccine were 30%, 20%, 10%, 0%, 0%, and 0%, respectively. However, 100%, 90%, 70%, 50%, 20%, 10%, and 10% of mice survived after i.c. inoculation of SRV9 at the indicated days. The increased permeability of the blood-brain barrier and the infiltration of CD19+ B cells into the central nervous system after i.c. inoculation of SRV9 are regarded as prerequisites for the clearance of the street virus. The obtained data suggest that SRV9 is a promising candidate for prophylactic and p.e. vaccination against rabies infection and that it exhibits a potential for the control of rabies in China.
Full Text Available Non-coding small RNAs are involved in many physiological responses including viral life cycles. Adenovirus-encoding small RNAs, known as virus-associated RNAs (VA RNAs, are transcribed throughout the replication process in the host cells, and their transcript levels depend on the copy numbers of the viral genome. Therefore, VA RNAs are abundant in infected cells after genome replication, i.e. during the late phase of viral infection. Their function during the late phase is the inhibition of interferon-inducible protein kinase R (PKR activity to prevent antiviral responses; recently, mivaRNAs, the microRNAs processed from VA RNAs, have been reported to inhibit cellular gene expression. Although VA RNA transcription starts during the early phase, little is known about its function. The reason may be because much smaller amount of VA RNAs are transcribed during the early phase than the late phase. In this study, we applied replication-deficient adenovirus vectors (AdVs and novel AdVs lacking VA RNA genes to analyze the expression changes in cellular genes mediated by VA RNAs using microarray analysis. AdVs are suitable to examine the function of VA RNAs during the early phase, since they constitutively express VA RNAs but do not replicate except in 293 cells. We found that the expression level of hepatoma-derived growth factor (HDGF significantly decreased in response to the VA RNAs under replication-deficient condition, and this suppression was also observed during the early phase under replication-competent conditions. The suppression was independent of mivaRNA-induced downregulation, suggesting that the function of VA RNAs during the early phase differs from that during the late phase. Notably, overexpression of HDGF inhibited AdV growth. This is the first report to show the function, in part, of VA RNAs during the early phase that may be contribute to efficient viral growth.
Dykes, Carrie; Wang, Jiong; Jin, Xia; Planelles, Vicente; An, Dong Sung; Tallo, Amanda; Huang, Yangxin; Wu, Hulin; Demeter, Lisa M
Human immunodeficiency virus type 1 (HIV-1) replication efficiency or fitness, as measured in cell culture, has been postulated to correlate with clinical outcome of HIV infection, although this is still controversial. One limitation is the lack of high-throughput assays that can measure replication efficiency over multiple rounds of replication. We have developed a multiple-cycle growth competition assay to measure HIV-1 replication efficiency that uses flow cytometry to determine the relative proportions of test and reference viruses, each of which expresses a different reporter gene in place of nef. The reporter genes are expressed on the surface of infected cells and are detected by commercially available fluorescence-labeled antibodies. This method is less labor-intensive than those that require isolation and amplification of nucleic acids. The two reporter gene products are detected with similar specificity and sensitivity, and the proportion of infected cells in culture correlates with the amount of viral p24 antigen produced in the culture supernatant. HIV replication efficiencies of six different drug-resistant site-directed mutants were reproducibly quantified and were similar to those obtained with a growth competition assay in which the relative proportion of each variant was measured by sequence analysis, indicating that recombination between the pol and reporter genes was negligible. This assay also reproducibly quantified the relative fitness conferred by protease and reverse transcriptase sequences containing multiple drug resistance mutations, amplified from patient plasma. This flow cytometry-based growth competition assay offers advantages over current assays for HIV replication efficiency and should prove useful for the evaluation of patient samples in clinical trials.
and-mouth disease in livestock was an infectious particle smaller than any bacteria. This was the first clue to the nature of viruses, genetic entities that lie somewhere in the gray area between living and non-living states.
Ellis, Brian L; Hirsch, Matthew L; Barker, Jenny C; Connelly, Jon P; Steininger, 3rd, Robert J; Porteus, Matthew H
.... Adeno-associated virus (AAV) is a useful gene transfer vector because of its ability to mediate efficient gene transduction in numerous dividing and quiescent cell types, without inducing any known pathogenicity...
Gopinath, Subash C B; Kumar, Penmetcha K R
Influenza virus hemagglutinin (HA) mediates both receptor (glycan) binding and membrane fusion for cell entry and has been the basis for typing influenza A viruses. In this study we have selected RNA aptamers (D-12 and D-26) that specifically target the HA protein of the recent pandemic influenza virus pdmH1N1 (A/California/07/2009). Among the selected aptamers the D-26 aptamer showed higher affinity for the HA of pdmH1N1 and was able to distinguish HA derived from other sub-types of influenza A viruses. The affinity of the D-26 aptamer was further improved upon incorporation of 2'-fluoropyrimidines to a level of 67 fM. Furthermore, the high affinity D-12 and D-26 aptamers were tested for their ability to interfere with HA-glycan interactions using a chicken red blood cell (RBC) agglutination assay. At a concentration of 200 nM the D-26 aptamer completely abolished the agglutination of RBCs, whereas D-12 only did so at 400 nM. These studies suggest that the selected aptamer D-26 not only has a higher affinity and specificity for the HA of pdmH1N1 but also has a better ability to efficiently interfere with HA-glycan interactions compared with the D-12 aptamer. The D-26 aptamer warrants further study regarding its application in developing topical virucidal products against the pdmH1N1 virus and also in surveillance of the pdmH1N1 influenza virus. Copyright © 2013 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Zhang, Guangyuan; Zhang, Shengwei; Ding, Binbin; Yang, Xiaodan; Chen, Longyun; Yan, Qin; Jiang, Yanliang; Zhong, Yi; Chen, Mingzhou
Paramyxovirus particles, like other enveloped virus particles, are formed by budding from membranes of infected cells, and matrix (M) proteins are critical for this process. To identify the M protein important for this process, we have characterized the budding of the human parainfluenza virus type 3 (HPIV3) M protein. Our results showed that expression of the HPIV3 M protein alone is sufficient to initiate the release of virus-like particles (VLPs). Electron microscopy analysis confirmed that VLPs are morphologically similar to HPIV3 virions. We identified a leucine (L302) residue within the C terminus of the HPIV3 M protein that is critical for M protein-mediated VLP production by regulating the ubiquitination of the M protein. When L302 was mutated into A302, ubiquitination of M protein was defective, the release of VLPs was abolished, and the membrane binding and budding abilities of M protein were greatly weakened, but the ML302A mutant retained oligomerization activity and had a dominant negative effect on M protein-mediated VLP production. Furthermore, treatment with a proteasome inhibitor also inhibited M protein-mediated VLP production and viral budding. Finally, recombinant HPIV3 containing the M(L302A) mutant could not be rescued. These results suggest that L302 acts as a critical regulating signal for the ubiquitination of the HPIV3 M protein and virion release. Human parainfluenza virus type 3 (HPIV3) is an enveloped virus with a nonsegmented negative-strand RNA genome. It can cause severe respiratory tract diseases, such as bronchiolitis, pneumonia, and croup in infants and young children. However, no valid antiviral therapy or vaccine is currently available. Thus, further elucidation of its assembly and budding will be helpful in the development of novel therapeutic approaches. Here, we show that a leucine residue (L302) located at the C terminus of the HPIV3 M protein is essential for efficient production of virus-like particles (VLPs). Furthermore
Schmid, Sonja; Metz, Philippe; Prat, Christine M A; Gonzalez-Dunia, Daniel; Schwemmle, Martin
Mutational analysis of the phosphate acceptor sites of the Borna disease virus (BDV) phosphoprotein (P) has suggested a role of phosphorylation for viral spread. However, the studied mutant viruses also had two amino acid exchanges in the X protein, because the reading frames of P and X overlap. To determine the relative contribution of P and X to viral attenuation, we studied a P variant with serine-to-leucine substitutions (P(S26L,S28L)) in which the wild-type X sequence was conserved. Viral spread of rBDV-P(S26L,S28L) was impaired in human oligodendroglioma cells and in adult rats. Thus, BDV-P phosphorylation contributes to efficient viral dissemination.
Vidya P Nair
Full Text Available Hepatitis E virus (HEV causes acute hepatitis in many parts of the world including Asia, Africa and Latin America. Though self-limiting in normal individuals, it results in ~30% mortality in infected pregnant women. It has also been reported to cause acute and chronic hepatitis in organ transplant patients. Of the seven viral genotypes, genotype-1 virus infects humans and is a major public health concern in South Asian countries. Sporadic cases of genotype-3 and 4 infection in human and animals such as pigs, deer, mongeese have been reported primarily from industrialized countries. Genotype-5, 6 and 7 viruses are known to infect animals such as wild boar and camel, respectively. Genotype-3 and 4 viruses have been successfully propagated in the laboratory in mammalian cell culture. However, genotype-1 virus replicates poorly in mammalian cell culture and no other efficient model exists to study its life cycle. Here, we report that endoplasmic reticulum (ER stress promotes genotype-1 HEV replication by inducing cap-independent, internal initiation mediated translation of a novel viral protein (named ORF4. Importantly, ORF4 expression and stimulatory effect of ER stress inducers on viral replication is specific to genotype-1. ORF4 protein sequence is mostly conserved among genotype-1 HEV isolates and ORF4 specific antibodies were detected in genotype-1 HEV patient serum. ORF4 interacted with multiple viral and host proteins and assembled a protein complex consisting of viral helicase, RNA dependent RNA polymerase (RdRp, X, host eEF1α1 (eukaryotic elongation factor 1 isoform-1 and tubulinβ. In association with eEF1α1, ORF4 stimulated viral RdRp activity. Furthermore, human hepatoma cells that stably express ORF4 or engineered proteasome resistant ORF4 mutant genome permitted enhanced viral replication. These findings reveal a positive role of ER stress in promoting genotype-1 HEV replication and pave the way towards development of an efficient
Knepper, Jessica; Schierhorn, Kristina L; Becher, Anne; Budt, Matthias; Tönnies, Mario; Bauer, Torsten T; Schneider, Paul; Neudecker, Jens; Rückert, Jens C; Gruber, Achim D; Suttorp, Norbert; Schweiger, Brunhilde; Hippenstiel, Stefan; Hocke, Andreas C; Wolff, Thorsten
A novel influenza A virus (IAV) of the H7N9 subtype has been isolated from severely diseased patients with pneumonia and acute respiratory distress syndrome and, apparently, from healthy poultry in March 2013 in Eastern China. We evaluated replication, tropism, and cytokine induction of the A/Anhui/1/2013 (H7N9) virus isolated from a fatal human infection and two low-pathogenic avian H7 subtype viruses in a human lung organ culture system mimicking infection of the lower respiratory tract. The A(H7N9) patient isolate replicated similarly well as a seasonal IAV in explanted human lung tissue, whereas avian H7 subtype viruses propagated poorly. Interestingly, the avian H7 strains provoked a strong antiviral type I interferon (IFN-I) response, whereas the A(H7N9) virus induced only low IFN levels. Nevertheless, all viruses analyzed were detected predominantly in type II pneumocytes, indicating that the A(H7N9) virus does not differ in its cellular tropism from other avian or human influenza viruses. Tissue culture-based studies suggested that the low induction of the IFN-β promoter correlated with an efficient suppression by the viral NS1 protein. These findings demonstrate that the zoonotic A(H7N9) virus is unusually well adapted to efficient propagation in human alveolar tissue, which most likely contributes to the severity of lower respiratory tract disease seen in many patients. Humans are usually not infected by avian influenza A viruses (IAV), but this large group of viruses contributes to the emergence of human pandemic strains. Transmission of virulent avian IAV to humans is therefore an alarming event that requires assessment of the biology as well as pathogenic and pandemic potentials of the viruses in clinically relevant models. Here, we demonstrate that an early virus isolate from the recent A(H7N9) outbreak in Eastern China replicated as efficiently as human-adapted IAV in explanted human lung tissue, whereas avian H7 subtype viruses were unable to
The present inventors developed hepatitis C virus 6a/2a intergenotypic recombinants in which the JFH1 structural genes (Core, E1 and E2), p7 and the complete NS2 were replaced by the corresponding genes of the genotype 6a reference strain HK6a. Sequence analysis of recovered 6a/2a recombinants fr...... 2 transfection experiments and subsequent reverse genetic studies revealed adaptive mutations in E1 and E2. Conclusion: The developed 6a/2a viruses provide a robust in vitro tool for research in HCV genotype 6, including vaccine studies and functional analysis......The present inventors developed hepatitis C virus 6a/2a intergenotypic recombinants in which the JFH1 structural genes (Core, E1 and E2), p7 and the complete NS2 were replaced by the corresponding genes of the genotype 6a reference strain HK6a. Sequence analysis of recovered 6a/2a recombinants from...
Pham, Long V.; Ramirez Almeida, Santseharay; Carlsen, Thomas H R
Hepatitis C virus (HCV) strains belong to seven genotypes with numerous subtypes that respond differently to antiviral therapies. Genotype 1, and primarily subtype 1b, is the most prevalent genotype worldwide. The development of recombinant HCV infectious cell culture systems for different variants...... cell culture adaptive substitutions A1226G, R1496L, and Q1773H. These viruses spread efficiently in Huh7.5 cells by acquiring additional adaptive substitutions, and final recombinants yielded peak supernatant infectivity titers of 4 to 5 log10 focus-forming units (FFU)/ml. We subsequently succeeded...... in adapting a JFH1- based 5=UTR-NS5A DH1 recombinant to efficient growth in cell culture. We evaluated the efficacy of clinically relevant NS3/4A protease and NS5A inhibitors against the novel genotype 1b viruses, as well as against previously developed 1a viruses. The inhibitors were efficient against all...
The present inventors developed hepatitis C virus 2b/2a intergenotypic recombinants in which the JFH1 structural genes (Core, E1 and E2), p7 and the complete NS2 were replaced by the corresponding genes of the genotype 2b reference strain J8. Sequence analysis of recovered 2b/2a recombinants from 2...... transfection experiments revealed that 2b/2a was genetically stable. Conclusion: The developed 2b/2a viruses provide a robust in vitro tool for research in HCV genotype 2b, including vaccine studies and functional analysis....
Loot, AE; Henning, RH; Deelman, LE; Tio, RA; Schoen, P; Wilschut, JC; van Gijst, WH; Roks, AJM
Gene therapy is emerging as a realistic addition to the therapeutic arsenal in heart failure, but the search for suitable vectors for cardiac transfection is still ongoing. In this study, we explore the applicability of recombinant Semliki Forest virus (SFV) in heart failure. SFV was intracoronarily
Plum transformed with an intron hairpin RNA CP (ihRNA-CP) were resistant to PPV infection through the specific process of RNA silencing involving both small interfering -RNA interfering (siRNA) and a methylated virus transgene. This recognition process specifically targeted the triggered PPV genome...
Cook, Kevin D; Whitmire, Jason K
NK cells have well-established functions in immune defense against virus infections and cancer through their cytolytic activity and production of cytokines. In this study, we examined the frequency of NK cells and their influence on T cell responses in mice given variants of lymphocytic choriomeningitis virus that cause acute or persisting infection. We found increased frequencies of circulating NK cells during disseminating infection compared with uninfected or acutely infected mice. Consistent with recent reports, we observed that the depletion of NK cells in mice with disseminated infection increased peak numbers of virus-specific cytokine producing CD8(+) T cells and resulted in the rapid resolution of disseminated infection. Additionally, we show that NK cell depletion sustained T cell responses across time and protected against T cell exhaustion. The positive effects of NK cell depletion on T cell responses only occurred when NK cells were depleted within the first 2 d of infection. We find that the improved CD8(+) T cell response correlated with an enhanced ability of APCs from NK cell-depleted mice to stimulate T cell proliferation, independently of the effects of NK cells on CD4(+) T cells. These results indicate that NK cells play an integral role in limiting the CD8 T cell response and contribute to T cell exhaustion by diminishing APC function during persisting virus infection.
Li, Xin; van Oers, Monique M; Vlak, Just M; Braakman, Ineke
Folding of influenza virus hemagglutinin (HA) in the endoplasmic reticulum has been well defined in mammalian cells. In different mammalian cell lines the protein follows the same folding pathway with identical folding intermediates, but folds with very different kinetics. To examine the effect of
Li, X.; Oers, van M.M.; Vlak, J.M.; Braakman, I.
Folding of influenza virus hemagglutinin (HA) in the endoplasmic reticulum has been well defined inmammalian cells. In different mammalian cell lines the protein follows the same folding pathway withidentical folding intermediates, but folds with very different kinetics. To examine the effect of
Recombinant Newcastle Disease Virus (rNDV) has shown oncolytic therapeutic effect in preclinical studies. Previous data indicate that rNDV carrying IL2 has shown promise in cancer therapy. Due to the significant side effects of IL2, IL15 has been introduced into cancer therapy. A number of studies h...
Ruhanya, Vurayai; Diez-Valcarce, Marta; D'Agostino, Martin; Cook, Nigel; Hernández, Marta; Rodríguez-Lázaro, David
When analysing food samples for enteric viruses, a sample process control virus (SPCV) must be added at the commencement of the analytical procedure, to verify that the analysis has been performed correctly. Samples can on occasion arrive at the laboratory late in the working day or week. The analyst may consequently have insufficient time to commence and complete the complex procedure, and the samples must consequently be stored. To maintain the validity of the analytical result, it will be necessary to consider storage as part of the process, and the analytical procedure as commencing on sample receipt. The aim of this study was to verify that an SPCV can be recovered after sample storage, and thus indicate the effective recovery of enteric viruses. Two types of samples (fresh and frozen raspberries) and two types of storage (refrigerated and frozen) were studied using Mengovirus vMC0 as SPCV. SPCV recovery was not significantly different (P > 0.5) regardless of sample type or duration of storage (up to 14 days at -20 °C). Accordingly, samples can be stored without a significant effect on the performance of the analysis. The results of this study should assist the analyst by demonstrating that they can verify that viruses can be extracted from food samples even if samples have been stored.
Di Nicola-Negri, Elisa; Brunetti, Angela; Tavazza, Mario; Ilardi, Vincenza
We report the application of the hairpin-mediated RNA silencing technology for obtaining resistance to Plum pox virus (PPV) infection in Nicotiana benthamiana plants. Four sequences, covering the P1 and silencing suppressor HC-Pro genes of an Italian PPV M isolate, were introduced into N. benthamiana plants as two inverted repeats separated by an intron sequence under the transcriptional control of the Cauliflower Mosaic Virus 35S promoter. In a leaf disk infection assay, 38 out of 40 T0 transgenic plants were resistant to PPV infection. Eight lines, 2 for each construct, randomly selected among the 38 resistant plants were further analysed. Two hundred forty eight out of 253 T1 transgenic plants were resistant to local and systemic PPV infection. All transgenic single locus lines were completely resistant. These data indicate that the RNA silencing of PPV P1/HCPro sequences results in an efficient and predictable PPV resistance, which may be utilized in obtaining stone fruit plants resistant to the devastating Sharka disease.
The M segment of the 2009 pandemic influenza virus confers increased neuraminidase activity, filamentous morphology, and efficient contact transmissibility to A/Puerto Rico/8/1934-based reassortant viruses.
Campbell, Patricia J; Danzy, Shamika; Kyriakis, Constantinos S; Deymier, Martin J; Lowen, Anice C; Steel, John
The 2009 H1N1 lineage represented the first detection of a novel, highly transmissible influenza A virus genotype: six gene segments originated from the North American triple-reassortant swine lineage, and two segments, NA and M, derived from the Eurasian avian-like swine lineage. As neither parental lineage transmits efficiently between humans, the adaptations and mechanisms underlying the pandemic spread of the swine-origin 2009 strain are not clear. To help identify determinants of transmission, we used reverse genetics to introduce gene segments of an early pandemic isolate, A/Netherlands/602/2009 [H1N1] (NL602), into the background of A/Puerto Rico/8/1934 [H1N1] (PR8) and evaluated the resultant viruses in a guinea pig transmission model. Whereas the NL602 virus spread efficiently, the PR8 virus did not transmit. Swapping of the HA, NA, and M segments of NL602 into the PR8 background yielded a virus with indistinguishable contact transmissibility to the wild-type pandemic strain. Consistent with earlier reports, the pandemic M segment alone accounted for much of the improvement in transmission. To aid in understanding how the M segment might affect transmission, we evaluated neuraminidase activity and virion morphology of reassortant viruses. Transmission was found to correlate with higher neuraminidase activity and a more filamentous morphology. Importantly, we found that introduction of the pandemic M segment alone resulted in an increase in the neuraminidase activity of two pairs of otherwise isogenic PR8-based viruses. Thus, our data demonstrate the surprising result that functions encoded by the influenza A virus M segment impact neuraminidase activity and, perhaps through this mechanism, have a potent effect on transmissibility. Our work uncovers a previously unappreciated mechanism through which the influenza A virus M segment can alter the receptor-destroying activity of an influenza virus. Concomitant with changes to neuraminidase activity, the M
Watson, Zachary L; Ertel, Monica K; Lewin, Alfred S; Tuli, Sonal S; Schultz, Gregory S; Neumann, Donna M; Bloom, David C
Following infection of epithelial tissues, herpes simplex virus 1 (HSV-1) virions travel via axonal transport to sensory ganglia and establish a lifelong latent infection within neurons. Recent studies have revealed that, following intraganglionic or intrathecal injection, recombinant adeno-associated virus (rAAV) vectors can also infect sensory neurons and are capable of stable, long-term transgene expression. We sought to determine if application of rAAV to peripheral nerve termini at the epithelial surface would allow rAAV to traffic to sensory ganglia in a manner similar to that seen with HSV. We hypothesized that footpad or ocular inoculation with rAAV8 would result in transduction of dorsal root ganglia (DRG) or trigeminal ganglia (TG), respectively. To test this, we inoculated the footpads of mice with various amounts of rAAV as well as rAAV capsid mutants. We demonstrated that this method of inoculation can achieve a transduction rate of >90% of the sensory neurons in the DRG that innervate the footpad. Similarly, we showed that corneal inoculation with rAAV vectors in the rabbit efficiently transduced >70% of the TG neurons in the optic tract. Finally, we demonstrated that coinfection of mouse footpads or rabbit eyes with rAAV vectors and HSV-1 resulted in colocalization in nearly all of the HSV-1-positive neurons. These results suggest that rAAV is a useful tool for the study of HSV-1 infection and may provide a means to deliver therapeutic cargos for the treatment of HSV infections or of dysfunctions of sensory ganglia. Adeno-associated virus (AAV) has been shown to transduce dorsal root ganglion sensory neurons following direct intraganglionic sciatic nerve injection and intraperitoneal and intravenous injection as well as intrathecal injection. We sought to determine if rAAV vectors would be delivered to the same sensory neurons that herpes simplex virus (HSV-1) infects when applied peripherally at an epithelial surface that had been treated to expose
Ruining WANG,Yubao ZHI,Junqing GUO,Qingmei LI,Li WANG,Jifei YANG,Qianyue JIN,Yinbiao WANG,Yanyan YANG,Guangxu XING,Songlin QIAO,Mengmeng ZHAO,Ruiguang DENG,Gaiping ZHANG
Full Text Available Large-scale production of cell culture-based classical swine fever virus (CSFV vaccine is hampered by the adverse reactions caused by contaminants from host cell and culture medium. Hence, we have developed an efficient method for purifying CSFV from cell-culture medium. Pure viral particles were obtained with two steps of tangential-flow filtration (TFF and size-exclusion chromatography (SEC, and were compared with particles from ultracentrifugation by transmission electron microscopy (TEM, infectivity and recovery test, and real time fluorescent quantitative PCR (FQ-PCR. TFF concentrated the virus particles effectively with a retention rate of 98.5%, and 86.2% of viral particles were obtained from the ultrafiltration retentate through a Sepharose 4 F F column on a biological liquid chromatography system. CSFV purified by TFF-SEC or ultracentrifugation were both biologically active from 1.0×10-4.25 TCID50·mL-1 to 3.0×10-6.25 TCID50·mL-1, but the combination of TFF and SEC produced more pure virus particles than by ultracentrifugation alone. In addition, pure CSFV particles with the expected diameter of 40—60 nm were roughly spherical without any visible contamination. Mice immunized with CSFV purified by TFF-SEC produced higher antibody levels compared with immunization with ultracentrifugation-purified CSFV (P<0.05. The purification procedures in this study are reliable technically and feasible for purification of large volumes of viruses.
Amraoui, Fadila; Krida, Ghazi; Bouattour, Ali; Rhim, Adel; Daaboub, Jabeur; Harrat, Zoubir; Boubidi, Said-Chawki; Tijane, Mhamed; Sarih, Mhammed; Failloux, Anna-Bella
West Nile fever (WNF) and Rift Valley fever (RVF) are emerging diseases causing epidemics outside their natural range of distribution. West Nile virus (WNV) circulates widely and harmlessly in the old world among birds as amplifying hosts, and horses and humans as accidental dead-end hosts. Rift Valley fever virus (RVFV) re-emerges periodically in Africa causing massive outbreaks. In the Maghreb, eco-climatic and entomologic conditions are favourable for WNV and RVFV emergence. Both viruses are transmitted by mosquitoes belonging to the Culex pipiens complex. We evaluated the ability of different populations of Cx. pipiens from North Africa to transmit WNV and the avirulent RVFV Clone 13 strain. Mosquitoes collected in Algeria, Morocco, and Tunisia during the summer 2010 were experimentally infected with WNV and RVFV Clone 13 strain at titers of 10(7.8) and 10(8.5) plaque forming units/mL, respectively. Disseminated infection and transmission rates were estimated 14-21 days following the exposure to the infectious blood-meal. We show that 14 days after exposure to WNV, all mosquito st developed a high disseminated infection and were able to excrete infectious saliva. However, only 69.2% of mosquito strains developed a disseminated infection with RVFV Clone 13 strain, and among them, 77.8% were able to deliver virus through saliva. Thus, Cx. pipiens from the Maghreb are efficient experimental vectors to transmit WNV and to a lesser extent, RVFV Clone 13 strain. The epidemiologic importance of our findings should be considered in the light of other parameters related to mosquito ecology and biology.
Full Text Available West Nile fever (WNF and Rift Valley fever (RVF are emerging diseases causing epidemics outside their natural range of distribution. West Nile virus (WNV circulates widely and harmlessly in the old world among birds as amplifying hosts, and horses and humans as accidental dead-end hosts. Rift Valley fever virus (RVFV re-emerges periodically in Africa causing massive outbreaks. In the Maghreb, eco-climatic and entomologic conditions are favourable for WNV and RVFV emergence. Both viruses are transmitted by mosquitoes belonging to the Culex pipiens complex. We evaluated the ability of different populations of Cx. pipiens from North Africa to transmit WNV and the avirulent RVFV Clone 13 strain. Mosquitoes collected in Algeria, Morocco, and Tunisia during the summer 2010 were experimentally infected with WNV and RVFV Clone 13 strain at titers of 10(7.8 and 10(8.5 plaque forming units/mL, respectively. Disseminated infection and transmission rates were estimated 14-21 days following the exposure to the infectious blood-meal. We show that 14 days after exposure to WNV, all mosquito st developed a high disseminated infection and were able to excrete infectious saliva. However, only 69.2% of mosquito strains developed a disseminated infection with RVFV Clone 13 strain, and among them, 77.8% were able to deliver virus through saliva. Thus, Cx. pipiens from the Maghreb are efficient experimental vectors to transmit WNV and to a lesser extent, RVFV Clone 13 strain. The epidemiologic importance of our findings should be considered in the light of other parameters related to mosquito ecology and biology.
Kozako, Tomohiro; Hirata, Shinya; Shimizu, Yoshitaka; Satoh, Yuichiro; Yoshimitsu, Makoto; White, Yohann; Lemonnier, François; Shimeno, Hiroshi; Soeda, Shinji; Arima, Naomichi
Human T-cell leukemia virus-1 (HTLV-1) causes adult T-cell leukemia/lymphoma, which is an aggressive peripheral T-cell neoplasm. Insufficient T-cell response to HTLV-1 is a potential risk factor in adult T-cell leukemia/lymphoma. Efficient induction of antigen-specific cytotoxic T lymphocytes is important for immunological suppression of virus-infected cell proliferation and oncogenesis, but efficient induction of antigen-specific cytotoxic T lymphocytes has evaded strategies utilizing poorly immunogenic free synthetic peptides. Here, we examined the efficient induction of an HTLV-1-specific CD8+ T-cell response by oligomannose-coated liposomes (OMLs) encapsulating the human leukocyte antigen (HLA)-A*0201-restricted HTLV-1 Tax-epitope (OML/Tax). Immunization of HLA-A*0201 transgenic mice with OML/Tax induced an HTLV-1-specific gamma-interferon reaction, whereas immunization with epitope peptide alone induced no reaction. Upon exposure of dendritic cells to OML/Tax, the levels of CD86, major histocompatibility complex class I, HLA-A02 and major histocompatibility complex class II expression were increased. In addition, our results showed that HTLV-1-specific CD8+ T cells can be efficiently induced by OML/Tax from HTLV-1 carriers compared with epitope peptide alone, and these HTLV-1-specific CD8+ T cells were able to lyse cells presenting the peptide. These results suggest that OML/Tax is capable of inducing antigen-specific cellular immune responses without adjuvants and may be useful as an effective vaccine carrier for prophylaxis in tumors and infectious diseases by substituting the epitope peptide. © 2011 The Authors Journal compilation © 2011 FEBS.
Wang, Yi-Ping; Huang, Li-Ping; Du, Wen-Juan; Wei, Yan-Wu; Wu, Hong-Li; Feng, Li; Liu, Chang-Ming
RNA interference (RNAi) is a conserved gene-silencing mechanism in which small interfering RNAs (siRNAs) induce the sequence-specific degradation of homologous RNAs. It has been shown to be a novel and effective antiviral therapy against a wide range of viruses. The pseudorabies virus (PRV) processivity factor UL42 can enhance the catalytic activity of the DNA polymerase and is essential for viral replication, thus it may represent a potential drug target of antiviral therapy against PRV infection. Here, we synthesized three siRNAs (siR-386, siR-517, and siR-849) directed against UL42 and determined their antiviral activities in cell culture. We first examined the kinetics of UL42 expression and found it was expressed with early kinetics during PRV replication. We verified that siR-386, siR-517, and siR-849 efficiently inhibited UL42 expression in an in vitro transfection system, thereby validating their inhibitory effects. Furthermore, we confirmed that these three siRNAs induced potent inhibitory effects on UL42 expression after PRV infection, comparable to the positive control siRNA, siR-1046, directed against the PRV DNA polymerase, the UL30 gene product, which is essential for virus replication. In addition, PRV replication was markedly reduced upon downregulation of UL42 expression. These results indicate that UL42-targeted RNAi efficiently inhibits target gene expression and impairs viral replication. This study provides a new clue for the design of an intervention strategy against herpesviruses by targeting their processivity factors. Copyright © 2016 Elsevier B.V. All rights reserved.
Sun, Qiming; Tsurimoto, Toshiki; Juillard, Franceline; Li, Lin; Li, Shijun; De León Vázquez, Erika; Chen, She; Kaye, Kenneth
Kaposi's sarcoma-associated herpesvirus (KSHV) latently infects tumor cells and persists as a multiple-copy, extrachromosomal, circular episome. To persist, the viral genome must replicate with each cell cycle. The KSHV latency-associated nuclear antigen (LANA) mediates viral DNA replication and persistence, but little is known regarding the underlying mechanisms. We find that LANA recruits replication factor C (RFC), the DNA polymerase clamp [proliferating cell nuclear antigen (PCNA)] loader, to drive DNA replication efficiently. Mutated LANA lacking RFC interaction was deficient for LANA-mediated DNA replication and episome persistence. RFC depletion had a negative impact on LANA's ability to replicate and maintain viral DNA in cells containing artificial KSHV episomes or in infected cells, leading to loss of virus. LANA substantially increased PCNA loading onto DNA in vitro and recruited RFC and PCNA to KSHV DNA in cells. These findings suggest that PCNA loading is a rate-limiting step in DNA replication that is incompatible with viral survival. LANA enhancement of PCNA loading permits efficient virus replication and persistence, revealing a previously unidentified mechanism for KSHV latency.
Gopinath, Subash C. B.; Hayashi, Kyoko
The ectodomain of the gD protein of herpes simplex viruses (HSVs) plays an important role in viral entry by binding to specific cellular coreceptors and mediating viral entry to the host cells. In the present study, we isolated RNA aptamers (aptamer-1 and aptamer-5) that specifically bind to the gD protein of HSV-1 with high affinity and are able to discriminate the gD protein of a different virus, HSV-2. Aptamer-1 efficiently interfered with the interaction between the gD protein and the HSV-1 target cell receptor (HVEM) in a dose-dependent manner. The 50% effective concentration (EC50) of aptamer-1 was estimated to be in the nanomolar range (60 nM). Furthermore, aptamer-1 was analyzed for anti-HSV-1 activity by using plaque assays, and it efficiently inhibited viral entry with an estimated Ki of 0.8 μM. To expand the future applications of aptamer-1, a shorter variant was designed by using both mapping and boundary analyses, resulting in the mini-1 aptamer (44-mer). Compared to the full-length aptamer, mini-1 had at least as high an affinity, specificity, and ability to interfere with gD-HVEM interactions. These studies suggest that the mini-1 aptamer could be explored further as an anti-HSV-1 topical therapy designed to prevent the risk of acquiring HSV-1 infection through physical contact. PMID:22514343
Hamann, Martin V; Stanke, Nicole; Müllers, Erik; Stirnnagel, Kristin; Hütter, Sylvia; Artegiani, Benedetta; Bragado Alonso, Sara; Calegari, Federico; Lindemann, Dirk
Vector systems based on different retroviruses are widely used to achieve stable integration and expression of transgenes. More recently, transient genetic manipulation systems were developed that are based on integration- or reverse transcription-deficient retroviruses. Lack of viral genome integration is desirable not only for reducing tumorigenic potential but also for applications requiring transient transgene expression such as reprogramming or genome editing. However, all existing transient retroviral vector systems rely on virus-encoded encapsidation sequences for the transfer of heterologous genetic material. We discovered that the transient transgene expression observed in target cells transduced by reverse transcriptase-deficient foamy virus (FV) vectors is the consequence of subgenomic RNA encapsidation into FV particles. Based on this initial observation, we describe here the establishment of FV vectors that enable the efficient transient expression of various transgenes by packaging, transfer, and de novo translation of nonviral RNAs both in vitro and in vivo. Transient transgene expression levels were comparable to integrase-deficient vectors but, unlike the latter, declined to background levels within a few days. Our results show that this new FV vector system provides a useful, novel tool for efficient transient genetic manipulation of target tissues by transfer of nonviral RNAs.
Full Text Available Programmed −1 ribosomal frameshifting (PRF and stop codon readthrough are two translational recoding mechanisms utilized by some RNA viruses to express their structural and enzymatic proteins at a defined ratio. Efficient recoding usually requires an RNA pseudoknot located several nucleotides downstream from the recoding site. To assess the strategic importance of the recoding pseudoknots, we have carried out a large scale genome-wide analysis in which we used an in-house developed program to detect all possible H-type pseudoknots within the genomic mRNAs of 81 animal viruses. Pseudoknots are detected downstream from ~85% of the recoding sites, including many previously unknown pseudoknots. ~78% of the recoding pseudoknots are the most stable pseudoknot within the viral genomes. However, they are not as strong as some designed pseudoknots that exhibit roadblocking effect on the translating ribosome. Strong roadblocking pseudoknots are not detected within the viral genomes. These results indicate that the decoding pseudoknots have evolved to possess optimal stability for efficient recoding. We also found that the sequence at the gag-pol frameshift junction of HIV1 harbors potential elaborated pseudoknots encompassing the frameshift site. A novel mechanism is proposed for possible involvement of the elaborated pseudoknots in the HIV1 PRF event.
Full Text Available Rice stripe mosaic virus (RSMV is a newly discovered species of cytorhabdovirus infecting rice plants that is transmitted by the leafhopper Recilia dorsalis. In this study, the transmission characteristics of RSMV by R. dorsalis were investigated. Under suitable growth conditions for R. dorsalis, the RSMV acquisition rate reached 71.9% in the second-generation population raised on RSMV-infected rice plants. The minimum acquisition and inoculation access periods of R. dorsalis were 3 and 30 min, respectively. The minimum and maximum latent transmission periods of RSMV in R. dorsalis were 6 and 18 d, respectively, and some R. dorsalis intermittently transmitted RSMV at 2–6 d intervals. Our findings revealed that the virus can replicate in the leafhopper body, but is likely not transovarially transmitted to offspring. These transmission characteristics will help guide the formulation of RSMV prevention and control strategies.
Ellis, Brian L.; Hirsch, Matthew L.; Barker, Jenny C.; Connelly, Jon P; Steininger, Robert J; Matthew H Porteus
Background The ability to deliver a gene of interest into a specific cell type is an essential aspect of biomedical research. Viruses can be a useful tool for this delivery, particularly in difficult to transfect cell types. Adeno-associated virus (AAV) is a useful gene transfer vector because of its ability to mediate efficient gene transduction in numerous dividing and quiescent cell types, without inducing any known pathogenicity. There are now a number of natural for that designed AAV ser...
Lemon, Ken; Nguyen, D Tien; Ludlow, Martin; Rennick, Linda J; Yüksel, Selma; van Amerongen, Geert; McQuaid, Stephen; Rima, Bert K; de Swart, Rik L; Duprex, W Paul
Human respiratory syncytial virus (HRSV) is the most important viral cause of severe respiratory tract disease in infants. Two subgroups (A and B) have been identified, which cocirculate during, or alternate between, yearly epidemics and cause indistinguishable disease. Existing in vitro and in vivo models of HRSV focus almost exclusively on subgroup A viruses. Here, a recombinant (r) subgroup B virus (rHRSV(B05)) was generated based on a consensus genome sequence obtained directly from an unpassaged clinical specimen from a hospitalized infant. An additional transcription unit containing the gene encoding enhanced green fluorescent protein (EGFP) was introduced between the phosphoprotein and matrix genes (position 5) of the genome to generate rHRSV(B05)EGFP(5). The recombinant viruses replicated efficiently in both HEp-2 cells and in well-differentiated normal human bronchial cells grown at air-liquid interface. Intranasal infection of cotton rats (Sigmodon hispidus) resulted in high numbers of EGFP(+) cells in epithelia of the nasal septum and conchae. When administered in a relatively large inoculum volume, the virus also replicated efficiently in bronchiolar epithelial cells and spread extensively in both the upper and lower respiratory tracts. Virus replication was not observed in ciliated epithelial cells of the trachea. This is the first virulent rHRSV strain with the genetic composition of a currently circulating wild-type virus. In vivo tracking of infected cells by means of EGFP fluorescence in the absence of cytopathic changes increases the sensitivity of virus detection in HRSV pathogenesis studies. Virology as a discipline has depended on monitoring cytopathic effects following virus culture in vitro. However, wild-type viruses isolated from patients often do not cause significant changes to infected cells, necessitating blind passage. This can lead to genetic and phenotypic changes and the generation of high-titer, laboratory-adapted viruses with
Kitani, Atsushi; Fichtner-Feigl, Stefan
This unit describes a method for in vivo delivery of oligonucleotides or plasmids using the hemagglutinating virus of Japan envelope (HVJ-E), an inactivated Sendai virus particle, as a delivery system. Viral transfection methods generally show a higher transfection efficiency than nonviral methods for the delivery of genes to cells. However, in using these methods one must bear in mind that the introduction of a virus particle into a host carries a risk for leukemia induction and for creation of disturbances in immune function due to cytotoxicity. © 2010 by John Wiley & Sons, Inc.
Merezak, C; Pierreux, C; Adam, E; Lemaigre, F; Rousseau, G G; Calomme, C; Van Lint, C; Christophe, D; Kerkhofs, P; Burny, A; Kettmann, R; Willems, L
Repression of viral expression is a major strategy developed by retroviruses to escape from the host immune response. The absence of viral proteins (or derived peptides) at the surface of an infected cell does not permit the establishment of an efficient immune attack. Such a strategy appears to have been adopted by animal oncoviruses such as bovine leukemia virus (BLV) and human T-cell leukemia virus (HTLV). In BLV-infected animals, only a small fraction of the infected lymphocytes (between 1 in 5,000 and 1 in 50,000) express large amounts of viral proteins; the vast majority of the proviruses are repressed at the transcriptional level. Induction of BLV transcription involves the interaction of the virus-encoded Tax protein with the CREB/ATF factors; the resulting complex is able to interact with three 21-bp Tax-responsive elements (TxRE) located in the 5' long terminal repeat (5' LTR). These TxRE contain cyclic AMP-responsive elements (CRE), but, remarkably, the "TGACGTCA" consensus is never strictly conserved in any viral strain (e.g.,AGACGTCA, TGACGGCA, TGACCTCA). To assess the role of these suboptimal CREs, we introduced a perfect consensus sequence within the TxRE and showed by gel retardation assays that the binding efficiency of the CREB/ATF proteins was increased. However, trans-activation of a luciferase-based reporter by Tax was not affected in transient transfection assays. Still, in the absence of Tax, the basal promoter activity of the mutated LTR was increased as much as 20-fold. In contrast, mutation of other regulatory elements within the LTR (the E box, NF-kappa B, and glucocorticoid- or interferon-responsive sites [GRE or IRF]) did not induce a similar alteration of the basal transcription levels. To evaluate the biological relevance of these observations made in vitro, the mutations were introduced into an infectious BLV molecular clone. After injection into sheep, it appeared that all the recombinants were infectious in vivo and did not revert
Full Text Available Endosomal sorting complex required for transport (ESCRT machinery supports the efficient budding of Marburg virus (MARV and many other enveloped viruses. Interaction between components of the ESCRT machinery and viral proteins is predominantly mediated by short tetrapeptide motifs, known as late domains. MARV contains late domain motifs in the matrix protein VP40 and in the genome-encapsidating nucleoprotein (NP. The PSAP late domain motif of NP recruits the ESCRT-I protein tumor susceptibility gene 101 (Tsg101. Here, we generated a recombinant MARV encoding NP with a mutated PSAP late domain (rMARV(PSAPmut. rMARV(PSAPmut was attenuated by up to one log compared with recombinant wild-type MARV (rMARV(wt, formed smaller plaques and exhibited delayed virus release. Nucleocapsids in rMARV(PSAPmut-infected cells were more densely packed inside viral inclusions and more abundant in the cytoplasm than in rMARV(wt-infected cells. A similar phenotype was detected when MARV-infected cells were depleted of Tsg101. Live-cell imaging analyses revealed that Tsg101 accumulated in inclusions of rMARV(wt-infected cells and was co-transported together with nucleocapsids. In contrast, rMARV(PSAPmut nucleocapsids did not display co-localization with Tsg101, had significantly shorter transport trajectories, and migration close to the plasma membrane was severely impaired, resulting in reduced recruitment into filopodia, the major budding sites of MARV. We further show that the Tsg101 interacting protein IQGAP1, an actin cytoskeleton regulator, was recruited into inclusions and to individual nucleocapsids together with Tsg101. Moreover, IQGAP1 was detected in a contrail-like structure at the rear end of migrating nucleocapsids. Down regulation of IQGAP1 impaired release of MARV. These results indicate that the PSAP motif in NP, which enables binding to Tsg101, is important for the efficient actin-dependent transport of nucleocapsids to the sites of budding. Thus
Kawaguchi, Yoshifumi; Miyamoto, Yasuhide; Inoue, Takehiro; Kaneda, Yasufumi
Hormone-refractory prostate cancer is one of the intractable human cancers in the world. Here, we examined the direct tumor-killing activity of inactivated Sendai virus particle [hemagglutinating virus of Japan envelope (HVJ-E)] through induction of Type I interferon (IFN) in the hormone-resistant human prostate cancer cell lines PC3 and DU145. Preferential binding of HVJ-E to PC3 and DU145 over hormone-sensitive prostate cancer cell and normal prostate epithelium was observed, resulting in a number of fused cells. After HVJ-E treatment, a number of IFN-related genes were up-regulated, resulting in Type I IFN production in PC3 cells. Then, retinoic acid-inducible gene-I (RIG-I) helicase which activates Type I IFN expression after Sendai virus infection was up-regulated in cancer cells after HVJ-E treatment. Produced IFN-alpha and -beta enhanced caspase 8 expression via Janus kinases/Signal Transducers and Activators of Transcription pathway, activated caspase 3 and induced apoptosis in cancer cells. When HVJ-E was directly injected into a mass of PC3 tumor cells in SCID (severe combined immunodeficiency) mice, a marked reduction in the bulk of each tumor mass was observed and 85% of the mice became tumor-free. Although co-injection of an anti-asialo GM1 antibody with HVJ-E into each tumor mass slightly attenuated the tumor suppressive activity of HVJ-E, significant suppression of tumor growth was observed even in the presence of anti-asialo GM1 antibody. This suggests that natural killer cell activation made small contribution to tumor regression following HVJ-E treatment in hormone-resistant prostate cancer model in vivo. Thus, HVJ-E effectively targets hormone-resistant prostate cancer by inducing apoptosis in tumor cells, as well as activating anti-tumor immunity. (c) 2009 Wiley-Liss, Inc.
Qualley, Dominic F., E-mail: email@example.com; Sokolove, Victoria L.; Ross, James L.
Nucleocapsid proteins (NCs) direct the rearrangement of nucleic acids to form the most thermodynamically stable structure, and facilitate many steps throughout the life cycle of retroviruses. NCs bind strongly to nucleic acids (NAs) and promote NA aggregation by virtue of their cationic nature; they also destabilize the NA duplex via highly structured zinc-binding motifs. Thus, they are considered to be NA chaperones. While most retroviral NCs are structurally similar, differences are observed both within and between retroviral genera. In this work, we compare the NA binding and chaperone activity of bovine leukemia virus (BLV) NC to that of two other retroviral NCs: human immunodeficiency virus type 1 (HIV-1) NC, which is structurally similar to BLV NC but from a different retrovirus genus, and human T-cell leukemia virus type 1 (HTLV-1) NC, which possesses several key structural differences from BLV NC but is from the same genus. Our data show that BLV and HIV-1 NCs bind to NAs with stronger affinity in relation to HTLV-1 NC, and that they also accelerate the annealing of complementary stem-loop structures to a greater extent. Analysis of kinetic parameters derived from the annealing data suggests that while all three NCs stimulate annealing by a two-step mechanism as previously reported, the relative contributions of each step to the overall annealing equilibrium are conserved between BLV and HIV-1 NCs but are different for HTLV-1 NC. It is concluded that while BLV and HTLV-1 belong to the same genus of retroviruses, processes that rely on NC may not be directly comparable. - Highlights: • BLV NC binds strongly to DNA and RNA. • BLV NC promotes mini-TAR annealing as well as HIV-1 NC. • Annealing kinetics suggest a low degree of similarity between BLV NC and HTLV-1 NC.
Sang C. Lee
Full Text Available Histone deacetylases (HDACs have been shown to be required for basal or inducible transcription at a variety of genes by poorly understood mechanisms. We demonstrated previously that HDAC inhibition rapidly repressed transcription from the mouse mammary tumor virus (MMTV promoter by a mechanism that does not require the binding of upstream transcription factors. In the current study, we find that HDACs work through the core promoter sequences of MMTV as well as those of several cellular genes to facilitate transcriptional initiation through deacetylation of nonhistone proteins.
Aydillo, Teresa; Ayllon, Juan; Pavlisin, Amzie; Martinez-Romero, Carles; Tripathi, Shashank; Mena, Ignacio; Moreira-Soto, Andrés; Vicente-Santos, Amanda; Corrales-Aguilar, Eugenia; Schwemmle, Martin; García-Sastre, Adolfo
Recently, two new influenza A-like viruses have been discovered in bats, HL17NL10 and HL18NL11. The hemagglutinin-like (HL) and neuraminidase like (NL) proteins of these viruses lack hemagglutination and neuraminidase activities despite their sequence and structural homologies with the HA and NA proteins of conventional influenza A virus. We now have investigated whether the NS1 proteins of HL17NL10 and HL18NL11 viruses can functionally substitute the NS1 protein of a conventional influenza A virus. For this purpose we generated recombinant influenza A/PR8/34 (PR8) H1N1 viruses containing the NS1 protein of PR8 WT, HL17NL10 and HL18NL11 viruses. These viruses (r/NS1PR8, r/NS1HL17, r/NS1HL18) were tested for replication in bat and non-bat mammalian cells and in mice. Our results demonstrate that r/NS1HL17 and r/NS1HL18 viruses are attenuated in vitro and in vivo However, bat NS1 recombinant viruses showed similar phenotypes as r/NS1PR8 virus in STAT1-/- human A549 cells and mice, unable to respond to IFN. Interestingly, multiple mouse passages of r/NS1HL17 and r/NS1HL18 viruses resulted in selection of mutant viruses containing single amino acid mutations in the viral PB2 protein. In contrast to the parental viruses, the selected PB2 mutants restored virulence and IFN antagonism. Our results indicate that the NS1 protein of bat influenza A-like viruses is less efficient than its conventional influenza A virus NS1 counterpart in antagonizing the IFN response, and that this deficiency can be overcome by the influenza virus PB2 protein.ImportanceSignificant gaps are still uncovered in our understanding of the basic features of the recently discovered bat influenza A-like viruses, HL17NL10 and HL18NL11. These unique viruses display both similarities and differences in basic biology compared to conventional influenza A viruses. In here, we show that recombinant influenza A viruses containing the NS1 protein from HL17NL10 and HL18NL11 are attenuated. This attenuation was
The present inventors developed hepatitis C virus 1a/2a and 1b/2a intergenotypic recombinants in which the JFH1 structural genes (Core, E1 and E2), p7 and NS2 were replaced by the corresponding genes of the genotype Ia reference strain H77C or TN or the corresponding genes of the genotype Ib...... reference strain J4. Sequence analysis of recovered 1a/2a and 1b/2a recombinants from 2 serial passages and subsequent reverse genetic studies revealed adaptive mutations in e.g. p7, NS2 and/or NS3. In addition, the inventors demonstrate the possibility of using adaptive mutations identified for one HCV...... be utilized e.g. in vaccine development and immunological prophylaxis. The inventors in addition demonstrate the use of the developed systems for screening of antiviral substances in vitro and functional studies of the virus, e.g. identification of receptors required for HCV entry...
Huang, Chih-Yu; Yao, Hui-Wen; Wang, Li-Chiu; Shen, Fang-Hsiu; Hsu, Sheng-Min; Chen, Shun-Hua
Herpes simplex virus 1 (HSV-1) establishes latency in neural tissues of immunocompetent mice but persists in both peripheral and neural tissues of lymphocyte-deficient mice. Thymidine kinase (TK) is believed to be essential for HSV-1 to persist in neural tissues of immunocompromised mice, because infectious virus of a mutant with defects in both TK and UL24 is detected only in peripheral tissues, but not in neural tissues, of severe combined immunodeficiency mice (T. Valyi-Nagy, R. M. Gesser, B. Raengsakulrach, S. L. Deshmane, B. P. Randazzo, A. J. Dillner, and N. W. Fraser, Virology 199:484-490, 1994, https://doi.org/10.1006/viro.1994.1150). Here we find infiltration of CD4 and CD8 T cells in peripheral and neural tissues of mice infected with a TK-negative mutant. We therefore investigated the significance of viral TK and host T cells for HSV-1 to persist in neural tissues using three genetically engineered mutants with defects in only TK or in both TK and UL24 and two strains of nude mice. Surprisingly, all three mutants establish persistent infection in up to 100% of brain stems and 93% of trigeminal ganglia of adult nude mice at 28 days postinfection, as measured by the recovery of infectious virus. Thus, in mouse neural tissues, host T cells block persistent HSV-1 infection, and viral TK is dispensable for the virus to establish persistent infection. Furthermore, we found 30- to 200-fold more virus in neural tissues than in the eye and detected glycoprotein C, a true late viral antigen, in brainstem neurons of nude mice persistently infected with the TK-negative mutant, suggesting that adult mouse neurons can support the replication of TK-negative HSV-1. Acyclovir is used to treat herpes simplex virus 1 (HSV-1)-infected immunocompromised patients, but treatment is hindered by the emergence of drug-resistant viruses, mostly those with mutations in viral thymidine kinase (TK), which activates acyclovir. TK mutants are detected in brains of immunocompromised
Jirintai, Suljid; Tanggis; Mulyanto; Suparyatmo, Joseph Benedictus; Takahashi, Masaharu; Kobayashi, Tominari; Nagashima, Shigeo; Nishizawa, Tsutomu; Okamoto, Hiroaki
Although rat hepatitis E virus (HEV) has been identified in wild rats, no cell culture systems for this virus have been established. A recent report suggesting the presence of antibodies against rat HEV in human sera encouraged us to cultivate rat HEV in human cells. When liver homogenates obtained from wild rats (Rattus rattus) in Indonesia were inoculated onto human hepatocarcinoma cells, the rat HEV replicated efficiently in PLC/PRF/5, HuH-7 and HepG2 cells, irrespective of its genetic group (G1-G3). The rat HEV particles released from cultured cells harbored lipid-associated membranes on their surface that were depleted by treatment with detergent and protease, with the buoyant density in sucrose shifting from 1.15-1.16 g/ml to 1.27-1.28 g/ml. A Northern blotting analysis revealed genomic RNA of 7.0 kb and subgenomic RNA of 2.0 kb in the infected cells. The subgenomic RNA of G1-G3 each possessed the extreme 5'-end sequence of GUAGC (nt 4933-4937), downstream of the highly conserved sequence of GAAUAACA (nt 4916-4923). The establishment of culture systems for rat HEV would allow for extended studies of the mechanisms of viral replication and functional roles of HEV proteins. Further investigation is required to clarify the zoonotic potential of rat HEV. Copyright © 2014 Elsevier B.V. All rights reserved.
Genotype 7a has been identified recently, thus not much is known about the biology of this new, major HCV genotype. The present inventors developed hepatitis C virus 7a/2a intergenotypic recombinants in which the JFH1 structural genes (Core, E1 and E2), p7 and the complete NS2 were replaced...... by the corresponding genes of the genotype 7a strain QC69 and characterized them in Huh7.5 cells. Sequence analysis of 7a/JFH1 recombinants recovered after viral passage in Huh7.5 cells following 4 independent transfection experiments revealed adaptive mutations in Core, E2, NS2, NS5A and NS5B. In reverse genetic...... in HCV genotype 7, including vaccine studies and functional analyses...
Risager, Peter Christian; Everett, Helen; Crooke, Helen
of the CSFV genome within cells can be achieved using autonomously replicating constructs (replicons) containing a reporter gene that expresses a readily quantifiable enzyme. Here, a newly implemented cloning technique was applied to genome modification of the fulllength CSFV cDNA previously inserted...... into a single-copy bacterial artificial chromosome (BAC). This technique, the Red/ET counter-selection method, is based upon homologous recombination, thus obviating the need for internal restriction sites or complex cloning strategies. Several CSFV replicons with deletions in regions encoding virus structural...... proteins considered non-essential for RNA replication were constructed and these deletions were replaced with an in-frame insertion of the Renilla luciferase (Rluc) sequence. RNA transcripts from these replicons should be translated as a single functional open reading frame. Full-genome cDNAs (~10-12,3 kb...
Full Text Available BACKGROUND: Since 2005, cases of chikungunya (CHIK were caused by an unusual vector, Aedes albopictus. This mosquito, present in Europe since 1979, has gained importance since its involvement in the first CHIK outbreak in Italy in 2007. The species is capable of transmitting experimentally 26 arboviruses. However, the vectorial status of its temperate populations has remained little investigated. In 2010, autochthonous cases of CHIK and dengue (DEN were reported in southeastern France. We evaluated the potential of a French population of Ae. albopictus in the transmission of both viruses. METHODOLOGY AND PRINCIPAL FINDINGS: We used two strains of each virus, CHIK AND DEN: one strain was isolated from an imported case, and one from an autochthonous case. We used as controls Aedes aegypti from India and Martinique, the source of the imported cases of CHIK and DEN, respectively. We showed that Ae. albopictus from Cagnes-sur-Mer (AL-CSM was as efficient as the typical tropical vector Ae. aegypti from India to experimentally transmit both CHIK strains isolated from patients in Fréjus, with around 35-67% of mosquitoes delivering up to 14 viral particles at day 3 post-infection (pi. The unexpected finding came from the high efficiency of AL-CSM to transmit both strains of DENV-1 isolated from patients in Nice. Almost 67% of Ae. albopictus AL-CSM which have ensured viral dissemination were able to transmit at day 9 pi when less than 21% of the typical DEN vector Ae. aegypti from Martinique could achieve transmission. CONCLUSIONS/SIGNIFICANCE: Temperate Ae. albopictus behaves differently compared to its counterpart from tropical regions, where recurrent epidemic outbreaks occur. Its potential responsibility for outbreaks in Europe should not be minimized.
Asami, Tatsuya; Katayama, Hiroyuki; Torrey, Jason Robert; Visvanathan, Chettiyappan; Furumai, Hiroaki
In order to properly assess and manage the risk of infection by enteric viruses in tap water, virus removal efficiency should be evaluated quantitatively for individual processes in actual drinking water treatment plants (DWTPs); however, there have been only a few studies due to technical difficulties in quantifying low virus concentration in water samples. In this study, the removal efficiency of indigenous viruses was evaluated for coagulation-sedimentation (CS) and rapid sand filtration (RSF) processes in a DWTP in Bangkok, Thailand by measuring the concentration of viruses before and after treatment processes using real-time polymerase chain reaction (qPCR). Water samples were collected and concentrated from raw source water, after CS, and after RSF, and inhibitory substances in water samples were reduced by use of a hydrophobic resin (DAX-8). Pepper mild mottle virus (PMMoV) and JC polyomavirus (JC PyV) were found to be highly prevalent in raw waters, with concentrations of 10(2.88 ± 0.35) and 10(3.06 ± 0.42) copies/L (geometric mean ± S.D.), respectively. Step-wise removal efficiencies were calculated for individual processes, with some variation observed between wet and dry seasons. During the wet season, PMMoV was removed less by CS and more by RSF on average (0.40 log10 vs 1.26 log10, respectively), while the reverse was true for JC PyV (1.91 log10 vs 0.49 log10, respectively). Both viruses were removed similarly during the dry season, with CS removing the most virus (PMMoV, 1.61 log10 and 0.78 log10; JC PyV, 1.70 log10, and 0.59 log10; CS and RSF, respectively). These differences between seasons were potentially due to variations in raw water quality and the characteristics of the viruses themselves. These results suggest that PMMoV and JC PyV, which are more prevalent in environmental waters than the other enteric viruses evaluated in this study, could be useful in determining viral fate for the risk management of viruses in water treatment
In replicated screen-house experiments, transmission of CBSV was achieved through cutting tools (22%) using susceptible cassava cv. Albert as test plants. Up to 54% transmission efficiency was achieved through sap inoculation of CBSV from infected cassava to CBSV-free cv. Mreteta. Grafting CBSV-free susceptible ...
Hacker, Ulrich T; Wingenfeld, Lisa; Kofler, David M; Schuhmann, Natascha K; Lutz, Sandra; Herold, Tobias; King, Susan B S; Gerner, Franz M; Perabo, Luca; Rabinowitz, Joseph; McCarty, Douglas M; Samulski, Richard J; Hallek, Michael; Büning, Hildegard
Gene therapy is an attractive new approach for the treatment of cancer. Therefore, the development of efficient vector systems is of crucial importance in this field. Different adeno-associated virus (AAV) serotypes have been characterized so far, which show considerable differences in tissue tropism. Consequently, we aimed to characterize the most efficient serotype for this application. To exclude all influences other than those provided by the capsid, all serotypes contained the same transgene cassette flanked by the AAV2 inverted terminal repeats. We systematically compared these vectors for efficiency in human cancer cell directed gene transfer. In order to identify limiting steps, the influence of second-strand synthesis and proteasomal degradation of AAV in a poorly transducible cell line were examined. AAV2 was the most efficient serotype in all solid tumor cells and primary melanoma cells with transduction rates up to 98 +/- 0.3%. Transduction above 70% could be reached with serotypes 1 (in cervical and prostate carcinoma) and 3 (in cervical, breast, prostate and colon carcinoma) using 1000 genomic particles per cell. In the colon carcinoma cell line HT-29 proteasomal degradation limited AAV1-AAV4-mediated gene transfer. Moreover, inefficient second-strand synthesis prevents AAV2-mediated transgene expression in this cell line. Recent advances in AAV-vector technology suggest that AAV-based vectors can be used for cancer gene therapy. Our comparative analysis revealed that, although AAV2 is the most promising candidate for such an application, serotypes 1 and 3 are valid alternatives. Furthermore, the use of self-complementary AAV vectors and proteasome inhibitors significantly improves cancer cell transduction. Copyright (c) 2005 John Wiley & Sons, Ltd.
Scheel, Troels Kasper Høyer; Gottwein, Judith M; Carlsen, Thomas H R
Hepatitis C virus (HCV) is an important cause of chronic liver disease, and interferon-based therapy cures only 40 to 80% of patients, depending on HCV genotype. Research was accelerated by genotype 2a (strain JFH1) infectious cell culture systems. We previously developed viable JFH1-based...... (HC-TN and DH6), 1b (DH1 and DH5), and 3a (DBN) isolates, using previously identified adaptive mutations. Introduction of mutations from isolates of the same subtype either led to immediate efficient virus production or accelerated culture adaptation. The DH6 and DH5 recombinants without introduced......) but not to ED43 (4a). The mutations permitting robust virus production in Huh7.5 cells had no apparent effect on viral replication but allowed efficient assembly of intracellular infectious HCV for adapted novel or previously developed recombinants. In conclusion, previously identified mutations permitted...
Quetglas, J I; Fioravanti, J; Ardaiz, N; Medina-Echeverz, J; Baraibar, I; Prieto, J; Smerdou, C; Berraondo, P
Semliki Forest virus (SFV) represents a promising gene therapy vector for tumor treatment, because it produces high levels of recombinant therapeutic proteins while inducing apoptosis in infected cells. In this study, we constructed a SFV vector expressing murine interferon alpha (IFNα). IFNα displays antitumor activity mainly by enhancing an antitumor immune response, as well as by a direct antiproliferative effect. In spite of the antiviral activity of IFNα, SFV-IFN could be produced in BHK cells at high titers. This vector was able to infect TC-1 cells, a tumor cell line expressing E6 and E7 proteins of human papillomavirus, leading to high production of IFNα both in vitro and in vivo. When injected into subcutaneous TC-1 tumors implanted in mice, SFV-IFN was able to induce an E7-specific cytotoxic T lymphocyte response, and to modify tumor infiltrating immune cells, reducing the percentage of T regulatory cells and activating myeloid cells. As a consequence, SFV-IFN was able to eradicate 58% of established tumors treated 21 days after implantation with long-term tumor-free survival and very low toxicity. SFV-IFN was also able to induce significant antitumor responses in a subcutaneous tumor model of murine colon adenocarcimoma. These data suggest that local production of IFNα by intratumoral injection of recombinant SFV-IFN could represent a potent new strategy to treat tumors in patients.
Full Text Available Previously we reported that nuclear export of both unspliced and spliced murine leukemia virus (MLV transcripts depends on the nuclear export factor (NXF1 pathway. Although the mRNA export complex TREX, which contains Aly/REF, UAP56, and the THO complex, is involved in the NXF1-mediated nuclear export of cellular mRNAs, its contribution to the export of MLV mRNA transcripts remains poorly understood. Here, we studied the involvement of TREX components in the export of MLV transcripts. Depletion of UAP56, but not Aly/REF, reduced the level of both unspliced and spliced viral transcripts in the cytoplasm. Interestingly, depletion of THO components, including THOC5 and THOC7, affected only unspliced viral transcripts in the cytoplasm. Moreover, the RNA immunoprecipitation assay showed that only the unspliced viral transcript interacted with THOC5. These results imply that MLV requires UAP56, THOC5 and THOC7, in addition to NXF1, for nuclear export of viral transcripts. Given that naturally intronless mRNAs, but not bulk mRNAs, require THOC5 for nuclear export, it is plausible that THOC5 plays a key role in the export of unspliced MLV transcripts.
Brandstadter, Joshua D; Huang, Xiaopei; Yang, Yiping
NK cells are important for the control of vaccinia virus (VV) in vivo. Recent studies have shown that multiple pathways are required for effective activation of NK cells. These include both TLR-dependent and -independent pathways, as well as the NKG2D activating receptor that recognizes host stress-induced NKG2D ligands. However, it remains largely unknown what controls the upregulation of NKG2D ligands in response to VV infection. In this study using C57BL/6 mice, we first showed that IL-18 is critical for NK-cell activation and viral clearance. We then demonstrated that IL-18 signaling on both NK cells and DCs is required for efficient NK-cell activation upon VV infection in vitro. We further showed in vivo that efficient NK-cell activation in response to VV is dependent on DCs and IL-18 signaling in non-NK cells, suggesting an essential role for NK cell-extrinsic IL-18 signaling in NK-cell activation. Mechanistically, IL-18 signaling in DCs promotes expression of Rae-1, an NKG2D ligand. Collectively, our data reveal a previously unrecognized role for NK cell-extrinsic IL-18 signaling in NK-cell activation through upregulation of NKG2D ligands. These observations may provide insights into the design of effective NK-cell-based therapies for viral infections and cancer. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.
Liu, Yuhe; Okada, Takashi; Sheykholeslami, Kianoush; Shimazaki, Kuniko; Nomoto, Tatsuya; Muramatsu, Shin-Ichi; Kanazawa, Takeharu; Takeuchi, Koichi; Ajalli, Rahim; Mizukami, Hiroaki; Kume, Akihiro; Ichimura, Keiichi; Ozawa, Keiya
Recombinant adeno-associated virus (AAV) vectors are of interest for cochlear gene therapy because of their ability to mediate the efficient transfer and long-term stable expression of therapeutic genes in a wide variety of postmitotic tissues with minimal vector-related cytotoxicity. In the present study, seven AAV serotypes (AAV1-5, 7, 8) were used to construct vectors. The expression of EGFP by the chicken beta-actin promoter associated with the cytomegalovirus immediate-early enhancer in cochlear cells showed that each of these serotypes successfully targets distinct cochlear cell types. In contrast to the other serotypes, the AAV3 vector specifically transduced cochlear inner hair cells with high efficiency in vivo, while the AAV1, 2, 5, 7, and 8 vectors also transduced these and other cell types, including spiral ganglion and spiral ligament cells. There was no loss of cochlear function with respect to evoked auditory brain-stem responses over the range of frequencies tested after the injection of AAV vectors. These findings are of value for further molecular studies of cochlear inner hair cells and for gene replacement strategies to correct recessive genetic hearing loss due to monogenic mutations in these cells.
Vandenberghe, Luk H; Xiao, Ru; Lock, Martin; Lin, Jianping; Korn, Michael; Wilson, James M
Vectors based on adeno-associated virus (AAV) are the subject of increasing interest as research tools and agents for in vivo gene therapy. A current limitation on the technology is the versatile and scalable manufacturing of vector. On the basis of experience with AAV2-based vectors, which remain strongly cell associated, AAV vector particles are commonly harvested from cell lysates, and must be extensively purified for use. We report here that vectors based on other AAV serotypes, including AAV1, AAV8, and AAV9, are found in abundance in, and can be harvested from, the medium of production cultures carried out with or without serum. For AAV2, this difference in compartmentalization is largely due to the affinity of the AAV2 particle for heparin, because an AAV2 variant in which the heparin-binding motif has been ablated gives higher yields and is efficiently released from cells. Vector particles isolated from the culture medium appear to be functionally equivalent to those purified from cell lysates in terms of transduction efficiency in vitro and in vivo, immunogenicity, and tissue tropism. Our findings will directly lead to methods for increasing vector yields and simplifying production processes for AAV vectors, which should facilitate laboratory-scale preparation and large-scale manufacture.
Full Text Available Controlling the specificity of retroviral DNA integration could improve the safety of gene therapy vectors, and fusions of heterologous chromatin binding modules to the integrase (IN–binding domain from the lentiviral integration host cofactor lens epithelium–derived growth factor (LEDGF/p75 are a promising retargeting strategy. We previously proposed the utility of IN mutant lentiviral vectors that are selectively activated by complementary LEDGF/p75 variants, and our initial modifications in human immunodeficiency virus type 1 IN and LEDGF/p75 supported about 13% of wild-type vector transduction activity. Here we describe the selection and characterization of the K42E gain-of-function mutation in IN, which greatly improves the efficiency of this system. Both K42E and initial reverse-charge mutations in IN negatively affected reverse transcription and integration, yet when combined together boosted viral transduction efficiency to ∼75% of the wild-type vector in a manner dependent on a complementary LEDGF/p75 variant. Although the K42E mutation conferred functional gains to IN mutant viral reverse transcription and integration, only the integration boost depended on the engineered LEDGF/p75 mutant. We conclude that the specificity of lentiviral retargeting strategies based on heterologous LEDGF/p75 fusion proteins will benefit from our optimized system that utilizes the unique complementation properties of reverse-charge IN mutant viral and LEDGF/p75 host proteins.
Eftekhariyan Ghamsari, Mohammad Reza; Karimi, Farah; Mousavi Gargari, Seyed Latif; Hosseini Tafreshi, Seyed Ali; Salami, Seyed Alireza
Datura stramonium is a well-known medicinal plant, which is important for its alkaloids. There are intrinsic limitations for the natural production of alkaloids in plants; metabolic engineering methods can be effectively used to conquer these limitations. In order for this the genes involved in corresponding pathways need to be studied. Virus-Induced Gene Silencing is known as a functional genomics technique to knock-down expression of endogenous genes. In this study, we silenced phytoene desaturase as a marker gene in D. stramonium in a heterologous and homologous manner by tobacco-rattle-virus-based VIGS vectors. Recombinant TRV vector containing pds gene from D. stramonium (pTRV2-Dspds) was constructed and injected into seedlings. The plants injected with pTRV2-Dspds showed photobleaching 2 weeks after infiltration. Spectrophotometric analysis demonstrated that the amount of chlorophylls and carotenoids in leaves of the bleached plants decreased considerably compared to that of the control plants. Semi-Quantitative RT-PCR results also confirmed that the expression of pds gene in the silenced plants was significantly reduced in comparison with the control plants. The results showed that the viral vector was able to influence the levels of total alkaloid content in D. stramonium. Our results illustrated that TRV-based VIGS vectors are able to induce effective and reliable functional gene silencing in D. stramonium as an alternative tool for studying the genes of interest in this plant, such as the targeted genes in tropane alkaloid biosynthetic pathway. The present work is the first report of establishing VIGS as an efficient method for transient silencing of any gene of interest in D. stramonium.
Platt, Emily J; Durnin, James P; Kabat, David
Replication of human immunodeficiency virus type 1 (HIV-1) in diverse conditions limiting for viral entry into cells frequently leads to adaptive mutations in the V3 loop of the gp120 envelope glycoprotein. This has suggested that the V3 loop limits the efficiencies of HIV-1 infections, possibly by directly affecting gp120-coreceptor affinities. In contrast, V3 loop mutations that enable HIV-1(JR-CSF) to use the low-affinity mutant coreceptor CCR5(Y14N) are shown here to have negligible effects on the virus-coreceptor affinity but to dramatically accelerate the irreversible conformational conversion of the envelope gp41 subunits from a three-stranded coil into a six-helix bundle. This slow step is blocked irreversibly by the inhibitor T-20. To further evaluate the role of entry rates in controlling infection efficiencies and viral adaptations, we developed methods to quantitatively measure viral entry kinetics. The virions were adsorbed by spinoculation at 4 degrees C onto HeLa-CD4/CCR5 cell clones that either had limiting or saturating concentrations of CCR5. After warming to 37 degrees C, the completion of entry was monitored over time by the resistance of infections to the competitive CCR5 inhibitor TAK-779. Our results suggest that the efficiency of entry of cell-attached infectious HIV-1 is principally controlled by three kinetic processes. The first is a lag phase that is caused in part by the concentration-dependent reversible association of virus with CD4 and CCR5 to form an equilibrium assemblage of complexes. Second, this assembly step lowers but does not eliminate a large activation energy barrier for a rate-limiting, CCR5-dependent conformational change in gp41 that is sensitive to blockage by T-20. The rate of infection therefore depends on the fraction of infectious virions that are sufficiently saturated with CCR5 to undergo this conformational change and on the magnitude of the activation energy barrier. Although only a small fraction of fully
Leong, L. E.-C.; Walker, P. A.; Porter, A. G.
The protease (3C pro) from human rhinovirus serotype-14 (HRV-14) has been cloned and efficiently expressed in E. coli. A straightforward single-step purification of the recombinant 3C pro has been achieved by fusing the protein to the car☐y-terminus of the glutathione-S-transferase from Schistosoma japonicum. Modifications made to the 5' end of the PCR fragment coding for the 3C pro have allowed the specific cleavage of the fusion protein using thrombin to yield mature 3C pro with the correct amino-terminal amino acid. This protease has been shown to be active when assayed using synthetic peptides corresponding to the natural cleavage recognition sequences within the polyprotein. Other substrates are being developed for this protease for possible use in the screening of inhibitors of 3C pro. Sufficient protease 3C pro has been purified for initial attempts at crystallization.
CHEN, SIFENG; KAPTURCZAK, MATTHIAS; LOILER, SCOTT A.; ZOLOTUKHIN, SERGEI; GLUSHAKOVA, OLENA Y.; MADSEN, KIRSTEN M.; SAMULSKI, RICHARD J.; HAUSWIRTH, WILLIAM W.; CAMPBELL-THOMPSON, MARTHA; BERNS, KENNETH I.; FLOTTE, TERENCE R.; ATKINSON, MARK A.; TISHER, C. CRAIG
Recombinant adeno-associated virus (rAAV) has become an attractive tool for gene therapy because of its ability to transduce both dividing and nondividing cells, elicit a limited immune response, and the capacity for imparting long-term transgene expression. Previous studies have utilized rAAV serotype 2 predominantly and found that transduction of vascular cells is relatively inefficient. The purpose of the present study was to evaluate the transduction efficiency of rAAV serotypes 1 through 5 in human and rat aortic endothelial cells (HAEC and RAEC). rAAV vectors with AAV2 inverted terminal repeats containing the human α1-antitrypsin (hAAT) gene were transcapsidated using helper plasmids to provide viral capsids for the AAV1 through 5 serotypes. True type rAAV2 and 5 vectors encoding β-galactosidase or green fluorescence protein were also studied. Infection with rAAV1 resulted in the most efficient transduction in both HAEC and RAEC compared to other serotypes (p ex vivo and in vivo demonstrated significant transgene expression in endothelial and smooth muscle cells with rAAV1 and 5 serotype vectors, in comparison to rAAV2. These results suggest the unique potential of rAAV1 and rAAV5-based vectors for vascular-targeted gene-based therapeutic strategies. OVERVIEW SUMMARY Gene delivery to the vasculature has significant potential as a therapeutic strategy for several cardiovascular disorders including atherosclerosis, hypertension, angiogenesis, and chronic vascular rejection of transplanted organs. However, limited advances have been made in achieving successful vascular endothelial cell gene transfer. The results of the present study demonstrate the superior efficacy of recombinant adeno-associated virus (rAAV) serotype 1 and 5 vectors in comparison to the traditionally used rAAV serotype 2 in transduction of primary vascular endothelial and smooth muscle cells in vitro. Our results have identified sialic acid residues for rAAV1 transduction in endothelial
Nowakowska, Justyna; Stuehler, Claudia; Egli, Adrian; Battegay, Manuel; Rauser, Georg; Bantug, Glenn Robert; Brander, Christian; Hess, Christoph; Khanna, Nina
Epstein-Barr virus (EBV)-associated post-transplant lymphoproliferative disorders (PTLD) belong to the most dreaded complications of immunosuppression. The efficacy of EBV-specific T-cell transfer for PTLD has been previously shown, yet the optimal choice of EBV-derived antigens inducing polyclonal CD4(+) and CD8(+) T cells that cover a wide range of human leukocyte antigen types and efficiently control PTLD remains unclear. A pool of 125 T-cell epitopes from seven latent and nine lytic EBV-derived proteins (EBVmix) and peptide pools of EBNA1, EBNA3c, LMP2a and BZLF1 were used to determine T-cell frequencies and to isolate T cells through the use of the interferon (IFN)-γ cytokine capture system. We further evaluated the phenotype and functionality of the generated T-cell lines in vitro. EBVmix induced significantly higher T-cell frequencies and allowed selecting more CD4(+)IFN-γ(+) and CD8(+)IFN-γ(+) cells than single peptide pools. T cells of all specificities expanded similarly in vitro, recognized cognate antigen, and, to a lower extent, EBV-infected cells, exerted moderate cytotoxicity and showed reduced alloreactivity. However, EBVmix-specific cells most efficiently controlled EBV-infected lymphoblastoid cell lines (LCLs). This control was mainly mediated by EBV-specific CD8(+) cells with an oligoclonal epitope signature covering both latent and lytic viral proteins. Notably, EBV-specific CD4(+) cells unable to control LCLs produced significantly less perforin and granzyme B, probably because of limited LCL epitope presentation. EBVmix induces a broader T-cell response, probably because of its coverage of latent and lytic EBV-derived proteins that may be important to control EBV-transformed B cells and might offer an improvement of T-cell therapies. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.
Chen, Sifeng; Kapturczak, Matthias; Loiler, Scott A; Zolotukhin, Sergei; Glushakova, Olena Y; Madsen, Kirsten M; Samulski, Richard J; Hauswirth, William W; Campbell-Thompson, Martha; Berns, Kenneth I; Flotte, Terence R; Atkinson, Mark A; Tisher, C Craig; Agarwal, Anupam
Recombinant adeno-associated virus (rAAV) has become an attractive tool for gene therapy because of its ability to transduce both dividing and nondividing cells, elicit a limited immune response, and the capacity for imparting long-term transgene expression. Previous studies have utilized rAAV serotype 2 predominantly and found that transduction of vascular cells is relatively inefficient. The purpose of the present study was to evaluate the transduction efficiency of rAAV serotypes 1 through 5 in human and rat aortic endothelial cells (HAEC and RAEC). rAAV vectors with AAV2 inverted terminal repeats containing the human alpha1-antitrypsin (hAAT) gene were transcapsidated using helper plasmids to provide viral capsids for the AAV1 through 5 serotypes. True type rAAV2 and 5 vectors encoding beta-galactosidase or green fluorescence protein were also studied. Infection with rAAV1 resulted in the most efficient transduction in both HAEC and RAEC compared to other serotypes (p Transduction with rAAV1 was completely inhibited by removal of sialic acid with sialidase, while heparin had no effect. These studies are the first demonstration that sialic acid residues are required for rAAV1 transduction in endothelial cells. Transduction of rat aortic segments ex vivo and in vivo demonstrated significant transgene expression in endothelial and smooth muscle cells with rAAV1 and 5 serotype vectors, in comparison to rAAV2. These results suggest the unique potential of rAAV1 and rAAV5-based vectors for vascular-targeted gene-based therapeutic strategies.
Full Text Available Adeno-associated viruses (AAVs are used extensively as a gene delivery vehicle for retinal gene therapy, yet its ability to target the anterior segment of the eye, critical to unlocking therapeutic opportunities, is less characterized. Previously, self-complimentary (sc AAV was shown to be necessary for transduction of the cornea and trabecular meshwork (TM, limiting the size of the gene transfer cassette, likely due to a block in second strand synthesis thought to be required for functional transduction. Here, we evaluated several AAV capsids in a single stranded (ss genome conformation for their ability to overcome the need for scAAV for targeting corneal endothelium and TM. AAV2, 8, and a recently synthetically developed AAV called Anc80L65 were evaluated in vitro and in vivo by intracameral injection in mice. Results show that although scAAV2 demonstrated superior infectivity in vitro including Human Trabecular meshwork (HTM immortalized cell lines; Anc80L65 transduced following a single intracameral injection efficiently all components of the mouse anterior segment, including the TM, corneal stroma, and endothelial cells. These results suggest that Anc80L65 is able to overcome the requirement for scAAV genomes to enable TM and corneal targeting, expanding the potential experimental and therapeutic use of AAV gene transfer in the anterior segment of the eye.
Linde A Miles
Full Text Available The oncolytic picornavirus Seneca Valley Virus (SVV-001 demonstrates anti-tumor activity in models of small cell lung cancer (SCLC, but may ultimately need to be combined with cytotoxic therapies to improve responses observed in patients. Combining SVV-001 virotherapy with a peptide prodrug activated by the viral protease 3Cpro is a novel strategy that may increase the therapeutic potential of SVV-001. Using recombinant SVV-001 3Cpro, we measured cleavage kinetics of predicted SVV-001 3Cpro substrates. An efficient substrate, L/VP4 (kcat/KM = 1932 ± 183 M(-1s(-1, was further optimized by a P2' N→P substitution yielding L/VP4.1 (kcat/KM = 17446 ± 2203 M(-1s(-1. We also determined essential substrate amino acids by sequential N-terminal deletion and substitution of amino acids found in other picornavirus genera. A peptide corresponding to the L/VP4.1 substrate was selectively cleaved by SVV-001 3Cpro in vitro and was stable in human plasma. These data define an optimized peptide substrate for SVV-001 3Cpro, with direct implications for anti-cancer therapeutic development.
Fleming, J; Ginn, S L; Weinberger, R P; Trahair, T N; Smythe, J A; Alexander, I E
Peripheral nervous system (PNS) sensory neurons are directly involved in the pathophysiology of numerous inherited and acquired neurological conditions. Therefore, efficient and stable gene delivery to these postmitotic cells has significant therapeutic potential. Among contemporary vector systems capable of neuronal transduction, only those based on herpes simplex virus have been extensively evaluated in PNS neurons. We therefore investigated the transduction performance of recombinant adeno-associated virus type 2 (AAV) and VSV-G-pseudotyped lentivirus vectors derived from human immunodeficiency virus (HIV-1) in newborn mouse and fetal human dorsal root ganglia (DRG) sensory neurons. In dissociated mouse DRG cultures both vectors achieved efficient transduction of sensory neurons at low multiplicities of infection (MOIs) and sustained transgene expression within a 28-day culture period. Interestingly, the lentivirus vector selectively transduced neurons in murine cultures, in contrast to human cultures, in which Schwann and fibroblast-like cells were also transduced. Recombinant AAV transduced all three cell types in both mouse and human cultures. After direct microinjection of murine DRG explants, maximal transduction efficiencies of 20 and 200 transducing units per neuronal transductant were achieved with AAV and lentivirus vectors, respectively. Most importantly, both vectors achieved efficient and sustained transduction of human sensory neurons in dissociated cultures, thereby directly demonstrating the exciting potential of these vectors for gene therapy applications in the PNS.
Full Text Available Abstract Background Treatment of feline immunodeficiency virus (FIV infection has been hampered by the absence of a specific combination antiretroviral treatment (ART. Integrase strand transfer inhibitors (INSTIs are emerging as a promising new drug class for HIV-1 treatment, and we evaluated the possibility of inhibiting FIV replication using INSTIs. Methods Phylogenetic analysis of lentiviral integrase (IN sequences was carried out using the PAUP* software. A theoretical three-dimensional structure of the FIV IN catalytic core domain (CCD was obtained by homology modeling based on a crystal structure of HIV-1 IN CCD. The interaction of the transferred strand of viral DNA with the catalytic cavity of FIV IN was deduced from a crystal structure of a structurally similar transposase complexed with transposable DNA. Molecular docking simulations were conducted using a genetic algorithm (GOLD. Antiviral activity was tested in feline lymphoblastoid MBM cells acutely infected with the FIV Petaluma strain. Circular and total proviral DNA was quantified by real-time PCR. Results The calculated INSTI-binding sites were found to be nearly identical in FIV and HIV-1 IN CCDs. The close similarity of primate and feline lentivirus IN CCDs was also supported by phylogenetic analysis. In line with these bioinformatic analyses, FIV replication was efficiently inhibited in acutely infected cell cultures by three investigational INSTIs, designed for HIV-1 and belonging to different classes. Of note, the naphthyridine carboxamide INSTI, L-870,810 displayed an EC50 in the low nanomolar range. Inhibition of FIV integration in situ was shown by real-time PCR experiments that revealed accumulation of circular forms of FIV DNA within cells treated with L-870,810. Conclusion We report a drug class (other than nucleosidic reverse transcriptase inhibitors that is capable of inhibiting FIV replication in vitro. The present study helped establish L-870,810, a compound
Savolainen-Kopra, Carita; Korpela, Terttu; Simonen-Tikka, Marja-Leena; Amiryousefi, Ali; Ziegler, Thedi; Roivainen, Merja; Hovi, Tapani
Ethanol-containing hand rubs are used frequently as a substitute for hand washing with water and soap. However, not all viruses are inactivated by a short term rubbing with alcohol. The capacity of a single round of instructed and controlled hand cleaning with water and soap or ethanol-containing hand rub, respectively, was tested for removal of human rhinovirus administered onto the skin of healthy volunteers on the back of the hands. Hand washing with soap and water appeared to be much more efficient for removing rhinoviruses from skin than rubbing hands with an ethanol-containing disinfectant. After washing with soap and water the virus was detected in 3/9 (33.3%) test persons from the left hand and 1/9 (11.1%) cases from the right hand, whereas the virus was detected invariably by real-time RT-PCR from both hands after cleaning with alcohol hand rub (P-value soap can clean efficiently hands contaminated with the virus responsible for an extensive share of common cold episodes. Copyright © 2012 Wiley Periodicals, Inc.
Suzuki, Youichi; Misawa, Naoko; Sato, Chihiro; Ebina, Hirotaka; Masuda, Takao; Yamamoto, Naoki; Koyanagi, Yoshio
We established a set of real-time PCR assay to accurately quantify human immunodeficiency virus type 1 (HIV-1) DNA in infected cells. Using this assay we were able to measure the strong-stop, full-length/ 1-LTR circle, 2-LTR circle, and integrated forms of viral DNA, and the data provided was quite consistent with the characteristics of mutant viruses in early phase of infection. Since our assay is particularly applicable to quantify the integrated DNA in small scale of samples, we measured the level of integrated DNA in wild-type virus (WT)- or Vpr-defective virus (deltaVpr)-infected peripheral blood mononuclear cells (PBMC), and examined whether quiescent condition of the PBMC influences integration step of HIV-1. Under stimulating condition approximately 25% of total viral DNA was in integrated form in either WT- or DeltaVpr-infected cells. In contrast, under unstimulated condition the level of integration efficiency was not significantly reduced in WT-infected cells, while this efficiency was severely impaired in the absence of vpr gene. This result clearly demonstrated a crucial role of the Vpr for nuclear localization and subsequent integration of viral DNA in nondividing cells. Therefore, our assay is useful for analyzing the events in early phase of HIV-1 infection under various conditions.
Ye, Wei; Xing, Yun; Paustian, Christopher; van de Ven, Rieneke; Moudgil, Tarsem; Hilton, Traci L; Fox, Bernard A; Urba, Walter J; Zhao, Wei; Hu, Hong-Ming
Autophagy regulates innate and adaptive immune responses to pathogens and tumors. We have reported that autophagosomes derived from tumor cells after proteasome inhibition, DRibbles (Defective ribosomal products in blebs), were excellent sources of antigens for efficient cross priming of tumor-specific CD8⁺ T cells, which mediated regression of established tumors in mice. But the activity of DRibbles in human has not been reported. DRibbles or cell lysates derived from HEK293T or UbiLT3 cell lines expressing cytomegalovirus (CMV) pp65 protein or transfected with a plasmid encoding dominant HLA-A2 restricted CMV, Epstein-Barr virus (EBV), and Influenza (Flu) epitopes (CEF) were loaded onto human monocytes or PBMCs and the response of human CMV pp65 or CEF antigen-specific CD4⁺ and CD8⁺ memory T cells was detected by intracellular staining. The effect of cytokines (GM-CSF, IL-4, IL-12, TNF-α, IFN-α and IFN-γ) TLR agonists (Lipopolysaccharide, Polyinosinic-polycytidylic acid (poly(I:C), M52-CpG, R848, TLR2 ligand) and CD40 ligand on the cross-presentation of antigens contained in DRibbles or cell lysates was explored. In this study we showed that purified monocytes, or human PBMCs, loaded with DRibbles isolated from cells expressing CMV or CEF epitopes, could activate CMV- or CEF-specific memory T cells. DRibbles were significantly more efficient at stimulating CD8⁺ memory T cells compared to cell lysates expressing the same antigenic epitopes. We optimized the conditions for T-cell activation and IFN-γ production following direct loading of DRibbles onto PBMCs. We found that the addition of Poly(I:C), CD40 ligand, and GM-CSF to the PBMCs together with DRibbles significantly increased the level of CD8⁺ T cell responses. DRibbles containing specific viral antigens are an efficient ex vivo activator of human antigen-specific memory T cells specific for those antigens. This function could be enhanced by combining with Poly(I:C), CD40 ligand, and GM
African swine fever is a contagious and often lethal disease for domestic pigs with a significant economic impact on the swine industry. The etiological agent, African swine fever virus (ASFV), is a highly structurally complex double stranded DNA virus. No effective vaccines or antiviral treatment ...
Wang, Anping; Wang, Yongjuan; Wu, Shuang; Zuo, Weiyong; Guo, Changming; Hong, Weiming; Zhu, Shanyuan
Recombinant avian adeno-associated virus (rAAAV) is a promising gene transfer vector for avian cells. Although rAAAV can be produced by co-transfection of HEK293 cells with three plasmids, both scalability and productivity of the transient transfection method can not meet the demand for large-scale in vivo experiments. In this study, a scalable rAAAV production method was established by using insect cell/baculovirus expression system. Three recombinant baculoviruses, namely BacARep, BacAVP and BacAGFP, were generated by transfection of Sf9 cells with the three plasmids expressing AAAV Rep genes, modified VP gene or the inverted terminal repeats-flanked green fluorescent protein (GFP) gene. After demonstration of the correct expression of AAAV genes, rAAAV-GFP was produced by triple infection of insect cells or triple transfection of HEK293 cells for comparison purpose. Electron microscopy revealed the formation of typical AAAV particles in the insect cells. Western blotting showed the correct assembly of rAAAV particles with a VP protein ratio similar to that of AAAV. Quantitative PCR showed that the insect cell-produced rAAAV yield was almost 25-fold higher than that produced by HEK293 cells. Fluorescent microscopy showed that the insect cell-produced rAAAV could transfer GFP reporter gene into two avian cell types with similar transfer efficiency to that of HEK293 cell-produced rAAAV. These data suggest that insect cell/baculovirus expression system could be used for scalable production of rAAAV, and the viral vector produced could be used as the gene transfer vehicle for avian cells. Copyright © 2016 Elsevier B.V. All rights reserved.
Porta, Claudine; Xu, Xiaodong; Loureiro, Silvia; Paramasivam, Saravanan; Ren, Junyuan; Al-Khalil, Tara; Burman, Alison; Jackson, Terry; Belsham, Graham J; Curry, Stephen; Lomonossoff, George P; Parida, Satya; Paton, David; Li, Yanmin; Wilsden, Ginette; Ferris, Nigel; Owens, Ray; Kotecha, Abhay; Fry, Elizabeth; Stuart, David I; Charleston, Bryan; Jones, Ian M
Foot-and-mouth disease virus (FMDV) is a significant economically and distributed globally pathogen of Artiodactyla. Current vaccines are chemically inactivated whole virus particles that require large-scale virus growth in strict bio-containment with the associated risks of accidental release or incomplete inactivation. Non-infectious empty capsids are structural mimics of authentic particles with no associated risk and constitute an alternate vaccine candidate. Capsids self-assemble from the processed virus structural proteins, VP0, VP3 and VP1, which are released from the structural protein precursor P1-2A by the action of the virus-encoded 3C protease. To date recombinant empty capsid assembly has been limited by poor expression levels, restricting the development of empty capsids as a viable vaccine. Here expression of the FMDV structural protein precursor P1-2A in insect cells is shown to be efficient but linkage of the cognate 3C protease to the C-terminus reduces expression significantly. Inactivation of the 3C enzyme in a P1-2A-3C cassette allows expression and intermediate levels of 3C activity resulted in efficient processing of the P1-2A precursor into the structural proteins which assembled into empty capsids. Expression was independent of the insect host cell background and leads to capsids that are recognised as authentic by a range of anti-FMDV bovine sera suggesting their feasibility as an alternate vaccine. Copyright © 2012 Elsevier B.V. All rights reserved.
Amarasiri, Mohan; Kitajima, Masaaki; Nguyen, Thanh H; Okabe, Satoshi; Sano, Daisuke
The multiple-barrier concept is widely employed in international and domestic guidelines for wastewater reclamation and reuse for microbiological risk management, in which a wastewater reclamation system is designed to achieve guideline values of the performance target of microbe reduction. Enteric viruses are one of the pathogens for which the target reduction values are stipulated in guidelines, but frequent monitoring to validate human virus removal efficacy is challenging in a daily operation due to the cumbersome procedures for virus quantification in wastewater. Bacteriophages have been the first choice surrogate for this task, because of the well-characterized nature of strains and the presence of established protocols for quantification. Here, we performed a meta-analysis to calculate the average log10 reduction values (LRVs) of somatic coliphages, F-specific phages, MS2 coliphage and T4 phage by membrane bioreactor, activated sludge, constructed wetlands, pond systems, microfiltration and ultrafiltration. The calculated LRVs of bacteriophages were then compared with reported human enteric virus LRVs. MS2 coliphage LRVs in MBR processes were shown to be lower than those of norovirus GII and enterovirus, suggesting it as a possible validation and operational monitoring tool. The other bacteriophages provided higher LRVs compared to human viruses. The data sets on LRVs of human viruses and bacteriophages are scarce except for MBR and conventional activated sludge processes, which highlights the necessity of investigating LRVs of human viruses and bacteriophages in multiple treatment unit processes. Copyright © 2017 Elsevier Ltd. All rights reserved.
Full Text Available Ducks are important maintenance hosts for avian influenza, including H5N1 highly pathogenic avian influenza viruses. A previous study indicated that persistence of H5N1 viruses in ducks after the development of humoral immunity may drive viral evolution following immune selection. As H5N1 HPAI is endemic in Indonesia, this mechanism may be important in understanding H5N1 evolution in that region. To determine the capability of domestic ducks to maintain prolonged shedding of Indonesian clade 2.1 H5N1 virus, two groups of Pekin ducks were inoculated through the eyes, nostrils and oropharynx and viral shedding and transmission investigated. Inoculated ducks (n = 15, which were mostly asymptomatic, shed infectious virus from the oral route from 1 to 8 days post inoculation, and from the cloacal route from 2-8 dpi. Viral ribonucleic acid was detected from 1-15 days post inoculation from the oral route and 1-24 days post inoculation from the cloacal route (cycle threshold <40. Most ducks seroconverted in a range of serological tests by 15 days post inoculation. Virus was efficiently transmitted during acute infection (5 inoculation-infected to all 5 contact ducks. However, no evidence for transmission, as determined by seroconversion and viral shedding, was found between an inoculation-infected group (n = 10 and contact ducks (n = 9 when the two groups only had contact after 10 days post inoculation. Clinical disease was more frequent and more severe in contact-infected (2 of 5 than inoculation-infected ducks (1 of 15. We conclude that Indonesian clade 2.1 H5N1 highly pathogenic avian influenza virus does not persist in individual ducks after acute infection.
Okamura, Tomotaka; Someya, Kenji; Matsuo, Kazuhiro; Hasegawa, Atsuhiko; Yamamoto, Naoki; Honda, Mitsuo
A highly attenuated vaccinia virus substrain of Dairen-I (DIs) shows promise as a candidate vector for eliciting positive immunity against immune deficiency virus. DIs was randomly obtained by serial 1-day egg passages of a chorioarantoic membrane-adapted Dairen strain (DIE), resulting in substantial genomic deletion, including various genes regulating the virus-host-range. To investigate the impact of that deletion and of the subsequent insertion of a foreign gene into that region of DIs on the ability of the DIs recombinant to induce antigen-specific immunity, we generated a recombinant vaccinia DIs expressing fulllength gag and pol genes of simian immunodeficiency virus (SIV) (rDIsSIV gag/pol) and studied the biological and immunological characteristics of the recombinant natural mutant. The rDIsSIV gag/pol developed a tiny plaque on the chick embryo fibroblast (CEF). Viral particles of rDIsSIV gag/pol as well as SIV Gag-like particles were electromicroscopically detected in the cytoplasm. Interestingly, the recombinant DIs strain grows well in CEF cells but not in mammalian cells. While rDIsSIV gag/pol produces SIV proteins in mammalian HeLa and CV-1 cells, recombinant modified vaccinia Ankara strain (MVA) expressing SIV gag and pol genes (MVA/SIV239 gag/pol) clearly replicates in HeLa and CV-1 cell lines under synchronized growth conditions and produces the SIV protein in all cell lines. Moreover, intradermal administration of rDIsSIV gag/pol or of MVA/SIV239 gag/pol elicited similar levels of IFN-gamma spot-forming cells specific for SIV Gag. If the non-productive infection characteristically induced by recombinant DIs is sufficient to trigger immune induction, as we believe it is, then a human immunodeficiency virus vaccine employing the DIs recombinant would have the twin advantages of being both effective and safe.
Mardanova, Eugenia S; Blokhina, Elena A; Tsybalova, Liudmila M; Peyret, Hadrien; Lomonossoff, George P; Ravin, Nikolai V
Agroinfiltration of plant leaves with binary vectors carrying a gene of interest within a plant viral vector is a rapid and efficient method for protein production in plants. Previously, we constructed a self-replicating vector, pA7248AMV, based on the genetic elements of potato virus X (PVX), and have shown that this vector can be used for the expression of recombinant proteins in Nicotiana benthamiana. However, this vector is almost 18 kb long and therefore not convenient for genetic manipulation. Furthermore, for efficient expression of the target protein it should be co-agroinfiltrated with an additional binary vector expressing a suppressor of post-transcriptional gene silencing. Here, we improved this expression system by creating the novel pEff vector. Its backbone is about 5 kb shorter than the original vector and it contains an expression cassette for the silencing suppressor, P24, from grapevine leafroll-associated virus-2 alongside PVX genetic elements, thus eliminating the need of co-agroinfiltration. The pEff vector provides green fluorescent protein expression levels of up to 30% of total soluble protein. The novel vector was used for expression of the influenza vaccine candidate, M2eHBc, consisting of an extracellular domain of influenza virus M2 protein (M2e) fused to hepatitis B core antigen. Using the pEff system, M2eHBc was expressed to 5-10% of total soluble protein, several times higher than with original pA7248AMV vector. Plant-produced M2eHBc formed virus-like particles in vivo, as required for its use as a vaccine. The new self-replicating pEff vector could be used for fast and efficient production of various recombinant proteins in plants.
刘爱萍; 谢贵林; 胡浩; 孔素娟; 李献林; 王晶; 袁菲; 吴兵; 刘方蕾; 赵志强
目的：建立微孔板蒽酮-硫酸法检测9V型肺炎球菌疫苗中多糖含量的检测方法，并对其进行验证和初步应用。方法通过对蒽酮-硫酸方法的改进，建立检测9V型肺炎球菌疫苗中多糖含量稳定可靠的微孔板蒽酮-硫酸法。分别对蒽酮-硫酸法中硫酸溶液浓度、加热时间进行优化，并对建立的方法进行特异性、线性、精密度及准确度的验证。结果最佳硫酸溶液比例为6∶1(浓硫酸∶水)，最佳加热时间为10 min。在检测9V型肺炎球菌多糖、多糖衍生物及多糖蛋白结合物中多糖含量时，此方法特异性强；在20~120μg/mL范围内，标准曲线线性良好( r2>0.995)；实验内及实验间均具有良好的精密度(CV值分别为2.92%~3.32%和3.10%~4.06%)；准确度试验中3个质量浓度的回收率均在96.17%~106.63%之间。结论微孔板蒽酮-硫酸法可被用来有效、准确、稳定地检测9V型肺炎球菌多糖、多糖衍生物及多糖蛋白结合物中多糖的含量，该方法较传统蒽酮-硫酸法操作简便快捷，节约样品、试剂等材料，非常适用于相关的疫苗生产过程中的质量控制。%Objective To establish and validate a microtiter anthrone-sulfuric acid method in determination of polysaccha-rides contained in serotype 9V pneumococcal vaccine,and a preliminary application of the method was performed. Metho-ds Colorimetry in microplate was introduced to the traditional method of anthrone-sulfuric acid in determination of polysac-charides. The concentration of sulfuric acid solution and the heating time were optimized. Absorbance was obtained in an ELISA reader and the polysaccharides content was quantified. The specificity, linearity, precision and accuracy of the method was validated. Results The appropriate concentration of sulfuric acid solution was 6 ∶ 1(sulfuric acid to H2O v/v), the heating time was 10 min. A high specificity was obtained in determination of
Del Toro, Francisco J.; Aguilar, Emmanuel; Hernández-Walias, Francisco J.; Tenllado, Francisco; Chung, Bong-Nam; Canto, Tomas
We compared infection of Nicotiana benthamiana plants by the positive-sense RNA viruses Cucumber mosaic virus (CMV), Potato virus Y (PVY), and by a Potato virus X (PVX) vector, the latter either unaltered or expressing the CMV 2b protein or the PVY HCPro suppressors of silencing, at 25°C vs. 30°C, or at standard (~401 parts per million, ppm) vs. elevated (970 ppm) CO2 levels. We also assessed the activities of their suppressors of silencing under those conditions. We found that at 30°C, accumulation of the CMV isolate and infection symptoms remained comparable to those at 25°C, whereas accumulation of the PVY isolate and those of the three PVX constructs decreased markedly, even when expressing the heterologous suppressors 2b or HCPro, and plants had either very attenuated or no symptoms. Under elevated CO2 plants grew larger, but contained less total protein/unit of leaf area. In contrast to temperature, infection symptoms remained unaltered for the five viruses at elevated CO2 levels, but viral titers in leaf disks as a proportion of the total protein content increased in all cases, markedly for CMV, and less so for PVY and the PVX constructs. Despite these differences, we found that neither high temperature nor elevated CO2 prevented efficient suppression of silencing by their viral suppressors in agropatch assays. Our results suggest that the strength of antiviral silencing at high temperature or CO2 levels, or those of the viral suppressors that counteract it, may not be the main determinants of the observed infection outcomes. PMID:26313753
Cui, Hongguang; Wang, Aiming
RNA silencing is a powerful technology for molecular characterization of gene functions in plants. A commonly used approach to the induction of RNA silencing is through genetic transformation. A potent alternative is to use a modified viral vector for virus-induced gene silencing (VIGS) to degrade RNA molecules sharing similar nucleotide sequence. Unfortunately, genomic studies in many allogamous woody perennials such as peach are severely hindered because they have a long juvenile period and are recalcitrant to genetic transformation. Here, we report the development of a viral vector derived from Prunus necrotic ringspot virus (PNRSV), a widespread fruit tree virus that is endemic in all Prunus fruit production countries and regions in the world. We show that the modified PNRSV vector, harbouring the sense-orientated target gene sequence of 100-200 bp in length in genomic RNA3, could efficiently trigger the silencing of a transgene or an endogenous gene in the model plant Nicotiana benthamiana. We further demonstrate that the PNRSV-based vector could be manipulated to silence endogenous genes in peach such as eukaryotic translation initiation factor 4E isoform (eIF(iso)4E), a host factor of many potyviruses including Plum pox virus (PPV). Moreover, the eIF(iso)4E-knocked down peach plants were resistant to PPV. This work opens a potential avenue for the control of virus diseases in perennial trees via viral vector-mediated silencing of host factors, and the PNRSV vector may serve as a powerful molecular tool for functional genomic studies of Prunus fruit trees. © 2016 The Authors. Plant Biotechnology Journal published by Society for Experimental Biology and The Association of Applied Biologists and John Wiley & Sons Ltd.
Fabres, Rafael Bandeira; da Luz, Roger Bordin; Soliman, Mayra Cristina; Staggemeier, Rodrigo; Fleck, Juliane Deise; Nascimento, Carlos Augusto do; Nascimento, Felipe Tiago do; Spilki, Fernando Rosado
In the present study, nine coagulants having potential to be used for sewage treatment were compared to assess their efficiency in removing total coliform bacteria, Escherichia coli and adenovirus. The coagulants tested were metallic and organic and their efficiency was compared when treating samples of raw and treated sewage (activated sludge). Before the efficiency tests of the coagulants, viral concentration methods were compared. Coagulation tests were carried out by using the jar-test system and the doses used ranged from 100 ppm to 1,000 ppm. Viral DNA was extracted and subjected to real-time polymerase chain reaction (qPCR) using primers for the gene of AdV hexon. Aluminum sulfate (1,000 ppm) presented the best results for raw sewage among metal coagulants whereas Acquapol® C118 and WW (1,000 ppm) had the most satisfactory results among organic coagulants, both reducing up to 7 logs for coliforms and 4 logs for virus. For the treated effluent, FeCl2 (1,000 ppm) presented best results for metal coagulants, whereas, from organic coagulants, the best removal rates were for Acquapol® 893/11 (1,000 ppm), both reducing up to 3 logs for coliforms and 4 logs for virus.
Jiao, Yue-Ying; Fu, Yuan-Hui; Yan, Yi-Fei; Hua, Ying; Ma, Yao; Zhang, Xiu-Juan; Song, Jing-Dong; Peng, Xiang-Lei; Huang, Jiaqiang; Hong, Tao; He, Jin-Sheng
Human respiratory syncytial virus (RSV) is an important pediatric pathogen causing acute viral respiratory disease in infants and young children. However, no licensed vaccines are currently available. Virus-like particles (VLPs) may bring new hope to producing RSV VLP vaccine with high immunogenicity and safety. Here, we constructed the recombinants of matrix protein (M) and fusion glycoprotein (F) of RSV, respectively into a replication-deficient first-generation adenoviral vector (FGAd), which were used to co-infect Vero cells to assemble RSV VLPs successfully. The resulting VLPs showed similar immunoreactivity and function to RSV virion in vitro. Moreover, Th1 polarized response, and effective mucosal virus-neutralizing antibody and CD8+ T-cell responses were induced by a single intranasal (i.n.) administration of RSV VLPs rather than intramuscular (i.m.) inoculation, although the comparable RSV F-specific serum IgG and long-lasting RSV-specific neutralizing antibody were detected in the mice immunized by both routes. Upon RSV challenge, VLP-immunized mice showed increased viral clearance but decreased signs of enhanced lung pathology and fewer eosinophils compared to mice immunized with formalin-inactivated RSV (FI-RSV). In addition, a single i.n. RSV VLP vaccine has the capability to induce RSV-specific long-lasting neutralizing antibody responses observable up to 15 months. Our results demonstrate that the long-term and memory immune responses in mice against RSV were induced by a single i.n. administration of RSV VLP vaccine, suggesting a successful approach of RSV VLPs as an effective and safe mucosal vaccine against RSV infection, and an applicable and qualified platform of FGAd-infected Vero cells for VLP production. Copyright © 2017. Published by Elsevier B.V.
Self-complementary adeno-associated virus 2 (AAV)-T cell protein tyrosine phosphatase vectors as helper viruses to improve transduction efficiency of conventional single-stranded AAV vectors in vitro and in vivo.
Zhong, Li; Chen, Linyuan; Li, Yanjun; Qing, Keyun; Weigel-Kelley, Kirsten A; Chan, Rebecca J; Yoder, Mervin C; Srivastava, Arun
Recombinant vectors based on adeno-associated virus type 2 (AAV) target the liver efficiently, but the transgene expression is limited to approximately 5% of hepatocytes. The lack of efficient transduction is due, in part, to the presence of a cellular protein, FKBP52, phosphorylated forms of which inhibit the viral second-strand DNA synthesis. We have documented that dephosphorylation of FKBP52 at tyrosine residues by the cellular T cell protein tyrosine phosphatase (TC-PTP) enhances AAV-mediated transduction in primary murine hematopoietic cells from TC-PTP-transgenic mice. We have also documented that AAV-mediated transduction is significantly enhanced in hepatocytes in TC-PTP-transgenic as well as in FKBP52-deficient mice because of efficient viral second-strand DNA synthesis. In this study, we evaluated whether co-infection of conventional single-stranded AAV vectors with self-complementary AAV-TC-PTP vectors leads to increased transduction efficiency of conventional AAV vectors in established human cell lines in vitro and in primary murine hepatocytes in vivo. We demonstrate here that scAAV-TC-PTP vectors serve as a helper virus in augmenting the transduction efficiency of conventional AAV vectors in vitro as well as in vivo which correlates directly with the extent of second-strand DNA synthesis of conventional single-stranded AAV vectors. Toxicological studies following tail-vein injections of scAAV-TC-PTP vectors in experimental mice show no evidence of any adverse effect in any of the organs in any of the mice for up to 13 weeks. Thus, this novel co-infection strategy should be useful in circumventing one of the major obstacles in the optimal use of recombinant AAV vectors in human gene therapy.
Kirnbauer, R; Taub, J; Greenstone, H; Roden, R; Dürst, M; Gissmann, L; Lowy, D R; Schiller, J T
The L1 genes of two human papillomavirus type 16 (HPV16) isolates derived from condylomata acuminata were used to express the L1 major capsid protein in insect cells via recombinant baculoviruses. Both L1 major capsid proteins self-assembled into virus-like particles (VLP) with high efficiency and could be purified in preparative amounts on density gradients. The yield of VLP was 3 orders of magnitude higher than what has been obtained previously, using L1 derived from the prototype HPV16. DN...
de Jonge, J; Schoen, P; ter Veer, W; Stegmann, T; Wilschut, J; Huckriede, A
Virosomes are reconstituted viral envelopes that can serve as vaccines and as vehicles for Cellular delivery of various macromolecules. To further advance the use of virosomes, we developed a novel dialysis procedure for the reconstitution of influenza virus membranes that is easily applicable to
Dyson, Ossie F; Pagano, Joseph S; Whitehurst, Christopher B
Epstein-Barr virus (EBV) infection and lytic replication are known to induce a cellular DNA damage response. We previously showed that the virally encoded BPLF1 protein interacts with and regulates several members of the translesion synthesis (TLS) pathway, a DNA damage tolerance pathway, and that these cellular factors enhance viral infectivity. BPLF1 is a late lytic cycle gene, but the protein is also packaged in the viral tegument, indicating that BPLF1 may function both early and late during infection. The BPLF1 protein expresses deubiquitinating activity that is strictly conserved across the Herpesviridae ; mutation of the active site cysteine results in a loss of enzymatic activity. Infection with an EBV BPLF1 knockout virus results in decreased EBV infectivity. Polymerase eta (Pol η), a specialized DNA repair polymerase, functions in TLS and allows for DNA replication complexes to bypass lesions in DNA. Here we report that BPLF1 interacts with Pol η and that Pol η protein levels are increased in the presence of functional BPLF1. BPLF1 promotes a nuclear relocalization of Pol η molecules which are focus-like in appearance, consistent with the localization observed when Pol η is recruited to sites of DNA damage. Knockdown of Pol η resulted in decreased production of infectious virus, and further, Pol η was found to bind to EBV DNA, suggesting that it may allow for bypass of damaged viral DNA during its replication. The results suggest a mechanism by which EBV recruits cellular repair factors, such as Pol η, to sites of viral DNA damage via BPLF1, thereby allowing for efficient viral DNA replication. IMPORTANCE Epstein-Barr virus is the causative agent of infectious mononucleosis and infects approximately 90% of the world's population. It causes lymphomas in individuals with acquired and innate immune disorders and is strongly associated with Hodgkin's lymphoma, Burkitt's lymphoma, diffuse large B-cell lymphomas, nasopharyngeal carcinoma (NPC), and
Sulfated polysaccharide, curdlan sulfate, efficiently prevents entry/fusion and restricts antibody-dependent enhancement of dengue virus infection in vitro: a possible candidate for clinical application.
Full Text Available Curdlan sulfate (CRDS, a sulfated 1→3-β-D glucan, previously shown to be a potent HIV entry inhibitor, is characterized in this study as a potent inhibitor of the Dengue virus (DENV. CRDS was identified by in silico blind docking studies to exhibit binding potential to the envelope (E protein of the DENV. CRDS was shown to inhibit the DENV replication very efficiently in different cells in vitro. Minimal effective concentration of CRDS was as low as 0.1 µg/mL in LLC-MK2 cells, and toxicity was observed only at concentrations over 10 mg/mL. CRDS can also inhibit DENV-1, 3, and 4 efficiently. CRDS did not inhibit the replication of DENV subgenomic replicon. Time of addition experiments demonstrated that the compound not only inhibited viral infection at the host cell binding step, but also at an early post-attachment step of entry (membrane fusion. The direct binding of CRDS to DENV was suggested by an evident reduction in the viral titers after interaction of the virus with CRDS following an ultrafiltration device separation, as well as after virus adsorption to an alkyl CRDS-coated membrane filter. The electron microscopic features also showed that CRDS interacted directly with the viral envelope, and caused changes to the viral surface. CRDS also potently inhibited DENV infection in DC-SIGN expressing cells as well as the antibody-dependent enhancement of DENV-2 infection. Based on these data, a probable binding model of CRDS to DENV E protein was constructed by a flexible receptor and ligand docking study. The binding site of CRDS was predicted to be at the interface between domains II and III of E protein dimer, which is unique to this compound, and is apparently different from the β-OG binding site. Since CRDS has already been tested in humans without serious side effects, its clinical application can be considered.
Sulfated polysaccharide, curdlan sulfate, efficiently prevents entry/fusion and restricts antibody-dependent enhancement of dengue virus infection in vitro: a possible candidate for clinical application.
Ichiyama, Koji; Gopala Reddy, Sindhoora Bhargavi; Zhang, Li Feng; Chin, Wei Xin; Muschin, Tegshi; Heinig, Lars; Suzuki, Youichi; Nanjundappa, Haraprasad; Yoshinaka, Yoshiyuki; Ryo, Akihide; Nomura, Nobuo; Ooi, Eng Eong; Vasudevan, Subhash G; Yoshida, Takashi; Yamamoto, Naoki
Curdlan sulfate (CRDS), a sulfated 1→3-β-D glucan, previously shown to be a potent HIV entry inhibitor, is characterized in this study as a potent inhibitor of the Dengue virus (DENV). CRDS was identified by in silico blind docking studies to exhibit binding potential to the envelope (E) protein of the DENV. CRDS was shown to inhibit the DENV replication very efficiently in different cells in vitro. Minimal effective concentration of CRDS was as low as 0.1 µg/mL in LLC-MK2 cells, and toxicity was observed only at concentrations over 10 mg/mL. CRDS can also inhibit DENV-1, 3, and 4 efficiently. CRDS did not inhibit the replication of DENV subgenomic replicon. Time of addition experiments demonstrated that the compound not only inhibited viral infection at the host cell binding step, but also at an early post-attachment step of entry (membrane fusion). The direct binding of CRDS to DENV was suggested by an evident reduction in the viral titers after interaction of the virus with CRDS following an ultrafiltration device separation, as well as after virus adsorption to an alkyl CRDS-coated membrane filter. The electron microscopic features also showed that CRDS interacted directly with the viral envelope, and caused changes to the viral surface. CRDS also potently inhibited DENV infection in DC-SIGN expressing cells as well as the antibody-dependent enhancement of DENV-2 infection. Based on these data, a probable binding model of CRDS to DENV E protein was constructed by a flexible receptor and ligand docking study. The binding site of CRDS was predicted to be at the interface between domains II and III of E protein dimer, which is unique to this compound, and is apparently different from the β-OG binding site. Since CRDS has already been tested in humans without serious side effects, its clinical application can be considered.
Full Text Available Hepatitis C virus (HCV infection is a challenge to prevent and treat because of the rapid development of drug resistance and escape. Viral entry is required for initiation, spread, and maintenance of infection, making it an attractive target for antiviral strategies.Using genetic immunization, we produced four monoclonal antibodies (mAbs against the HCV host entry factor CD81. The effects of antibodies on inhibition of HCV infection and dissemination were analyzed in HCV permissive human liver cell lines.The anti-CD81 mAbs efficiently inhibited infection by HCV of different genotypes as well as a HCV escape variant selected during liver transplantation and re-infecting the liver graft. Kinetic studies indicated that anti-CD81 mAbs target a post-binding step during HCV entry. In addition to inhibiting cell-free HCV infection, one antibody was also able to block neutralizing antibody-resistant HCV cell-cell transmission and viral dissemination without displaying any detectable toxicity.A novel anti-CD81 mAb generated by genetic immunization efficiently blocks HCV spread and dissemination. This antibody will be useful to further unravel the role of virus-host interactions during HCV entry and cell-cell transmission. Furthermore, this antibody may be of interest for the development of antivirals for prevention and treatment of HCV infection.
Ramirez, Santseharay; Li, Yi-Ping; Jensen, Sanne B
UNLABELLED: Hepatitis C virus (HCV) is a genetically diverse virus with multiple genotypes exhibiting remarkable differences, particularly in drug susceptibility. Drug and vaccine development will benefit from high-titer HCV cultures mimicking the complete viral life cycle, but such systems only...... exist for genotypes 1a and 2a. We developed efficient culture systems for the epidemiologically important genotype 2b. Full-length molecular clones of patient strains DH8 and DH10 were adapted to efficient growth in Huh7.5 cells by using F1468L/A1676S/D3001G (LSG) mutations. The previously developed J8......cc prototype 2b recombinant was further adapted. DH8 and J8 achieved infectivity titers >4.5 log10 Focus-Forming Units/mL. A defined set of DH8 mutations had cross-isolate adapting potential. A chimeric genome with the DH10 polyprotein coding sequence inserted into a vector with J8 untranslated...
Pañeda, Astrid; Collantes, Maria; Beattie, Stuart G; Otano, Itzia; Snapper, Jolanda; Timmermans, Eric; Guembe, Laura; Petry, Harald; Lanciego, Jose Luis; Benito, Alberto; Prieto, Jesus; Rodriguez-Pena, Maria Sol; Peñuelas, Iván; Gonzalez-Aseguinolaza, Gloria
Recombinant adeno-associated virus 5 (rAAV5) represents a candidate vector with unique advantages for the treatment of hepatic disorders because of its narrow hepatic tropism. Noninvasive in vivo imaging of transgene expression provides an important tool with which to quantify the transduction efficiency, and duration and location, of transgene expression. In this study, we used positron emission tomography (PET) and positron emission tomography-computed tomography (PET-CT) imaging to monitor liver transduction efficacy in rodents and nonhuman primates that received rAAV5 vector encoding herpes simplex virus thymidine kinase (HSV-TK). HSV-TK expression in liver was also measured by immunohistochemistry. Notable differences in liver transduction efficiency were found, dependent on the animal species and sex. Male rodents were better transduced than females, as previously described. Moreover, male nonhuman primates also displayed increased hepatic expression of the rAAV5-delivered transgene, indicating that differences in rAAV-mediated liver transduction can be anticipated in humans. Our results demonstrate the high sensitivity and reproducibility of PET, using HSV-TK and [(18)F]FHBG, to detect gene expression after rAAV vector administration into living animals, confirming the utility of this technology in the quantification of transgene expression, even at low expression levels. However, we also describe how an immune response against HSV-TK hampered analysis of long-term expression in nonhuman primates.
Fofana, Isabel; Xiao, Fei; Thumann, Christine; Turek, Marine; Zona, Laetitia; Tawar, Rajiv G; Grunert, Fritz; Thompson, John; Zeisel, Mirjam B; Baumert, Thomas F
Hepatitis C virus (HCV) infection is a challenge to prevent and treat because of the rapid development of drug resistance and escape. Viral entry is required for initiation, spread, and maintenance of infection, making it an attractive target for antiviral strategies. Using genetic immunization, we produced four monoclonal antibodies (mAbs) against the HCV host entry factor CD81. The effects of antibodies on inhibition of HCV infection and dissemination were analyzed in HCV permissive human liver cell lines. The anti-CD81 mAbs efficiently inhibited infection by HCV of different genotypes as well as a HCV escape variant selected during liver transplantation and re-infecting the liver graft. Kinetic studies indicated that anti-CD81 mAbs target a post-binding step during HCV entry. In addition to inhibiting cell-free HCV infection, one antibody was also able to block neutralizing antibody-resistant HCV cell-cell transmission and viral dissemination without displaying any detectable toxicity. A novel anti-CD81 mAb generated by genetic immunization efficiently blocks HCV spread and dissemination. This antibody will be useful to further unravel the role of virus-host interactions during HCV entry and cell-cell transmission. Furthermore, this antibody may be of interest for the development of antivirals for prevention and treatment of HCV infection.
Davies, M V; Kaufman, R J
Translation initiation on poliovirus and encephalomyocarditis virus (EMCV) mRNAs occurs by a cap-independent mechanism utilizing an internal ribosomal entry site (IRES). However, no unifying mechanism for AUG initiation site selection has been proposed. Analysis of initiation of mRNAs translated in vitro has suggested that initiation of poliovirus mRNA translation likely involves both internal binding of ribosomes and scanning to the first AUG which is in a favorable context for initiation. I...
Aoki, M; Morishita, R; Muraishi, A; Moriguchi, A; Sugimoto, T; Maeda, K; Dzau, V J; Kaneda, Y; Higaki, J; Ogihara, T
The lack of efficient treatment for myocardial infarction remains an unresolved problem in the field of cardiovascular disease. Gene therapy may be a potential therapeutic strategy for the treatment of myocardial infarction. However, current methods of in vivo gene transfer into the heart are limited by their low efficiency and/or potential toxicity. In the present study, we developed an efficient technique of gene transfer into the intact heart in vivo using the Sendai virus (HVJ: Hemagglutinating Virus of Japan)--liposome method. We used the beta-galactosidase gene, luciferase gene and human angiotensin converting enzyme (ACE) gene as markers. In vivo gene transfer into the rat heart was performed as follows: (1) direct injection into the rat heart, (2) incubation within the pericardium, and (3) infusion into a coronary artery. Direct injection of the HVJ-liposome complex containing the beta-galactosidase vector into the rat heart resulted in limited staining of beta-galactosidase 3 days after transfection. To compare transfection efficiency between "naked" plasmid DNA transfection and the HVJ-liposome method, we also transfected the luciferase reporter gene into the heart. Luciferase activity was significantly higher in hearts transfected by the HVJ-liposome method than that in hearts transfected by direct "naked" plasmid transfection (P HVJ-liposome complex, containing beta-galactosidase vector, within the pericardium resulted in widespread staining of cardiac myocytes and fibroblasts, mainly located in several surface layers beneath the pericardium. More importantly, widespread stained areas of beta-galactosidase were also observed in the middle of the myocardium around the vasa vasorum. We also examined the efficiency of gene transfer by the HVJ-liposome method in a rat myocardial infarction model. In the infarction model, using the pericardium incubation approach, staining for beta-galactosidase was observed in the viable cells around the infarction area
Zurnic, Irena; Hütter, Sylvia; Rzeha, Ute; Stanke, Nicole; Reh, Juliane; Müllers, Erik; Hamann, Martin V; Kern, Tobias; Gerresheim, Gesche K; Lindel, Fabian; Serrao, Erik; Lesbats, Paul; Engelman, Alan N; Cherepanov, Peter; Lindemann, Dirk
Unlike for other retroviruses, only a few host cell factors that aid the replication of foamy viruses (FVs) via interaction with viral structural components are known. Using a yeast-two-hybrid (Y2H) screen with prototype FV (PFV) Gag protein as bait we identified human polo-like kinase 2 (hPLK2), a member of cell cycle regulatory kinases, as a new interactor of PFV capsids. Further Y2H studies confirmed interaction of PFV Gag with several PLKs of both human and rat origin. A consensus Ser-Thr/Ser-Pro (S-T/S-P) motif in Gag, which is conserved among primate FVs and phosphorylated in PFV virions, was essential for recognition by PLKs. In the case of rat PLK2, functional kinase and polo-box domains were required for interaction with PFV Gag. Fluorescently-tagged PFV Gag, through its chromatin tethering function, selectively relocalized ectopically expressed eGFP-tagged PLK proteins to mitotic chromosomes in a Gag STP motif-dependent manner, confirming a specific and dominant nature of the Gag-PLK interaction in mammalian cells. The functional relevance of the Gag-PLK interaction was examined in the context of replication-competent FVs and single-round PFV vectors. Although STP motif mutated viruses displayed wild type (wt) particle release, RNA packaging and intra-particle reverse transcription, their replication capacity was decreased 3-fold in single-cycle infections, and up to 20-fold in spreading infections over an extended time period. Strikingly similar defects were observed when cells infected with single-round wt Gag PFV vectors were treated with a pan PLK inhibitor. Analysis of entry kinetics of the mutant viruses indicated a post-fusion defect resulting in delayed and reduced integration, which was accompanied with an enhanced preference to integrate into heterochromatin. We conclude that interaction between PFV Gag and cellular PLK proteins is important for early replication steps of PFV within host cells.
French, R; Ahlquist, P
The genome of brome mosaic virus (BMV) is divided among messenger polarity RNA1, RNA2, and RNA3 (3.2, 2.9, and 2.1 kilobases, respectively). cis-Acting sequences required for BMV RNA amplification were investigated with RNA3. By using expressible cDNA clones, deletions were constructed throughout RNA3 and tested in barley protoplasts coinoculated with RNA1 and RNA2. In contrast to requirements for 5'- and 3'-terminal noncoding sequences, either of the two RNA3 coding regions can be deleted in...
Pedersen, K.; Lovmand, S.; Bonefeld-Jørgensen, Eva Cecilie
The effect of deletions within the enhancer region in the U3 part of the LTR derived from the murine retrovirus Akv was studied. The deletions were stably transmitted through normal virus replication as shown by sequence analysis of cloned polymerase chain reaction product of the cDNA copy...... of the viral RNA. Genetic tagging of the retrovirus with lacO facilitated the analysis. Among the individual mutated LTRs an over 100-fold difference in a transient expression assay was previously detected. This difference was not revealed in studies of viral replication in cell culture, where the expression...
French, R; Ahlquist, P
The genome of brome mosaic virus (BMV) is divided among messenger polarity RNA1, RNA2, and RNA3 (3.2, 2.9, and 2.1 kilobases, respectively). cis-Acting sequences required for BMV RNA amplification were investigated with RNA3. By using expressible cDNA clones, deletions were constructed throughout RNA3 and tested in barley protoplasts coinoculated with RNA1 and RNA2. In contrast to requirements for 5'- and 3'-terminal noncoding sequences, either of the two RNA3 coding regions can be deleted individually and both can be simultaneously inactivated by N-terminal frameshift mutations without significantly interfering with amplification of RNA3 or production of its subgenomic mRNA. However, simultaneous major deletions in both coding regions greatly attenuate RNA3 accumulation. RNA3 levels can be largely restored by insertion of a heterologous, nonviral sequence in such mutants, suggesting that RNA3 requires physical separation of its terminal domains or a minimum overall size for normal replication or stability. Unexpectedly, deletions in a 150-base segment of the intercistronic noncoding region drastically reduce RNA3 accumulation. This segment contains a sequence element homologous to sequences found near the 5' ends of BMV RNA1 and RNA2 and in analogous positions in the three genomic RNAs of the related cucumber mosaic virus, suggesting a possible role in plus-strand synthesis.
Yellow dwarf viruses cause the most economically important virus diseases of cereal crops worldwide and are vectored by aphids. The identification of vector proteins mediating virus transmission is critical to develop sustainable virus management practices and to understand viral strategies for cir...
Ellis, Brian L; Hirsch, Matthew L; Barker, Jenny C; Connelly, Jon P; Steininger, Robert J; Porteus, Matthew H
The ability to deliver a gene of interest into a specific cell type is an essential aspect of biomedical research. Viruses can be a useful tool for this delivery, particularly in difficult to transfect cell types. Adeno-associated virus (AAV) is a useful gene transfer vector because of its ability to mediate efficient gene transduction in numerous dividing and quiescent cell types, without inducing any known pathogenicity. There are now a number of natural for that designed AAV serotypes that each has a differential ability to infect a variety of cell types. Although transduction studies have been completed, the bulk of the studies have been done in vivo, and there has never been a comprehensive study of transduction ex vivo/in vitro. Each cell type was infected with each serotype at a multiplicity of infection of 100,000 viral genomes/cell and transduction was analyzed by flow cytometry + . We found that AAV1 and AAV6 have the greatest ability to transduce a wide range of cell types, however, for particular cell types, there are specific serotypes that provide optimal transduction. In this work, we describe the transduction efficiency of ten different AAV serotypes in thirty-four different mammalian cell lines and primary cell types. Although these results may not be universal due to numerous factors such as, culture conditions and/ or cell growth rates and cell heterogeneity, these results provide an important and unique resource for investigators who use AAV as an ex vivo gene delivery vector or who work with cells that are difficult to transfect.
Sasaki, Jun; Ishikawa, Kumiko; Taniguchi, Koki
Picornavirus genomes are translated into a single large polyprotein, which is processed by virus-encoded proteases into individual functional proteins. 3C of all picornaviruses is a protease, and the leader (L) and 2A proteins of some picornaviruses are also involved in polyprotein processing. Aichi virus (AiV), which is associated with acute gastroenteritis in humans, is a member of the genus Kobuvirus of the family Picornaviridae. The AiV L and 2A proteins have already been shown to exhibit no protease activity. In this study, we investigated AiV polyprotein processing by 3C and 3CD using a cell-free translation system. 3C and 3CD were capable of processing the polyprotein in trans; 3C, however, cleaved the VP1/2A site inefficiently, while 3CD cleaved this site almost completely. Mammalian two-hybrid and coimmunoprecipitation assays showed an interaction between 2A and 3CD. Using a 3CD mutant and various 2A mutants of substrate proteins, we showed a clear correlation between the 2A-3CD interaction and the VP1/2A cleavage by 3CD. Thus, this study suggests that tight interaction of 3CD with the 2A region of a precursor protein is required for efficient cleavage at the VP1/2A site. Copyright © 2011 Elsevier B.V. All rights reserved.
Kato, Naoki; Nakanishi, Kuniaki; Nemoto, Koichi; Morishita, Ryuichi; Kaneda, Yasufumi; Uenoyama, Maki; Ikeda, Tomosumi; Fujikawa, Kyosuke
We evaluated the feasibility of gene delivery into the peripheral and central nervous systems via retrograde axonal transport following injection of a haemagglutinating virus of Japan (HVJ)-liposome-DNA complex vector into an innervated muscle. Transfection efficiency was assessed by measuring luciferase activity, and was compared statistically with that achieved using a liposome-DNA control vector. High luciferase activity was observed in the injected muscle, the ipsilateral sciatic nerve, and the ipsilateral dorsal root ganglia on day 1 after gene transfer. The spinal cord also showed luciferase activity, although this was lower than in the other tissues. However, no activity was observed in the contralateral sciatic nerve or the contralateral dorsal root ganglia. In addition, we performed gene transfer twice, with a 1-week interval, to evaluate the feasibility of repeated therapeutic gene delivery. Again, a high transfection efficiency was observed immediately, even after the second gene transfer, and transfection efficiency was significantly higher at each defined time-point using the HVJ-liposome complex vector than using a control vector. These results indicate that this method could be used for repeated therapeutic gene delivery into muscle, nerve, dorsal root ganglia, and possibly spinal cord, without the need for a surgical approach, making it well suited to clinical applications.
Full Text Available Unlike for other retroviruses, only a few host cell factors that aid the replication of foamy viruses (FVs via interaction with viral structural components are known. Using a yeast-two-hybrid (Y2H screen with prototype FV (PFV Gag protein as bait we identified human polo-like kinase 2 (hPLK2, a member of cell cycle regulatory kinases, as a new interactor of PFV capsids. Further Y2H studies confirmed interaction of PFV Gag with several PLKs of both human and rat origin. A consensus Ser-Thr/Ser-Pro (S-T/S-P motif in Gag, which is conserved among primate FVs and phosphorylated in PFV virions, was essential for recognition by PLKs. In the case of rat PLK2, functional kinase and polo-box domains were required for interaction with PFV Gag. Fluorescently-tagged PFV Gag, through its chromatin tethering function, selectively relocalized ectopically expressed eGFP-tagged PLK proteins to mitotic chromosomes in a Gag STP motif-dependent manner, confirming a specific and dominant nature of the Gag-PLK interaction in mammalian cells. The functional relevance of the Gag-PLK interaction was examined in the context of replication-competent FVs and single-round PFV vectors. Although STP motif mutated viruses displayed wild type (wt particle release, RNA packaging and intra-particle reverse transcription, their replication capacity was decreased 3-fold in single-cycle infections, and up to 20-fold in spreading infections over an extended time period. Strikingly similar defects were observed when cells infected with single-round wt Gag PFV vectors were treated with a pan PLK inhibitor. Analysis of entry kinetics of the mutant viruses indicated a post-fusion defect resulting in delayed and reduced integration, which was accompanied with an enhanced preference to integrate into heterochromatin. We conclude that interaction between PFV Gag and cellular PLK proteins is important for early replication steps of PFV within host cells.
Lopez, Gerardo U; Gerba, Charles P; Tamimi, Akrum H; Kitajima, Masaaki; Maxwell, Sheri L; Rose, Joan B
Fomites can serve as routes of transmission for both enteric and respiratory pathogens. The present study examined the effect of low and high relative humidity on fomite-to-finger transfer efficiency of five model organisms from several common inanimate surfaces (fomites). Nine fomites representing porous and nonporous surfaces of different compositions were studied. Escherichia coli, Staphylococcus aureus, Bacillus thuringiensis, MS2 coliphage, and poliovirus 1 were placed on fomites in 10-μl drops and allowed to dry for 30 min under low (15% to 32%) or high (40% to 65%) relative humidity. Fomite-to-finger transfers were performed using 1.0 kg/cm(2) of pressure for 10 s. Transfer efficiencies were greater under high relative humidity for both porous and nonporous surfaces. Most organisms on average had greater transfer efficiencies under high relative humidity than under low relative humidity. Nonporous surfaces had a greater transfer efficiency (up to 57%) than porous surfaces (humidity, as well as under high relative humidity (nonporous, up to 79.5%; porous, <13.4%). Transfer efficiency also varied with fomite material and organism type. The data generated can be used in quantitative microbial risk assessment models to assess the risk of infection from fomite-transmitted human pathogens and the relative levels of exposure to different types of fomites and microorganisms.
He, Huan; Xue, Jing; Wang, Weiming; Liu, Lihong; Ye, Chaobaihui; Cong, Zhe; Kimata, Jason T; Qin, Chuan; Zhou, Paul
Human immunodeficiency virus type 1 (HIV-1)-based lentiviral vectors efficiently transduce genes to human, but not rhesus, primary T cells and hematopoietic stem cells (HSCs). The poor transduction of HIV-1 vectors to rhesus cells is mainly due to species-specific restriction factors such as rhesus TRIM5α. Previously, several strategies to modify HIV-1 vectors were developed to overcome rhesus TRIM5α restriction. While the modified HIV-1 vectors efficiently transduce rhesus HSCs, they remain suboptimal for rhesus primary T cells. Recently, HIV-1 variants that encode combinations of LNEIE mutations in capsid (CA) protein and SIVmac239 Vif were found to replicate efficiently in rhesus primary T cells. Thus, the present study tested whether HIV-1 vectors packaged by a packaging construct containing these CA substitutions could efficiently transduce both human and rhesus primary CD4 T cells. To accomplish this, LNEIE mutations were made in the packaging construct CEMΔ8.9, and recombinant HIV-1 vectors packaged by Δ8.9 WT or Δ8.9 LNEIE were generated. Transduction rates, CA stability, and vector integration in CEMss-CCR5 and CEMss-CCR5-rhTRIM5α/green fluorescent protein cells, as well as transduction rates in human and rhesus primary CD4 T cells by Δ8.9 WT or Δ8.9 LNEIE-packaged HIV-1 vectors, were compared. Finally, the influence of rhesus TRIM5α variations in transduction rates to primary CD4 T cells from a cohort of 37 Chinese rhesus macaques was studied. While it maintains efficient transduction for human T-cell line and primary CD4 T cells, Δ8.9 LNEIE-packaged HIV-1 vector overcomes rhesus TRIM5α-mediated CA degradation, resulting in significantly higher transduction efficiency of rhesus primary CD4 T cells than Δ8.9 WT-packaged HIV-1 vector. Rhesus TRIM5α variations strongly influence transduction efficiency of rhesus primary CD4 T cells by both Δ8.9 WT or Δ8.9 LNEIE-packaged HIV-1 vectors. Thus, it is concluded that Δ8.9 LNEIE-packaged HIV-1
Feng, Na; Liu, Yuxiu; Wang, Jianzhong; Xu, Weiwei; Li, Tiansong; Wang, Tiecheng; Wang, Lei; Yu, Yicong; Wang, Hualei; Zhao, Yongkun; Yang, Songtao; Gao, Yuwei; Hu, Guixue; Xia, Xianzhu
In 2008, an outbreak of canine distemper virus (CDV) infection in monkeys was reported in China. We isolated CDV strain (subsequently named Monkey-BJ01-DV) from lung tissue obtained from a rhesus monkey that died in this outbreak. We evaluated the ability of this virus on Vero cells expressing SLAM receptors from dog, monkey and human origin, and analyzed the H gene of Monkey-BJ01-DV with other strains. The Monkey-BJ01-DV isolate replicated to the highest titer on Vero cells expressing dog-origin SLAM (10(5.2±0.2) TCID50/ml) and monkey-origin SLAM (10(5.4±0.1) TCID50/ml), but achieved markedly lower titers on human-origin SLAM cells (10(3.3±0.3) TCID50/ml). Phylogenetic analysis of the full-length H gene showed that Monkey-BJ01-DV was highly related to other CDV strains obtained during recent CDV epidemics among species of the Canidae family in China, and these Monkey strains CDV (Monkey-BJ01-DV, CYN07-dV, Monkey-KM-01) possessed a number of amino acid specific substitutions (E276V, Q392R, D435Y and I542F) compared to the H protein of CDV epidemic in other animals at the same period. Our results suggested that the monkey origin-CDV-H protein could possess specific substitutions to adapt to the new host. Monkey-BJ01-DV can efficiently use monkey- and dog-origin SLAM to infect and replicate in host cells, but further adaptation may be required for efficient replication in host cells expressing the human SLAM receptor.
Kozako, Tomohiro; Fukada, Katsuhiko; Hirata, Shinya; White, Yohann; Harao, Michiko; Nishimura, Yasuharu; Kino, Youichiro; Soeda, Shinji; Shimeno, Hiroshi; Lemonnier, François; Sonoda, Shunro; Arima, Naomichi
Adult T-cell leukemia-lymphoma (ATL) is an aggressive peripheral T-cell neoplasm that develops after long-term infection with the human T-cell leukemia virus-1 (HTLV-1). HTLV-1-specific cytotoxic T lymphocytes (CTLs) play an important role in suppressing proliferation of HTLV-1-infected or transformed T-cells in vitro. Efficient induction of antigen-specific CTLs is important for immunologic suppression of oncogenesis, but has evaded strategies utilizing poorly immunogenic free synthetic peptides. In the present study, we examined the efficient induction of HTLV-1-specific CD8+ T-cell response by an HTLV-1/hepatitis B virus core (HBc) chimeric particle incorporating the HLA-A*0201-restricted HTLV-1 Tax-epitope. The immunization of HLA-A*0201-transgenic mice with the chimeric particle induced antigen-specific gamma-interferon reaction, whereas immunization with epitope peptide only induced no reaction as assessed by enzyme-linked immunospot assay. Immunization with the chimeric particle also induced HTLV-1-specific CD8+ T-cells in spleen and inguinal lymph nodes. Furthermore, upon exposure of dendritic cells from HLA-A*0201-transgenic mice to the chimeric particle, the expression of CD86, HLA-A02, TLR4 and MHC class II was increased. Additionally, our results show that HTLV-1-specific CD8+ T-cells can be induced by peptide with HTLV-1/HBc particle from ATL patient, but not by peptide only and these HTLV-1-specific CD8+ T-cells were able to lyse cells presenting the peptide. These results suggest that HTLV-1/HBc chimeric particle is capable of inducing strong cellular immune responses without adjuvants via effective maturation of dendritic cells and is potentially useful as an effective carrier for therapeutic vaccines in tumors, or in infectious diseases by substituting the epitope peptide.
Wirblich, Christoph; Coleman, Christopher M; Kurup, Drishya; Abraham, Tara S; Bernbaum, John G; Jahrling, Peter B; Hensley, Lisa E; Johnson, Reed F; Frieman, Matthew B; Schnell, Matthias J
Middle East respiratory syndrome coronavirus (MERS-CoV) emerged in 2012 and is a highly pathogenic respiratory virus. There are no treatment options against MERS-CoV for humans or animals, and there are no large-scale clinical trials for therapies against MERS-CoV. To address this need, we developed an inactivated rabies virus (RABV) that contains the MERS-CoV spike (S) protein expressed on its surface. Our initial recombinant vaccine, BNSP333-S, expresses a full-length wild-type MERS-CoV S protein; however, it showed significantly reduced viral titers compared to those of the parental RABV strain and only low-level incorporation of full-length MERS-CoV S into RABV particles. Therefore, we developed a RABV-MERS vector that contained the MERS-CoV S1 domain of the MERS-CoV S protein fused to the RABV G protein C terminus (BNSP333-S1). BNSP333-S1 grew to titers similar to those of the parental vaccine vector BNSP333, and the RABV G-MERS-CoV S1 fusion protein was efficiently expressed and incorporated into RABV particles. When we vaccinated mice, chemically inactivated BNSP333-S1 induced high-titer neutralizing antibodies. Next, we challenged both vaccinated mice and control mice with MERS-CoV after adenovirus transduction of the human dipeptidyl peptidase 4 (hDPP4) receptor and then analyzed the ability of mice to control MERS-CoV infection. Our results demonstrated that vaccinated mice were fully protected from the MERS-CoV challenge, as indicated by the significantly lower MERS-CoV titers and MERS-CoV and mRNA levels in challenged mice than those in unvaccinated controls. These data establish that an inactivated RABV-MERS S-based vaccine may be effective for use in animals and humans in areas where MERS-CoV is endemic. Rabies virus-based vectors have been proven to be efficient dual vaccines against rabies and emergent infectious diseases such as Ebola virus. Here we show that inactivated rabies virus particles containing the MERS-CoV S1 protein induce potent immune
Manhães, Ana Marcia E de A; de Oliveira, Marcos V V; Shan, Libo
Several VIGS protocols have been established for high-throughput functional genomic screens as it bypasses the time-consuming and laborious process of generation of transgenic plants. The silencing efficiency in this approach is largely hindered by a technically demanding step in which the first pair of newly emerged true leaves at the 2-week-old stage are infiltrated with a needleless syringe. To further optimize VIGS efficiency and achieve rapid inoculation for a large-scale functional genomic study, here we describe a protocol of an efficient VIGS assay in Arabidopsis using Agrobacterium-mediated rubbing infection. The Agrobacterium inoculation is performed by simply rubbing the leaves with Filter Agent Celite(®) 545. The highly efficient and uniform silencing effect was indicated by the development of a visibly albino phenotype due to silencing of the Cloroplastos alterados 1 (CLA1) gene in the newly emerged leaves. In addition, the albino phenotype could be observed in stems and flowers, indicating its potential application for gene functional studies in the late vegetative development and flowering stages.
Qin, Yanli; Tang, Xiaoli; Garcia, Tamako; Hussain, Munira; Zhang, Jiming; Lok, Anna; Wands, Jack; Li, Jisu; Tong, Shuping
Infection by hepatitis B virus (HBV) genotype C is associated with a prolonged viremic phase, delayed hepatitis B e antigen (HBeAg) seroconversion, and an increased incidence of liver cirrhosis and hepatocellular carcinoma compared with genotype B infection. Genotype C is also associated with the more frequent emergence of core promoter mutations, which increase genome replication and are independently associated with poor clinical outcomes. We amplified full-length HBV genomes from serum samples from Chinese and U. S. patients with chronic HBV infection and transfected circularized genome pools or dimeric constructs of individual clones into Huh7 cells. The two genotypes could be differentiated by Western blot analysis due to the reactivities of M and L proteins toward a monoclonal pre-S2 antibody and slightly different S-protein mobilities. Great variability in replication capacity was observed for both genotypes. The A1762T/G1764A core promoter mutations were prevalent in genotype C isolates and correlated with increased replication capacity, while the A1752G/T mutation frequently found in genotype B isolates correlated with a low replication capacity. Importantly, most genotype C isolates with wild-type core promoter sequence replicated less efficiently than the corresponding genotype B isolates due to less efficient transcription of the 3.5-kb RNA. However, genotype C isolates often displayed more efficient virion secretion. We propose that the low intracellular levels of viral DNA and core protein of wild-type genotype C delay immune clearance and trigger the subsequent emergence of A1762T/G1764A core promoter mutations to upregulate replication; efficient virion secretion compensates for the low replication capacity to ensure the establishment of persistent infection by genotype C. PMID:21775451
Lee, Meng-Shiou; Sun, Fang-Chun; Huang, Chi-Hung; Lien, Yi-Yang; Feng, Shin-Huei; Lai, Guan-Hua; Lee, Meng-Shiunn; Chao, Jung; Chen, Hsi-Jien; Tzen, Jason T C; Cheng, Hao-Yuan
Apoptin, a nonstructural protein encoded by the VP3 gene of chicken anemia virus (CAV), has been shown to not only induce apoptosis when introduced into the precursors of chicken thymocytes, but has been found to specifically kill human cancer cells, tumor cell and transformed cells without affecting the proliferation of normal cells. This tumor-specific apoptotic characteristic of the protein potentially may allow the development of a protein drug that has applications in tumor therapy. However, several major problems, which include poor expression and poor protein solubility, have hampered the production of apoptin in bacteria. Significantly increased expression of recombinant full-length apoptin that originated from chicken anemia virus was demonstrated using an E. coli expression system. The CAV VP3 gene was fused with a synthetic sequence containing a trans-acting activator of transcription (TAT) protein transduction domain (PTD). The resulting construct was cloned into various different expression vectors and these were then expressed in various E. coli strains. The expression of the TAT-Apoptin in E. coli was significantly increased when TAT-Apoptin was fused with GST-tag rather than a His-tag. When the various rare amino acid codons of apoptin were optimized, the expression level of the GST-TAT-Apoptin(opt) in E. coli BL21(DE3) was significantly further increased. The highest protein expression level obtained was 8.33 g/L per liter of bacterial culture after induction with 0.1 mM IPTG for 4 h at 25 °C. Moreover, approximately 90% of the expressed GST-TAT-Apoptin(opt) under these conditions was soluble. After purification by GST affinity chromatography, the purified recombinant TAT-Apoptin(opt) protein was used to evaluate the recombinant protein's apoptotic activity on tumor cells. The results demonstrated that the E. coli-expressed GST-TAT-apoptin(opt) showed apoptotic activity and was able to induce human premyelocytic leukemia HL-60 cells to enter
Full Text Available Abstract Background Apoptin, a nonstructural protein encoded by the VP3 gene of chicken anemia virus (CAV, has been shown to not only induce apoptosis when introduced into the precursors of chicken thymocytes, but has been found to specifically kill human cancer cells, tumor cell and transformed cells without affecting the proliferation of normal cells. This tumor-specific apoptotic characteristic of the protein potentially may allow the development of a protein drug that has applications in tumor therapy. However, several major problems, which include poor expression and poor protein solubility, have hampered the production of apoptin in bacteria. Results Significantly increased expression of recombinant full-length apoptin that originated from chicken anemia virus was demonstrated using an E. coli expression system. The CAV VP3 gene was fused with a synthetic sequence containing a trans-acting activator of transcription (TAT protein transduction domain (PTD. The resulting construct was cloned into various different expression vectors and these were then expressed in various E. coli strains. The expression of the TAT-Apoptin in E. coli was significantly increased when TAT-Apoptin was fused with GST-tag rather than a His-tag. When the various rare amino acid codons of apoptin were optimized, the expression level of the GST-TAT-Apoptinopt in E. coli BL21(DE3 was significantly further increased. The highest protein expression level obtained was 8.33 g/L per liter of bacterial culture after induction with 0.1 mM IPTG for 4 h at 25 °C. Moreover, approximately 90% of the expressed GST-TAT-Apoptinopt under these conditions was soluble. After purification by GST affinity chromatography, the purified recombinant TAT-Apoptinopt protein was used to evaluate the recombinant protein’s apoptotic activity on tumor cells. The results demonstrated that the E. coli-expressed GST-TAT-apoptinopt showed apoptotic activity and was able to induce human
Merkel, Steven F; Andrews, Allison M; Lutton, Evan M; Mu, Dakai; Hudry, Eloise; Hyman, Bradley T; Maguire, Casey A; Ramirez, Servio H
Developing therapies for central nervous system (CNS) diseases is exceedingly difficult because of the blood-brain barrier (BBB). Notably, emerging technologies may provide promising new options for the treatment of CNS disorders. Adeno-associated virus serotype 9 (AAV9) has been shown to transduce cells in the CNS following intravascular administration in rodents, cats, pigs, and non-human primates. These results suggest that AAV9 is capable of crossing the BBB. However, mechanisms that govern AAV9 transendothelial trafficking at the BBB remain unknown. Furthermore, possibilities that AAV9 may transduce brain endothelial cells or affect BBB integrity still require investigation. Using primary human brain microvascular endothelial cells as a model of the human BBB, we performed transduction and transendothelial trafficking assays comparing AAV9 to AAV2, a serotype that does not cross the BBB or transduce endothelial cells effectively in vivo. Results of our in vitro studies indicate that AAV9 penetrates brain microvascular endothelial cells barriers more effectively than AAV2, but has reduced transduction efficiency. In addition, our data suggest that (i) AAV9 penetrates endothelial barriers through an active, cell-mediated process, and (ii) AAV9 fails to disrupt indicators of BBB integrity such as transendothelial electrical resistance, tight junction protein expression/localization, and inflammatory activation status. Overall, this report shows how human brain endothelial cells configured in BBB models can be utilized for evaluating transendothelial movement and transduction kinetics of various AAV capsids. Importantly, the use of a human in vitro BBB model can provide import insight into the possible effects that candidate AVV gene therapy vectors may have on the status of BBB integrity. Read the Editorial Highlight for this article on page 192. © 2016 International Society for Neurochemistry.
David H Stitelman
Full Text Available Efficient gene transfer to muscle stem cells (satellite cells has not been achieved despite broad transduction of skeletal muscle by systemically administered adeno-associated virus serotype 2/9 (AAV-9 in mice. We hypothesized that cellular migration during fetal development would make satellite cells accessible for gene transfer following in utero intravascular injection. We injected AAV-9 encoding green fluorescent protein (GFP marker gene into the vascular space of mice ranging in ages from post-coital day 12 (E12 to postnatal day 1 (P1. Satellite cell transduction was examined using: immunohistochemistry and confocal microscopy, satellite cell migration assay, myofiber isolation and FACS analysis. GFP positive myofibers were detected in all mature skeletal muscle groups and up to 100% of the myofibers were transduced. We saw gestational variation in cardiac and skeletal muscle expression. E16 injection resulted in 27.7 ± 10.0% expression in satellite cells, which coincides with the timing of satellite cell migration, and poor satellite cell expression before and after satellite cell migration (E12 and P1. Our results demonstrate that efficient gene expression is achieved in differentiated myofibers and satellite cells after injection of AAV-9 in utero. These findings support the potential of prenatal gene transfer for muscle based treatment strategies.
Nakamura, Hitomi; Kimura, Tadashi; Ikegami, Hiroyuki; Ogita, Kazuhide; Koyama, Shinsuke; Shimoya, Koichiro; Tsujie, Tomoko; Koyama, Masayasu; Kaneda, Yasufumi; Murata, Yuji
The uterus is obviously critical in implantation, development of the fetus and parturition. Endometrial cancer derived from endometrial epithelium is one of the common malignancies in the female reproductive tract. In order to clarify the local mechanisms of reproductive physiology and establish a non-systemic therapeutic strategy for reproductive failure as well as for endometrial cancer, we applied haemagglutinating virus of Japan envelope (HVJ-E) vector to in-vivo gene transfer into the uterine cavity of IVCS mice. Injection of HVJ-E vector into mouse uterine cavity on day 1.5 post coitum (p.c.) introduced a reporter gene approximately 120-fold more efficiently than introduction using the cationic liposome method. The expression of the introduced gene continued for at least 3 days. The plasmid vector was localized in the endometrial epithelium, whereas oligo deoxynucleotides were distributed throughout the epithelium, stromal cells and myometrium. HVJ-E vector did not affect the pregnancy rate, course of pregnancy, litter size, fetal growth in utero or parturition, and did not transfect the exogenous gene to the fetus. These results indicate that gene transfer into the uterus using HVJ-E vector is highly efficient and safe during pregnancy, and results in a well controlled distribution of the exogenous DNA. We believe that this procedure should be widely applicable for investigations of reproductive physiology as well as for methods of local gene therapy in the uterus.
Duarte, Elisabeth Carmen; Garcia, Leila Posenato; de Araújo, Wildo Navegantes; Velez, Maria P
Zika infection during pregnancy (ZIKVP) is known to be associated with adverse outcomes. Studies on this matter involve both rare outcomes and rare exposures and methodological choices are not straightforward. Cohort studies will surely offer more robust evidences, but their efficiency must be enhanced. We aim to contribute to the debate on sample selection strategies in cohort studies to assess outcomes associated with ZKVP. A study can be statistically more efficient than another if its estimates are more accurate (precise and valid), even if the studies involve the same number of subjects. Sample size and specific design strategies can enhance or impair the statistical efficiency of a study, depending on how the subjects are distributed in subgroups pertinent to the analysis. In most ZIKVP cohort studies to date there is an a priori identification of the source population (pregnant women, regardless of their exposure status) which is then sampled or included in its entirety (census). Subsequently, the group of pregnant women is classified according to exposure (presence or absence of ZIKVP), respecting the exposed:unexposed ratio in the source population. We propose that the sample selection be done from the a priori identification of groups of pregnant women exposed and unexposed to ZIKVP. This method will allow for an oversampling (even 100%) of the pregnant women with ZKVP and a optimized sampling from the general population of pregnant women unexposed to ZIKVP, saving resources in the unexposed group and improving the expected number of incident cases (outcomes) overall. We hope that this proposal will broaden the methodological debate on the improvement of statistical power and protocol harmonization of cohort studies that aim to evaluate the association between Zika infection during pregnancy and outcomes for the offspring, as well as those with similar objectives.
Saeed, Mohsan; Scheel, Troels K H; Gottwein, Judith M
to express a chimeric fusion protein of firefly luciferase and neomycin phosphotransferase to yield stable replicon-expressing cells. Using these constructs, the inhibitory effects of beta interferon (IFN-β), an NS3 protease inhibitor, and an NS5B nucleoside polymerase inhibitor were readily detected...... culture adaptive mutations originally reported for genotype 1b replicons. RNA replication was confirmed by quantitative reverse transcription-PCR and detection of viral protein. Sequencing of multiple independent replicon clones revealed the presence of additional nonsynonymous mutations. Interestingly......, all potentially adaptive mutations mapped to the NS3 protein. These mutations, when introduced back into original constructs, substantially increased colony formation efficiency. To make these replicons useful for high-throughput screening and evaluation of antiviral compounds, they were modified...
Chen, Chiachen; Akerstrom, Victoria; Baus, James; Lan, Michael S; Breslin, Mary B
Lung cancer is the leading cause of cancer-related deaths in the US. Recombinant vectors based on adeno-associated virus (AAV) and lentivirus are promising delivery tools for gene therapy due to low toxicity and long term expression. The efficiency of the gene delivery system is one of the most important factors directly related to the success of gene therapy. We infected SCLC cell lines, SHP-77, DMS 53, NCI-H82, NCI-H69, NCI-H727, NCI-H1155, and NSCLC cell lines, NCI-H23, NCI-H661, and NCI-H460 with VSV-G pseudo-typed lentivirus or 5 AAV serotypes, AAV2/1, AAV2/2, AAV2/4, AAV2/5, and AAV2/8 expressing the CMV promoter mCherry or green fluorescent protein transgene (EGFP). The transduction efficiency was analyzed by fluorescent microscopy and flow cytometry. Of all the serotypes of AAV examined, AAV2/1 was the optimal serotype in most of the lung cancer cell lines except for NCI-H69 and NCI-H82. The highest transduction rate achieved with AAV2/1 was between 30-50% at MOI 100. Compared to all AAV serotypes, lentivirus had the highest transduction efficiency of over 50% at MOI 1. Even in NCI-H69 cells resistant to all AAV serotypes, lentivirus had a 10-40% transduction rate. To date, AAV2 is the most widely-used serotype to deliver a transgene. Our results showed the transduction efficiency of AAVs tested was AAV2/1 > AA2/5 = AAV2/2> > AAV2/4 and AAV2/8. This study demonstrated that VSV-G pseudotyped lentivirus and AAV2/1 can mediate expression of a transgene for lung cancer gene therapy. Overall, our results showed that lentivirus is the best candidate to deliver a transgene into lung cancer cells for treatment.
Kirnbauer, R; Taub, J; Greenstone, H; Roden, R; Dürst, M; Gissmann, L; Lowy, D R; Schiller, J T
The L1 genes of two human papillomavirus type 16 (HPV16) isolates derived from condylomata acuminata were used to express the L1 major capsid protein in insect cells via recombinant baculoviruses. Both L1 major capsid proteins self-assembled into virus-like particles (VLP) with high efficiency and could be purified in preparative amounts on density gradients. The yield of VLP was 3 orders of magnitude higher than what has been obtained previously, using L1 derived from the prototype HPV16. DNA sequence comparison identified a single nonconserved amino acid change to be responsible for the inefficient self-assembly of the prototype L1. VLP were also obtained by expressing L1 of HPV6, HPV11, and cottontail rabbit papillomavirus, indicating that L1 from a variety of papillomaviruses has the intrinsic capacity to self-assemble into VLP. Coexpression of HPV16 L1 plus L2 by using a baculovirus double-expression vector also resulted in efficient self-assembly of VLP, and the average particle yield increased about fourfold in comparison to when L1 only was expressed. Coimmunoprecipitation of L1 and L2 and cosedimentation of the two proteins in a sucrose gradient demonstrated that L2 was incorporated into the particles. The ability to generate preparative amounts of HPV16 L1 and L1-L2 VLP may have implications for the development of a serological assay to detect anti-HPV16 virion immune responses to conformational epitopes and for immunoprophylaxis against HPV16 infection.
Catanese, Maria Teresa; Graziani, Rita; von Hahn, Thomas; Moreau, Martine; Huby, Thierry; Paonessa, Giacomo; Santini, Claudia; Luzzago, Alessandra; Rice, Charles M; Cortese, Riccardo; Vitelli, Alessandra; Nicosia, Alfredo
The human scavenger class B type 1 receptor (SR-B1/Cla1) was identified as a putative receptor for hepatitis C virus (HCV) because it binds to soluble recombinant HCV envelope glycoprotein E2 (sE2). High-density lipoprotein (HDL), a natural SR-B1 ligand, was shown to increase the in vitro infectivity of retroviral pseudoparticles bearing HCV envelope glycoproteins and of cell culture-derived HCV (HCVcc), suggesting that SR-B1 promotes viral entry in an HDL-dependent manner. To determine whether SR-B1 participates directly in HCV infection or facilitates HCV entry through lipoprotein uptake, we generated a panel of monoclonal antibodies (MAbs) against native human SR-B1. Two of them, 3D5 and C167, bound to conformation-dependent SR-B1 determinants and inhibited the interaction of sE2 with SR-B1. These antibodies efficiently blocked HCVcc infection of Huh-7.5 hepatoma cells in a dose-dependent manner. To examine the role of HDL in SR-B1-mediated HCVcc infection, we set up conditions for HCVcc production and infection in serum-free medium. HCVcc efficiently infected Huh-7.5 cells in the absence of serum lipoproteins, and addition of HDL led to a twofold increase in infectivity. However, the HDL-induced enhancement of infection had no impact on the neutralization potency of MAb C167, despite its ability to inhibit both HDL binding to cells and SR-B1-mediated lipid transfer. Of note, MAb C167 also potently blocked Huh-7.5 infection by an HCV strain recovered from HCVcc-infected chimpanzees. These results demonstrate that SR-B1 is essential for infection with HCV produced in vitro and in vivo and suggest the possible use of anti-SR-B1 antibodies as therapeutic agents.
Veron, Philippe; Allo, Valérie; Rivière, Christel; Bernard, Jacky; Douar, Anne-Marie; Masurier, Carole
Dendritic cells (DC) are antigen-presenting cells pivotal for inducing immunity or tolerance. Gene transfer into DC is an important strategy for developing immunotherapeutic approaches against infectious pathogens and cancers. One of the vectors previously described for the transduction of human monocytes or DC is the recombinant adeno-associated virus (rAAV), with a genome conventionally packaged as a single-stranded (ss) molecule. Nevertheless, its use is limited by the poor and variable transduction efficiency of DC. In this study, AAV type 1 (AAV1) and AAV2 vectors, which expressed the enhanced green fluorescent protein and were packaged as ss or self-complementary (sc) duplex strands, were used to transduce different DC subsets generated ex vivo and the immunophenotypes, states of differentiation, and functions of the subsets were carefully examined. We show here for the first time that a single exposure of monocytes (M(o)) or CD34(+) progenitors (CD34) to sc rAAV1 or sc rAAV2 leads to high transduction levels (5 to 59%) of differentiated M(o)-DC, M(o)-Langerhans cells (LC), CD34-LC, or CD34-plasmacytoid DC (pDC), with no impact on their phenotypes and functional maturation of these cells, compared to those of exposure to ss rAAV. Moreover, we show that all these DC subpopulations can also be efficiently transduced after commitment to their differentiation pathways. Furthermore, these DC subsets transduced with sc rAAV1 expressing a tumor antigen were potent activators of a CD8(+)-T-cell clone. Altogether, these results show the high potential of sc AAV1 and sc AAV2 vectors to transduce ex vivo conventional DC, LC, or pDC or to directly target them in vivo for the design of new DC-based immunotherapies.
Matsuzaki, Yasunori; Konno, Ayumu; Mochizuki, Ryuta; Shinohara, Yoichiro; Nitta, Keisuke; Okada, Yukihiro; Hirai, Hirokazu
Intravenous administration of adeno-associated virus (AAV)-PHP.B, a capsid variant of AAV9 containing seven amino acid insertions, results in a greater permeability of the blood brain barrier (BBB) than standard AAV9 in mice, leading to highly efficient and global transduction of the central nervous system (CNS). The present study aimed to examine whether the enhanced BBB penetrance of AAV-PHP.B observed in mice also occurs in non-human primates. Thus, a young adult (age, 1.6 years) and an old adult (age, 7.2 years) marmoset received an intravenous injection of AAV-PHP.B expressing enhanced green fluorescent protein (EGFP) under the control of the constitutive CBh promoter (a hybrid of cytomegalovirus early enhancer and chicken β-actin promoter). Age-matched control marmosets were treated with standard AAV9-capsid vectors. The animals were sacrificed 6 weeks after the viral injection. Based on the results, only limited transduction of neurons (0-2%) and astrocytes (0.1-2.5%) was observed in both AAV-PHP.B- and AAV9-treated marmosets. One noticeable difference between AAV-PHP.B and AAV9 was the marked transduction of the peripheral dorsal root ganglia neurons. Indeed, the soma and axons in the projection from the spinal cord to the nucleus cuneatus in the medulla oblongata were strongly labeled with EGFP by AAV-PHP.B. Thus, except for the peripheral dorsal root ganglia neurons, the AAV-PHP.B transduction efficiency in the CNS of marmosets was comparable to that of AAV9 vectors. Copyright © 2017 Elsevier B.V. All rights reserved.
Haukoos, Jason S; Hopkins, Emily; Byyny, Richard L; Conroy, Amy A; Silverman, Morgan; Eisert, Sheri; Thrun, Mark; Wilson, Michael; Boyett, Brian; Heffelfinger, James D
In 2006, the Centers for Disease Control and Prevention (CDC) released revised recommendations for performing human immunodeficiency virus (HIV) testing in health care settings, including implementing routine rapid HIV screening, the use of an integrated opt-out consent, and limited prevention counseling. Emergency departments (EDs) have been a primary focus of these efforts. These revised CDC recommendations were primarily based on feasibility studies and have not been evaluated through the application of rigorous research methods. This article describes the design and implementation of a large prospective controlled clinical trial to evaluate the CDC's recommendations in an ED setting. From April 15, 2007, through April 15, 2009, a prospective quasi-experimental equivalent time-samples clinical trial was performed to compare the clinical effectiveness and efficiency of routine (nontargeted) opt-out rapid HIV screening (intervention) to physician-directed diagnostic rapid HIV testing (control) in a high-volume urban ED. In addition, three nested observational studies were performed to evaluate the cost-effectiveness and patient and staff acceptance of the two rapid HIV testing methods. This article describes the rationale, methodologies, and study design features of this program evaluation clinical trial. It also provides details regarding the integration of the principal clinical trial and its nested observational studies. Such ED-based trials are rare, but serve to provide valid comparisons between testing approaches. Investigators should consider similar methodology when performing future ED-based health services research.
Porta, Claudine; Xu, Xiaodong; Loureiro, Silvia; Paramasivam, Saravanan; Ren, Junyuan; Al-Khalil, Tara; Burman, Alison; Jackson, Terry; Belsham, Graham J.; Curry, Stephen; Lomonossoff, George P.; Parida, Satya; Paton, David; Li, Yanmin; Wilsden, Ginette
Foot-and-mouth disease virus (FMDV) is a significant economically and distributed globally pathogen of Artiodactyla. Current vaccines are chemically inactivated whole virus particles that require large-scale virus growth in strict bio-containment with the associated risks of accidental release or incomplete inactivation. Non-infectious empty capsids are structural mimics of authentic particles with no associated risk and constitute an alternate vaccine candidate. Capsids self-assemble from th...
Fowke Keith R
Full Text Available Abstract Background In addition to mediating the integration process, HIV-1 integrase (IN has also been implicated in different steps during viral life cycle including reverse transcription and viral DNA nuclear import. Although the karyophilic property of HIV-1 IN has been well demonstrated using a variety of experimental approaches, the definition of domain(s and/or motif(s within the protein that mediate viral DNA nuclear import and its mechanism are still disputed and controversial. In this study, we performed mutagenic analyses to investigate the contribution of different regions in the C-terminal domain of HIV-1 IN to protein nuclear localization as well as their effects on virus infection. Results Our analysis showed that replacing lysine residues in two highly conserved tri-lysine regions, which are located within previously described Region C (235WKGPAKLLWKGEGAVV and sequence Q (211KELQKQITK in the C-terminal domain of HIV-1 IN, impaired protein nuclear accumulation, while mutations for RK263,4 had no significant effect. Analysis of their effects on viral infection in a VSV-G pseudotyped RT/IN trans-complemented HIV-1 single cycle replication system revealed that all three C-terminal mutant viruses (KK215,9AA, KK240,4AE and RK263,4AA exhibited more severe defect of induction of β-Gal positive cells and luciferase activity than an IN class 1 mutant D64E in HeLa-CD4-CCR5-β-Gal cells, and in dividing as well as non-dividing C8166 T cells, suggesting that some viral defects are occurring prior to viral integration. Furthermore, by analyzing viral DNA synthesis and the nucleus-associated viral DNA level, the results clearly showed that, although all three C-terminal mutants inhibited viral reverse transcription to different extents, the KK240,4AE mutant exhibited most profound effect on this step, whereas KK215,9AA significantly impaired viral DNA nuclear import. In addition, our analysis could not detect viral DNA integration in each C
Broekman, M L D; Comer, L A; Hyman, B T; Sena-Esteves, M
Adeno-associated virus (AAV) vectors have gained a preeminent position in the field of gene delivery to the normal brain through their ability to achieve extensive transduction of neurons and to mediate long-term gene expression with no apparent toxicity. In adult animals direct infusion of AAV vectors into the brain parenchyma results in highly efficient transduction of target structures. However AAV-mediated global delivery to the adult brain has been an elusive goal. In contrast, widespread global gene delivery has been obtained by i.c.v. injection of AAV1 or AAV2 in neonates. Among the novel AAV serotypes cloned and engineered for production of recombinant vectors, AAV8 has shown a tremendous potential for in vivo gene delivery with nearly complete transduction of many tissues in rodents after intravascular infusion. Here we compare the efficiency of an AAV8 serotyped vector with that of AAV1 and AAV2 serotyped vectors for the extent of gene delivery to the brain after neonatal injection into the lateral ventricles. The vectors all encoded green fluorescent protein (GFP) under control of a hybrid CMV enhancer/chicken beta-actin promoter with AAV2 inverted terminal repeats, but differed from each other with respect to the capsid type. A total of 6.8 x 10(10) genome copies were injected into the lateral ventricles of postnatal day 0 mice. Mice were killed at postnatal day 30 and brains analyzed for distribution of GFP-positive cells. AAV8 proved to be more efficient than AAV1 or AAV2 vectors for gene delivery to all of the structures analyzed, including the cerebral cortex, hippocampus, olfactory bulb, and cerebellum. Moreover the intensity of gene expression, assessed using a microarray reader, was considerably higher for AAV8 in all structures analyzed. In conclusion, the enhanced transduction achieved by AAV8 compared with AAV1 and AAV2 indicates that AAV8 is the superior serotype for gene delivery to the CNS.
Efficient and stable expression of GFP through Wheat streak mosaic virus-based vectors in cereal hosts using a range of cleavage sites: Formation of dense fluorescent aggregates for sensitive virus tracking
A series of Wheat streak mosaic virus (WSMV)-based expression vectors were developed by engineering cycle 3 GFP (GFP) cistron between P1 and HC-Pro cistrons with several catalytic/cleavage peptides at the C-terminus of GFP. WSMV-GFP vectors with the Foot-and-mouth disease virus 1D/2A or 2A catalytic...
Ebola virus and Marburg virus Overview Ebola virus and Marburg virus are related viruses that cause hemorrhagic fevers — illnesses marked by severe bleeding (hemorrhage), organ failure and, in many ...
Porta, Claudine; Xu, Xiaodong; Loureiro, Silvia
Foot-and-mouth disease virus (FMDV) is a significant economically and distributed globally pathogen of Artiodactyla. Current vaccines are chemically inactivated whole virus particles that require large-scale virus growth in strict bio-containment with the associated risks of accidental release...... or incomplete inactivation. Non-infectious empty capsids are structural mimics of authentic particles with no associated risk and constitute an alternate vaccine candidate. Capsids self-assemble from the processed virus structural proteins, VP0, VP3 and VP1, which are released from the structural protein...... precursor P1-2A by the action of the virus-encoded 3C protease. To date recombinant empty capsid assembly has been limited by poor expression levels, restricting the development of empty capsids as a viable vaccine. Here expression of the FMDV structural protein precursor P1-2A in insect cells is shown...
Kim, Young Jae
The third variable (V3) loop of the human immunodeficiency virus type 1 (HIV-1) envelope glycoprotein has been intensively studied for AIDS vaccine development. Bacille Calmette-Guérin (BCG) is widely used to immunize against tuberculosis and has many advantages as a vaccine vehicle, such as low toxicity, adjuvant potential, low cost, and long-lasting immune-inducing capacity. This work was initiated to investigate the immunogenicity of recombinant BCG (rBCG-mV3) designed to express trimeric HIV-1 V3 loop (mV3) in rBCG-mV3-immunized animals. HIV-1 V3-concatamer was cloned into pMV261, a BCG-expression vector, and then rBCG-mV3 was constructed by introducing the recombinant plasmid (pMV-V3). The recombinant BCG was examined with regard to its expression of V3-concatamer and the genetic stability in vivo and in vitro. The immune responses induced by recombinant BCG were tested in immunized mice and guinea pigs. The rBCG-mV3 expressed detectable amounts of V3-concatamer when induced by single heat-shock. The recombinant BCG was genetically stable and maintained the introduced mV3 gene for several weeks. V3-specific antibodies were clearly detected 6 weeks after inoculation. The antibody titer rapidly increased after immunization up to 10 weeks, and then maintained for over 4 weeks. IgG2a was prevalent in the V3-specific antiserum. The recombinant BCG was also effective in inducing delayed-type hypersensitivity responses in the immunized guinea pigs. rBCG-immunized mice retained substantial amounts of V3-specific T cells in the spleen, even 5 months after the first immunization. Recombinant BCG-mV3 is very efficient in inducing humoral and long-lasting cell-mediated immunity against HIV-1 V3 in the immunized animals.
Zhang, Quan; Zhang, Xuanmiao; Chen, Tijia; Wang, Xinyi; Fu, Yao; Jin, Yun; Sun, Xun; Gong, Tao; Zhang, Zhirong
A safe and efficient liver targeted PEGylated liposome (PEG-Lip) based on N-terminal myristoylated preS1/21-47 (preS1/21-47myr) of hepatitis B virus was successfully developed. The study aimed to elucidate the cellular uptake mechanism of preS1/21-47myr modified PEG-Lip (preS1/21-47myr-PEG-Lip) in hepatogenic cells and the distribution behavior of preS1/21-47myr-PEG-Lip in Vr:CD1 (ICR) mice. The cellular uptake results showed that preS1/21-47myr-PEG-Lip was effectively taken up by hepatogenic cells (including primary hepatocytes and liver tumor cells) through a receptor-mediated endocytosis pathway compared with non-hepatogenic cells. After systemic administration to H22 hepatoma-bearing mice, preS1/21-47myr-PEG-Lip showed significant liver-specific delivery and an increase in the distribution of preS1/21-47myr-PEG-Lip in hepatic tumor. Furthermore, the antitumor effect of preS1/21-47myr-PEG-Lip loaded with paclitaxel (PTX) was remarkably stronger than that of PTX injection and PTX loaded liposomes (including common liposomes and PEG-Lip). In safety evaluation, no acute systemic toxicity and immunotoxicity were observed after intravenous injection of preS1/21-47myr-PEG-Lip. No liver toxicity was observed despite the dramatic increase of preS1/21-47myr-PEG-Lip in liver. Taken together, preS1/21-47myr-PEG-Lip represents a promising carrier system for targeted liver disease therapy and imaging.
Wu, Zhijian; Miller, Edward; Agbandje-McKenna, Mavis; Samulski, Richard Jude
Recombinant adeno-associated viruses (AAVs) are promising vectors in the field of gene therapy. Different AAV serotypes display distinct tissue tropism, believed to be related to the distribution of their receptors on target cells. Of the 11 well-characterized AAV serotypes, heparan sulfate proteoglycan and sialic acid have been suggested to be the attachment receptors for AAV type 2 and types 4 and 5, respectively. In this report, we identify the receptor for the two closely related serotypes, AAV1 and AAV6. First, we demonstrate using coinfection experiments and luciferase reporter analysis that AAV1 and AAV6 compete for similar receptors. Unlike heparin sulfate, enzymatic or genetic removal of sialic acid markedly reduced AAV1 and AAV6 binding and transduction. Further analysis using lectin staining and lectin competition assays identified that AAV1 and AAV6 use either alpha2,3-linked or alpha2,6-linked sialic acid when transducing numerous cell types (HepG2, Pro-5, and Cos-7). Treatment of cells with proteinase K but not glycolipid inhibitor reduced AAV1 and AAV6 infection, supporting the hypothesis that the sialic acid that facilitates infection is associated with glycoproteins rather than glycolipids. In addition, we determined by inhibitor (N-benzyl GalNAc)- and cell line-specific (Lec-1) studies that AAV1 and AAV6 require N-linked and not O-linked sialic acid. Furthermore, a resialylation experiment on a deficient Lec-2 cell line confirmed a 2,3 and 2,6 N-linked sialic acid requirement, while studies of mucin with O-linked sialic acid showed no inhibition effect for AAV1 and AAV6 transduction on Cos-7 cells. Finally, using a glycan array binding assay we determined that AAV1 efficiently binds to NeuAcalpha2-3GalNAcbeta1-4GlcNAc, as well as two glycoproteins with alpha2,3 and alpha2,6 N-linked sialic acids. Taken together, competition, genetic, inhibitor, enzymatic reconstitution, and glycan array experiments support alpha2,3 and alpha2,6 sialic acids that
Wu, Zhijian; Miller, Edward; Agbandje-McKenna, Mavis; Samulski, Richard Jude
Recombinant adeno-associated viruses (AAVs) are promising vectors in the field of gene therapy. Different AAV serotypes display distinct tissue tropism, believed to be related to the distribution of their receptors on target cells. Of the 11 well-characterized AAV serotypes, heparan sulfate proteoglycan and sialic acid have been suggested to be the attachment receptors for AAV type 2 and types 4 and 5, respectively. In this report, we identify the receptor for the two closely related serotypes, AAV1 and AAV6. First, we demonstrate using coinfection experiments and luciferase reporter analysis that AAV1 and AAV6 compete for similar receptors. Unlike heparin sulfate, enzymatic or genetic removal of sialic acid markedly reduced AAV1 and AAV6 binding and transduction. Further analysis using lectin staining and lectin competition assays identified that AAV1 and AAV6 use either α2,3-linked or α2,6-linked sialic acid when transducing numerous cell types (HepG2, Pro-5, and Cos-7). Treatment of cells with proteinase K but not glycolipid inhibitor reduced AAV1 and AAV6 infection, supporting the hypothesis that the sialic acid that facilitates infection is associated with glycoproteins rather than glycolipids. In addition, we determined by inhibitor (N-benzyl GalNAc)- and cell line-specific (Lec-1) studies that AAV1 and AAV6 require N-linked and not O-linked sialic acid. Furthermore, a resialylation experiment on a deficient Lec-2 cell line confirmed a 2,3 and 2,6 N-linked sialic acid requirement, while studies of mucin with O-linked sialic acid showed no inhibition effect for AAV1 and AAV6 transduction on Cos-7 cells. Finally, using a glycan array binding assay we determined that AAV1 efficiently binds to NeuAcα2-3GalNAcβ1-4GlcNAc, as well as two glycoproteins with α2,3 and α2,6 N-linked sialic acids. Taken together, competition, genetic, inhibitor, enzymatic reconstitution, and glycan array experiments support α2,3 and α2,6 sialic acids that are present on N
The novel H1N1 influenza virus that emerged in humans in Mexico in early 2009 and transmitted efficiently in the human population with global spread was declared a pandemic strain. The introduction of different avian and human influenza virus genes into swine influenza viruses often result in viruses of increased fitness ...
Neumann, Gabriele; Kawaoka, Yoshihiro
Influenza A viruses cause respiratory infections that range from asymptomatic to deadly in humans. Widespread outbreaks (pandemics) are attributable to ‘novel’ viruses that possess a viral hemagglutinin (HA) gene to which humans lack immunity. After a pandemic, these novel viruses form stable virus lineages in humans and circulate until they are replaced by other novel viruses. The factors and mechanisms that facilitate virus transmission among hosts and the establishment of novel lineages are not completely understood, but the HA and basic polymerase 2 (PB2) proteins are thought to play essential roles in these processes by enabling avian influenza viruses to infect mammals and replicate efficiently in their new host. Here, we summarize our current knowledge of the contributions of HA, PB2, and other viral components to virus transmission and the formation of new virus lineages. PMID:25812763
Efficient reverse genetics reveals genetic determinants of budding and fusogenic differences between Nipah and Hendra viruses and enables real-time monitoring of viral spread in small animal models of henipavirus infection.
Yun, Tatyana; Park, Arnold; Hill, Terence E; Pernet, Olivier; Beaty, Shannon M; Juelich, Terry L; Smith, Jennifer K; Zhang, Lihong; Wang, Yao E; Vigant, Frederic; Gao, Junling; Wu, Ping; Lee, Benhur; Freiberg, Alexander N
Nipah virus (NiV) and Hendra virus (HeV) are closely related henipaviruses of the Paramyxovirinae. Spillover from their fruit bat reservoirs can cause severe disease in humans and livestock. Despite their high sequence similarity, NiV and HeV exhibit apparent differences in receptor and tissue tropism, envelope-mediated fusogenicity, replicative fitness, and other pathophysiologic manifestations. To investigate the molecular basis for these differences, we first established a highly efficient reverse genetics system that increased rescue titers by ≥3 log units, which offset the difficulty of generating multiple recombinants under constraining biosafety level 4 (BSL-4) conditions. We then replaced, singly and in combination, the matrix (M), fusion (F), and attachment glycoprotein (G) genes in mCherry-expressing recombinant NiV (rNiV) with their HeV counterparts. These chimeric but isogenic rNiVs replicated well in primary human endothelial and neuronal cells, indicating efficient heterotypic complementation. The determinants of budding efficiency, fusogenicity, and replicative fitness were dissociable: HeV-M budded more efficiently than NiV-M, accounting for the higher replicative titers of HeV-M-bearing chimeras at early times, while the enhanced fusogenicity of NiV-G-bearing chimeras did not correlate with increased replicative fitness. Furthermore, to facilitate spatiotemporal studies on henipavirus pathogenesis, we generated a firefly luciferase-expressing NiV and monitored virus replication and spread in infected interferon alpha/beta receptor knockout mice via bioluminescence imaging. While intraperitoneal inoculation resulted in neuroinvasion following systemic spread and replication in the respiratory tract, intranasal inoculation resulted in confined spread to regions corresponding to olfactory bulbs and salivary glands before subsequent neuroinvasion. This optimized henipavirus reverse genetics system will facilitate future investigations into the
Ping, Jihui; Lopes, Tiago J S; Neumann, Gabriele; Kawaoka, Yoshihiro
The burden of human infections with influenza A and B viruses is substantial, and the impact of influenza B virus infections can exceed that of influenza A virus infections in some seasons. Over the past few decades, viruses of two influenza B virus lineages (Victoria and Yamagata) have circulated in humans, and both lineages are now represented in influenza vaccines, as recommended by the World Health Organization. Influenza B virus vaccines for humans have been available for more than half a century, yet no systematic efforts have been undertaken to develop high-yield candidates. Therefore, we screened virus libraries possessing random mutations in the six "internal" influenza B viral RNA segments [i.e., those not encoding the major viral antigens, hemagglutinin (HA) and neuraminidase NA)] for mutants that confer efficient replication. Candidate viruses that supported high yield in cell culture were tested with the HA and NA genes of eight different viruses of the Victoria and Yamagata lineages. We identified combinations of mutations that increased the titers of candidate vaccine viruses in mammalian cells used for human influenza vaccine virus propagation and in embryonated chicken eggs, the most common propagation system for influenza viruses. These influenza B virus vaccine backbones can be used for improved vaccine virus production.
Rasmussen, Thomas Bruun; Risager, Peter Christian; Fahnøe, Ulrik
Background Infectious cDNA clones are a prerequisite for directed genetic manipulation of RNA viruses. Here, a strategy to facilitate manipulation and rescue of classical swine fever viruses (CSFVs) from full-length cDNAs present within bacterial artificial chromosomes (BACs) is described....... This strategy allows manipulation of viral cDNA by targeted recombination-mediated mutagenesis within bacteria. Results A new CSFV-BAC (pBeloR26) derived from the Riems vaccine strain has been constructed and subsequently modified in the E2 coding sequence, using the targeted recombination strategy to enable...... rescue of chimeric pestiviruses (vR26_E2gif and vR26_TAV) with potential as new marker vaccine candidates. Sequencing of the BACs revealed a high genetic stability during passages within bacteria. The complete genome sequences of rescued viruses, after extensive passages in mammalian cells showed...
Martin, H; Soumet, C; Fresnel, R; Morin, T; Lamaudière, S; Le Sauvage, A L; Deleurme, K; Maris, P
The virucidal activity of peroxy-products was evaluated and compared with sodium hypochlorite using the EN 14675 European suspension test and a surface test developed in our laboratory. The classical approach on infectivity of viruses was complemented with a prospective approach on virus genomes. Both infectivity tests were adapted and/or developed to determine the activity of disinfectants against reference bovine enterovirus type 1 [enteric cytopathogenic bovine orphan virus (ECBO)] and resistant hepatitis A virus (HAV) in conditions simulating practical use. Similar concentrations of active chlorine were virucidal against both viruses, either at 0·062% using the suspension test or at 0·50-1% using the surface test. However, for potassium monopersulfate and peracetic acid products, concentrations of approximately three times (3%) to 72 times (9%) higher were necessary against HAV than ECBO when determined with the suspension test. With the surface test, 4-8% peroxy-products were virucidal against HAV, either 16 times more peroxy-products concentrations than against ECBO. No significant impact on the targeted area of the viral genome measured by real-time RT-PCRs was obtained for ECBO and HAV suspensions treated with disinfectants, even with doses higher than the minimal virucidal concentrations. Sodium hypochlorite, but not peroxy-products, had similar activity against ECBO and HAV. No relation could be established between infectivity tests and genome destruction. This is the first comparative study that investigates with novel suspension and surface tests the reduction of infectivity and genome destruction of two resistant viruses by peroxy-compounds. The results and conclusions collected with European standards are discussed. © 2013 The Society for Applied Microbiology.
Full Text Available Abstract Background Measuring virus attachment to host cells is of great importance when trying to identify novel receptors. The presence of a usable receptor is a major determinant of viral host range and cell tropism. Furthermore, identification of appropriate receptors is central for the understanding of viral pathogenesis and gives possibilities to develop antiviral drugs. Attachment is presently measured using radiolabeled and subsequently gradient purified viruses. Traditional methods are expensive and time-consuming and not all viruses are stable during a purification procedure; hence there is room for improvement. Real-time PCR (RT-PCR has become the standard method to detect and quantify virus infections, including enteroviruses, in clinical samples. For instance, primers directed to the highly conserved 5' untranslated region (5'UTR of the enterovirus genome enable detection of a wide spectrum of enteroviruses. Here, we evaluate the capacity of the RT-PCR technology to study enterovirus host cell interactions at the cell surface and compare this novel implementation with an established assay using radiolabeled viruses. Results Both purified and crude viral extracts of CVB5 generated comparable results in attachment studies when analyzed with RT-PCR. In addition, receptor binding studies regarding viruses with coxsackie- and adenovirus receptor (CAR and/or decay accelerating factor (DAF affinity, further demonstrated the possibility to use RT-PCR to measure virus attachment to host cells. Furthermore, the RT-PCR technology and crude viral extracts was used to study attachment with low multiplicity of infection (0.05 × 10-4TCID50/cell and low cell numbers (250, which implies the range of potential implementations of the presented technique. Conclusion We have implemented the well-established RT-PCR technique to measure viral attachment to host cells with high accuracy and reproducibility, at low cost and with less effort than
Jonsson, Nina; Gullberg, Maria; Israelsson, Stina; Lindberg, A Michael
Measuring virus attachment to host cells is of great importance when trying to identify novel receptors. The presence of a usable receptor is a major determinant of viral host range and cell tropism. Furthermore, identification of appropriate receptors is central for the understanding of viral pathogenesis and gives possibilities to develop antiviral drugs. Attachment is presently measured using radiolabeled and subsequently gradient purified viruses. Traditional methods are expensive and time-consuming and not all viruses are stable during a purification procedure; hence there is room for improvement. Real-time PCR (RT-PCR) has become the standard method to detect and quantify virus infections, including enteroviruses, in clinical samples. For instance, primers directed to the highly conserved 5' untranslated region (5'UTR) of the enterovirus genome enable detection of a wide spectrum of enteroviruses. Here, we evaluate the capacity of the RT-PCR technology to study enterovirus host cell interactions at the cell surface and compare this novel implementation with an established assay using radiolabeled viruses. Both purified and crude viral extracts of CVB5 generated comparable results in attachment studies when analyzed with RT-PCR. In addition, receptor binding studies regarding viruses with coxsackie- and adenovirus receptor (CAR) and/or decay accelerating factor (DAF) affinity, further demonstrated the possibility to use RT-PCR to measure virus attachment to host cells. Furthermore, the RT-PCR technology and crude viral extracts was used to study attachment with low multiplicity of infection (0.05 x 10(-4)TCID50/cell) and low cell numbers (250), which implies the range of potential implementations of the presented technique. We have implemented the well-established RT-PCR technique to measure viral attachment to host cells with high accuracy and reproducibility, at low cost and with less effort than traditional methods. Furthermore, replacing traditional
Zulu, Gcwalisile B; Venter, Estelle H
Bluetongue (BT) is a non-contagious disease of sheep and other domestic and wild ruminants caused by the bluetongue virus (BTV). Currently 26 serotypes of the virus have been identified. In South Africa, 22 serotypes have been identified and BT is controlled mainly by annual vaccinations using a freeze-dried live attenuated polyvalent BTV vaccine. The vaccine is constituted of 15 BTV serotypes divided into three separate bottles and the aim is to develop a vaccine using fewer serotypes without compromising the immunity against the disease. This study is based on previously reported cross-neutralisation of specific BTV serotypes in in vitro studies. Bluetongue virus serotype 4 was selected for this trial and was tested for cross-protection against serotype 4 (control), 1 (unrelated serotype), 9, 10 and 11 in sheep using the serum neutralisation test. The purpose of the study was to determine possible cross-protection of different serotypes in sheep. Of those vaccinated with BTV-4 and challenged with BTV-1, which is not directly related to BTV-4, 20% were completely protected and 80% showed clinical signs, but the reaction was not as severe as amongst the unvaccinated animals. In the group challenged with BTV-10, some showed good protection and some became very sick. Those challenged with BTV-9 and BTV-11 had good protection. The results showed that BTV-4 does not only elicit a specific immune response but can also protect against other serotypes.
Gcwalisile B. Zulu
Full Text Available Bluetongue (BT is a non-contagious disease of sheep and other domestic and wild ruminants caused by the bluetongue virus (BTV. Currently 26 serotypes of the virus have been identified. In South Africa, 22 serotypes have been identified and BT is controlled mainly by annual vaccinations using a freeze-dried live attenuated polyvalent BTV vaccine. The vaccine is constituted of 15 BTV serotypes divided into three separate bottles and the aim is to develop a vaccine using fewer serotypes without compromising the immunity against the disease. This study is based on previously reported cross-neutralisation of specific BTV serotypes in in vitro studies. Bluetongue virus serotype 4 was selected for this trial and was tested for cross-protection against serotype 4 (control, 1 (unrelated serotype, 9, 10 and 11 in sheep using the serum neutralisation test. The purpose of the study was to determine possible cross-protection of different serotypes in sheep. Of those vaccinated with BTV-4 and challenged with BTV-1, which is not directly related to BTV-4, 20% were completely protected and 80% showed clinical signs, but the reaction was not as severe as amongst the unvaccinated animals. In the group challenged with BTV-10, some showed good protection and some became very sick. Those challenged with BTV-9 and BTV-11 had good protection. The results showed that BTV-4 does not only elicit a specific immune response but can also protect against other serotypes.
Di Gennaro, Annapia; Casaccia, Claudia; Conte, Annamaria; Monaco, Federica; Savini, Giovanni
A serum neutralization assay (SN) was compared with the official plaque reduction neutralization test for the quantitation of West Nile virus antibodies. A total of 1,348 samples from equid sera and 38 from human sera were tested by these two methods. Statistically significant differences were not observed, thus supporting the use of SN for routine purposes. PMID:25100824
K. Lemon (Ken); D.T. Nguyen (Tien); M. Ludlow (Martin); L.J. Rennick (Linda); S. Yüksel (Selma); G. van Amerongen (Geert); S. McQuaid (Stephen); B.K. Rima (Bert); R.L. de Swart (Rik); W.P. Duprex (Paul)
textabstractHuman respiratory syncytial virus (HRSV) is the most important viral cause of severe respiratory tract disease in infants. Two subgroups (A and B) have been identified, which cocirculate during, or alternate between, yearly epidemics and cause indistinguishable disease. Existing in vitro
Arzul, Isabelle; Corbeil, Serge; Morga, Benjamin; Renault, Tristan
Although a wide range of viruses have been reported in marine molluscs, most of these reports rely on ultrastructural examination and few of these viruses have been fully characterized. The lack of marine mollusc cell lines restricts virus isolation capacities and subsequent characterization works. Our current knowledge is mostly restricted to viruses affecting farmed species such as oysters Crassostrea gigas, abalone Haliotis diversicolor supertexta or the scallop Chlamys farreri. Molecular approaches which are needed to identify virus affiliation have been carried out for a small number of viruses, most of them belonging to the Herpesviridae and birnaviridae families. These last years, the use of New Generation Sequencing approach has allowed increasing the number of sequenced viral genomes and has improved our capacity to investigate the diversity of viruses infecting marine molluscs. This new information has in turn allowed designing more efficient diagnostic tools. Moreover, the development of experimental infection protocols has answered some questions regarding the pathogenesis of these viruses and their interactions with their hosts. Control and management of viral diseases in molluscs mostly involve active surveillance, implementation of effective bio security measures and development of breeding programs. However factors triggering pathogen development and the life cycle and status of the viruses outside their mollusc hosts still need further investigations. Copyright © 2017 Elsevier Inc. All rights reserved.
Wheat streak mosaic virus (WSMV)-based transient expression vector was developed to express GFP as a marker protein. The GFP cistron was engineered between the P1 and HC-Pro cistrons in an infectious cDNA clone of WSMV. The cleavage sites, P3/6KI, 6KI/CI, NIa/NIb, or NIb/CP, from WSMV were fused to ...
Wu, Zhijian; Miller, Edward; Agbandje-McKenna, Mavis; Samulski, Richard Jude
Recombinant adeno-associated viruses (AAVs) are promising vectors in the field of gene therapy. Different AAV serotypes display distinct tissue tropism, believed to be related to the distribution of their receptors on target cells. Of the 11 well-characterized AAV serotypes, heparan sulfate proteoglycan and sialic acid have been suggested to be the attachment receptors for AAV type 2 and types 4 and 5, respectively. In this report, we identify the receptor for the two closely related serotype...
Grein, Tanja A; Michalsky, Ronald; Czermak, Peter
Industrial manufacturing of cell culture-derived viruses or virus-like particles for gene therapy or vaccine production are complex multistep processes. In addition to the bioreactor, such processes require a multitude of downstream unit operations for product separation, concentration, or purification. Similarly, before a biopharmaceutical product can enter the market, removal or inactivation of potential viral contamination has to be demonstrated. Given the complexity of biological solutions and the high standards on composition and purity of biopharmaceuticals, downstream processing is the bottleneck in many biotechnological production trains. Membrane-based filtration can be an economically attractive and efficient technology for virus separation. Viral clearance, for instance, of up to seven orders of magnitude has been reported for state of the art polymeric membranes under best conditions.This chapter summarizes the fundamentals of virus ultrafiltration, diafiltration, or purification with adsorptive membranes. In lieu of an impractical universally applicable protocol for virus filtration, application of these principles is demonstrated with two examples. The chapter provides detailed methods for production, concentration, purification, and removal of a rod-shaped baculovirus (Autographa californica M nucleopolyhedrovirus, about 40 × 300 nm in size, a potential vector for gene therapy, and an industrially important protein expression system) or a spherical parvovirus (minute virus of mice, 22-26 nm in size, a model virus for virus clearance validation studies).
Efficient transfer of synthetic ribozymes into cells using hemagglutinating virus of Japan (HVJ)-cationic liposomes. Application for ribozymes that target human t-cell leukemia virus type I tax/rex mRNA.
Kitajima, I; Hanyu, N; Soejima, Y; Hirano, R; Arahira, S; Yamaoka, S; Yamada, R; Maruyama, I; Kaneda, Y
We investigated the usefulness of ribozymes in inhibiting the expression of human T-cell leukemia virus type I (HTLV-I) gene. Two hammerhead ribozymes that were against HTLV-I rex (RR) and tax (TR) mRNA were synthesized. Both ribozymes were sequence-specific in the in vitro cleavage analysis of run-off transcripts from tax/rex cDNA. Intracellular activities of the ribozymes were studied in HTLV-I tax cDNA-transfected rat embryonic fibroblasts (Rat/Tax cells), which expressed the Tax but not Rex. Ribozymes were delivered into cells using anionic or cationic liposomes fused with hemagglutinating virus of Japan (HVJ). Cellular uptake of ribozymes complexed with HVJ-cationic liposomes was 15-20 times higher cellular uptake than naked ribozymes, and 4-5 times higher than that of ribozymes complexed with HVJ-anionic liposomes. HVJ-cationic liposomes promoted accumulation of ribozymes in cytoplasm and accelerated transport to the nucleus. Tax protein levels were decreased about 95% and were five times lower when the same amount of TR was introduced into the cells using HVJ-cationic, rather than HVJ-anionic liposomes. Inactive ribozyme and tax antisense oligodeoxynucleotides reduced Tax expression by about 20%, whereas RR and tax sense oligodeoxynucleotides had no effect. These results suggest that the ribozymes' effect against tax mRNA was sequence-specific, and HVJ-cationic liposomes can be useful for intracellular introduction of ribozymes.
Kaludov, Nikola; Brown, Kevin E.; Walters, Robert W.; Zabner, Joseph; Chiorini, John A.
Adeno-associated virus serotype 4 (AAV4) and AAV5 have different tropisms compared to AAV2 and to each other. We recently reported that α2-3 sialic acid is required for AAV5 binding and transduction. In this study, we characterized AAV4 binding and transduction and found it also binds sialic acid, but the specificity is significantly different from AAV5. AAV4 can hemagglutinate red blood cells from several species, whereas AAV5 hemagglutinates only rhesus monkey red blood cells. Treatment of ...
Catanese, Maria Teresa; Graziani, Rita; von Hahn, Thomas; Moreau, Martine; Huby, Thierry; Paonessa, Giacomo; Santini, Claudia; Luzzago, Alessandra; Rice, Charles M.; Cortese, Riccardo; Vitelli, Alessandra; Nicosia, Alfredo
The human scavenger class B type 1 receptor (SR-B1/Cla1) was identified as a putative receptor for hepatitis C virus (HCV) because it binds to soluble recombinant HCV envelope glycoprotein E2 (sE2). High-density lipoprotein (HDL), a natural SR-B1 ligand, was shown to increase the in vitro infectivity of retroviral pseudoparticles bearing HCV envelope glycoproteins and of cell culture-derived HCV (HCVcc), suggesting that SR-B1 promotes viral entry in an HDL-dependent manner. To determine wheth...
Lieveld, M; Carregosa, A; Benoy, I; Redzic, N; Berth, M; Vanden Broeck, D
Genital herpes can be caused by two very similar viruses, herpes simplex virus (HSV)-1 or HSV-2. These two HSV types cannot be distinguished clinically, but genotyping is recommended in the first-episodes of genital herpes to guide counselling and management. Quantitative polymerase chain reaction (qPCR) is the preferred diagnostic method for HSV typing. However, commercial qPCR methods use expensive fluorescent labeled probes for detection. Furthermore, most low-cost methods are not able to differentiate between HSV-1 and -2. The aim of this study was to develop a high resolution melting (HRM) technology-based assay for sensitive HSV-1 and HSV-2 detection and genotyping. Using a panel of 46 clinical specimens, the performance of the HRM assay was compared to two commercial HSV tests: the HRM assay detected HSV in all 23 positive samples, with no false positive results (100% concordance with HSV I/II Real-TM assay). Additionally, the HRM assay correctly genotyped both HSV types in a subset of these clinical samples, as determined by the Realstar HSV PCR Kit. The HSV HRM assay provides a cost-effective alternative method to conventional more expensive assays and can be used in routine clinical specimens, in cases where it is particularly necessary to detect and distinguish HSV-1 from -2. Copyright © 2017 Elsevier B.V. All rights reserved.
Mohanty, Nihar Nalini; Chacko, Nirmal; Biswas, Sanchay Kumar; Chand, Karam; Pandey, Awadh Bihari; Mondal, Bimalendu; Hemadri, Divakar; Shivachandra, Sathish Bhadravati
Serological diagnostics for bluetongue (BT), which is an infectious, non-contagious and arthropod-borne virus disease of ruminants, are primarily dependent on availability of high quality native or recombinant antigen(s) based on either structural/non-structural proteins in sufficient quantity. Non-structural proteins (NS1-NS4) of BT virus are presumed candidate antigens in development of DIVA diagnostics. In the present study, NS3 fusion gene encoding for NS3 protein containing the N- and C-termini with a deletion of two hydrophobic domains (118A to S141 aa and 162S to A182 aa) and intervening variable central domain (142D to K161 aa) of bluetongue virus 23 was constructed, cloned and over-expressed using prokaryotic expression system. The recombinant NS3ΔHD fusion protein (∼38 kDa) including hexa-histidine tag on its both termini was found to be non-cytotoxic to recombinant Escherichia coli cells and purified by affinity chromatography. The purified rNS3ΔHD fusion protein was found to efficiently detect BTV-NS3 specific antibodies in indirect-ELISA format with diagnostic sensitivity (DSn = 94.4%) and specificity (DSp = 93.9%). The study indicated the potential utility of rNS3ΔHD fusion protein as candidate diagnostic reagent in developing an indirect-ELISA for sero-surveillance of animals for BTV antibodies under DIVA strategy, wherever monovalent/polyvalent killed BT vaccine formulations devoid of NS proteins are being practiced for immunization. Copyright © 2016 International Alliance for Biological Standardization. Published by Elsevier Ltd. All rights reserved.
Fischer, Robert J; Judson, Seth; Miazgowicz, Kerri; Bushmaker, Trent; Munster, Vincent J
On March 20, 2015, a case of Ebola virus disease was identified in Liberia that most likely was transmitted through sexual contact. We assessed the efficiency of detecting Ebola virus in semen samples by molecular diagnostics and the stability of Ebola virus in ex vivo semen under simulated tropical conditions.
Jensen, Tanja B; Gottwein, Judith Margarete; Scheel, Troels Kasper Høyer
of recovered genomes and reverse-genetic studies. Receptor blockage was performed with anti-CD81 and anti-SR-BI. For neutralization experiments, SA13/JFH1 or JFH1-based viruses of other genotypes were incubated with patient sera. Results. @nbsp; SA13/JFH1 with NS2 and NS3 mutations yielded infectivity titers...... was to adapt the system to employ genotype 5. Methods. @nbsp; Huh7.5 cells infected with SA13/JFH1, containing Core-NS2 of strain SA13 (genotype 5a), were monitored for Core expression and for supernatant infectivity and HCV-RNA titers. Adaptive mutations of SA13/JFH1 were identified by sequence analysis...
Full Text Available Abstract Background Previous studies from our own and other labs reported the surprising finding that the soluble V domain of the herpes simplex virus type 1 (HSV-1 entry receptor nectin-1 can both block HSV infection of receptor-bearing cells and mediate infection of receptor-deficient cells. Here we show that this property is not unique to nectin-1. We generated a pair of truncated, soluble forms of the other major HSV-1 entry receptor, herpes virus entry mediator (HVEM or HveA, and examined its effects on HSV-1 infection of receptor-deficient cells. Results In cultures of CHO-K1 cells, sHveA102 comprising the two amino-terminal cysteine-rich pseudorepeats (CRPs of HVEM enabled infection of greater than 80% of the cells at an MOI of 3, while sHveA162 comprising the complete ectodomain failed to mediate infection. Both sHveA102 and sHveA162 blocked infection of CHO-K1 cells stably expressing HVEM in a dose-dependent manner, indicating that both were capable of binding to viral gD. We found that sHveA102-mediated infection involves pH-independent endocytosis whereas HSV infection of HVEM-expressing CHO-K1 cells is known to be pH-dependent. Conclusions Our results suggest that the C-terminal portion of the soluble HVEM ectodomain inhibits gD activation and that this effect is neutralized in the full-length form of HVEM in normal infection.
Ohtsuka, J; Fukumura, M; Tsurudome, M; Hara, K; Nishio, M; Kawano, M; Nosaka, T
A stable packaging cell line (Vero/BC-F) constitutively expressing fusion (F) protein of the human parainfluenza virus type 2 (hPIV2) was established for production of the F-defective and single round-infectious hPIV2 vector in a strategy for recombinant vaccine development. The F gene expression has not evoked cytostatic or cytotoxic effects on the Vero/BC-F cells and the F protein was physiologically active to induce syncytial formation with giant polykaryocytes when transfected with a plasmid expressing hPIV2 hemagglutinin-neuraminidase (HN). Transduction of the F-defective replicon RNA into the Vero/BC-F cells led to the release of the infectious particles that packaged the replicon RNA (named as hPIV2ΔF) without detectable mutations, limiting the infectivity to a single round. The maximal titer of the hPIV2ΔF was 6.0 × 10(8) median tissue culture infections dose per ml. The influenza A virus M2 gene was inserted into hPIV2ΔF, and the M2 protein was found to be highly expressed in a human lung cancer cell line after transduction. Furthermore, in vivo airway infection experiments revealed that the hPIV2ΔF was capable of delivering transgenes to hamster tracheal cells. Thus, non-transmissible or single round-infectious hPIV2 vector will be potentially applicable to human gene therapy or recombinant vaccine development.
Emerson Suzanne U
Full Text Available Abstract A recombinant baculovirus(vBacORF2 that expressed the full-length ORF2 capsid protein of a genotype 1 strain of hepatitis E virus(HEV was constructed. Transduction of S10-3 human hepatoma cells with this baculovirus led to large amounts of ORF2 protein production in ~50% of the cells as determined by immune fluorescence microscopy. The majority of the ORF2 protein detected by Western blot was 72 kDa, the size expected for the full-length protein. To determine if the exogenously-supplied ORF2 protein could transencapsidate viral genomes, S10-3 cell cultures that had been transfected the previous day with an HEV replicon of genotype 1 that contained the gene for green fluorescent protein(GFP, in place of that for ORF2 protein, were transduced with the vBacORF2 virus. Cell lysates were prepared 5 days later and tested for the ability to deliver the GFP gene to HepG2/C3A cells, another human hepatoma cell line. FACS analysis indicated that lysates from cell cultures receiving only the GFP replicon were incapable of introducing the replicon into the HepG2/C3A cells whereas ~2% of the HepG2/C3A cells that received lysate from cultures that had received both the replicon and the baculovirus produced GFP. Therefore, the baculovirus-expressed ORF2 protein was able to trans-encapsidate the viral replicon and form a particle that could infect naïve HepG2/C3A cells. This ex vivo RNA packaging system should be useful for studying many aspects of HEV molecular biology.
Liang, Shuang; Ratnayake, Punsisi; Keinath, Craig; Jia, Lihui; Wolfe, Robert; Ranaweera, Ahinsa; Weliky, David P
Human immunodeficiency virus (HIV) is membrane-enveloped and an initial infection step is joining/fusion of viral and cell membranes. This step is catalyzed by gp41 which is a single-pass integral viral membrane protein. The protein contains a ~170-residue ectodomain located outside the virus that is important for fusion, and includes the fusion peptide (FP), N-helix, loop, C-helix, and viral membrane-proximal external region (MPER). The virion initially has non-covalent complexes between three gp41 ectodomains and three gp120 proteins. A gp120 contains ~500-residues and functions to identify target T-cells and macrophages via binding to specific protein receptors of the target cell membrane. Gp120 moves away from the gp41 ectodomain, and the ectodomain is thought to bind to the target cell membrane and mediate membrane fusion. The secondary and tertiary structures of the ectodomain are different in the initial complex with gp120 and the final state without gp120. There isn't yet imaging of gp41 during fusion, so the temporal relationship between the gp41 and membrane structures isn't known. The present study describes biophysical and functional characterization of large gp41 constructs that include the ectodomain and transmembrane domain (TM). Significant fusion is observed of both neutral and anionic vesicles at neutral pH which reflects the expected conditions of HIV/cell fusion. Fusion is enhanced by the FP, which in HIV/cell fusion likely contacts the host membrane, and the MPER and TM, which respectively interfacially contact and traverse the HIV membrane. Initial contact with vesicles is made by protein trimers which are in a native oligomeric state that reflects the initial complex with gp120, and also is commonly observed for the ectodomain without gp120. Circular dichroism data support helical structure for the N-helix, C-helix, and MPER, and non-helical structure for the FP and loop. Distributions of monomer, trimer, and hexamer states are observed by
Chikungunya virus infection; Chikungunya ... Where Chikungunya is Found Before 2013, the virus was found in Africa, Asia, Europe, and the Indian and Pacific oceans. In late 2013, outbreaks occurred for the first time in the ...
... through blood transfusions. There have been outbreaks of Zika virus in the United States, Africa, Southeast Asia, the ... not travel to areas where there is a Zika virus outbreak. If you do decide to travel, first ...
... Gaines, PhD, MPH, MA, CHES Differentiating Chikungunya From Dengue: A Clinical Challenge For Travelers CDC Travelers' Health Chikungunya Virus Home Prevention Transmission Symptoms & Treatment Geographic Distribution Chikungunya virus in the United States ...
... Funding CDC Activities For Healthcare Providers Clinical Evaluation & Disease Sexual Transmission HIV Infection & Zika Virus Testing for Zika Test Specimens – At Time of Birth Diagnostic Tests Understanding Zika Virus Test Results ...
Full Text Available Previous studies have reported the production of malformed virus-like-particles (VLP in recombinant host systems. Here we computationally investigate the case of a large triple-layered rotavirus VLP (RLP. In vitro assembly, disassembly and reassembly data provides strong evidence of microscopic reversibility of RLP assembly. Light scattering experimental data also evidences a slow and reversible assembly untypical of kinetic traps, thus further strengthening the fidelity of a thermodynamically controlled assembly. In silico analysis further reveals that under favourable conditions particles distribution is dominated by structural subunits and completely built icosahedra, while other intermediates are present only at residual concentrations. Except for harshly unfavourable conditions, assembly yield is maximised when proteins are provided in the same VLP protein mass composition. The assembly yield decreases abruptly due to thermodynamic equilibrium when the VLP protein mass composition is not obeyed. The latter effect is more pronounced the higher the Gibbs free energy of subunit association is and the more complex the particle is. Overall this study shows that the correct formation of complex multi-layered VLPs is restricted to a narrow range of association energies and protein concentrations, thus the choice of the host system is critical for successful assembly. Likewise, the dynamic control of intracellular protein expression rates becomes very important to minimize wasted proteins.
Villanova, Gabriela V.; Gardiol, Daniela; Taborda, Miguel A.; Reggiardo, Virginia; Tanno, Hugo; Rivadeneira, Emilia D.; Perez, Germán R.; Giri, Adriana A.
Molecular diagnostics based on reverse transcription (RT)-PCR are routinely complicated by the lack of stable internal controls, leading to falsely negative results. We describe a strategy to produce a stable competitive internal control (CIC) based on a Qβ phage derivative (recombinant Qβ [rQβ]) bearing primers KY78 and KY80, which are widely used in the detection of hepatitis C virus (HCV). rQβ was RNase resistant and stable at 4°C for 452 days in SM medium (0.1 M NaCl, 8 mM MgSO4·7H2O, 50 mM Tris HCl [pH 7.5], 2% gelatin) and for 125 days after lyophilization and reconstitution. rQβ performance as a CIC was evaluated. rQβ was added to HCV-positive samples, followed by RNA extraction and a CIC-HCV RT-PCR assay. This method combines RT-PCR, liquid hybridization with nonradioactive probes, and enzyme immunoanalysis. No influence of the CIC on qualitative HCV detection was observed independently of viral load, and results had high concordance with those of commercial kits. In conclusion, we describe a versatile, low-cost alternative strategy to armored RNA technology that can be adapted for detection or real-time applications of any RNA target. Moreover, the CIC reported here is an essential reagent for HCV screening in blood banks in resource-limited settings. PMID:17699653
Hatano, Ben; Kojima, Asato; Sata, Tetsutaro; Katano, Harutaka
Intentional contamination of beverages with microbes is one type of bioterrorist threat. While bacteria and fungus can be easily collected by a centrifuge, viruses are difficult to collect from virus-contaminated beverages. In this study, we demonstrated that Viro-Adembeads, a rapid-capture system for viruses using anionic polymer-coated magnetic beads, collected viruses from beverages contaminated intentionally with vaccinia virus and human herpesvirus 8. Real-time PCR showed that the recovery rates of the contaminated viruses in green tea and orange juice were lower than those in milk and water. Plaque assay showed that green tea and orange juice cut the efficiency of vaccinia virus infection in CV-1 cells. These results suggest that the efficiency of virus detection depends on the kind of beverage being tested. Viro-Adembeads would be a useful tool for detecting viruses rapidly in virus-contaminated beverages used in a bioterrorist attack.
Wang, Yingying; Aïssi-Rothe, Lamia; Virion, Jean Marc; De Carvalho Bittencourt, Marcelo; Ulas, Neslihan; Audonnet, Sandra; Salmon, Alexandra; Clement, Laurence; Venard, Veronique; Jeulin, Helène; Stoltz, Jean-François; Decot, Veronique; Bensoussan, Danièle
Epstein-Barr virus (EBV) infection is a major cause of morbidity following hematopoietic stem cell transplantation. EBV-infected B cells may not respond to rituximab treatment and may lead to a life-threatening post-transplantation lymphoproliferative disorder. Adoptive cellular immunotherapy using EBV-lymphoblastoid cell lines (LCL) as stimulating antigen has proved effective in restoring specific immunity. However, EBV presents several immunodominant antigens, and developing a swift and effective clinical-grade immunotherapy relies on the definition of a Good Manufacturing Practices (GMP) universal stimulating antigen. Peripheral blood mononuclear cells (PBMCs) from six donors with a cellular immune response against EBV were immunoselected after stimulation with a new EBV antigen associated with an EBNA3 peptide pool. After immunoselection, a mean of 0.53 ± 0.25 × 10⁶ cells was recovered consisting of a mean of 24.77 ± 18.01% CD4⁺-secreting interferon (IFN)-γ and 51.42 ± 26.92% CD8⁺-secreting IFN-γ. The T memory stem cell sub-population was identified. EBV-specific T cells were expanded in vitro, and their ability to secrete IFN-γ and to proliferate after re-stimulation with EBV antigen was confirmed. A specific lysis was observed against autologous target cells pulsed with EBV peptide pools (57.6 ± 11.5%) and against autologous EBV-LCL (18.3 ± 7.3%). A mean decrease of 94.7 ± 3.3% in alloreactivity against third-party donor mononuclear cells with EBV-specific T cells was observed compared with PBMCs before selection. Our results show that a combination of peptide pools including EBNA3 is needed to generate EBV-specific T cells with good specific cytotoxicity and devoid of alloreactivity, but as yet GMP grade is not fully achieved. Copyright © 2014 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.
Full Text Available Oxidative stress is thought to compromise muscle contractility. However, administration of generic antioxidants has failed to convincingly improve performance during exhaustive exercise. One possible explanation may relate to the inability of the supplemented antioxidants to effectively eliminate excessive free radicals at the site of generation. Here, we tested whether delivering catalase to the mitochondria, a site of free radical production in contracting muscle, could improve treadmill performance in C57Bl/6 mice. Recombinant adeno-associated virus serotype-9 (AV.RSV.MCAT was generated to express a mitochondria-targeted catalase gene. AV.RSV.MCAT was delivered to newborn C57Bl/6 mouse circulation at the dose of 10(12 vector genome particles per mouse. Three months later, we observed a approximately 2 to 10-fold increase of catalase protein and activity in skeletal muscle and the heart. Subcellular fractionation western blot and double immunofluorescence staining confirmed ectopic catalase expression in the mitochondria. Compared with untreated control mice, absolute running distance and body weight normalized running distance were significantly improved in AV.RSV.MCAT infected mice during exhaustive treadmill running. Interestingly, ex vivo contractility of the extensor digitorum longus muscle was not altered. Taken together, we have demonstrated that forced catalase expression in the mitochondria enhances exercise performance. Our result provides a framework for further elucidating the underlying mechanism. It also raises the hope of applying similar strategies to remove excessive, pathogenic free radicals in certain muscle diseases (such as Duchenne muscular dystrophy and ameliorate muscle disease.
Nazerai, Loulieta; Scholler, Amalie Skak; Buus, Soren
Zika virus (ZIKV) is a mosquito-borne flavivirus that has drawn worldwide attention due to its association to neurologic complications, particularly severe congenital malformations. While ZIKV can replicate efficiently and cause disease in human hosts, it fails to replicate to substantial titers...... mice by introducing the virus directly in the brain via intracerebral (i.c.) inoculation. In this way, the antigen is precisely placed at the site of interest, evading the first line of defense, and thus rendering the mice susceptible to infection. We found that, while intravenous (i.v.) inoculation...... of two different strains of WT mice with low doses of ZIKV does not result in viremia, it is nevertheless able to induce both cell-mediated and humoral immunity as well as clinical protection against subsequent i.c challenge with lethal doses of the virus. In order to determine the contribution of key...
Yamada, Takashi; Onimatsu, Hideki; Van Etten, James L.
Chlorella viruses or chloroviruses are large, icosahedral, plaque‐forming, double‐stranded‐DNA—containing viruses that replicate in certain strains of the unicellular green alga Chlorella. DNA sequence analysis of the 330‐kbp genome of Paramecium bursaria chlorella virus 1 (PBCV‐1), the prototype of this virus family (Phycodnaviridae), predict ∼366 protein‐encoding genes and 11 tRNA genes. The predicted gene products of ∼50% of these genes resemble proteins of known function, including many that are completely unexpected for a virus. In addition, the chlorella viruses have several features and encode many gene products that distinguish them from most viruses. These products include: (1) multiple DNA methyltransferases and DNA site‐specific endonucleases, (2) the enzymes required to glycosylate their proteins and synthesize polysaccharides such as hyaluronan and chitin, (3) a virus‐encoded K+ channel (called Kcv) located in the internal membrane of the virions, (4) a SET domain containing protein (referred to as vSET) that dimethylates Lys27 in histone 3, and (5) PBCV‐1 has three types of introns; a self‐splicing intron, a spliceosomal processed intron, and a small tRNA intron. Accumulating evidence indicates that the chlorella viruses have a very long evolutionary history. This review mainly deals with research on the virion structure, genome rearrangements, gene expression, cell wall degradation, polysaccharide synthesis, and evolution of PBCV‐1 as well as other related viruses. PMID:16877063
Fry, Elizabeth; Logan, Derek; Stuart, David
Crystallography provides a means of visualizing intact virus particles as well as their isolated constituent proteins and enzymes (1-3) at near-atomic resolution, and is thus an extraordinarily powerful tool in the pursuit of a fuller understanding of the functioning of these simple biological systems. We have already expanded our knowledge of virus evolution, assembly, antigenic variation, and host-cell interactions; further studies will no doubt reveal much more. Although the rewards are enormous, an intact virus structure determination is not a trivial undertaking and entails a significant scaling up in terms of time and resources through all stages of data collection and processing compared to a traditional protein crystallographic structure determination. It is the methodology required for such studies that will be the focus of this chapter. The computational requirements were satisfied in the late 1970s, and when combined with the introduction of phase improvement techniques utilizing the virus symmetry (4,5), the application of crystallography to these massive macromolecular assemblies became feasible. This led to the determination of the first virus structure (the small RNA plant virus, tomato bushy stunt virus), by Harrison and coworkers in 1978 (6). The structures of two other plant viruses followed rapidly (7,8). In the 1980s, a major focus of attention was a family of animal RNA viruses; the Picornaviridae.
Viruses use synthetic mechanism and organelles of the host cells to facilitate their replication and make new viruses. Host's ATP provides necessary energy. Hepatitis C virus (HCV) is a major cause of liver disease. Like other positive-strand RNA viruses, the HCV genome is thought to be synthesized by the replication complex, which consists of viral- and host cell-derived factors, in tight association with structurally rearranged vesicle-like cytoplasmic membranes. The virus-induced remodeling of subcellular membranes, which protect the viral RNA from nucleases in the cytoplasm, promotes efficient replication of HCV genome. The assembly of HCV particle involves interactions between viral structural and nonstructural proteins and pathways related to lipid metabolisms in a concerted fashion. Association of viral core protein, which forms the capsid, with lipid droplets appears to be a prerequisite for early steps of the assembly, which are closely linked with the viral genome replication. This review presents the recent progress in understanding the mechanisms for replication and assembly of HCV through its interactions with organelles or distinct organelle-like structures.
The "one-step" Bean pod mottle virus (BPMV)-derived vector is a functional genomics tool for efficient overexpression of heterologous protein, virus-induced gene silencing and genetic mapping of BPMV R-gene in common bean (Phaseolus vulgaris L.).
Pflieger, Stéphanie; Blanchet, Sophie; Meziadi, Chouaib; Richard, Manon M S; Thareau, Vincent; Mary, Fanny; Mazoyer, Céline; Geffroy, Valérie
Over the last two years, considerable advances have been made in common bean (Phaseolus vulgaris L.) genomics, especially with the completion of the genome sequence and the availability of RNAseq data. However, as common bean is recalcitrant to stable genetic transformation, much work remains to be done for the development of functional genomics tools adapted to large-scale studies. Here we report the successful implementation of an efficient viral vector system for foreign gene expression, virus-induced gene silencing (VIGS) and genetic mapping of a BPMV resistance gene in common bean, using a "one-step" BPMV vector originally developed in soybean. With the goal of developing this vector for high-throughput VIGS studies in common bean, we optimized the conditions for rub-inoculation of infectious BPMV-derived plasmids in common bean cv. Black Valentine. We then tested the susceptibility to BPMV of six cultivars, and found that only Black Valentine and JaloEEP558 were susceptible to BPMV. We used a BPMV-GFP construct to detect the spatial and temporal infection patterns of BPMV in vegetative and reproductive tissues. VIGS of the PHYTOENE DESATURASE (PvPDS) marker gene was successfully achieved with recombinant BPMV vectors carrying fragments ranging from 132 to 391 bp. Finally, we mapped a gene for resistance to BPMV (R-BPMV) at one end of linkage group 2, in the vicinity of a locus (I locus) previously shown to be involved in virus resistance. The "one-step" BPMV vector system therefore enables rapid and simple functional studies in common bean, and could be suitable for large-scale analyses. In the post-genomic era, these advances are timely for the common bean research community.
First page Back Continue Last page Overview Graphics. CHANDIPURA VIRUS. First isolated from a village called Chandipura near Nagpur in 1965 in India. Belongs to rhabdoviridae family. Used as a Model System to study RNA virus multiplication in the infected cell at molecular level. Notes:
Evaluation of different embryonating bird eggs and cell cultures for isolation efficiency of avian influenza A virus and avian paramyxovirus serotype 1 from real-time reverse transcription polymerase chain reaction--positive
Two hundred samples collected from Anseriformes, Charadriiformes, Gruiformes, and Galliformes were assayed using real-time reverse transcriptase polymerase chain reaction (RRT-PCR) for presence of avian influenza virus and avian paramyxovirus-1. Virus isolation using embryonating chicken eggs, embr...
Belsham, Graham; Hua Guan, Su
Foot-and-mouth disease virus (FMDV) is a picornavirus and its RNA genome encodes a large polyprotein. The N-terminal part of this polyprotein is the Leader protein, a cysteine protease, termed Lpro. The virus causes the rapid inhibition of host cell capdependent protein synthesis within infected...
Denning, Peter J.
The worm, Trojan horse, bacterium, and virus are destructive programs that attack information stored in a computer's memory. Virus programs, which propagate by incorporating copies of themselves into other programs, are a growing menace in the late-1980s world of unprotected, networked workstations and personal computers. Limited immunity is offered by memory protection hardware, digitally authenticated object programs,and antibody programs that kill specific viruses. Additional immunity can be gained from the practice of digital hygiene, primarily the refusal to use software from untrusted sources. Full immunity requires attention in a social dimension, the accountability of programmers.
Katoh, Hiroshi; Kubota, Toru; Ihara, Toshiaki; Maeda, Ken; Takeda, Makoto; Kidokoro, Minoru
Recently, a new paramyxovirus closely related to human mumps virus (MuV) was detected in bats. We generated recombinant MuVs carrying either or both of the fusion and hemagglutinin-neuraminidase bat virus glycoproteins. These viruses showed replication kinetics similar to human MuV in cultured cells and were neutralized efficiently by serum from healthy humans.
Cardoso de Carvalho Ferreira, H.
African swine fever is a haemorrhagic disease of swine caused by African swine fever virus (ASFV). Estimates of virus transmission (direct or indirect) parameters for ASFV are necessary in order to model the spread of the virus, and to design more efficient control measures. Results presented on
The Glycosylphosphatidylinositol-Anchored Variable Region of Llama Heavy Chain-Only Antibody JM4 Efficiently Blocks both Cell-Free and T Cell-T Cell Transmission of Human Immunodeficiency Virus Type 1.
Liu, Lihong; Wang, Weiming; Matz, Julie; Ye, Chaobaihui; Bracq, Lucie; Delon, Jerome; Kimata, Jason T; Chen, Zhiwei; Benichou, Serge; Zhou, Paul
The variable regions (VHHs) of two heavy chain-only antibodies, JM2 and JM4, from llamas that have been immunized with a trimeric gp140 bound to a CD4 mimic have been recently isolated (here referred to as VHH JM2 and VHH JM4, respectively). JM2 binds the CD4-binding site of gp120 and neutralizes HIV-1 strains from subtypes B, C, and G. JM4 binds gp120 and neutralizes HIV-1 strains from subtypes A, B, C, A/E, and G in a CD4-dependent manner. In the present study, we constructed glycosylphosphatidylinositol (GPI)-anchored VHH JM2 and JM4 along with an E4 control and transduced them into human CD4+ cell lines and primary CD4 T cells. We report that by genetically linking the VHHs with a GPI attachment signal, VHHs are targeted to the lipid rafts of the plasma membranes. Expression of GPI-VHH JM4, but not GPI-VHH E4 and JM2, on the surface of transduced TZM.bl cells potently neutralizes multiple subtypes of HIV-1 isolates, including tier 2 or 3 strains, transmitted founders, quasispecies, and soluble single domain antibody (sdAb) JM4-resistant viruses. Moreover, transduction of CEMss-CCR5 cells with GPI-VHH JM4, but not with GPI-VHH E4, confers resistance to both cell-free and T cell-T cell transmission of HIV-1 and HIV-1 envelope-mediated fusion. Finally, GPI-VHH JM4-transduced human primary CD4 T cells efficiently resist both cell-free and T cell-T cell transmission of HIV-1. Thus, we conclude that VHH JM4, when targeted to the lipid rafts of the plasma membrane, efficiently neutralizes HIV-1 infection via both cell-free and T cell-T cell transmission. Our findings should have important implications for GPI-anchored antibody-based therapy against HIV-1. Lipid rafts are specialized dynamic microdomains of the plasma membrane and have been shown to be gateways for HIV-1 budding as well as entry into T cells and macrophages. In nature, many glycosylphosphatidylinositol (GPI)-anchored proteins localize in the lipid rafts. In the present study, we developed GPI
Jurado Hernández, Daniel José
Fundamentals of Life - Origin and Fundamentals of Living Things. Evaluation rubric to evaluate the debate and presentation about the point of view regarding the possibility of viruses from the outer space.
Musso, Didier; Gubler, Duane J.
Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) in the genus Flavivirus and the family Flaviviridae. ZIKV was first isolated from a nonhuman primate in 1947 and from mosquitoes in 1948 in Africa, and ZIKV infections in humans were sporadic for half a century before emerging in the Pacific and the Americas. ZIKV is usually transmitted by the bite of infected mosquitoes. The clinical presentation of Zika fever is nonspecific and can be misdiagnosed as other infectious diseases, especi...
Asjes, C.J.; Blom-Barnhoorn, G.J.; Piron, P.G.M.; Harrewijn, P.; Oosten, van A.M.
In this study on the air-borne viruses in Lilium, mainly lily symptomless virus (LSV) and tulip breaking virus (TBV), various factors involved in the efficiency of control are dealt with. The incidence of LSV was reduced very substantially from the old 100␛ate. TBV occurs at fairly low rates. Lily
Quantification and localization of Watermelon chlorotic stunt virus and Tomato yellow leaf curl virus (Geminiviridae in populations of Bemisia tabaci (Hemiptera, Aleyrodidae with differential virus transmission characteristics.
Full Text Available Bemisia tabaci (Gennadius is one of the economically most damaging insects to crops in tropical and subtropical regions. Severe damage is caused by feeding and more seriously by transmitting viruses. Those of the genus begomovirus (Geminiviridae cause the most significant crop diseases and are transmitted by B. tabaci in a persistent circulative mode, a process which is largely unknown. To analyze the translocation and to identify critical determinants for transmission, two populations of B. tabaci MEAM1 were compared for transmitting Watermelon chlorotic stunt virus (WmCSV and Tomato yellow leaf curl virus (TYLCV. Insect populations were chosen because of their high and respectively low virus transmission efficiency to compare uptake and translocation of virus through insects. Both populations harbored Rickettsia, Hamiltonella and Wolbachia in comparable ratios indicating that endosymbionts might not contribute to the different transmission rates. Quantification by qPCR revealed that WmCSV uptake and virus concentrations in midguts and primary salivary glands were generally higher than TYLCV due to higher virus contents of the source plants. Both viruses accumulated higher in insects from the efficiently compared to the poorly transmitting population. In the latter, virus translocation into the hemolymph was delayed and virus passage was impeded with limited numbers of viruses translocated. FISH analysis confirmed these results with similar virus distribution found in excised organs of both populations. No virus accumulation was found in the midgut lumen of the poor transmitter because of a restrained virus translocation. Results suggest that the poorly transmitting population comprised insects that lacked transmission competence. Those were selected to develop a population that lacks virus transmission. Investigations with insects lacking transmission showed that virus concentrations in midguts were reduced and only negligible virus amounts
Erdemci-Tandogan, G; Wagner, J.; Schoot, van der, PPAM Paul; Podgornik, R.; Zandi, R
Simple RNA viruses efficiently encapsulate their genome into a nano-sized protein shell: the capsid. Spontaneous coassembly of the genome and the capsid proteins is driven predominantly by electrostatic interactions between the negatively charged RNA and the positively charged inner capsid wall. Using field theoretic formulation we show that the inherently branched RNA secondary structure allows viruses to maximize the amount of encapsulated genome and make assembly more efficient, allowing v...
... to Ask about Your Treatment Research Newcastle Disease Virus (PDQ®)–Patient Version Overview Go to Health Professional ... Question 8 ). Questions and Answers About Newcastle Disease Virus What is Newcastle disease virus? Newcastle disease virus ( ...
... Professionals Related Topics For International Travelers Powassan (POW) Virus Basics Download this fact sheet formatted for print: ... POW) Virus Fact Sheet (PDF) What is Powassan virus? Powassan (POW) virus is a flavivirus that is ...
Sviben, Dora; Forčić, Dubravko; Kurtović, Tihana; Halassy, Beata; Brgles, Marija
Measles virus and mumps virus (MeV and MuV) are enveloped RNA viruses used for production of live attenuated vaccines for prophylaxis of measles and mumps disease, respectively. For biotechnological production of and basic research on these viruses, the preparation of highly purified and infectious viruses is a prerequisite, and to meet that aim, knowledge of their stability and biophysical properties is crucial. Our goal was to carry out a detailed investigation of the stability of MeV and MuV under various pH, temperature, shear stress, filtration and storage conditions, as well as to evaluate two commonly used purification techniques, ultracentrifugation and diafiltration, with regard to their efficiency and effect on virus properties. Virus titers were estimated by CCID50 assay, particle size and concentration were measured by Nanoparticle tracking analysis (NTA) measurements, and the host cell protein content was determined by ELISA. The results demonstrated the stability of MuV and MeV at pH 9. Storage without stabilizer did not result in structural changes, but the reduction in infectivity after 24 hours was significant at +37 °C. Vortexing of the viruses resulted in significant particle degradation, leading to lower virus titers, whereas pipetting had much less impact on virus viability. Diafiltration resulted in higher recovery of both total and infectious virus particles than ultracentrifugation. These results provide important data for research on all upstream and downstream processes on these two viruses regarding biotechnological production and basic research.
Ponder, Tim, Comp.; Ropog, Marty, Comp.; Keating, Joseph, Comp.
This document provides general information on computer viruses, how to help protect a computer network from them, measures to take if a computer becomes infected. Highlights include the origins of computer viruses; virus contraction; a description of some common virus types (File Virus, Boot Sector/Partition Table Viruses, Trojan Horses, and…
... human cytomegalovirus, herpes simplex virus, human immunodeficiency virus I, influenza, lymphocytic choriomeningitis virus, measles, papilloma, rabies, respiratory syncitial virus, simian immunodeficiency virus, simian virus 40. Bacteria Borrelia burgdorferi (Lyme disease), Moraxella bovis, Mycobacterium tuberculosis, ...
This thesis investigates a recently discovered vulnerability in computer systems which opens the possibility that a single individual with an average user's knowledge could cause widespread damage to information residing in computer networks. This vulnerability is due to a transitive integrity corrupting mechanism called a computer virus which causes corrupted information to spread from program to program. Experiments have shown that a virus can spread at an alarmingly rapid rate from user to user, from system to system, and from network to network, even when the best-availability security techniques are properly used. Formal definitions of self-replication, evolution, viruses, and protection mechanisms are used to prove that any system that allows sharing, general functionality, and transitivity of information flow cannot completely prevent viral attack. Computational aspects of viruses are examined, and several undecidable problems are shown. It is demonstrated that a virus may evolve so as to generate any computable sequence. Protection mechanisms are explored, and the design of computer networks that prevent both illicit modification and dissemination of information are given. Administration and protection of information networks based on partial orderings are examined, and probably correct automated administrative assistance is introduced.
Hendra virus infection of horses occurred sporadically between 1994 and 2010 as a result of spill-over from the viral reservoir in Australian mainland flying-foxes, and occasional onward transmission to people also followed from exposure to affected horses. An unprecedented number of outbreaks were recorded in 2011 leading to heightened community concern. Release of an inactivated subunit vaccine for horses against Hendra virus represents the first commercially available product that is focused on mitigating the impact of a Biosafety Level 4 pathogen. Through preventing the development of acute Hendra virus disease in horses, vaccine use is also expected to reduce the risk of transmission of infection to people. Crown Copyright © 2014. Published by Elsevier Inc. All rights reserved.
Dowdle, W R
Marburg virus disease, which produced 20 per cent mortality when it first occured during 1967 in Germany and Yugoslavia, recently appeared again in South Africa. The source of the first outbreak was monkeys shipped from Africa; the origin of the second episode is unclear. Because distribution of the virus in nature is unknown, its threat to man cannot be readily determined. Differential laboratory diagnoses of hemorrhagic fevers should be encouraged in order to learn more about the epidemiology of these diseases and to better assess the risks which their etiologic agents may pose for attending medical personnel.
Full Text Available irradiation, temperature, adsorption onto organic and inorganic suspended solids with eventual sedimentation and attack by bacterial enz~es or other organisrns~~. ._?._, .~. r ...-~ Little work has been done to substantiate the efficiencies and mechanisms... and the turbidity of t1~e water. Duripg the routine testing of ten litre samples of natural water resources in Southern Africa, virus was recovered from five out of 52 weekly samples taken from a natural reservoir situated close to a city. This reservoir...
Monocistronic mRNAs containing defective hepatitis C virus-like picornavirus internal ribosome entry site elements in their 5 ' untranslated regions are efficiently translated in cells by a cap-dependent mechanism
Belsham, Graham; Nielsen, Inge; Normann, Preben
secondary structure and multiple upstream AUG codons. These features can be expected to inhibit cap-dependent initiation of translation. However, we have now shown that certain mutant hepatitis C virus-like picornavirus IRES elements (from porcine teschovirus-1 and avian encephalomyelitis virus), which...... cleavage of eIF4G) and is also inhibited by hippuristanol, a specific inhibitor of eIF4A function, in contrast to their parental wild-type IRES elements. These results provide a possible basis for the evolution of viral IRES elements within the context of functional mRNAs that are translated by a cap...
Full Text Available Bats harbor many viruses, which are periodically transmitted to humans resulting in outbreaks of disease (e.g., Ebola, SARS-CoV. Recently, influenza virus-like sequences were identified in bats; however, the viruses could not be cultured. This discovery aroused great interest in understanding the evolutionary history and pandemic potential of bat-influenza. Using synthetic genomics, we were unable to rescue the wild type bat virus, but could rescue a modified bat-influenza virus that had the HA and NA coding regions replaced with those of A/PR/8/1934 (H1N1. This modified bat-influenza virus replicated efficiently in vitro and in mice, resulting in severe disease. Additional studies using a bat-influenza virus that had the HA and NA of A/swine/Texas/4199-2/1998 (H3N2 showed that the PR8 HA and NA contributed to the pathogenicity in mice. Unlike other influenza viruses, engineering truncations hypothesized to reduce interferon antagonism into the NS1 protein didn't attenuate bat-influenza. In contrast, substitution of a putative virulence mutation from the bat-influenza PB2 significantly attenuated the virus in mice and introduction of a putative virulence mutation increased its pathogenicity. Mini-genome replication studies and virus reassortment experiments demonstrated that bat-influenza has very limited genetic and protein compatibility with Type A or Type B influenza viruses, yet it readily reassorts with another divergent bat-influenza virus, suggesting that the bat-influenza lineage may represent a new Genus/Species within the Orthomyxoviridae family. Collectively, our data indicate that the bat-influenza viruses recently identified are authentic viruses that pose little, if any, pandemic threat to humans; however, they provide new insights into the evolution and basic biology of influenza viruses.
Full Text Available The lecture is devoted to oncogenic viruses, particularly human papilloma virus. Papilloma viral infection is found in all parts of the globe and highly contagious. In addition to exhaustive current data on classification, specifics of papilloma viruses composition and epidemiology, the author describes in great detail the malignization mechanisms of papilloma viruses pockets. Also, issues of diagnostics and specific prevention and treatment of diseases caused by this virus are illustrated. Key words: oncogenic viruses, papilloma viruses, prevention, vaccination. (Pediatric Pharmacology. – 2010; 7(4:48-55
Salim Mattar V.
Full Text Available Bunyaviruses are RNA viruses that affect animals and plants; they have five genera and four of them affect humans: Orthobunyavirus, Nairovirus, Phlebovirus and Hantavirus. All of them are Arbovirus, except Hantavirus. The Orthobunyaviruses comprise Oropouche, Tahyna, La Crosse virus, California encephalitis virus and Heartland virus recently discovered (1. Except for Heartland virus which is transmitted by ticks of the genus Amblyoma, these Phleboviruses have as vectors mosquitoes, which bite small mammals which are able to be as reservoirs amplifiers.
Virus Hanta kurang infeksius, kecuali di dalam lingkungan tertentu. Lamanya waktu virus ini dapat bertahan di lingkungan, setelah keluar dari tubuh tikus tidaklah diketahui secara pasti. Tetapi percobaan laboratorium menunjukkan bahwa, daya infektifitasnya tidak dijumpai setelah dua hari pengeringan. Genus hanta virus terdiri dari 22 spesies virus, dapat menyebabkan hemorrhagic fever with renal syndrome (HFRS) dan hanta virus pulmonary syndrome (HPS).
Prangishvili, D.; Garrett, R. A.
, when one examines the archaeal viruses, the picture appears complex. Most viruses that are known to infect members of the kingdom Euryarchaeota resemble bacterial viruses, whereas those associated with the kingdom Crenarchaeota show little resemblance to either bacterial or eukaryal viruses....... This review summarizes our current knowledge of this group of exceptional and highly diverse archaeal viruses....
Krepstakies, Marcel; Lucifora, Julie; Nagel, Claus-Henning; Zeisel, Mirjam B; Holstermann, Barbara; Hohenberg, Heinrich; Kowalski, Ina; Gutsmann, Thomas; Baumert, Thomas F; Brandenburg, Klaus; Hauber, Joachim; Protzer, Ulrike
Many enveloped viruses, including herpes viruses, hepatitis B virus (HBV), and hepatitis C virus (HCV), and human immunodeficiency virus (HIV), are among the most important human pathogens and are often responsible for coinfections involving ≥2 types of viruses. However, therapies that are effective against multiple virus classes are rare. Here we present a new class of synthetic anti-lipopolysaccharide peptides (SALPs) that bind to heparan sulfate moieties on the cell surface and inhibit infection with a variety of enveloped viruses. We demonstrate that SALPs inhibit entry of human immunodeficiency virus type 1 (HIV-1), herpes simplex virus (HSV) 1 and 2, HBV, and HCV to their respective host cells. Despite their high antiviral efficiency, SALPs were well tolerated, and neither toxicity nor measurable inhibitor-induced adverse effects were observed. Since these broad-spectrum antiviral peptides target a host cell rather than a viral component, they may also be useful for suppression of viruses that are resistant to antiviral drugs.
Musso, Didier; Gubler, Duane J
Zika virus (ZIKV) is an arthropod-borne virus (arbovirus) in the genus Flavivirus and the family Flaviviridae. ZIKV was first isolated from a nonhuman primate in 1947 and from mosquitoes in 1948 in Africa, and ZIKV infections in humans were sporadic for half a century before emerging in the Pacific and the Americas. ZIKV is usually transmitted by the bite of infected mosquitoes. The clinical presentation of Zika fever is nonspecific and can be misdiagnosed as other infectious diseases, especially those due to arboviruses such as dengue and chikungunya. ZIKV infection was associated with only mild illness prior to the large French Polynesian outbreak in 2013 and 2014, when severe neurological complications were reported, and the emergence in Brazil of a dramatic increase in severe congenital malformations (microcephaly) suspected to be associated with ZIKV. Laboratory diagnosis of Zika fever relies on virus isolation or detection of ZIKV-specific RNA. Serological diagnosis is complicated by cross-reactivity among members of the Flavivirus genus. The adaptation of ZIKV to an urban cycle involving humans and domestic mosquito vectors in tropical areas where dengue is endemic suggests that the incidence of ZIKV infections may be underestimated. There is a high potential for ZIKV emergence in urban centers in the tropics that are infested with competent mosquito vectors such as Aedes aegypti and Aedes albopictus. Copyright © 2016, American Society for Microbiology. All Rights Reserved.
Savini, G; Lorusso, A; Paladini, C; Migliaccio, P; Di Gennaro, A; Di Provvido, A; Scacchia, M; Monaco, F
The recent outbreak caused by Schmallenberg virus, which affected sheep, goats and cattle in Europe, highlighted the importance of having a robust surveillance plan capable of monitoring abortions and malformations in the livestock offspring. In this context, bluetongue viruses (BTVs) represented and represent one of the major threats to the European livestock industry. Aiming to improve the understanding on BTV cross placental transmission and serotype involvement, in this retrospective study foetal spleens and/or brains of 663 ovines, 429 bovines, 155 goats and 17 buffaloes were tested for the presence of BTV by virus isolation. BTV vaccine strains were isolated from 31 foetuses (2.4%; 95% CI: 1.7-3.4%): 24 (3.6%; 95% CI: 2.4-5.3%) from ovine foetal tissues; 6 (1.4%; 95% CI: 0.6-3.0%) from bovine foetal tissues and 1 (0.6%; 95% CI: 0.2-3.5%) from the spleen of a caprine foetus. All foetuses were from animals vaccinated with either BTV-2 or BTV-2, and BTV-9 modified live vaccines (MLVs) produced by Onderstepoort Biological Products (OBP), South Africa. Among the 31 isolated vaccine strains, serotype 9 (n = 28) was more frequently isolated (P < 0.05) than serotype 2 (n = 3). In two cases infectious vaccine strains were found in the foetal tissues 2 months after the vaccine administration. Other pathogens known to be causative agents of abortion in ruminants were not detected nor isolated. This study demonstrates, for the first time, that BTV-2 and BTV-9 vaccine strains are able to cross the placental barrier of sheep, cattle and goats. BTV-2 and BTV-9 vaccine strains are able to infect foetuses and cause abortions or malformations depending on the period of pregnancy at the time of vaccination. © 2012 Blackwell Verlag GmbH.
Janke, B H
Influenza has been recognized as a respiratory disease in swine since its first appearance concurrent with the 1918 "Spanish flu" human pandemic. All influenza viruses of significance in swine are type A, subtype H1N1, H1N2, or H3N2 viruses. Influenza viruses infect epithelial cells lining the surface of the respiratory tract, inducing prominent necrotizing bronchitis and bronchiolitis and variable interstitial pneumonia. Cell death is due to direct virus infection and to insult directed by leukocytes and cytokines of the innate immune system. The most virulent viruses consistently express the following characteristics of infection: (1) higher or more prolonged virus replication, (2) excessive cytokine induction, and (3) replication in the lower respiratory tract. Nearly all the viral proteins contribute to virulence. Pigs are susceptible to infection with both human and avian viruses, which often results in gene reassortment between these viruses and endemic swine viruses. The receptors on the epithelial cells lining the respiratory tract are major determinants of infection by influenza viruses from other hosts. The polymerases, especially PB2, also influence cross-species infection. Methods of diagnosis and characterization of influenza viruses that infect swine have improved over the years, driven both by the availability of new technologies and by the necessity of keeping up with changes in the virus. Testing of oral fluids from pigs for virus and antibody is a recent development that allows efficient sampling of large numbers of animals.
Meyer, Denise; Schmeiser, Stefanie; Postel, Alexander; Becher, Paul
Translation and replication of positive stranded RNA viruses are directly initiated in the cellular cytoplasm after uncoating of the viral genome. Accordingly, infectious virus can be generated by transfection of RNA genomes into susceptible cells. In the present study, efficiency of conventional virus isolation after inoculation of cells with infectious sample material was compared to virus recovery after transfection of total RNA derived from organ samples of pigs infected with Classical swine fever virus (CSFV). Compared to the conventional method of virus isolation applied in three different porcine cell lines used in routine diagnosis of CSF, RNA transfection showed a similar efficiency for virus rescue. For two samples, recovery of infectious virus was only possible by RNA transfection, but not by the classical approach of virus isolation. Therefore, RNA transfection represents a valuable alternative to conventional virus isolation in particular when virus isolation is not possible, sample material is not suitable for virus isolation or when infectious material is not available. To estimate the potential risk of RNA prepared from sample material for infection of pigs, five domestic pigs were oronasally inoculated with RNA that was tested positive for virus rescue after RNA transfection. This exposure did not result in viral infection or clinical disease of the animals. In consequence, shipment of CSFV RNA can be regarded as a safe alternative to transportation of infectious virus and thereby facilitates the exchange of virus isolates among authorized laboratories with appropriate containment facilities.
Idrees, Sobia; Ashfaq, Usman A
Dengue virus infection has become a global threat affecting around 100 countries in the world. Currently, there is no licensed antiviral agent available against dengue. Thus, there is a strong need to develop therapeutic strategies that can tackle this life threatening disease. RNA interference is an important and effective gene silencing process which degrades targeted RNA by a sequence specific process. Several studies have been conducted during the last decade to evaluate the efficiency of siRNA in inhibiting dengue virus replication. This review summarizes siRNAs as a therapeutic approach against dengue virus serotypes and concludes that siRNAs against virus and host genes can be next generation treatment of dengue virus infection.
Full Text Available ... Education & Events Advocacy For Patients About ACOG Zika Virus and Pregnancy Home For Patients Zika Virus and ... Education Pamphlets - Spanish Share: PEV002, September 2016 Zika Virus and Pregnancy There are risks to your fetus ...
... Management Education & Events Advocacy For Patients About ACOG Zika Virus and Pregnancy Home For Patients Zika Virus and ... Patient Education Pamphlets - Spanish Share: PEV002, September 2016 Zika Virus and Pregnancy There are risks to your fetus ...
Full Text Available ... Management Education & Events Advocacy For Patients About ACOG Zika Virus and Pregnancy Home For Patients Zika Virus and ... Patient Education Pamphlets - Spanish Share: PEV002, September 2016 Zika Virus and Pregnancy There are risks to your fetus ...
Discusses the early history and current proliferation of computer viruses that occur on Macintosh and DOS personal computers, mentions virus detection programs, and offers suggestions for how libraries can protect themselves and their users from damage by computer viruses. (LRW)
Virus Marburg dan Ebola diklasifikasikan sebagai virus yang sangat menular dan dimasukkan dalam klasifikasi sebagai virus/pathogen dengan derajat biosafety 4, sehingga untuk menanganinya diperlukan laboratorium khusus tingkat 4.
Full Text Available ... Advocacy For Patients About ACOG Zika Virus and Pregnancy Home For Patients Zika Virus and Pregnancy Page ... Spanish Share: PEV002, September 2016 Zika Virus and Pregnancy There are risks to your fetus if you ...
Full Text Available ... Management Education & Events Advocacy For Patients About ACOG Zika Virus and Pregnancy Home For Patients Zika Virus ... Patient Education Pamphlets - Spanish Share: PEV002, September 2016 Zika Virus and Pregnancy There are risks to your ...
Tutut Handayani; Soenarto Usna,Drs.MMSI
Since its appearance the first time in the mid-1980s, computer virus has invited various controversies that still lasts to this day. Along with the development of computer systems technology, viruses komputerpun find new ways to spread itself through a variety of existing communications media. This paper discusses about some things related to computer viruses, namely: the definition and history of computer viruses; the basics of computer viruses; state of computer viruses at this time; and ...
With more than 1 200 species, bats and flying foxes (Order Chiroptera) constitute the most important and diverse order of Mammals after Rodents. Many species of bats are insectivorous while others are frugivorous and few of them are hematophagous. Some of these animals fly during the night, others are crepuscular or diurnal. Some fly long distances during seasonal migrations. Many species are colonial cave-dwelling, living in a rather small home range while others are relatively solitary. However, in spite of the importance of bats for terrestrial biotic communities and ecosystem ecology, the diversity in their biology and lifestyles remain poorly known and underappreciated. More than sixty viruses have been detected or isolated in bats; these animals are therefore involved in the natural cycles of many of them. This is the case, for instance, of rabies virus and other Lyssavirus (Family Rhabdoviridae), Nipah and Hendra viruses (Paramyxoviridae), Ebola and Marburg viruses (Filoviridae), SARS-CoV and MERS-CoV (Coronaviridae). For these zoonotic viruses, a number of bat species are considered as important reservoir hosts, efficient disseminators or even directly responsible of the transmission. Some of these bat-borne viruses cause highly pathogenic diseases while others are of potential significance for humans and domestic or wild animals; so, bats are an important risk in human and animal public health. Moreover, some groups of viruses developed through different phylogenetic mechanisms of coevolution between viruses and bats. The fact that most of these viral infections are asymptomatic in bats has been observed since a long time but the mechanisms of the viral persistence are not clearly understood. The various bioecology of the different bat populations allows exchange of virus between migrating and non-migrating conspecific species. For a better understanding of the role of bats in the circulation of these viral zoonoses, epidemiologists must pay attention to
Folimonova, Svetlana Y; Robertson, Cecile J; Shilts, Turksen; Folimonov, Alexey S; Hilf, Mark E; Garnsey, Stephen M; Dawson, William O
importantly, build a foundation for the strategy of selecting mild isolates that would efficiently exclude severe virus isolates as a practical means to control CTV diseases.
Rashnonejad, Afrooz; Chermahini, Gholamhossein Amini; Li, Shaoyong; Ozkinay, Ferda; Gao, Guangping
Recombinant AAV (rAAV) vectors are a suitable vector for gene therapy studies because of desired characteristics such as low immunogenicity, transfection of non-dividing and dividing cells, and long-term expression of the transgene. In this study, the large-scale production of single stranded (ss) and self-complementary (sc) AAV9 carrying the human survival motor neuron (SMN) gene (AAV9-SMN) suitable for in vivo gene therapy studies of SMA was described. SMN cDNA has been cloned into pAAV-CB6-PI and pAAVsc-CB6-PI with and without its specific UTRs, respectively. Both plasmids bear CMV enhancer/beta-actin (CB) promoter, CMV IE enhancer, and polyadenylation signal sequences. 2.5 μg of constructed pAAV-CB6-PI-SMN and pAAVsc-CB6-PI-SMN cause to, respectively, 4.853- and 2.321-fold increases in SMN protein levels in transfected cells compared to untransfected cells. Ss and scAAV9-SMN vectors were also produced from these plasmids by transient transfection of HEK293 cells using CaCl2 solution. The silver staining and electron microscopy analysis demonstrated good quality of both isolated vectors, ssAAV9-SMN and scAAV9-SMN, with the titers of 2.00E+13 and 1.00E+13 GC/ml. The results of this study show that, the plasmid containing UTR elements causes to twice more SMN gene expression in transfected cells. The quality control results show that both produced ss and scAAV9-SMN are suitable for in vivo studies.
Nadege Goumkwa Mafopa
Full Text Available A serosurvey of anti-Ebola Zaire virus nucleoprotein IgG prevalence was carried out among Ebola virus disease survivors and their Community Contacts in Bombali District, Sierra Leone. Our data suggest that the specie of Ebola virus (Zaire responsible of the 2013-2016 epidemic in West Africa may cause mild or asymptomatic infection in a proportion of cases, possibly due to an efficient immune response.
... OK for Kids? Your Teeth Heart Murmurs What's West Nile Virus? KidsHealth > For Kids > What's West Nile Virus? Print A A A en español ¿Qué es ... Virus del Nilo Occidental? What exactly is the West Nile virus? And why is everyone talking about mosquitoes ? Even ...
Juliana Cristina Santiago Bastos; Cláudia Beatriz Afonso de Menezes; Fabiana Fantinatti-Garboggini; Marina Aiello Padilla; Clarice Weis Arns; Luciana Konecny Kohn
The Hepatitis C virus (Flaviviridae family, Hepacivirus genus) represents a major public health problem worldwide and it is responsible for chronic infections in humans, which can develop to liver cirrhosis and hepatocellular carcinoma. As this virus does not replicate efficiently in cell culture and in animals, bovine viral diarrhea virus (BVDV) is used as a surrogate model for screening assays of antiviral activity, and mechanism of action assays. From marine invertebrates and their microor...
Krstić, Branka; Stanković, Ivana; Bulajić, Aleksandra
Over 40 plant viruses has been known to cause diseases of maize, but economically the most important yield looses, which in certain years can be total, are caused by viruses from Potyvirus genera, known to be aphid-transmitted in a non-persistant maner. The most important viruses, pathogens of maize, sugar cane and sorghum are considered to be Maize dwarf mosaic virus (MDMV), Sorghum mosaic virus (SrMV), Sugarcane mosaic virus (SCMV), and Johnsongrass mosaic virus (JGMV). In Serbia, the prese...
Erdemci-Tandogan, Gonca; Wagner, Jef; van der Schoot, Paul; Podgornik, Rudolf; Zandi, Roya
Simple RNA viruses efficiently encapsulate their genome into a nano-sized protein shell: the capsid. Spontaneous coassembly of the genome and the capsid proteins is driven predominantly by electrostatic interactions between the negatively charged RNA and the positively charged inner capsid wall. Using field theoretic formulation we show that the inherently branched RNA secondary structure allows viruses to maximize the amount of encapsulated genome and make assembly more efficient, allowing viral RNAs to out-compete cellular RNAs during replication in infected host cells.
Soon after the discovery that viruses cause human disease, started the idea of using viruses to treat cancer. After the initial indiscriminate use, crude preparations of each novel virus in the early twentieth century, a second wave of virotherapy blossomed in the 60s with purified and selected viruses. Responses were rare and short-lived. Immune rejection of the oncolytic viruses was identified as the major problem and virotherapy was abandoned. During the past two decades virotherapy has re-emerged with engineered viruses, with a trend towards using them as tumor-debulking immunostimulatory agents combined with radio or chemotherapy. Currently, oncolytic Reovirus, Herpes, and Vaccinia virus are in late phase clinical trials. Despite the renewed hope, efficacy will require improving systemic tumor targeting, overcoming stroma barriers for virus spread, and selectively stimulating immune responses against tumor antigens but not against the virus. Virotherapy history, viruses, considerations for clinical trials, and hurdles are briefly overviewed.
Liu, Ye V.; Massare, Michael J.; Barnard, Dale L.; Kort, Thomas; Nathan, Margret; Wang, Lei; Smith, Gale
SARS-CoV was the cause of the global pandemic in 2003 that infected over 8000 people in 8 months. Vaccines against SARS are still not available. We developed a novel method to produce high levels of a recombinant SARS virus-like particles (VLPs) vaccine containing the SARS spike (S) protein and the influenza M1 protein using the baculovirus insect cell expression system. These chimeric SARS VLPs have a similar size and morphology to the wild type SARS-CoV. We tested the immunogenicity and protective efficacy of purified chimeric SARS VLPs and full length SARS S protein vaccines in a mouse lethal challenge model. The SARS VLP vaccine, containing 0.8 μg of SARS S protein, completely protected mice from death when administered intramuscular (IM) or intranasal (IN) routes in the absence of an adjuvant. Likewise, the SARS VLP vaccine, containing 4 μg of S protein without adjuvant, reduced lung virus titer to below detectable level, protected mice from weight loss, and elicited a high level of neutralizing antibodies against SARS-CoV. Sf9 cell-produced full length purified SARS S protein was also an effective vaccine against SARS-CoV but only when co-administered IM with aluminum hydroxide. SARS-CoV VLPs are highly immunogenic and induce neutralizing antibodies and provide protection against lethal challenge. Sf9 cell-based VLP vaccines are a potential tool to provide protection against novel pandemic agents. PMID:21762752
Srivastava, Ruchi; Khan, Arif A; Chilukuri, Sravya; Syed, Sabrina A; Tran, Tien T; Furness, Julie; Bahraoui, Elmostafa; BenMohamed, Lbachir
Herpes simplex virus 1 (HSV-1) establishes latency within the sensory neurons of the trigeminal ganglia (TG). HSV-specific memory CD8 + T cells play a critical role in preventing HSV-1 reactivation from TG and subsequent virus shedding in tears that trigger recurrent corneal herpetic disease. The CXC chemokine ligand 10 (CXCL10)/CXC chemokine receptor 3 (CXCR3) chemokine pathway promotes T cell immunity to many viral pathogens, but its importance in CD8 + T cell immunity to recurrent herpes has been poorly elucidated. In this study, we determined how the CXCL10/CXCR3 pathway affects TG- and cornea-resident CD8 + T cell responses to recurrent ocular herpesvirus infection and disease using a well-established murine model in which HSV-1 reactivation was induced from latently infected TG by UV-B light. Following UV-B-induced HSV-1 reactivation, a significant increase in both the number and function of HSV-specific CXCR3 + CD8 + T cells was detected in TG and corneas of protected C57BL/6 (B6) mice, but not in TG and corneas of nonprotected CXCL10 -/- or CXCR3 -/- deficient mice. This increase was associated with a significant reduction in both virus shedding and recurrent corneal herpetic disease. Furthermore, delivery of exogenous CXCL10 chemokine in TG of CXCL10 -/- mice, using the neurotropic adeno-associated virus type 8 (AAV8) vector, boosted the number and function of effector memory CD8 + T cells (T EM ) and tissue-resident memory CD8 + T cells (T RM ), but not of central memory CD8 + T cells (T CM ), locally within TG, and improved protection against recurrent herpesvirus infection and disease in CXCL10 -/- deficient mice. These findings demonstrate that the CXCL10/CXCR3 chemokine pathway is critical in shaping CD8 + T cell immunity, locally within latently infected tissues, which protects against recurrent herpesvirus infection and disease. IMPORTANCE We determined how the CXCL10/CXCR3 pathway affects CD8 + T cell responses to recurrent ocular herpesvirus
Full Text Available Abstract Background There is an increasing number of complete and incomplete virus genome sequences available in public databases. This large body of sequence data harbors information about epidemiology, phylogeny, and virulence. Several specialized databases, such as the NCBI Influenza Virus Resource or the Los Alamos HIV database, offer sophisticated query interfaces along with integrated exploratory data analysis tools for individual virus species to facilitate extracting this information. Thus far, there has not been a comprehensive database for dengue virus, a significant public health threat. Results We have created an integrated web resource for dengue virus. The technology developed for the NCBI Influenza Virus Resource has been extended to process non-segmented dengue virus genomes. In order to allow efficient processing of the dengue genome, which is large in comparison with individual influenza segments, we developed an offline pre-alignment procedure which generates a multiple sequence alignment of all dengue sequences. The pre-calculated alignment is then used to rapidly create alignments of sequence subsets in response to user queries. This improvement in technology will also facilitate the incorporation of additional virus species in the future. The set of virus-specific databases at NCBI, which will be referred to as Virus Variation Resources (VVR, allow users to build complex queries against virus-specific databases and then apply exploratory data analysis tools to the results. The metadata is automatically collected where possible, and extended with data extracted from the literature. Conclusion The NCBI Dengue Virus Resource integrates dengue sequence information with relevant metadata (sample collection time and location, disease severity, serotype, sequenced genome region and facilitates retrieval and preliminary analysis of dengue sequences using integrated web analysis and visualization tools.
Full Text Available Virus Hanta kurang infeksius, kecuali di dalam lingkungan tertentu. Lamanya waktu virus ini dapat bertahan di lingkungan, setelah keluar dari tubuh tikus tidaklah diketahui secara pasti. Tetapi percobaan laboratorium menunjukkan bahwa, daya infektifitasnya tidak dijumpai setelah dua hari pengeringan. Genus hanta virus terdiri dari 22 spesies virus, dapat menyebabkan hemorrhagic fever with renal syndrome (HFRS dan hanta virus pulmonary syndrome (HPS.
Oct 15, 2008 ... Recent studies on the isolation of HEV-like viruses from animal species also suggest zoonotic transfer of the virus. The absence of small animal models of infection and efficient cell culture systems has precluded virological studies on the replication cycle and pathogenesis of HEV. A vaccine against HEV ...
E.G.J. Hulskotte (Ellen); M.E.M. Dings (Marlinda); S.G. Norley (Stephen); A.D.M.E. Osterhaus (Albert)
textabstractThe efficiency of paraformaldehyde (PFA) and binary ethylenimine (BEI) in inactivating recombinant vaccinia virus (rVV), present in baby hamster kidney cells expressing simian immunodeficiency virus envelope glycoproteins (SIV-Env), was measured in a series of inactivation studies. Both
Hong, Zheng-Yuan; Lv, Cheng; Liu, An-An; Liu, Shu-Lin; Sun, En-Ze; Zhang, Zhi-Ling; Lei, Ai-Wen; Pang, Dai-Wen
Real-time tracking of fluorophore-tagged viruses in living cells can help uncover virus infection mechanisms. Certainly, the indispensable prerequisite for virus-tracking is to label viruses with some bright and photostable beacons such as quantum dots (QDs) via an appropriate labeling strategy. Herein, we devise a convenient hydrazine-aldehyde based strategy to label viruses with QDs through the conjugation of 4-formylbenzoate (4FB) modified QDs to 6-hydrazinonicotinate acetone hydrazone (HyNic) modified viruses under mild conditions. On the basis of this strategy, viruses can be successfully labeled with QDs with high selectivity, stable conjugation, good reproducibility, high labeling efficiency of 92-93% and maximum retention of both fluorescence properties of QDs and infectivity of viruses, which is very meaningful to tracking and statistical analysis of virus infection processes. By further comparing with the most widely used labeling strategy based on the Biotin-SA system, this new strategy has advantages of both high labeling efficiency and good retention of virus infectivity, thus offering a promising alternative for virus-labeling. Moreover, due to the ubiquitous presence of exposed amino groups on the surface of various viruses, this selective, efficient, reproducible and biofriendly strategy should have good universality for labeling both enveloped and nonenveloped viruses.
Andersen, Rikke Sand; Vedsted, Peter
on institutional logics, we illustrate how a logic of efficiency organise and give shape to healthcare seeking practices as they manifest in local clinical settings. Overall, patient concerns are reconfigured to fit the local clinical setting and healthcare professionals and patients are required to juggle...... efficiency in order to deal with uncertainties and meet more complex or unpredictable needs. Lastly, building on the empirical case of cancer diagnostics, we discuss the implications of the pervasiveness of the logic of efficiency in the clinical setting and argue that provision of medical care in today......'s primary care settings requires careful balancing of increasing demands of efficiency, greater complexity of biomedical knowledge and consideration for individual patient needs....
Iversen, Astrid K N; Stewart-Jones, Guillaume; Learn, Gerald H
variant(s) prevailed in the virus population. The pathways notably influenced the amount of plasma virus, as patients with efficient CTL selection had lower plasma viral loads than did patients without efficient selection. Thus, viral escape from CTL responses does not necessarily correlate with disease......Cytotoxic T lymphocytes (CTLs) are critical for the control of human immunodeficiency virus, but containment of virus replication can be undermined by mutations in CTL epitopes that lead to virus escape. We analyzed the evolution in vivo of an immunodominant, HLA-A2-restricted CTL epitope and found...
Schmidt, Michael; Grot, Emmanuelle; Cervenka, Peter; Wainer, Sandra; Buck, Charles; Chiorini, John A
Adeno-associated viruses (AAVs) depend on a helper virus for efficient replication. To identify novel AAV isolates, we screened a diverse set of virus isolates for the presence of AAV DNA. AAVs found in 10 simian adenovirus isolates showed greater than 96% homology to AAV1 and AAV6 but had distinct biological properties. Two representatives of this group, AAV(VR-195) and AAV(VR-355), were studied in more detail. While the novel AAVs had high sequence homologies and required sialic acid for cell binding and transduction, differences were observed in lectin competition, resulting in distinct tropisms in human cancer cell lines.
Schmidt, Michael; Grot, Emmanuelle; Cervenka, Peter; Wainer, Sandra; Buck, Charles; Chiorini, John A.
Adeno-associated viruses (AAVs) depend on a helper virus for efficient replication. To identify novel AAV isolates, we screened a diverse set of virus isolates for the presence of AAV DNA. AAVs found in 10 simian adenovirus isolates showed greater than 96% homology to AAV1 and AAV6 but had distinct biological properties. Two representatives of this group, AAV(VR-195) and AAV(VR-355), were studied in more detail. While the novel AAVs had high sequence homologies and required sialic acid for ce...
Marschang, Rachel E.
A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions. PMID:22163336
Rachel E. Marschang
Full Text Available A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch’s postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.
Marschang, Rachel E
A large number of viruses have been described in many different reptiles. These viruses include arboviruses that primarily infect mammals or birds as well as viruses that are specific for reptiles. Interest in arboviruses infecting reptiles has mainly focused on the role reptiles may play in the epidemiology of these viruses, especially over winter. Interest in reptile specific viruses has concentrated on both their importance for reptile medicine as well as virus taxonomy and evolution. The impact of many viral infections on reptile health is not known. Koch's postulates have only been fulfilled for a limited number of reptilian viruses. As diagnostic testing becomes more sensitive, multiple infections with various viruses and other infectious agents are also being detected. In most cases the interactions between these different agents are not known. This review provides an update on viruses described in reptiles, the animal species in which they have been detected, and what is known about their taxonomic positions.
Scull, Margaret A; Gillim-Ross, Laura; Santos, Celia; Roberts, Kim L; Bordonali, Elena; Subbarao, Kanta; Barclay, Wendy S; Pickles, Raymond J
.... Using an in vitro model of human ciliated airway epithelium (HAE), we demonstrate that while human and avian influenza viruses efficiently infect at temperatures of the human distal airways (37 degrees C...
Evaluation of the suitability of a plant virus, pepper mild mottle virus, as a surrogate of human enteric viruses for assessment of the efficacy of coagulation-rapid sand filtration to remove those viruses.
Shirasaki, N; Matsushita, T; Matsui, Y; Yamashita, R
Here, we evaluated the removal of three representative human enteric viruses - adenovirus (AdV) type 40, coxsackievirus (CV) B5, and hepatitis A virus (HAV) IB - and one surrogate of human caliciviruses - murine norovirus (MNV) type 1 - by coagulation-rapid sand filtration, using water samples from eight water sources for drinking water treatment plants in Japan. The removal ratios of a plant virus (pepper mild mottle virus; PMMoV) and two bacteriophages (MS2 and φX174) were compared with the removal ratios of human enteric viruses to assess the suitability of PMMoV, MS2, and φX174 as surrogates for human enteric viruses. The removal ratios of AdV, CV, HAV, and MNV, evaluated via the real-time polymerase chain reaction (PCR) method, were 0.8-2.5-log10 when commercially available polyaluminum chloride (PACl, basicity 1.5) and virgin silica sand were used as the coagulant and filter medium, respectively. The type of coagulant affected the virus removal efficiency, but the age of silica sand used in the rapid sand filtration did not. Coagulation-rapid sand filtration with non-sulfated, high-basicity PACls (basicity 2.1 or 2.5) removed viruses more efficiently than the other aluminum-based coagulants. The removal ratios of MS2 were sometimes higher than those of the three human enteric viruses and MNV, whereas the removal ratios of φX174 tended to be smaller than those of the three human enteric viruses and MNV. In contrast, the removal ratios of PMMoV were similar to and strongly correlated with those of the three human enteric viruses and MNV. Thus, PMMoV appears to be a suitable surrogate for human enteric viruses for the assessment of the efficacy of coagulation-rapid sand filtration to remove viruses. Copyright © 2017 Elsevier Ltd. All rights reserved.
Miest, Tanner S; Cattaneo, Roberto
Early-stage clinical trials of oncolytic virotherapy have reported the safety of several virus platforms, and viruses from three families have progressed to advanced efficacy trials. In addition, preclinical studies have established proof-of-principle for many new genetic engineering strategies. Thus, the virotherapy field now has available a diverse collection of viruses that are equipped to address unmet clinical needs owing to improved systemic administration, greater tumour specificity and enhanced oncolytic efficacy. The current key challenge for the field is to develop viruses that replicate with greater efficiency within tumours while achieving therapeutic synergy with currently available treatments.
... education Fact Sheet PFS005: Testing for Human Immunodeficiency Virus AUGUST 2015 • Reasons for Getting Tested • Who Should ... For More Information • Glossary Testing for Human Immunodeficiency Virus Human immunodeficiency virus (HIV) is the virus that ...
Full Text Available Of 168 patients with chronic hepatitis B virus (HBV infection-related liver disease, 20 patients who had received 100 mg of lamivudine plus 10 mg/day of adefovir dipivoxil (ADV (ADV group and 124 patients who had received 0.5 mg/day of entecavir or 100 mg/day of lamivudine (non-ADV group for >1 year were enrolled. For comparative analyses, 19 well-matched pairs were obtained from the groups by propensity scores. At the time of enrollment, serum creatinine and phosphate concentrations were similar between the ADV and non-ADV groups; however, urinary phosphate ( and serum bone-specific alkaline phosphatase (BAP ( concentrations were significantly higher in the ADV group than in the non-ADV group. Serum BAP was significantly higher at the time of enrollment than before ADV administration in the ADV group (, although there was no significant change in serum BAP concentration in the non-ADV group. There was a significant positive correlation between the period of ADV therapy and ΔBAP (, . Serum BAP concentration increased before increase in serum creatinine concentration and was useful for early detection of adverse events and for developing adequate measures for continuing ADV for chronic HBV infection-related liver disease.
Schwickerath, U; Uria, C; CERN. Geneva. IT Department
A frequent source of concern for resource providers is the efficient use of computing resources in their centers. This has a direct impact on requests for new resources. There are two different but strongly correlated aspects to be considered: while users are mostly interested in a good turn-around time for their jobs, resource providers are mostly interested in a high and efficient usage of their available resources. Both things, the box usage and the efficiency of individual user jobs, need to be closely monitored so that the sources of the inefficiencies can be identified. At CERN, the Lemon monitoring system is used for both purposes. Examples of such sources are poorly written user code, inefficient access to mass storage systems, and dedication of resources to specific user groups. As a first step for improvements CERN has launched a project to develop a scheduler add-on that allows careful overloading of worker nodes that run idle jobs.
Sogni, Philippe; Gilbert, Camille; Lacombe, Karine; Piroth, Lionel; Rosenthal, Eric; Miailhes, Patrick; Gervais, Anne; Esterle, Laure; Chas, Julie; Poizot-Martin, Isabelle; Dominguez, Stéphanie; Simon, Anne; Morlat, Philippe; Neau, Didier; Zucman, David; Bouchaud, Olivier; Lascoux-Combe, Caroline; Bani-Sadr, Firouzé; Alric, Laurent; Goujard, Cécile; Vittecoq, Daniel; Billaud, Eric; Aumaître, Hugues; Boué, François; Valantin, Marc-Antoine; Dabis, François; Salmon, Dominique; Wittkop, Linda
Human immunodeficiency virus (HIV)/hepatitis C virus (HCV)-coinfected patients with cirrhosis have long been considered to be difficult to treat, and real-life efficacy and tolerance data with all-oral direct-acting antiviral (DAA) combinations in these patients are scarce. Cirrhotic HIV/HCV-coinfected patients enrolled in the French National Agency for Research on AIDS and Viral Hepatitis (ANRS) CO13 HEPAVIH cohort initiating an all-oral DAA regimen were consecutively included. A negative HCV RNA result at 12 weeks of follow-up or thereafter was assumed as a sustained virologic response (SVR12). Adjusted exact logistic regression was used to study factors associated with treatment outcome. We included 189 patients who initiated an all-oral DAA regimen with the following characteristics: median age 53.2 years; 74.6% male; Centers for Disease Control and Prevention classification A/B/C: 37%/31%/32%; Child-Pugh class A/B/C: 91%/8%/1%; 87% with HIV RNA <50 copies/mL; 99% on antiretrovirals; median CD4 count: 489 cells/µL; HCV treatment naive 29%; HCV genotype 1/2/3/4: 58%/4%/17%/21%. Sofosbuvir (SOF) + daclatasvir ± ribavirin (RBV) was used in 123 patients, SOF + RBV in 30, SOF + simeprevir in 11, and SOF + ledipasvir in 23. An SVR12 was reported in 93.1% of the patients (95% confidence interval, 88.5%-96.3%). In adjusted analyses, no difference was found between 12 or 24 weeks of treatment, in patients receiving RBV or not, and in treatment-naive vs experienced patients. Premature stop of DAA was reported for 8 patients. One patient died during treatment (unknown cause), and 12 other patients developed liver-related events. In this prospective real-life cohort, all-oral DAA regimens were well tolerated and associated with a high virologic efficacy in cirrhotic HIV/HCV-coinfected patients. This should not alleviate the surveillance for liver-related events in these patients. © The Author 2016. Published by Oxford University Press for the Infectious Diseases Society
Song, A; You, Y; Chen, F; Li, P; Jiang, J; Chen, S
Chrysanthemum plants are subject to serious virus diseases, so detection and identification of virus pathogens is important to prevent the virus spread. A reliable one-step multiplex RT-PCR was developed to simultaneously detect two viruses and two viriods: chrysanthemum virus B, tomato Aspermy virus, chrysanthemum stunt viroid and chrysanthemum chlorotic mottle viroid. In addition, we investigated the detection limit and the efficiency of single and multiplex RT-PCR assays. The results showed that the multiplex RT-PCR assay proved to be as sensitive as the single one. In conclusion, this technique is potentially useful in routine diagnosis of chrysanthemum viruses and viroids. The multiplex RT-PCR assay described in this study is the first report of simultaneous detection of virus and viroid in chrysanthemum, which provides a fast, convenient, cost-saving way to detect the virus and viroid mixed infections in plants. © 2012 The Society for Applied Microbiology.
Chesnais, Quentin; Couty, Aude; Uzest, Maryline; Brault, Véronique; Ameline, Arnaud
Insect-vectored plant viruses can induce changes in plant phenotypes, thus influencing plant-vector interactions in a way that may promote their dispersal according to their mode of transmission (i.e., circulative vs. noncirculative). This indirect vector manipulation requires host-virus-vector coevolution and would thus be effective solely in very specific plant-virus-vector species associations. Some studies suggest this manipulation may depend on multiple factors relative to various intrinsic characteristics of vectors such as transmission efficiency. In anintegrative study, we tested the effects of infection of the Brassicaceae Camelina sativa with the noncirculative Cauliflower mosaic virus (CaMV) or the circulative Turnip yellows virus (TuYV) on the host-plant colonization of two aphid species differing in their virus transmission efficiency: the polyphagous Myzus persicae, efficient vector of both viruses, and the Brassicaceae specialist Brevicoryne brassicae, poor vector of TuYV and efficient vector of CaMV. Results confirmed the important role of virus mode of transmission as plant-mediated effects of CaMV on the two aphid species induced negative alterations of feeding behavior (i.e., decreased phloem sap ingestion) and performance that were both conducive for virus fitness by promoting dispersion after a rapid acquisition. In addition, virus transmission efficiency may also play a role in vector manipulation by viruses as only the responses of the efficient vector to plant-mediated effects of TuYV, that is, enhanced feeding behavior and performances, were favorable to their acquisition and further dispersal. Altogether, this work demonstrated that vector transmission efficiency also has to be considered when studying the mechanisms underlying vector manipulation by viruses. Our results also reinforce the idea that vector manipulation requires coevolution between plant, virus and vector. © 2017 Institute of Zoology, Chinese Academy of Sciences.
Erdemci-Tandogan, Gonca; Wagner, Jef; Van Der Schoot, Paul; Podgornik, Rudolf; Zandi, Roya
Simple RNA viruses efficiently encapsulate their genome into a nano-sized protein shell: the capsid. Spontaneous coassembly of the genome and the capsid proteins is driven predominantly by electrostatic interactions between the negatively charged RNA and the positively charged inner capsid wall.
Claire E Stewart
Full Text Available Virus replication efficiency is influenced by two conflicting factors, kinetics of the cellular interferon (IFN response and induction of an antiviral state versus speed of virus replication and virus-induced inhibition of the IFN response. Disablement of a virus's capacity to circumvent the IFN response enables both basic research and various practical applications. However, such IFN-sensitive viruses can be difficult to grow to high-titer in cells that produce and respond to IFN. The current default option for growing IFN-sensitive viruses is restricted to a limited selection of cell-lines (e.g. Vero cells that have lost their ability to produce IFN. This study demonstrates that supplementing tissue-culture medium with an IFN inhibitor provides a simple, effective and flexible approach to increase the growth of IFN-sensitive viruses in a cell-line of choice. We report that IFN inhibitors targeting components of the IFN response (TBK1, IKK2, JAK1 significantly increased virus replication. More specifically, the JAK1/2 inhibitor Ruxolitinib enhances the growth of viruses that are sensitive to IFN due to (i loss of function of the viral IFN antagonist (due to mutation or species-specific constraints or (ii mutations/host cell constraints that slow virus spread such that it can be controlled by the IFN response. This was demonstrated for a variety of viruses, including, viruses with disabled IFN antagonists that represent live-attenuated vaccine candidates (Respiratory Syncytial Virus (RSV, Influenza Virus, traditionally attenuated vaccine strains (Measles, Mumps and a slow-growing wild-type virus (RSV. In conclusion, supplementing tissue culture-medium with an IFN inhibitor to increase the growth of IFN-sensitive viruses in a cell-line of choice represents an approach, which is broadly applicable to research investigating the importance of the IFN response in controlling virus infections and has utility in a number of practical applications
First page Back Continue Last page Overview Graphics. VIRUS FAMILIES – contd. Minus strand RNA viruses. Rhabdovirus e.g. rabies. Paramyxovirus e.g. measles, mumps. Orthomyxovirus e.g. influenza. Retroviruses. RSV, HTLV, MMTV, HIV. Notes:
... Fact files Questions & answers Features Multimedia Contacts Zika virus Fact sheet Updated 6 September 2016 Key facts ... last for 2-7 days. Complications of Zika virus disease Based on a systematic review of the ...
Johnson, John E.
We use two techniques to look at three-dimensional virus structure: electron cryomicroscopy (cryoEM) and X-ray crystallography. Figure 1 is a gallery of virus particles whose structures Timothy Baker, one of my former colleagues at Purdue University, used cryoEM to determine. It illustrates the variety of sizes of icosahedral virus particles. The largest virus particle on this slide is the Herpes simplex virus, around 1200Å in diameter; the smallest we examined was around 250Å in diameter. Viruses bear their genomic information either as positive-sense DNA and RNA, double-strand DNA, double-strand RNA, or negative-strand RNA. Viruses utilize the various structure and function "tactics" seen throughout cell biology to replicate at high levels. Many of the biological principles that we consider general were in fact discovered in the context of viruses ...
RSV; Palivizumab; Respiratory syncytial virus immune globulin; Bronchiolitis - RSV ... Crowe JE. Respiratory syncytial virus. In: Kliegman RM, Stanton BF, St Geme JW, Schor NF, eds. Nelson Textbook of Pediatrics . 20th ...
... sheets Fact files Questions & answers Features Multimedia Contacts Zika virus Fact sheet Updated 6 September 2016 Key facts ... and last for 2-7 days. Complications of Zika virus disease Based on a systematic review of the ...
... Are Here: Home → Multiple Languages → All Health Topics → Zika Virus URL of this page: https://medlineplus.gov/languages/ ... V W XYZ List of All Topics All Zika Virus - Multiple Languages To use the sharing features on ...
Lawson, James S., E-mail: firstname.lastname@example.org; Heng, Benjamin [School of Biotechnology and Biomolecular Sciences, University of New South Wales, Sydney (Australia)
Viruses are the accepted cause of many important cancers including cancers of the cervix and anogenital area, the liver, some lymphomas, head and neck cancers and indirectly human immunodeficiency virus associated cancers. For over 50 years, there have been serious attempts to identify viruses which may have a role in breast cancer. Despite these efforts, the establishment of conclusive evidence for such a role has been elusive. However, the development of extremely sophisticated new experimental techniques has allowed the recent development of evidence that human papilloma virus, Epstein-Barr virus, mouse mammary tumor virus and bovine leukemia virus may each have a role in the causation of human breast cancers. This is potentially good news as effective vaccines are already available to prevent infections from carcinogenic strains of human papilloma virus, which causes cancer of the uterine cervix.
West Nile virus (WNV) is an infectious disease that first appeared in the United States in 1999. Infected mosquitoes ... and usually go away on their own. If West Nile virus enters the brain, however, it can be life- ...
Full Text Available ... My ACOG ACOG Departments Donate Shop Career Connection Home Clinical Guidance & Publications Practice Management Education & Events Advocacy For Patients About ACOG Zika Virus and Pregnancy Home For Patients Zika Virus and Pregnancy Page Navigation ▼ ...
Full Text Available ... Resources & Publications Practice Management Education & Events Advocacy For Patients About ACOG Zika Virus and Pregnancy Home For Patients Zika Virus and Pregnancy Page Navigation ▼ ACOG Pregnancy ...
Full Text Available ... My ACOG ACOG Departments Donate Shop Career Connection Home Resources & Publications Practice Management Education & Events Advocacy For Patients About ACOG Zika Virus and Pregnancy Home For Patients Zika Virus and Pregnancy Page Navigation ▼ ...
Otrashevskaia, E V; Kulak, M V; Otrashevskaia, A V; Karpov, I A; Fisenko, E G; Ignat'ev, G M
In this work we report the mumps vaccine virus shedding based on the laboratory confirmed cases of the mumps virus (MuV) infection. The likely epidemiological sources of the transmitted mumps virus were children who were recently vaccinated with the mumps vaccine containing Leningrad-Zagreb or Leningrad-3 MuV. The etiology of the described cases of the horizontal transmission of both mumps vaccine viruses was confirmed by PCR with the sequential restriction analysis.
Melcher, Ulrich; Muthukumar, Vijay; Wiley, Graham B; Min, Byoung Eun; Palmer, Michael W; Verchot-Lubicz, Jeanmarie; Ali, Akhtar; Nelson, Richard S; Roe, Bruce A; Thapa, Vaskar; Pierce, Margaret L
To test the hypothesis that many viruses remain to be discovered in plants, a procedure was developed to sequence nucleic acids cloned randomly from virus-like particle fractions of plant homogenates. As a test of the efficiency of the procedure we targeted Ambrosia psilostachya, western ragweed, plants growing at the Tallgrass Prairie Preserve of northeastern Oklahoma. Amplifiable nucleic acid was found in the fractions from six of twelve specimens and sequences were characterized from four of them. Evidence was obtained for the presence of viruses belonging to two families (Caulimoviridae, Flexiviridae). Multiple viral species were found in two of the four specimens and their level within the isolated nucleic acid population varied from less than 1-37%. None of the sequences were derived from reported sequences of known viruses. Thus, the analysis of nucleic acid from virus-like particles is a useful tool to expand our knowledge of the universe of viruses to non-cultivated species.
M D, Baron; B, Holzer
Nairobi sheep disease virus (NSDV) is a tick-borne virus which causes a severe disease in sheep and goats, and has been responsible for several outbreaks of disease in East Africa. The virus is also found in the Indian subcontinent, where it is known as Ganjam virus. The virus only spreads through the feeding of competent infected ticks, and is therefore limited in its geographic distribution by the distribution of those ticks, Rhipicephalus appendiculata in Africa and Haemaphysalis intermedia in India. Animals bred in endemic areas do not normally develop disease, and the impact is therefore primarily on animals being moved for trade or breeding purposes. The disease caused by NSDV has similarities to several other ruminant diseases, and laboratory diagnosis is necessary for confirmation. There are published methods for diagnosis based on polymerase chain reaction, for virus growth in cell culture and for other simple diagnostic tests, though none has been commercialised. There is no established vaccine against NSDV, although cell-culture attenuated strains have been developed which show promise and could be put into field trials if it were deemed necessary. The virus is closely related to Crimean-Congo haemorrhagic fever virus, and studies on NSDV may therefore be useful in understanding this important human pathogen.
Surveillance of respiratory viruses. A 10-year laboratory-based study. J. M. McAnerney, S. Johnson, B. D. Schoub. Respiratory virus isolates made at the National Institute for. Virology from 1982 to 1991 were studied. An active virus surveillance programme, 'viral watch', which recruits throat swab specimens from a network ...
First page Back Continue Last page Graphics. Characteristic of pandemic virus. The virus was highly transmissible. Risk of hospitalization was 2X and risk of death was about 11X more in comparison to seasonal influenza. Virus continues to be susceptible to Osaltamivir, the only drug available. Vaccines are available but ...
Simmonds, Peter; Becher, Paul; Bukh, Jens
borne, and many are important human and veterinary pathogens (e.g. yellow fever virus, dengue virus). This is a summary of the current International Committee on Taxonomy of Viruses (ICTV) report on the taxonomy of the Flaviviridae, which is available at www.ictv.global/report/flaviviridae....
Rajala, Judith B.
A computer virus is a program--a piece of executable code--that has the unique ability to replicate. Like biological viruses, computer viruses can spread quickly and are often difficult to eradicate. They can attach themselves to just about any type of file, and are spread by replicating and being sent from one individual to another. Simply having…
Donchenko, E. K.; Karpova, O. V.; Kudryavtseva, A. D.; Pershin, S. M.; Savichev, V. I.; Strokov, M. A.; Tcherniega, N. V.; Zemskov, K. I.
The study deals with laser pulse interaction with plant viruses: we investigated tobacco mosaic virus (TMV) and two types of potato viruses (PVX and PVA) in Tris-HCl pH7.5 buffer and in water. We used 20 ns ruby laser pulses for excitation. We employed Fabry–Pérot interferometers to record spectra of the light passing through the sample and reflected from it. For TMV and PVX in Tris-HCl pH7.5 buffer, same as for PVA in water, we observed additional spectral lines corresponding to the stimulated low-frequency Raman scattering (SLFRS). We believe we were the first to measure SLFRS frequency shifts, conversion efficiency and threshold. High conversion efficiency of the scattered light is evidence of laser pulses efficiently exciting gigahertz vibrations in viruses. SLFRS can be used to identify and affect biological nanoparticles.
Smit, Gerardus Johannes Maria
In this extended abstract the need for efficient and reliable ICT is discussed. Efficiency of ICT not only deals with energy-efficient ICT hardware, but also deals with efficient algorithms, efficient design methods, efficient networking infrastructures, etc. Efficient and reliable ICT is a
Pan, Maohua; Bonny, Tania S; Loeb, Julia; Jiang, Xiao; Lednicky, John A; Eiguren-Fernandez, Arantzazu; Hering, Susanne; Fan, Z Hugh; Wu, Chang-Yu
The dynamics and significance of aerosol transmission of respiratory viruses are still controversial, for the major reasons that virus aerosols are inefficiently collected by commonly used air samplers and that the collected viruses are inactivated by the collection method. Without knowledge of virus viability, infection risk analyses lack accuracy. This pilot study was performed to (i) determine whether infectious (viable) respiratory viruses in aerosols could be collected from air in a real world environment by the viable virus aerosol sampler (VIVAS), (ii) compare and contrast the efficacy of the standard bioaerosol sampler, the BioSampler, with that of the VIVAS for the collection of airborne viruses in a real world environment, and (iii) gain insights for the use of the VIVAS for respiratory virus sampling. The VIVAS operates via a water vapor condensation process to enlarge aerosolized virus particles to facilitate their capture. A variety of viable human respiratory viruses, including influenza A H1N1 and H3N2 viruses and influenza B viruses, were collected by the VIVAS located at least 2 m from seated patients, during a late-onset 2016 influenza virus outbreak. Whereas the BioSampler when operated following our optimized parameters also collected virus aerosols, it was nevertheless overall less successful based on a lower frequency of virus isolation in most cases. This side-by-side comparison highlights some limitations of past studies based on impingement-based sampling, which may have generated false-negative results due to either poor collection efficiency and/or virus inactivation due to the collection process. IMPORTANCE The significance of virus aerosols in the natural transmission of respiratory diseases has been a contentious issue, primarily because it is difficult to collect or sample virus aerosols using currently available air sampling devices. We tested a new air sampler based on water vapor condensation for efficient sampling of viable
At least six viruses have been found in highbush blueberry plantings in the Pacific Northwest: Blueberry mosaic virus, Blueberry red ringspot virus, Blueberry scorch virus, Blueberry shock virus, Tobacco ringspot virus, and Tomato ringspot virus. Six other virus and virus-like diseases of highbush b...
Vonnemann, Jonathan; Sieben, Christian; Wolff, Christopher; Ludwig, Kai; Böttcher, Christoph; Herrmann, Andreas; Haag, Rainer
The development of antiviral agents is one of the major challenges in medical science. So far, small monovalent molecular drugs that inhibit the late steps in the viral replication cycle, i.e., virus budding, have not worked well which emphasizes the need for alternative approaches. Polyvalently presented viral receptors, however, show potential as good inhibitors of virus-cell binding, which is the first step in the viral infection cycle. By gradually increasing the size of ligand functionalized gold nanoparticles, up to virus-like dimensions, we are now able to quantify the polyvalent enhancement of virus-cell binding inhibition and to identify varying mechanisms of virus inhibition with different efficacies: by employing a new binding assay we found that surface area-normalized polysulfated gold nanoparticles of diameters equal to and larger than the virus diameter (>50 nm) more efficiently inhibit the binding of vesicular stomatitis virus (VSV) to cells than smaller particles. On a per particle basis, larger sized gold nanoparticles were surprisingly shown to inhibit the viral infection up to two orders of magnitude more efficiently than smaller particles, which suggests different mechanisms of virus inhibition. Based on complementary electron microscopic data, we noticed that larger gold nanoparticles act as efficient cross-linkers between virions, whereas smaller gold nanoparticles decorate the surface of individual virus particles. Our systematic study accentuates the need for the design of biodegradable, virus-sized inhibitors capitalizing on polyvalent binding.The development of antiviral agents is one of the major challenges in medical science. So far, small monovalent molecular drugs that inhibit the late steps in the viral replication cycle, i.e., virus budding, have not worked well which emphasizes the need for alternative approaches. Polyvalently presented viral receptors, however, show potential as good inhibitors of virus-cell binding, which is the
Miyaho, Rie Nakaoka; Nakagawa, So; Hashimoto-Gotoh, Akira; Nakaya, Yuki; Shimode, Sayumi; Sakaguchi, Shoichi; Yoshikawa, Rokusuke; Takahashi, Mahoko Ueda; Miyazawa, Takayuki
Retroviral vectors are used for gene transduction into cells and have been applied to gene therapy. Retroviral vectors using envelope protein (Env) of RD-114 virus, a feline endogenous retrovirus, have been used for gene transduction. In this study, we investigated the susceptibility to RD-114 Env-pseudotyped virus in twelve domestic animals including cattle, sheep, horse, pig, dog, cat, ferret, mink, rabbit, rat, mouse, and quail. Comparison of nucleotide sequences of ASCT2 (SLC1A5), a receptor of RD-114 virus, in 10 mammalian and 2 avian species revealed that insertion and deletion events at the region C of ASCT2 where RD-114 viral Env interacts occurred independently in the mouse and rat lineage and in the chicken and quail lineage. By the pseudotype virus infection assay, we found that RD-114 Env-pseudotyped virus could efficiently infect all cell lines except those from mouse and rat. Furthermore, we confirmed that bovine ASCT2 (bASCT2) functions as a receptor for RD-114 virus infection. We also investigated bASCT2 mRNA expression in cattle tissues and found that it is expressed in various tissues including lung, spleen and kidney. These results indicate that retrovirus vectors with RD-114 virus Env can be used for gene therapy in large domestic animals in addition to companion animals such as cat and dog. Copyright © 2015 Elsevier B.V. All rights reserved.
Full Text Available Japanese encephalitis virus (JEV is among the major threats to public health in Asia. For disease control and prevention, the efficient production of safe and effective vaccines against JEV is in urgent need. In this study, we produced a plant-made JEV vaccine candidate using a chimeric virus particle (CVP strategy based on bamboo mosaic virus (BaMV for epitope presentation. The chimeric virus, designated BJ2A, was constructed by fusing JEV envelope protein domain III (EDIII at the N-terminus of BaMV coat protein, with an insertion of the foot-and-mouth disease virus 2A peptide to facilitate the production of both unfused and epitope-presenting for efficient assembly of the CVP vaccine candidate. The strategy allowed stable maintenance of the fusion construct over long-term serial passages in plants. Immuno-electron microscopy examination and immunization assays revealed that BJ2A is able to present the EDIII epitope on the surface of the CVPs, which stimulated effective neutralizing antibodies against JEV infection in mice. This study demonstrates the efficient production of an effective CVP vaccine candidate against JEV in plants by the BaMV-based epitope presentation system.
Chen, Tsung-Hsien; Hu, Chung-Chi; Liao, Jia-Teh; Lee, Yi-Ling; Huang, Ying-Wen; Lin, Na-Sheng; Lin, Yi-Ling; Hsu, Yau-Heiu
Japanese encephalitis virus (JEV) is among the major threats to public health in Asia. For disease control and prevention, the efficient production of safe and effective vaccines against JEV is in urgent need. In this study, we produced a plant-made JEV vaccine candidate using a chimeric virus particle (CVP) strategy based on bamboo mosaic virus (BaMV) for epitope presentation. The chimeric virus, designated BJ2A, was constructed by fusing JEV envelope protein domain III (EDIII) at the N-terminus of BaMV coat protein, with an insertion of the foot-and-mouth disease virus 2A peptide to facilitate the production of both unfused and epitope-presenting for efficient assembly of the CVP vaccine candidate. The strategy allowed stable maintenance of the fusion construct over long-term serial passages in plants. Immuno-electron microscopy examination and immunization assays revealed that BJ2A is able to present the EDIII epitope on the surface of the CVPs, which stimulated effective neutralizing antibodies against JEV infection in mice. This study demonstrates the efficient production of an effective CVP vaccine candidate against JEV in plants by the BaMV-based epitope presentation system.
Liu, Guang Bin; Zhao, Liang; Zhang, Lifang; Zhao, Kong-Nan
Prostate cancer (PCa), a disease, is characterized by abnormal cell growth in the prostate - a gland in the male reproductive system. Although older age and a family history of the disease have been recognized as the risk factors of PCa, the cause of this cancer remains unclear. Currently, PCa is one of the leading causes of cancer death among men of all races. In this review study, we first discuss the controversy of the contribution of virus infection to PCa, and subsequently summarize the development of oncolytic virotherapy for PCa in the past several years. Mounting evidence suggests that infections with various viruses are causally linked to PCa pathogenesis. Published studies have provided strong evidence that at least two viruses (RXMV and HPV) contribute to prostate tumourigenicity and impact on the survival of patients with malignant PCa. Traditional therapies including chemotherapy and radiotherapy are unable to distinguish cancer cells from normal cells, which are a significant drawback and leads to toxicities for PCa patients undergoing treatment. So far, few other options are available for treating patients with advanced PCa. For PCa treatment, oncolytic virotherapy appears to be much more attractive, which uses live viruses to selectively kill cancer cells. Oncolytic viruses can be genetically engineered to induce cancer cell lysis through virus replication and expression of cytotoxic proteins. Virotherapy is being developed to be a novel therapy for cancers, which uses oncotropic and oncolytic viruses with their abilities to find and destroy malignant cells in the body. As oncolytic viruses are a relatively new class of anti-cancer immunotherapy agents, several important barriers still exist on the road to the use of oncolytic viruses for PCa therapy. Copyright© Bentham Science Publishers; For any queries, please email at email@example.com.
Wong, Gary; Qiu, Xiangguo; Richardson, Jason S; Cutts, Todd; Collignon, Brad; Gren, Jason; Aviles, Jenna; Embury-Hyatt, Carissa; Kobinger, Gary P
Ebola virus (EBOV) transmission is currently poorly characterized and is thought to occur primarily by direct contact with infectious material; however transmission from swine to nonhuman primates via the respiratory tract has been documented. To establish an EBOV transmission model for performing studies with statistical significance, groups of six guinea pigs (gps) were challenged intranasally (i.n.) or intraperitoneally (i.p.) with 10,000 times the 50% lethal dose (LD50) of gp-adapted EBOV, and naive gps were then introduced as cage mates for contact exposure at 1 day postinfection (p.i.). The animals were monitored for survival and clinical signs of disease and quantitated for virus shedding postexposure. Changes in the duration of contact of naive gps with infected animals were evaluated for their impact on transmission efficiency. Transmission was more efficient from i.n.- than from i.p.-challenged gps, with 17% versus 83% of naive gps surviving exposure, respectively. Virus shedding was detected beginning at 3 days p.i. from both i.n.- and i.p.-challenged animals. Contact duration positively correlated with transmission efficiency, and the abrogation of direct contact between infected and naive animals through the erection of a steel mesh was effective at stopping virus spread, provided that infectious animal bedding was absent from the cages. Histopathological and immunohistochemical findings show that i.n.-infected gps display enhanced lung pathology and EBOV antigen in the trachea, which supports increased virus transmission from these animals. The results suggest that i.n.-challenged gps are more infectious to naive animals than their systemically infected counterparts and that transmission occurs through direct contact with infectious materials, including those transported through air movement over short distances. Ebola is generally thought to be spread between humans though infectious bodily fluids. However, a study has shown that Ebola can be spread
Verhaelen, Katharina; Bouwknegt, Martijn; Rutjes, Saskia; de Roda Husman, Ana Maria; Duizer, Erwin
Transmission of enteric and respiratory viruses, including human norovirus (hNoV) and human influenza virus, may involve surfaces. In food preparation and health care settings, surfaces are cleaned with wipes; however, wiping may not efficiently reduce contamination or may even spread viruses,
Lehtoranta, L; Pitkäranta, A; Korpela, R
Viral respiratory infections are the most common diseases in humans. A large range of etiologic agents challenge the development of efficient therapies. Research suggests that probiotics are able to decrease the risk or duration of respiratory infection symptoms. However, the antiviral mechanisms of probiotics are unclear. The purpose of this paper is to review the current knowledge on the effects of probiotics on respiratory virus infections and to provide insights on the possible antiviral mechanisms of probiotics. A PubMed and Scopus database search was performed up to January 2014 using appropriate search terms on probiotic and respiratory virus infections in cell models, in animal models, and in humans, and reviewed for their relevance. Altogether, thirty-three clinical trials were reviewed. The studies varied highly in study design, outcome measures, probiotics, dose, and matrices used. Twenty-eight trials reported that probiotics had beneficial effects in the outcome of respiratory tract infections (RTIs) and five showed no clear benefit. Only eight studies reported investigating viral etiology from the respiratory tract, and one of these reported a significant decrease in viral load. Based on experimental studies, probiotics may exert antiviral effects directly in probiotic-virus interaction or via stimulation of the immune system. Although probiotics seem to be beneficial in respiratory illnesses, the role of probiotics on specific viruses has not been investigated sufficiently. Due to the lack of confirmatory studies and varied data available, more randomized, double-blind, and placebo-controlled trials in different age populations investigating probiotic dose response, comparing probiotic strains/genera, and elucidating the antiviral effect mechanisms are necessary.
Prescott, Joseph; Bushmaker, Trenton; Fischer, Robert; Miazgowicz, Kerri; Judson, Seth; Munster, Vincent J
The ongoing Ebola virus outbreak in West Africa has highlighted questions regarding stability of the virus and detection of RNA from corpses. We used Ebola virus-infected macaques to model humans who died of Ebola virus disease. Viable virus was isolated <7 days posteuthanasia; viral RNA was detectable for 10 weeks.
Interim Report on SNP analysis and forensic microarray probe design for South American hemorrhagic fever viruses, tick-borne encephalitis virus, henipaviruses, Old World Arenaviruses, filoviruses, Crimean-Congo hemorrhagic fever viruses, Rift Valley fever
Jaing, C; Gardner, S
The goal of this project is to develop forensic genotyping assays for select agent viruses, enhancing the current capabilities for the viral bioforensics and law enforcement community. We used a multipronged approach combining bioinformatics analysis, PCR-enriched samples, microarrays and TaqMan assays to develop high resolution and cost effective genotyping methods for strain level forensic discrimination of viruses. We have leveraged substantial experience and efficiency gained through year 1 on software development, SNP discovery, TaqMan signature design and phylogenetic signature mapping to scale up the development of forensics signatures in year 2. In this report, we have summarized the whole genome wide SNP analysis and microarray probe design for forensics characterization of South American hemorrhagic fever viruses, tick-borne encephalitis viruses and henipaviruses, Old World Arenaviruses, filoviruses, Crimean-Congo hemorrhagic fever virus, Rift Valley fever virus and Japanese encephalitis virus.
Full Text Available Influenza A virus is a dreadful pathogen of animals and humans, causing widespread infection and severe morbidity and mortality. It is essential to characterize the influenza A virus-host interaction and develop efficient counter measures against the viral infection. Autophagy is known as a catabolic process for the recycling of the cytoplasmic macromolecules. Recently, it has been shown that autophagy is a critical mechanism underlying the interaction between influenza A virus and its host. Autophagy can be induced by the infection with influenza A virus, which is considered as a necessary process for the viral proliferation, including the accumulation of viral elements during the replication of influenza A virus. On the other hand, influenza A virus can inhibit the autophagic formation via interaction with the autophagy-related genes (Atg and signaling pathways. In addition, autophagy is involved in the influenza virus-regulated cell deaths, leading to significant changes in host apoptosis. Interestingly, the high pathogenic strains of influenza A virus, such as H5N1, stimulate autophagic cell death and appear to interplay with the autophagy in distinct ways as compared with low pathogenic strains. This review discusses the regulation of autophagy, an influenza A virus driven process.
Muharemagic, Darija; Zamay, Anna; Ghobadloo, Shahrokh M; Evgin, Laura; Savitskaya, Anna; Bell, John C; Berezovski, Maxim V
Oncolytic viruses promise to significantly improve current cancer treatments through their tumor-selective replication and multimodal attack against cancer cells. However, one of the biggest setbacks for oncolytic virus therapy is the intravenous delivery of the virus, as it can be cleared from the bloodstream by neutralizing antibodies before it reaches the tumor cells. We have selected DNA aptamers against an oncolytic virus, vesicular stomatitis virus, using a competitive binding approach, as well as against the antigen binding fragment (Fab) of antivesicular stomatitis virus polyclonal antibodies, in order to shield the virus from nAbs and enhance its in vivo survival. We used flow cytometry to identify these aptamers and evaluated their efficiency to shield vesicular stomatitis virus in a cell-based plaque forming assay. These oligonucleotides were then modified to obtain multivalent binders, which led to a decrease of viral aggregation, an increase in its infectivity and an increase in its stability in serum. The aptamers were also incubated in nondiluted serum, showing their effectiveness under conditions mimicking those in vivo. With this approach, we were able to increase viral infectivity by more than 70% in the presence of neutralizing antibodies. Thus, this method has the potential to enhance the delivery of vesicular stomatitis virus through the bloodstream without compromising the patient's immune system.
da Fontoura Budaszewski, Renata; Hudacek, Andrew; Sawatsky, Bevan; Krämer, Beate; Yin, Xiangping; Schnell, Matthias J; von Messling, Veronika
The development of multivalent vaccines is an attractive methodology for the simultaneous prevention of several infectious diseases in vulnerable populations. Both canine distemper virus (CDV) and rabies virus (RABV) cause lethal disease in wild and domestic carnivores. While RABV vaccines are inactivated, the live-attenuated CDV vaccines retain residual virulence for highly susceptible wildlife species. In this study, we developed recombinant bivalent vaccine candidates based on recombinant vaccine strain rabies virus particles, which concurrently display the protective CDV and RABV glycoprotein antigens. The recombinant viruses replicated to near-wild-type titers, and the heterologous glycoproteins were efficiently expressed and incorporated in the viral particles. Immunization of ferrets with beta-propiolactone-inactivated recombinant virus particles elicited protective RABV antibody titers, and animals immunized with a combination of CDV attachment protein- and fusion protein-expressing recombinant viruses were protected from lethal CDV challenge. However, animals that were immunized with only a RABV expressing the attachment protein of CDV vaccine strain Onderstepoort succumbed to infection with a more recent wild-type strain, indicating that immune responses to the more conserved fusion protein contribute to protection against heterologous CDV strains.IMPORTANCE Rabies virus and canine distemper virus (CDV) cause high mortality rates and death in many carnivores. While rabies vaccines are inactivated and thus have an excellent safety profile and high stability, live-attenuated CDV vaccines can retain residual virulence in highly susceptible species. Here we generated recombinant inactivated rabies viruses that carry one of the CDV glycoproteins on their surface. Ferrets immunized twice with a mix of recombinant rabies viruses carrying the CDV fusion and attachment glycoproteins were protected from lethal CDV challenge, whereas all animals that received
Full Text Available This paper presents the study of combination tube boilers, as applicable to commercial use, along with the significant features, limitations, and applicability. A heat balance sheet is prepared to know the various heat losses in two different two-pass combination tube boilers, using low grade coal and rice husk as a fuel. Also, the efficiency of the combination tube boilers is studied by the direct and heat loss methods. It is observed that the dry flue gas loss is a major loss in the combination tube boilers. The loss due to the unburnt in the fly ash is very less in the combination tube boilers, due to the surrounded membrane wall. It is also observed that the loss due to the unburnt in the bottom ash has a considerable amount for the heat loss, and cannot be ignored.
Tripp, Ralph A.; Tompkins, S. Mark
Despite the availability of an inactivated vaccine that has been licensed for >50 years, the influenza virus continues to cause morbidity and mortality worldwide. Constant evolution of circulating influenza virus strains and the emergence of new strains diminishes the effectiveness of annual vaccines that rely on a match with circulating influenza strains. Thus, there is a continued need for new, efficacious vaccines conferring cross-clade protection to avoid the need for biannual reformul...
Full Text Available Bats (Chiroptera host major human pathogenic viruses including corona-, paramyxo, rhabdo- and filoviruses. We analyzed six different cell lines from either Yinpterochiroptera (including African flying foxes and a rhinolophid bat or Yangochiroptera (genera Carollia and Tadarida for susceptibility to infection by different enveloped RNA viruses. None of the cells were sensitive to infection by transmissible gastroenteritis virus (TGEV, a porcine coronavirus, or to infection mediated by the Spike (S protein of SARS-coronavirus (SARS-CoV incorporated into pseudotypes based on vesicular stomatitis virus (VSV. The resistance to infection was overcome if cells were transfected to express the respective cellular receptor, porcine aminopeptidase N for TGEV or angiotensin-converting enzyme 2 for SARS-CoV. VSV pseudotypes containing the S proteins of two bat SARS-related CoV (Bg08 and Rp3 were unable to infect any of the six tested bat cell lines. By contrast, viral pseudotypes containing the surface protein GP of Marburg virus from the family Filoviridae infected all six cell lines though at different efficiency. Notably, all cells were sensitive to infection by two paramyxoviruses (Sendai virus and bovine respiratory syncytial virus and three influenza viruses from different subtypes. These results indicate that bat cells are more resistant to infection by coronaviruses than to infection by paramyxoviruses, filoviruses and influenza viruses. Furthermore, these results show a receptor-dependent restriction of the infection of bat cells by CoV. The implications for the isolation of coronaviruses from bats are discussed.
Schmid, Melanie; Speiseder, Thomas; Dobner, Thomas
Viruses employ a variety of strategies to usurp and control cellular activities through the orchestrated recruitment of macromolecules to specific cytoplasmic or nuclear compartments. Formation of such specialized virus-induced cellular microenvironments, which have been termed viroplasms, virus factories, or virus replication centers, complexes, or compartments, depends on molecular interactions between viral and cellular factors that participate in viral genome expression and replication and are in some cases associated with sites of virion assembly. These virus-induced compartments function not only to recruit and concentrate factors required for essential steps of the viral replication cycle but also to control the cellular mechanisms of antiviral defense. In this review, we summarize characteristic features of viral replication compartments from different virus families and discuss similarities in the viral and cellular activities that are associated with their assembly and the functions they facilitate for viral replication. PMID:24257611
Basta, T.; Garrett, Roger Antony; Prangishvili,, David
Double-stranded deoxyribonucleic acid (DNA) viruses that infect members of the third domain of life, the Archaea, are diverse and exceptional in both their morphotypes and their genomic properties. The majority of characterized species infect hyperthermophilic hosts and carry morphological features...... which have not been observed for viruses from the other domains of life, the Bacteria and the Eukarya. This exceptional status of the archaeal viruses is reinforced by the finding that a large majority of their predicted genes yield no sequence matches in public sequence databases, and their functions...... remain unknown. One of the viruses, the bicaudavirus ATV (Acidianus two-tailed virus), is quite unique in that it undergoes a major morphological change, growing long tail structures, extracellularly. A small minority of archaeal viruses, which exclusively infect mesophilic or moderately thermophilic...
Goldberg, L.A. [Warwick Univ., Coventry (United Kingdom) Dept. of Computer Science; Goldberg, P.W. [Aston Univ., Birmingham (United Kingdom) Dept. of Applied Mathematics; Phillips, C.A. [Sandia National Labs., Albuquerque, NM (United States); Sorkin, G.B. [International Business Machines Corp., Yorktown Heights, NY (United States). Thomas J. Watson Research Center
There has been much recent algorithmic work on the problem of reconstructing the evolutionary history of biological species. Computer virus specialists are interested in finding the evolutionary history of computer viruses--a virus is often written using code fragments from one or more other viruses, which are its immediate ancestors. A phylogeny for a collection of computer viruses is a directed acyclic graph whose nodes are the viruses and whose edges map ancestors to descendants and satisfy the property that each code fragment is ``invented`` only once. To provide a simple explanation for the data, we consider the problem of constructing such a phylogeny with a minimal number of edges. In general, this optimization problem cannot be solved in quasi-polynomial time unless NQP=QP; we present positive and negative results for associated approximated problems. When tree solutions exist, they can be constructed and randomly sampled in polynomial time.
Pougnet, Laurence; Thill, Chloé; Pougnet, Richard; Auvinet, Henri; Giacardi, Christophe; Drouillard, Isabelle
A 21-year old woman from New-Caledonia had 40 ̊C fever with vomiting, arthralgia, myalgia, and measles-like rash. Etiological analyses showed primary infection with Zika virus. Because of severe clinical presentation, she was hospitalized in the intensive care unit of the Brest military Hospital. Zika virus is mainly transmitted by Aedes mosquitoes. If they settle in Metropolitan France, Zika virus might also spread there.
Cremonesi, C.; Martella, G. (Milan Univ. (Italy). Dipt. di Scienza dell' Informazione)
This article reveals the origin and nature of what is known as the 'computer virus'. For illustrative purposes, the most common types of computer viruses are described and classified; the relative contagion and damage mechanisms are analyzed. Then techniques are presented to assist wary users in detecting and removing viruses, as well as, in protecting their computer systems from becoming contaminated.
Full Text Available Proviral factors are host proteins hijacked by viruses for processes essential for virus propagation such as cellular entry and replication. Pathogens and their hosts co-evolve. It follows that replacing a proviral factor with a functional ancestral form of the same protein could prevent viral propagation without fatally compromising organismal fitness. Here, we provide proof of concept of this notion. Thioredoxins serve as general oxidoreductases in all known cells. We report that several laboratory resurrections of Precambrian thioredoxins display substantial levels of functionality within Escherichia coli. Unlike E. coli thioredoxin, however, these ancestral thioredoxins are not efficiently recruited by the bacteriophage T7 for its replisome and therefore prevent phage propagation in E. coli. These results suggest an approach to the engineering of virus resistance. Diseases caused by viruses may have a devastating effect in agriculture. We discuss how the suggested approach could be applied to the engineering of plant virus resistance.
Escaffre, Olivier; Borisevich, Viktoriya; Rockx, Barry
Hendra virus (HeV) and Nipah virus (NiV) are emerging zoonotic viruses that cause severe and often lethal respiratory illness and encephalitis in humans. Henipaviruses can infect a wide range of species and human-to-human transmission has been observed for NiV. While the exact route of transmission in humans is not known, experimental infection in different animal species suggests that infection can be efficiently initiated after respiratory challenge. The limited data on histopathological changes in fatal human cases of HeV and NiV suggest that endothelial cells are an important target during the terminal stage of infection; however, it is unknown where these viruses initially establish infection and how the virus disseminates from the respiratory tract to the central nervous system and other organs. Here we review the current concepts in henipavirus pathogenesis in humans.
Electron microscopy is widely used in virology because viruses are generally too small for a direct inspection by light microscopy. Analysis of virus morphology is necessary in many circumstances, e.g., for the diagnosis of a virus in particular clinical situations or the analysis of virus entry and assembly. Moreover, quality control of virus particle integrity is required if a virus is propagated in cell culture, particularly if the virus genome has changed. In most cases already the basic methodology for transmission electron microscopy, i.e., negative staining and ultrathin sectioning, is sufficient to give relevant information on virus ultrastructure. This chapter gives detailed information on the principles of these basic methodologies and provides simple but reliable protocols for a quick start. Moreover, the description of standard protocols for negative staining and ultrathin sectioning are supplemented by protocols on immuno-negative staining and rapid ultrathin sectioning. Finally, principles of methods for an extended ultrastructural research using more elaborate techniques, such as cryotechniques or methods to reveal the three-dimensional virus architecture, are briefly reviewed. Copyright © 2010 Elsevier Inc. All rights reserved.
Zhao, Richard Yuqi
Budding yeast (Saccharomyces cerevisiae) and fission yeast (Schizosaccharomyces pombe) are two popular model organisms for virus research. They are natural hosts for viruses as they carry their own indigenous viruses. Both yeasts have been used for studies of plant, animal and human viruses. Many positive sense (+) RNA viruses and some DNA viruses replicate with various levels in yeasts, thus allowing study of those viral activities during viral life cycle. Yeasts are single cell eukaryotic organisms. Hence, many of the fundamental cellular functions such as cell cycle regulation or programed cell death are highly conserved from yeasts to higher eukaryotes. Therefore, they are particularly suited to study the impact of those viral activities on related cellular activities during virus-host interactions. Yeasts present many unique advantages in virus research over high eukaryotes. Yeast cells are easy to maintain in the laboratory with relative short doubling time. They are non-biohazardous, genetically amendable with small genomes that permit genome-wide analysis of virologic and cellular functions. In this review, similarities and differences of these two yeasts are described. Studies of virologic activities such as viral translation, viral replication and genome-wide study of virus-cell interactions in yeasts are highlighted. Impacts of viral proteins on basic cellular functions such as cell cycle regulation and programed cell death are discussed. Potential applications of using yeasts as hosts to carry out functional analysis of small viral genome and to develop high throughput drug screening platform for the discovery of antiviral drugs are presented. PMID:29082230
Wu, Qunfeng; Yu, Fulai; Xu, Jinfang; Li, Yang; Chen, Huanchun; Xiao, Shaobo; Fu, Zhen F; Fang, Liurong
Rabies virus has been an ongoing threat to humans and animals. Here, we developed a new strategy to generate a rabies virus vaccine based on a pseudotyped baculovirus. The recombinant baculovirus (BV-RVG/RVG) was pseudotyped with the rabies virus glycoprotein (RVG) and also simultaneously expressed another RVG under the control of the immediate early CMV promoter. In vitro, this RVG-pseudotyped baculovirus vector induced syncytium formation in insect cells and displayed more efficient gene delivery into mammalian cells. Mice immunized with BV-RVG/RVG developed higher levels of virus-neutralizing antibodies, and conferred 100% protection against rabies viral challenge. These data indicate that the RVG-pseudotyped baculovirus BV-RVG/RVG can be used as an alternative strategy to develop a safe and efficacious vaccine against the rabies virus. Copyright © 2014 Elsevier B.V. All rights reserved.
Full Text Available Rice (Oryza sativa L. is cultivated in more than 100 countries and supports nearly half of the world’s population. Developing efficient methods to control rice viruses is thus an urgent necessity because viruses cause serious losses in rice yield. Most rice viruses are transmitted by insect vectors, notably planthoppers and leafhoppers. Viruliferous insect vectors can disperse their viruses over relatively long distances, and eradication of the viruses is very difficult once they become widespread. Exploitation of natural genetic sources of resistance is one of the most effective approaches to protect crops from virus infection; however, only a few naturally occurring rice genes confer resistance against rice viruses. In an effort to improve control, many investigators are using genetic engineering of rice plants as a potential strategy to control viral diseases. Using viral genes to confer pathogen-derived resistance against crops is a well-established procedure, and the expression of various viral gene products has proved to be effective in preventing or reducing infection by various plant viruses since the 1990s. RNA-interference (RNAi, also known as RNA silencing, is one of the most efficient methods to confer resistance against plant viruses on their respective crops. In this article, we review the recent progress, mainly conducted by our research group, in transgenic strategies to confer resistance against tenuiviruses and reoviruses in rice plants. Our findings also illustrate that not all RNAi constructs against viral RNAs are equally effective in preventing virus infection and that it is important to identify the viral Achilles’ heel gene to target for RNAi attack when engineering plants.
Sasaya, Takahide; Nakazono-Nagaoka, Eiko; Saika, Hiroaki; Aoki, Hideyuki; Hiraguri, Akihiro; Netsu, Osamu; Uehara-Ichiki, Tamaki; Onuki, Masatoshi; Toki, Seichi; Saito, Koji; Yatou, Osamu
Rice (Oryza sativa L.) is cultivated in more than 100 countries and supports nearly half of the world's population. Developing efficient methods to control rice viruses is thus an urgent necessity because viruses cause serious losses in rice yield. Most rice viruses are transmitted by insect vectors, notably planthoppers and leafhoppers. Viruliferous insect vectors can disperse their viruses over relatively long distances, and eradication of the viruses is very difficult once they become widespread. Exploitation of natural genetic sources of resistance is one of the most effective approaches to protect crops from virus infection; however, only a few naturally occurring rice genes confer resistance against rice viruses. Many investigators are using genetic engineering of rice plants as a potential strategy to control viral diseases. Using viral genes to confer pathogen-derived resistance against crops is a well-established procedure, and the expression of various viral gene products has proved to be effective in preventing or reducing infection by various plant viruses since the 1990s. RNA interference (RNAi), also known as RNA silencing, is one of the most efficient methods to confer resistance against plant viruses on their respective crops. In this article, we review the recent progress, mainly conducted by our research group, in transgenic strategies to confer resistance against tenuiviruses and reoviruses in rice plants. Our findings also illustrate that not all RNAi constructs against viral RNAs are equally effective in preventing virus infection and that it is important to identify the viral "Achilles' heel" gene to target for RNAi attack when engineering plants.
Barr, John N; Fearns, Rachel
RNA genomes are vulnerable to corruption by a range of activities, including inaccurate replication by the error-prone replicase, damage from environmental factors, and attack by nucleases and other RNA-modifying enzymes that comprise the cellular intrinsic or innate immune response. Damage to coding regions and loss of critical cis-acting signals inevitably impair genome fitness; as a consequence, RNA viruses have evolved a variety of mechanisms to protect their genome integrity. These include mechanisms to promote replicase fidelity, recombination activities that allow exchange of sequences between different RNA templates, and mechanisms to repair the genome termini. In this article, we review examples of these processes from a range of RNA viruses to showcase the diverse approaches that viruses have evolved to maintain their genome sequence integrity, focusing first on mechanisms that viruses use to protect their entire genome, and then concentrating on mechanisms that allow protection of the genome termini, which are especially vulnerable. In addition, we discuss examples in which it might be beneficial for a virus to 'lose' its genomic termini and reduce its replication efficiency.
Zaidi, Syed Shan-e-Ali
Genomic engineering has been used to precisely alter eukaryotic genomes at the single-base level for targeted gene editing, replacement, fusion, and mutagenesis, and plant viruses such as Tobacco rattle virus have been developed into efficient vectors for delivering genome-engineering reagents. In addition to altering the host genome, these methods can target pathogens to engineer molecular immunity. Indeed, recent studies have shown that clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated 9 (Cas9) systems that target the genomes of DNA viruses can interfere with viral activity and limit viral symptoms in planta, demonstrating the utility of this system for engineering molecular immunity in plants. CRISPR/Cas9 can efficiently target single and multiple viral infections and confer plant immunity. Here, we discuss the use of site-specific nucleases to engineer molecular immunity against DNA and RNA viruses in plants. We also explore how to address the potential challenges encountered when producing plants with engineered resistance to single and mixed viral infections.
Full Text Available The rapid worldwide spread of severe viral infections, often involving novel mutations of viruses, poses major challenges to our health-care systems. This means that tools that can efficiently and specifically diagnose viruses are much needed. To be relevant for broad applications in local health-care centers, such tools should be relatively cheap and easy to use. In this paper, we discuss the biophysical potential for the macroscopic detection of viruses based on the induction of a mechanical stress in a bundle of prestretched DNA molecules upon binding of viruses to the DNA. We show that the affinity of the DNA to the charged virus surface induces a local melting of the double helix into two single-stranded DNA. This process effects a mechanical stress along the DNA chains leading to an overall contraction of the DNA. Our results suggest that when such DNA bundles are incorporated in a supporting matrix such as a responsive hydrogel, the presence of viruses may indeed lead to a significant, macroscopic mechanical deformation of the matrix. We discuss the biophysical basis for this effect and characterize the physical properties of the associated DNA melting transition. In particular, we reveal several scaling relations between the relevant physical parameters of the system. We promote this DNA-based assay as a possible tool for efficient and specific virus screening.
Sacristán, Soledad; Díaz, Maira; Fraile, Aurora; García-Arenal, Fernando
Transmission between hosts is required for the maintenance of parasites in the host population and determines their ultimate evolutionary success. The transmission ability of parasites conditions their evolution in two ways: on one side, it affects the genetic structure of founded populations in new hosts. On the other side, parasite traits that increase transmission efficiency will be selected for. Therefore, knowledge of the factors and parameters that determine transmission efficiency is critical to predict the evolution of parasites. For plant viruses, little is known about the parameters of contact transmission, a major way of transmission of important virus genera and species. Here, we analyze the factors determining the efficiency of contact transmission of Tobacco mosaic virus (TMV) that may affect virus evolution. As it has been reported for other modes of transmission, the rate of TMV transmission by contact depended on the contact opportunities between an infected and a noninfected host. However, TMV contact transmission differed from other modes of transmission, in that a positive correlation between the virus titer in the source leaf and the rate of transmission was not found within the range of our experimental conditions. Other factors associated with the nature of the source leaf, such as leaf age and the way in which it was infected, had an effect on the rate of transmission. Importantly, contact transmission resulted in severe bottlenecks, which did not depend on the host susceptibility to infection. Interestingly, the effective number of founders initiating the infection of a new host was highly similar to that reported for aphid-transmitted plant viruses, suggesting that this trait has evolved to an optimum value.
bluetongue virus (BTV) infection cycle is initiated when the virus core is delivered into the cytoplasm of ... products available for the consumer market; therefore, .... BTV life cycle. BTV interacts with the target cell surface via VP2 timers which is then internalized in endosomes via a clathrin- dependent endocytosis pathway ...
Olesen, Niels Jørgen; Skall, Helle Frank
This chapter covers the genetics (genotypes and serotypes), clinical signs, host species, transmission, prevalence, diagnosis, control and prevention of viral haemorrhagic septicaemia virus.......This chapter covers the genetics (genotypes and serotypes), clinical signs, host species, transmission, prevalence, diagnosis, control and prevention of viral haemorrhagic septicaemia virus....
Wernike, K.; Elbers, A.R.W.; Beer, M.
Since Schmallenberg virus, an orthobunyavirus of the Simbu serogroup, was identified near the German-Dutch border for the first time in late 2011 it has spread extremely quickly and caused a large epidemic in European livestock. The virus, which is transmitted by Culicoides biting midges, infects
Avian influenza virus (AIV) is type A influenza that is adapted to avian host species. Although the virus can be isolated from numerous avian species, the natural host reservoir species are dabbling ducks, shorebirds and gulls. Domestic poultry species (poultry being defined as birds that are rais...
Respiratory virus isolates made at the National Institute for. Virology from 1982 to 1991 were studied. An active virus surveillance programme, 'viral watch', which recruits throat swab specimens from a network of monitoring centres - mainly in the Witwatersrand and Vereeniging area with one centre in Middelburg - that ...
The etiology of reptilian viral diseases can be attributed to a wide range of viruses occurring across different genera and families. Thirty to forty years ago, studies of viruses in reptiles focused mainly on the zoonotic potential of arboviruses in reptiles and much effort went into surveys and challenge trials of a range of reptiles with eastern and western equine encephalitis as well as Japanese encephalitis viruses. In the past decade, outbreaks of infection with West Nile virus in human populations and in farmed alligators in the USA has seen the research emphasis placed on the issue of reptiles, particularly crocodiles and alligators, being susceptible to, and reservoirs for, this serious zoonotic disease. Although there are many recognised reptilian viruses, the evidence for those being primary pathogens is relatively limited. Transmission studies establishing pathogenicity and cofactors are likewise scarce, possibly due to the relatively low commercial importance of reptiles, difficulties with the availability of animals and permits for statistically sound experiments, difficulties with housing of reptiles in an experimental setting or the inability to propagate some viruses in cell culture to sufficient titres for transmission studies. Viruses as causes of direct loss of threatened species, such as the chelonid fibropapilloma associated herpesvirus and ranaviruses in farmed and wild tortoises and turtles, have re-focused attention back to the characterisation of the viruses as well as diagnosis and pathogenesis in the host itself.
Hepatitis is major cause of morbidity or mortality worldwide, particularly in the developing world. The major causes of infective hepatitis are hepatitis viruses. A, B, C, D or E. In the acute phase, there are no clinical features that can reliably differentiate between these viruses. Infection may be asymptomatic or can present as.
Krul MRL; van Kranen HJ; van Kreijl CF; Steerenberg PA; van Loon AM
The aim of this report is to review the relationship between viruses and the development of human cancer. It is currently known at least four viruses are directly implicated in the aetiology of human cancers and are involved in the induction of 15 to 20% of the worldwide tumor burden. Infection
Cowpea breeding lines were infected with cucumber mosaic virus (CMV) by mechanical inoculation to investigate seed transmission rates for this virus. Transmission rates ranging from 0% to 6% were scored by symptom assessment. However, when cowpeas grown from seeds of infected mother plants were tested by.
African Journal of Environmental Science and Technology Vol. 7(3), pp. 68-80, March ..... However, the disadvantages of attenuated BTV vaccines (Schultz ..... Sciences vol. 13, Nature Publishing Group, pp. 533–547. Mertens PPC, Diprose J (2004). The bluetongue virus core: a nano- scale transcription machine. Virus Res.
Abstract. Hepatitis E virus (HEV) is the most common cause of acute viral hepatitis in the developing world. It is a waterborne virus that can cause epidemics in the face of overcrowding and poor sanitation. Although the hepatitis illness is usually self-limiting, it has a high mortality in pregnant women and can become a ...
Kazimírová, Mária; Thangamani, Saravanan; Bartíková, Pavlína; Hermance, Meghan; Holíková, Viera; Štibrániová, Iveta; Nuttall, Patricia A.
Ticks are efficient vectors of arboviruses, although less than 10% of tick species are known to be virus vectors. Most tick-borne viruses (TBV) are RNA viruses some of which cause serious diseases in humans and animals world-wide. Several TBV impacting human or domesticated animal health have been found to emerge or re-emerge recently. In order to survive in nature, TBV must infect and replicate in both vertebrate and tick cells, representing very different physiological environments. Information on molecular mechanisms that allow TBV to switch between infecting and replicating in tick and vertebrate cells is scarce. In general, ticks succeed in completing their blood meal thanks to a plethora of biologically active molecules in their saliva that counteract and modulate different arms of the host defense responses (haemostasis, inflammation, innate and acquired immunity, and wound healing). The transmission of TBV occurs primarily during tick feeding and is a complex process, known to be promoted by tick saliva constituents. However, the underlying molecular mechanisms of TBV transmission are poorly understood. Immunomodulatory properties of tick saliva helping overcome the first line of defense to injury and early interactions at the tick-host skin interface appear to be essential in successful TBV transmission and infection of susceptible vertebrate hosts. The local host skin site of tick attachment, modulated by tick saliva, is an important focus of virus replication. Immunomodulation of the tick attachment site also promotes co-feeding transmission of viruses from infected to non-infected ticks in the absence of host viraemia (non-viraemic transmission). Future research should be aimed at identification of the key tick salivary molecules promoting virus transmission, and a molecular description of tick-host-virus interactions and of tick-mediated skin immunomodulation. Such insights will enable the rationale design of anti-tick vaccines that protect against
Dawei Zhao; Haipeng Peng; Lixiang Li; Yixian Yang; Shudong Li
Mobile phones and personal digital assistants are becoming increasingly important in our daily life since they enable us to access a large variety of ubiquitous services. Mobile networks, formed by the connection of mobile devices following some relationships among mobile users, provide good platforms for mobile virus spread. Quick and efficient security patch dissemination strategy is necessary for the update of antivirus software so that it can detect mobile virus, especially the new vir...
Margaret A Scull; Laura Gillim-Ross; Celia Santos; Kim L Roberts; Elena Bordonali; Kanta Subbarao; Wendy S Barclay; Raymond J Pickles
.... Using an in vitro model of human ciliated airway epithelium (HAE), we demonstrate that while human and avian influenza viruses efficiently infect at temperatures of the human distal airways (37°C...
Bhattarai, Nirjal; Stapleton, Jack T.
GB virus C (GBV-C) is a lymphotropic human virus discovered in 1995 that is related to hepatitis C virus (HCV). GBV-C infection has not been convincingly associated with any disease; however, several studies found an association between persistent GBV-C infection and improved survival in HIV-positive individuals. GBV-C infection modestly alters T cell homeostasis in vivo through various mechanisms, including modulation of chemokine and cytokine release and receptor expression, and by diminution of T cell activation, proliferation and apoptosis, all of which may contribute to improved HIV clinical outcomes. In vitro studies confirm these clinical observations and demonstrate an anti-HIV replication effect of GBV-C. This review summarizes existing data on potential mechanisms by which GBV-C interferes with HIV, and the research needed to capitalize on this epidemiological observation. PMID:22325031
Krupovic, Mart; White, Malcolm F; Forterre, Patrick; Prangishvili, David
Ever since their discovery, archaeal viruses have fascinated biologists with their unusual virion morphotypes and their ability to thrive in extreme environments. Attempts to understand the biology of these viruses through genome sequence analysis were not efficient. Genomes of archaeoviruses proved to be terra incognita with only a few genes with predictable functions but uncertain provenance. In order to facilitate functional characterization of archaeal virus proteins, several research groups undertook a structural genomics approach. This chapter summarizes the outcome of these efforts. High-resolution structures of 30 proteins encoded by archaeal viruses have been solved so far. Some of these proteins possess new structural folds, whereas others display previously known topologies, albeit without detectable sequence similarity to their structural homologues. Structures of the major capsid proteins have illuminated intriguing evolutionary connections between viruses infecting hosts from different domains of life and also revealed new structural folds not yet observed in currently known bacterial and eukaryotic viruses. Structural studies, discussed here, have advanced our understanding of the archaeal virosphere and provided precious information on different aspects of biology of archaeal viruses and evolution of viruses in general. Copyright Â© 2012 Elsevier Inc. All rights reserved.
Prangishvili,, David; Basta, Tamara; Garrett, Roger Antony
Viruses infecting members of Archaea, the third domain of life, constitute an integral, yet unique part of the virosphere. Many of these viruses, specifically the species that infect hyperthermophilic hosts, display morphotypes – for example, bottle shaped, spindle shaped, droplet shaped, coil...... shaped, bacilliform – not known to be associated with the other two cellular domains, Bacteria and Eukarya. The distinctiveness of the hyperthermophilic archaeal viruses extends to their genome sequences: a large majority of the predicted genes yield no sequence matches in public databases and encode...... proteins with exceptional structures and unknown functions. Moreover, the ways in which these viruses interact with their hosts are also unique, as indicated by a unique virion egress mechanism, which involves formation of pyramidal portals on the cell surface. Some viruses that infect extremely halophilic...
Gao, Shengjie; Hu, Xuesong; Xu, Fengping
Background: DNA methylation plays a key role in the regulation of gene expression and carcinogenesis. Bisulfite sequencing studies mainly focus on calling SNP, DMR, and ASM. Until now, only a few software tools focus on virus integration using bisulfite sequencing data. Findings: We have developed...... a new and easy-to-use software tool, named BS-virus-finder (BSVF, RRID:SCR_015727), to detect viral integration breakpoints in whole human genomes. The tool is hosted at https://github.com/BGI-SZ/BSVF. Conclusions: BS-virus-finder demonstrates high sensitivity and specificity. It is useful in epigenetic...... studies and to reveal the relationship between viral integration and DNA methylation. BS-virus-finder is the first software tool to detect virus integration loci by using bisulfite sequencing data....
J. M. S. Mezencio
Full Text Available Mayaro virus was grown in BHK-21 cells and purified by centrifugation in a potassium-tartrate gradient (5-50%. The electron microscopy analyses of the purified virus showed an homogeneous population of enveloped particles with 69 ñ 2.3 nm in diameter. Three structural virus proteins were identified and designated pl, p2 and p3. Their average molecular weight were p1, 54 KDa; p2, 50 KDa and p3, 34 KDa. In Mayaro virus infected. Aedes albopictus cells and in BHK-21 infected cells we detected six viral proteins, in wich three of them are the structural virus proteins and the other three were products from processing of precursors of viral proteins, whose molecular weights are 62 KDa, 64 KDa and 110 KDa. The 34 KDa protein was the first viral protein sinthesized at 5 hours post-infection in both cell lines studied.
Crops that are propagated vegetatively are viruses or putative viruses have been isolated particularly prone to virus ... eight viruses known to infect are selected and used for repeated cycles of crop cassava in Africa and on the diseases they cause. ... vein mosaic pararetrovirus. Cassava Colombian symptomless potexvirus.
Margaret A Scull
Full Text Available Transmission of avian influenza viruses from bird to human is a rare event even though avian influenza viruses infect the ciliated epithelium of human airways in vitro and ex vivo. Using an in vitro model of human ciliated airway epithelium (HAE, we demonstrate that while human and avian influenza viruses efficiently infect at temperatures of the human distal airways (37 degrees C, avian, but not human, influenza viruses are restricted for infection at the cooler temperatures of the human proximal airways (32 degrees C. These data support the hypothesis that avian influenza viruses, ordinarily adapted to the temperature of the avian enteric tract (40 degrees C, rarely infect humans, in part due to differences in host airway regional temperatures. Previously, a critical residue at position 627 in the avian influenza virus polymerase subunit, PB2, was identified as conferring temperature-dependency in mammalian cells. Here, we use reverse genetics to show that avianization of residue 627 attenuates a human virus, but does not account for the different infection between 32 degrees C and 37 degrees C. To determine the mechanism of temperature restriction of avian influenza viruses in HAE at 32 degrees C, we generated recombinant human influenza viruses in either the A/Victoria/3/75 (H3N2 or A/PR/8/34 (H1N1 genetic background that contained avian or avian-like glycoproteins. Two of these viruses, A/Victoria/3/75 with L226Q and S228G mutations in hemagglutinin (HA and neuraminidase (NA from A/Chick/Italy/1347/99 and A/PR/8/34 containing the H7 and N1 from A/Chick/Italy/1347/99, exhibited temperature restriction approaching that of wholly avian influenza viruses. These data suggest that influenza viruses bearing avian or avian-like surface glycoproteins have a reduced capacity to establish productive infection at the temperature of the human proximal airways. This temperature restriction may limit zoonotic transmission of avian influenza viruses and
Chen, Xueqing; Si, Longlong; Liu, Dong; Proksch, Peter; Zhang, Lihe; Zhou, Demin; Lin, Wenhan
A class of prenylated indole diketopiperazine alkaloids including 15 new compounds namely rubrumlines A-O obtained from marine-derived fungus Eurotium rubrum, were tested against influenza A/WSN/33 virus. Neoechinulin B (18) exerted potent inhibition against H1N1 virus infected in MDCK cells, and is able to inhibit a panel of influenza virus strains including amantadine- and oseltamivir-resistant clinical isolates. Mechanism of action studies indicated that neoechinulin B binds to influenza envelope hemagglutinin, disrupting its interaction with the sialic acid receptor and the attachment of viruses to host cells. In addition, neoechinulin B was still efficient in inhibiting influenza A/WSN/33 virus propagation even after a fifth passage. The high potency and broad-spectrum activities against influenza viruses with less drug resistance make neoechinulin B as a new lead for the development of potential inhibitor of influenza viruses. Copyright © 2015 Elsevier Masson SAS. All rights reserved.
Maxwell, John R.; Lamon, William E.
Explains how computer viruses were originally created, how a computer can become infected by a virus, how viruses operate, symptoms that indicate a computer is infected, how to detect and remove viruses, and how to prevent a reinfection. A sidebar lists eight antivirus resources. (four references) (LRW)
Meulenberg, J.J.M.; Petersen-den Besten, A.; Kluyver, de E.; Nieuwstadt, van A.; Wensvoort, G.; Moormann, R.J.M.
Lelystad virus (LV), the prototype of porcine reproductive respiratory syndrome virus, is a small enveloped virus, containing a positive strand RNA genome of 15 kb. LV is tentatively classified in the family Arteriviridae, which consists of lactate dehydrogenase-elevating virus (LDV), equine
Buck, Christopher B.; Diana V Pastrana; Lowy, Douglas R.; Schiller, John T.
Although the papillomavirus structural proteins, L1 and L2, can spontaneously coassemble to form virus-like particles, currently available methods for production of L1/L2 particles capable of transducing reporter plasmids into mammalian cells are technically demanding and relatively low-yield. In this report, we describe a simple 293 cell transfection method for efficient intracellular production of papillomaviral-based gene transfer vectors carrying reporter plasmids. Using bovine papillomav...
Viruses cause epidemics on all major cultures of agronomic importance, representing a serious threat to global food security. As strict intracellular pathogens, they cannot be controlled chemically and prophylactic measures consist mainly in the destruction of infected plants and excessive pesticide applications to limit the population of vector organisms. A powerful alternative frequently employed in agriculture relies on the use of crop genetic resistances, approach that depends on mechanisms governing plant–virus interactions. Hence, knowledge related to the molecular bases of viral infections and crop resistances is key to face viral attacks in fields. Over the past 80 years, great advances have been made on our understanding of plant immunity against viruses. Although most of the known natural resistance genes have long been dominant R genes (encoding NBS-LRR proteins), a vast number of crop recessive resistance genes were cloned in the last decade, emphasizing another evolutive strategy to block viruses. In addition, the discovery of RNA interference pathways highlighted a very efficient antiviral system targeting the infectious agent at the nucleic acid level. Insidiously, plant viruses evolve and often acquire the ability to overcome the resistances employed by breeders. The development of efficient and durable resistances able to withstand the extreme genetic plasticity of viruses therefore represents a major challenge for the coming years. This review aims at describing some of the most devastating diseases caused by viruses on crops and summarizes current knowledge about plant–virus interactions, focusing on resistance mechanisms that prevent or limit viral infection in plants. In addition, I will discuss the current outcomes of the actions employed to control viral diseases in fields and the future investigations that need to be undertaken to develop sustainable broad-spectrum crop resistances against viruses. PMID:25484888
Krauss, Scott; Walker, David; Webster, Robert G
The isolation of influenza viruses is important for the diagnosis of respiratory diseases in lower animals and humans, for the detection of the infecting agent in surveillance programs, and is an essential element in the development and production of vaccine. Since influenza is caused by a zoonotic virus it is necessary to do surveillance in the reservoir species (aquatic waterfowls), intermediate hosts (quails, pigs), and in affected mammals including humans. Two of the hemagglutinin (HA) subtypes of influenza A viruses (H5 and H7) can evolve into highly pathogenic (HP) strains for gallinaceous poultry; some HP H5 and H7 strains cause lethal infection of humans. In waterfowls, low pathogenic avian influenza (LPAI) isolates are obtained primarily from the cloaca (or feces); in domestic poultry, the virus is more often recovered from the respiratory tract than from cloacal samples; in mammals, the virus is most often isolated from the respiratory tract, and in cases of high pathogenic avian influenza (HPAI) from the blood and internal organs of infected birds. Virus isolation procedures are performed by inoculation of clinical specimens into embryonated eggs (primarily chicken eggs) or onto a variety of primary or continuous tissue culture systems. Successful isolation of influenza virus depends on the quality of the sample and matching the appropriate culture method to the sample type.
Belser, Jessica A; Rota, Paul A; Tumpey, Terrence M
Respiratory viruses (including adenovirus, influenza virus, respiratory syncytial virus, coronavirus, and rhinovirus) cause a broad spectrum of disease in humans, ranging from mild influenza-like symptoms to acute respiratory failure. While species D adenoviruses and subtype H7 influenza viruses are known to possess an ocular tropism, documented human ocular disease has been reported following infection with all principal respiratory viruses. In this review, we describe the anatomical proximity and cellular receptor distribution between ocular and respiratory tissues. All major respiratory viruses and their association with human ocular disease are discussed. Research utilizing in vitro and in vivo models to study the ability of respiratory viruses to use the eye as a portal of entry as well as a primary site of virus replication is highlighted. Identification of shared receptor-binding preferences, host responses, and laboratory modeling protocols among these viruses provides a needed bridge between clinical and laboratory studies of virus tropism.
Vähä-Koskela, Markus J V; Heikkilä, Jari E; Hinkkanen, Ari E
Oncolytic virotherapy is a promising form of gene therapy for cancer, employing nature's own agents to find and destroy malignant cells. The purpose of this review is to provide an introduction to this very topical field of research and to point out some of the current observations, insights and ideas circulating in the literature. We have strived to acknowledge as many different oncolytic viruses as possible to give a broader picture of targeting cancer using viruses. Some of the newest additions to the panel of oncolytic viruses include the avian adenovirus, foamy virus, myxoma virus, yaba-like disease virus, echovirus type 1, bovine herpesvirus 4, Saimiri virus, feline panleukopenia virus, Sendai virus and the non-human coronaviruses. Although promising, virotherapy still faces many obstacles that need to be addressed, including the emergence of virus-resistant tumor cells.
Full Text Available Abstract The etiology of reptilian viral diseases can be attributed to a wide range of viruses occurring across different genera and families. Thirty to forty years ago, studies of viruses in reptiles focused mainly on the zoonotic potential of arboviruses in reptiles and much effort went into surveys and challenge trials of a range of reptiles with eastern and western equine encephalitis as well as Japanese encephalitis viruses. In the past decade, outbreaks of infection with West Nile virus in human populations and in farmed alligators in the USA has seen the research emphasis placed on the issue of reptiles, particularly crocodiles and alligators, being susceptible to, and reservoirs for, this serious zoonotic disease. Although there are many recognised reptilian viruses, the evidence for those being primary pathogens is relatively limited. Transmission studies establishing pathogenicity and cofactors are likewise scarce, possibly due to the relatively low commercial importance of reptiles, difficulties with the availability of animals and permits for statistically sound experiments, difficulties with housing of reptiles in an experimental setting or the inability to propagate some viruses in cell culture to sufficient titres for transmission studies. Viruses as causes of direct loss of threatened species, such as the chelonid fibropapilloma associated herpesvirus and ranaviruses in farmed and wild tortoises and turtles, have re-focused attention back to the characterisation of the viruses as well as diagnosis and pathogenesis in the host itself. 1. Introduction 2. Methods for working with reptilian viruses 3. Reptilian viruses described by virus families 3.1. Herpesviridae 3.2. Iridoviridae 3.2.1 Ranavirus 3.2.2 Erythrocytic virus 3.2.3 Iridovirus 3.3. Poxviridae 3.4. Adenoviridae 3.5. Papillomaviridae 3.6. Parvoviridae 3.7. Reoviridae 3.8. Retroviridae and inclusion body disease of Boid snakes 3.9. Arboviruses 3.9.1. Flaviviridae 3
Full Text Available Zika virus (ZIKV is an emerging mosquito-borne virus that was first isolated from a sentinel rhesus monkey in the Zika Forest in Uganda in 1947. In Asia, the virus was isolated in Malaysia from Aedes aegypti mosquitoes in 1966, and the first human infections were reported in 1977 in Central Java, Indonesia. In this review, all reported cases of ZIKV infection in Asia as of September 1, 2016 are summarized and some of the hypotheses that could currently explain the apparently low incidence of Zika cases in Asia are explored.
Nazimek, Katarzyna; Bociaga-Jasik, Monika; Bryniarski, Krzysztof; Gałas, Aleksander; Garlicki, Aleksander; Gawda, Anna; Gawlik, Grzegorz; Gil, Krzysztof; Kosz-Vnenchak, Magdalena; Mrozek-Budzyn, Dorota; Olszanecki, Rafał; Piatek, Anna; Zawilińska, Barbara; Marcinkiewicz, Janusz
Ebola is one of the most virulent zoonotic RNA viruses causing in humans haemorrhagic fever with fatality ratio reaching 90%. During the outbreak of 2014 the number of deaths exceeded 8.000. The "imported" cases reported in Western Europe and USA highlighted the extreme risk of Ebola virus spreading outside the African countries. Thus, haemorrhagic fever outbreak is an international epidemiological problem, also due to the lack of approved prevention and therapeutic strategies. The editorial review article briefly summarizes current knowledge on Ebola virus disease epidemiology, etiology, pathogenesis, clinical presentation, diagnosis as well as possible prevention and treatment.
Duong, Veasna; Dussart, Philippe; Buchy, Philippe
Zika virus (ZIKV) is an emerging mosquito-borne virus that was first isolated from a sentinel rhesus monkey in the Zika Forest in Uganda in 1947. In Asia, the virus was isolated in Malaysia from Aedes aegypti mosquitoes in 1966, and the first human infections were reported in 1977 in Central Java, Indonesia. In this review, all reported cases of ZIKV infection in Asia as of September 1, 2016 are summarized and some of the hypotheses that could currently explain the apparently low incidence of Zika cases in Asia are explored. Copyright © 2016 The Author(s). Published by Elsevier Ltd.. All rights reserved.
The etiology of reptilian viral diseases can be attributed to a wide range of viruses occurring across different genera and families. Thirty to forty years ago, studies of viruses in reptiles focused mainly on the zoonotic potential of arboviruses in reptiles and much effort went into surveys and challenge trials of a range of reptiles with eastern and western equine encephalitis as well as Japanese encephalitis viruses. In the past decade, outbreaks of infection with West Nile virus in human populations and in farmed alligators in the USA has seen the research emphasis placed on the issue of reptiles, particularly crocodiles and alligators, being susceptible to, and reservoirs for, this serious zoonotic disease. Although there are many recognised reptilian viruses, the evidence for those being primary pathogens is relatively limited. Transmission studies establishing pathogenicity and cofactors are likewise scarce, possibly due to the relatively low commercial importance of reptiles, difficulties with the availability of animals and permits for statistically sound experiments, difficulties with housing of reptiles in an experimental setting or the inability to propagate some viruses in cell culture to sufficient titres for transmission studies. Viruses as causes of direct loss of threatened species, such as the chelonid fibropapilloma associated herpesvirus and ranaviruses in farmed and wild tortoises and turtles, have re-focused attention back to the characterisation of the viruses as well as diagnosis and pathogenesis in the host itself. 1. Introduction 2. Methods for working with reptilian viruses 3. Reptilian viruses described by virus families 3.1. Herpesviridae 3.2. Iridoviridae 3.2.1 Ranavirus 3.2.2 Erythrocytic virus 3.2.3 Iridovirus 3.3. Poxviridae 3.4. Adenoviridae 3.5. Papillomaviridae 3.6. Parvoviridae 3.7. Reoviridae 3.8. Retroviridae and inclusion body disease of Boid snakes 3.9. Arboviruses 3.9.1. Flaviviridae 3.9.2. Togaviridae 3.10. Caliciviridae
Obed Madsen, Søren
and organizations. In this paper, the virus theory is used to analyze a strategy process in an organization as an example of a technology. It shows how the strategy over time creates a memory loss, where the managers who are exposed to the virus forget their critique of the new strategy concept. The article also...... shows how resistant can be understood as being immune to a virus, since the strategy concepts bears resemblance to a former strategy concept. The article also argues that there should be more focus on the negative impacts of management tool and especially how organizations and managers are dealing...
© 2015 Elsevier Inc. Replication and intercellular spread of viruses depend on host mechanisms supporting the formation transport and turnover of functional complexes between viral genomes virus encoded products and cellular factors. To enhance these processes viruses assemble and replicate in membrane associated complexes that may develop into "virus factories" or "viroplasms" in which viral components and host factors required for replication are concentrated. Many plant viruses replicate i...
Wommack, K. Eric; Colwell, Rita R.
The discovery that viruses may be the most abundant organisms in natural waters, surpassing the number of bacteria by an order of magnitude, has inspired a resurgence of interest in viruses in the aquatic environment. Surprisingly little was known of the interaction of viruses and their hosts in nature. In the decade since the reports of extraordinarily large virus populations were published, enumeration of viruses in aquatic environments has demonstrated that the virioplankton are dynamic co...
Carr, John Peter; Groen, SC; Wamonje, Francis; Murphy, Alexandra Marie
Engineering plants for resistance to virus transmission by invertebrate vectors has lagged behind other forms of plant protection. Vectors typically transmit more than one virus. Thus, vector resistance could provide a wider range of protection than defenses directed solely against one virus or virus group. We discuss current knowledge of vector-host-virus interactions, the roles of viral gene products in host and vector manipulation, and the effects of semiochemicals on host-vector interact...
bacteriophage and Escherichia coli have been eliminated. III. METHODS AND MATERIALS A. Viruses, Cell Cultures and Virus Purification 1. HAV. The HM175 (NIH...bacteria and cysts of Entamoeba histolytica are inactivated more efficiently by iodine at lower pH where iodine exists primarily as I (Chang, 1958
Full Text Available Formaldehyde (FA fixation of infectious samples is a well-established protocol in diagnostic electron microscopy of viruses. However, published experimental data that demonstrate virus inactivation by these fixation procedures are lacking. Usually, fixation is performed immediately before the sample preparation for microscopy. The fixation procedure should transform viruses in a non–infectious but nonetheless structurally intact form in order to allow a proper diagnosis based on morphology. FA provides an essential advantage in comparison to other disinfectants, because it preserves the ultrastructure of biological material without interfering significantly with the preparation (i.e., the negative staining and the detection of viruses. To examine the efficiency of FA inactivation, we used Vaccinia virus, Human adenovirus and Murine norovirus as models and treated them with FA under various conditions. Critical parameters for the inactivation efficiency were the temperature, the duration of the FA treatment, and the resistance of the virus in question. Our results show that FA inactivation at low temperature (4 °C bears a high risk of incomplete inactivation. Higher temperatures (25 °C are more efficient, although they still require rather long incubation times to fully inactivate a complex and highly robust virus like Vaccinia. A protocol, which applied 2% buffered FA for 60 min and a temperature–shift from 25 to 37 °C after 30 min was efficient for the complete inactivation of all test viruses, and therefore has the potential to improve both biosafety and speed of diagnostic electron microscopy.
Kitajima, Masayuki; Takaku, Hiroshi
The baculovirus Autographa californica multiple nuclear polyhedrosis virus (AcMNPV) has been studied as a gene therapy vector. Here, we demonstrated that AcMNPV induces antitumor acquired immunity. These results suggest that AcMNPV has the potential to be an efficient virus or tumor therapy agent which induces innate and acquired immunity.
Rurup, W.F.; Cornelissen, Jeroen Johannes Lambertus Maria; Koay, M.S.T.; Orner, Brendan P.
Ultracentrifugation, particularly the use of sucrose or cesium chloride density gradients, is a highly reliable and efficient technique for the purification of virus-like particles and protein cages. Since virus-like particles and protein cages have a unique size compared to cellular macromolecules
Rurup, W.F.; Cornelissen, Jeroen Johannes Lambertus Maria; Koay, M.S.T.; Orner, Brendan P.
Ultracentrifugation, particularly the use of sucrose or cesium chloride density gradients, is a highly reliable and efficient technique for the purification of virus-like particles and protein cages. Since virus-like particles and protein cages have a unique size compared to cellular macromolecules
Vidya, Padmanabhan; Ponnambalam, Arun; Gunasekeran, Palani; Arunagiri, Kavitha; Sambasivam, Mohana; Krishnasami, Kaveri
...: Molecular typing methods for viruses should aim to provide clinically and biologically useful information about field viruses, particularly with regard to virulence, viral epidemiology, and virus...
Triticum mosaic virus (TriMV) (genus Poacevirus, family Potyviridae) is a recently described eriophyid mite-transmitted wheat virus. In vitro RNA transcripts generated from full-length cDNA clones of TriMV proved infectious on wheat, and the progeny virus was efficiently transmitted by wheat curl m...
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... of Whether Lower Respiratory Tract Infections Improve with Antibacterial Treatment , February 13, 2018 NIH Scientists Adapt New ... ecological patterns in the United States, and insecticide resistance. Read more about West Nile virus biology, genetics ...
Hepatitis B is also known as serum hepatitis and is spread through blood and sexual contact. It is ... population. This photograph is an electronmicroscopic image of hepatitis B virus particles. (Image courtesy of the Centers for ...
Kjær, Peter; Frankel, Christian
The virus metaphor may be used in studies of management knowledge not only as a way ofdescribing diffusion processes but also as a way of thinking about viral elements of knowledgeproduction. In the present article, organizational viruses are viewed as ensembles of basicdistinctions...... that are constitutive of concrete bodies of knowledge and which form mutable enginesof organizational self-descriptions. Organizational viruses, we contend, are both characterized bystability in terms of their basic productive configuration, while at the same time allowing for a highdegree of variation in terms...... of concrete management knowledge and practice. The article isstructured as follows. After the introduction, we first develop the notion of organizational virus asinto an analytical approach. Second, we discern in the work of Frederick Taylor on scientificmanagement and Max Weber on bureaucracy, two quite...
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... Virus Testing Clinical Signs & Symptoms of Influenza Symptoms & Laboratory Diagnosis Information for Clinicians on Rapid Diagnostic Testing for ... Help: How do I view different file formats (PDF, DOC, PPT, MPEG) on this site? Adobe PDF ...
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... patients at home. Reducing the risk of possible sexual transmission, based on further analysis of ongoing research and consideration by the WHO Advisory Group on the Ebola Virus Disease Response, WHO recommends that male survivors of Ebola ...
... When to Call the Doctor en español Virus respiratorio sincitial About RSV Respiratory syncytial (sin-SISH-ul) ... diseases that affect the lungs, heart, or immune system , RSV infections can lead to other more serious ...
PV Bhargavan; PV Shiji; Jare Jagannath Udhavrao; Nagaraj Desai
Ebola virus is named after the river in the former Zaire where a haemorrhagic fever initially identified in 1976 involved human to human transmission, as well as spread by contaminated injection equipments...
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Full Text Available ... Donate Shop Career Connection Home Resources & Publications Practice Management Education & Events Advocacy For Patients About ACOG Zika Virus ... Infographic Resources & Publications Committee Opinions Practice ... Coding Health Info Technology Professional Liability Managing Your ...
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Schoen, P; Leserman, L; Wilschut, J
Reconstituted influenza virus envelopes (virosomes) containing the viral hemagglutinin (HA) represent an efficient fusogenic cellular delivery system, By interaction of HA with its natural receptors, sialylated lipids (gangliosides) or proteins, virosomes bind to cells and, following endocytic
ORTIZ, A; WILSCHUT, J
In this paper it is demonstrated that reconstituted influenza virus envelopes (virosomes) fuse efficiently with membranes of the endosomal cell compartment of cultured cells, after internalization through receptor-mediated endocytosis. As a consequence, molecules, encapsulated in the virosomal
Respiratory Syncytial Virus, or RSV, causes cold-like symptoms but can be serious for infants and older adults. In this podcast, CDCâs Dr. Eileen Schneider discusses this common virus and offers tips to prevent its spread. Created: 2/4/2013 by National Center for Immunization and Respiratory Diseases (NCIRD), Division of Viral Diseases (DVD). Date Released: 2/13/2013.
Hayes, Edward B.
Zika virus (ZIKV) is a flavivirus related to yellow fever, dengue, West Nile, and Japanese encephalitis viruses. In 2007 ZIKV caused an outbreak of relatively mild disease characterized by rash, arthralgia, and conjunctivitis on Yap Island in the southwestern Pacific Ocean. This was the first time that ZIKV was detected outside of Africa and Asia. The history, transmission dynamics, virology, and clinical manifestations of ZIKV disease are discussed, along with the possibility for diagnostic ...
Full Text Available Hepatitis E virus (HEV is the most common cause of acute viral hepatitis in the developing world. It is a waterborne virus that can cause epidemics in the face of overcrowding and poor sanitation. Although the hepatitis illness is usually self-limiting, it has a high mortality in pregnant women and can become a chronic infection in the immunosuppressed. Treatment is mostly supportive and prevention is by good water hygiene.
Hepatitis C virus (HCV) is an enveloped, single-stranded RNA virus, belonging to the Flaviviridae family. HCV infection is a major cause of chronic hepatitis worldwide, leading to steatosis, liver cirrosis and hepatocellular carcinoma. Significant advances in understanding the mechanisms of HCV infection have been made since the development of a cell culture system reproducing the complete HCV cell cycle in vitro. HCV represents a new paradigm in interactions between the virus and its target cell, the human hepatocyte, due to the central role of lipoproteins in the HCV life cycle. Very low density lipoproteins are required for virus particle assembly and secretion. Upon the release, the infectious virus circulates in the blood as triglyceride-rich particles and infects cells using lipoprotein-receptor dependent mechanisms. HCV cell entry is a multi-step process: heparan sulphate and/or low-density lipoprotein receptor are cell surface factors mediating an initial virus attachment; subsequent virus interaction with tetraspanin CD81 and the human scavenger receptor SR-BI, the main HCV receptors, triggers virus movement to the tight junctions and its uptake via Claudin-1 and occludin. Another originality of HCV is that initiation of productive infection requires dynamic microtubules. Whereas other viruses use kinesin or dynein-dependent transport, HCV exploits mechanisms driven by microtubule polymerization to efficiently infect its target cell, in which virus nucleocapsid protein might play a particular role. An improved of understanding of the cellular events involved in HCV cell entry and transport, leading to the initiation of productive HCV infection, may reveal novel targets for anti-viral interventions.
Kamdar, Maulik R.; Dumontier, Michel
Ebola virus (EBOV), of the family Filoviridae viruses, is a NIAID category A, lethal human pathogen. It is responsible for causing Ebola virus disease (EVD) that is a severe hemorrhagic fever and has a cumulative death rate of 41% in the ongoing epidemic in West Africa. There is an ever-increasing need to consolidate and make available all the knowledge that we possess on EBOV, even if it is conflicting or incomplete. This would enable biomedical researchers to understand the molecular mechanisms underlying this disease and help develop tools for efficient diagnosis and effective treatment. In this article, we present our approach for the development of an Ebola virus-centered Knowledge Base (Ebola-KB) using Linked Data and Semantic Web Technologies. We retrieve and aggregate knowledge from several open data sources, web services and biomedical ontologies. This knowledge is transformed to RDF, linked to the Bio2RDF datasets and made available through a SPARQL 1.1 Endpoint. Ebola-KB can also be explored using an interactive Dashboard visualizing the different perspectives of this integrated knowledge. We showcase how different competency questions, asked by domain users researching the druggability of EBOV, can be formulated as SPARQL Queries or answered using the Ebola-KB Dashboard. Database URL: http://ebola.semanticscience.org. PMID:26055098
Kamdar, Maulik R; Dumontier, Michel
Ebola virus (EBOV), of the family Filoviridae viruses, is a NIAID category A, lethal human pathogen. It is responsible for causing Ebola virus disease (EVD) that is a severe hemorrhagic fever and has a cumulative death rate of 41% in the ongoing epidemic in West Africa. There is an ever-increasing need to consolidate and make available all the knowledge that we possess on EBOV, even if it is conflicting or incomplete. This would enable biomedical researchers to understand the molecular mechanisms underlying this disease and help develop tools for efficient diagnosis and effective treatment. In this article, we present our approach for the development of an Ebola virus-centered Knowledge Base (Ebola-KB) using Linked Data and Semantic Web Technologies. We retrieve and aggregate knowledge from several open data sources, web services and biomedical ontologies. This knowledge is transformed to RDF, linked to the Bio2RDF datasets and made available through a SPARQL 1.1 Endpoint. Ebola-KB can also be explored using an interactive Dashboard visualizing the different perspectives of this integrated knowledge. We showcase how different competency questions, asked by domain users researching the druggability of EBOV, can be formulated as SPARQL Queries or answered using the Ebola-KB Dashboard. © The Author(s) 2015. Published by Oxford University Press.
Rossman, Jeremy S.; Leser, George P.
Influenza virus is pleiomorphic, producing both spherical (100-nm-diameter) and filamentous (100-nm by 20-μm) virions. While the spherical virions are known to enter host cells through exploitation of clathrin-mediated endocytosis, the entry pathway for filamentous virions has not been determined, though the existence of an alternative, non-clathrin-, non-caveolin-mediated entry pathway for influenza virus has been known for many years. In this study, we confirm recent results showing that influenza virus utilizes macropinocytosis as an alternate entry pathway. Furthermore, we find that filamentous influenza viruses use macropinocytosis as the primary entry mechanism. Virions enter cells as intact filaments within macropinosomes and are trafficked to the acidic late-endosomal compartment. Low pH triggers a conformational change in the M2 ion channel protein, altering membrane curvature and leading to a fragmentation of the filamentous virions. This fragmentation may enable more-efficient fusion between the viral and endosomal membranes. PMID:22875971
Full Text Available Jonathan G Pol, Julien Rességuier, Brian D LichtyMcMaster Immunology Research Centre, Department of Pathology and Molecular Medicine, McMaster University, Hamilton, Ontario, CanadaAbstract: Oncolytic virotherapy is currently under investigation in phase I–III clinical trials for approval as a new cancer treatment. Oncolytic viruses (OVs selectively infect, replicate in, and kill tumor cells. For a long time, the therapeutic efficacy was thought to depend on the direct viral oncolysis (virocentric view. The host immune system was considered as a brake that impaired virus delivery and spread. Attention was paid primarily to approaches enhancing virus tumor selectivity and cytotoxicity and/or that limited antiviral responses. Thinking has changed over the past few years with the discovery that OV therapy was also inducing indirect oncolysis mechanisms. Among them, induction of an antitumor immunity following OV injection appeared to be a key factor for an efficient therapeutic activity (immunocentric view. Indeed, tumor-specific immune cells persist post-therapy and can search and destroy any tumor cells that escape the OVs, and thus immune memory may prevent relapse of the disease. Various strategies, which are summarized in this manuscript, have been developed to enhance the efficacy of OV therapy with a focus on its immunotherapeutic aspects. These include genetic engineering and combination with existing cancer treatments. Several are currently being evaluated in human patients and already display promising efficacy.Keywords: oncolytic virus, cancer immunotherapy, tumor antigen, cancer vaccine, combination strategies
Ui, Hiroki; Yamayoshi, Seiya; Uraki, Ryuta; Kiso, Maki; Oishi, Kohei; Murakami, Shin; Mimori, Shigetaka; Kawaoka, Yoshihiro
Vaccination is the first line of protection against influenza virus infection in humans. Although inactivated and live-attenuated vaccines are available, each vaccine has drawbacks in terms of immunogenicity and safety. To overcome these issues, our group has developed a replication-incompetent PB2-knockout (PB2-KO) influenza virus that replicates only in PB2-expressing cells. Here we generated PB2-KO viruses possessing the hemagglutinin (HA) and neuraminidase (NA) segments from H1N1pdm09 or type B viruses and tested their vaccine potential. The two PB2-KO viruses propagated efficiently in PB2-expressing cells, and expressed chimeric HA as expected. Virus-specific IgG and IgA antibodies were detected in mice immunized with the viruses, and the immunized mice showed milder clinical signs and/or lower virus replication levels in the respiratory tract upon virus challenge. Our results indicate that these PB2-KO viruses have potential as vaccine candidates. Copyright © 2017 Elsevier Ltd. All rights reserved.
Temple, Bradley L; Finger, John W; Jones, Cheryl A; Gabbard, Jon D; Jelesijevic, Tomislav; Uhl, Elizabeth W; Hogan, Robert J; Glenn, Travis C; Tompkins, S Mark
Avian influenza has emerged as one of the most ubiquitous viruses within our biosphere. Wild aquatic birds are believed to be the primary reservoir of all influenza viruses; however, the spillover of H5N1 highly pathogenic avian influenza (HPAI) and the recent swine-origin pandemic H1N1 viruses have sparked increased interest in identifying and understanding which and how many species can be infected. Moreover, novel influenza virus sequences were recently isolated from New World bats. Crocodilians have a slow rate of molecular evolution and are the sister group to birds; thus they are a logical reptilian group to explore susceptibility to influenza virus infection and they provide a link between birds and mammals. A primary American alligator (Alligator mississippiensis) cell line, and embryos, were infected with four, low pathogenic avian influenza (LPAI) strains to assess susceptibility to infection. Embryonated alligator eggs supported virus replication, as evidenced by the influenza virus M gene and infectious virus detected in allantoic fluid and by virus antigen staining in embryo tissues. Primary alligator cells were also inoculated with the LPAI viruses and showed susceptibility based upon antigen staining; however, the requirement for trypsin to support replication in cell culture limited replication. To assess influenza virus replication in culture, primary alligator cells were inoculated with H1N1 human influenza or H5N1 HPAI viruses that replicate independent of trypsin. Both viruses replicated efficiently in culture, even at the 30 C temperature preferred by the alligator cells. This research demonstrates the ability of wild-type influenza viruses to infect and replicate within two crocodilian substrates and suggests the need for further research to assess crocodilians as a species potentially susceptible to influenza virus infection.
Wu, Guanghui; Selden, David; Fooks, Anthony R; Banyard, Ashley
Rabies virus is a notifiable pathogen that must be handled in high containment facilities where national and international guidelines apply. For the effective inactivation of rabies virus, a number of reagents were tested. Virkon S (1%) solution caused more than 4log reduction of rabies virus in culture medium supplemented with 10% foetal calf serum within 1min. Isopropyl alcohol (70%) treatment resulted in >3log reduction of rabies virus within 20s when applied at a ratio of 19:1, making it a suitable agent for surface decontamination whereas 70% ethanol was ineffective. Rabies virus (from 102.33 to 103ffu/ml) was also inactivated when cell cultures were fixed with 3% or 4% paraformaldehyde for 30min. Regardless of inactivation procedure, when taking inactivated virus preparations out of a biological containment envelope, proof of inocuity must be demonstrated to cover any possible error/deviation from procedure. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.
Full Text Available Nivesh H Sewlall,1,2 Janusz T Paweska2,3 1Department of Medicine, Morningside MediClinic, Johannesburg, South Africa; 2Department of Medicine, University of the Witwatersrand, Johannesburg, South Africa; 3Department of Medicine, National Institute for Communicable Diseases of the National Health Laboratory Service, Johannesburg, South Africa Abstract: Lujo virus (LUJV, a novel Old World arenavirus, was found to cause a fulminant viral hemorrhagic fever syndrome in an outbreak in 2008. The primary patient was from Lusaka, Zambia, and subsequent nosocomial transmission occurred to four other patients in Johannesburg, South Africa, hence the name Lujo virus. Like all arenaviruses, LUJV is a segmented, single-stranded, negative-sense RNA virus. Genomic sequencing confirmed that LUJV G1 glycoprotein was novel, diverse and genetically equidistant from other arenaviruses. A clinical syndrome resembling severe, fulminant Lassa virus infection was responsible for a high case fatality rate of 80% (4/5 cases. This review describes briefly the clinical course of the disease, laboratory findings and diagnosis. Recent studies address the current aspects of epidemiology, pathophysiology and treatments, specifically comparing with Lassa virus. Keywords: Lujo virus, viral hemorrhagic fever, outbreak, epidemiology, pathophysiology, treatment
Yu, Christine; Wales, Samantha Q; Mammel, Mark K; Hida, Kaoru; Kulka, Michael
Viruses are major pathogens causing foodborne illnesses and are often present at low levels in foods, thus requiring sensitive techniques for their detection in contaminated foods. The lack of efficient culture methods for many foodborne viruses and the potential for multi-species viral contamination have driven investigation toward non-amplification based methods for virus detection and identification. A custom DNA microarray (FDA_EVIR) was assessed for its sensitivity in the detection and identification of low-input virus targets, human hepatitis A virus, norovirus, and coxsackievirus, individually and in combination. Modifications to sample processing were made to accommodate low input levels of unamplified virus targets, which included addition of carrier cDNA, RNase treatment, and optimization of DNase I-mediated target fragmentation. Amplification-free detection and identification of foodborne viruses were achieved in the range of 250-500 copies of virus RNA. Alternative data analysis methods were employed to distinguish the genotypes of the viruses particularly at lower levels of target input and the single probe-based analysis approach made it possible to identify a minority species in a multi-virus complex. The oligonucleotide array is shown to be a promising platform to detect foodborne viruses at low levels close to what are anticipated in food or environmental samples. Published by Elsevier B.V.
Full Text Available RNA viruses have a great potential for genetic variation, rapid evolution and adaptation. Characterization of the genetic variation of viral populations provides relevant information on the processes involved in virus evolution and epidemiology and it is crucial for designing reliable diagnostic tools and developing efficient and durable disease control strategies. Here we performed an updated analysis of sequences available in Genbank and reviewed present knowledge on the genetic variability and evolutionary processes of viruses of the family Closteroviridae. Several factors have shaped the genetic structure and diversity of closteroviruses. I A strong negative selection seems to be responsible for the high genetic stability in space and time for some viruses. II Long distance migration, probably by human transport of infected propagative plant material, have caused that genetically similar virus isolates are found in distant geographical regions. III Recombination between divergent sequence variants have generated new genotypes and plays an important role for the evolution of some viruses of the family Closteroviridae. IV Interaction between virus strains or between different viruses in mixed infections may alter accumulation of certain strains. V Host change or virus transmission by insect vectors induced changes in the viral population structure due to positive selection of sequence variants with higher fitness for host-virus or vector-virus interaction (adaptation or by genetic drift due to random selection of sequence variants during the population bottleneck associated to the transmission process.
Andrea R Moore
Full Text Available Adeno-associated virus (AAV has been widely used as a gene therapy vector to treat a variety of disorders. While these vectors are increasingly popular and successful in the clinic, there is still much to learn about the viruses. Understanding the biology of these viruses is essential in engineering better vectors and generating vectors more efficiently for large-scale use. AAV requires a helper for production and replication making this aspect of the viral life cycle crucial. Vaccinia virus (VV has been widely cited as a helper virus for AAV. However, to date, there are no detailed analyses of its helper function. Here, the helper role of VV was studied in detail. In contrast to common belief, we demonstrated that VV was not a sufficient helper virus for AAV replication. Vaccinia failed to produce rAAV and activate AAV promoters. While this virus could not support rAAV production, Vaccinia could initiate AAV replication and packaging when AAV promoter activation is not necessary. This activity is due to the ability of Vaccinia-driven Rep78 to transcribe in the cytoplasm and subsequently translate in the nucleus and undergo typical functions in the AAV life cycle. As such, VV is subhelper for AAV compared to complete helper functions of adenovirus.
Son, Kwangmin; Guasto, Jeffrey S.; Cubillos-Ruiz, Andres; Chisholm, Sallie W.; Sullivan, Matthew B.; Stocker, Roman
Viruses are non-motile infectious agents that rely on Brownian motion to encounter and subsequently adsorb to their hosts. Paradoxically, the viral adsorption rate is often reported to be larger than the theoretical limit imposed by the virus-host encounter rate, highlighting a major gap in the experimental quantification of virus-host interactions. Here we present the first direct quantification of the viral adsorption rate, obtained using live imaging of individual host cells and viruses for thousands of encounter events. The host-virus pair consisted of Prochlorococcus MED4, a 800 nm small non-motile bacterium that dominates photosynthesis in the oceans, and its virus PHM-2, a myovirus that has a 80 nm icosahedral capsid and a 200 nm long rigid tail. We simultaneously imaged hosts and viruses moving by Brownian motion using two-channel epifluorescent microscopy in a microfluidic device. This detailed quantification of viral transport yielded a 20-fold smaller adsorption efficiency than previously reported, indicating the need for a major revision in infection models for marine and likely other ecosystems.
Moore, Andrea R; Dong, Biao; Chen, Lingxia; Xiao, Weidong
Adeno-associated virus (AAV) has been widely used as a gene therapy vector to treat a variety of disorders. While these vectors are increasingly popular and successful in the clinic, there is still much to learn about the viruses. Understanding the biology of these viruses is essential in engineering better vectors and generating vectors more efficiently for large-scale use. AAV requires a helper for production and replication making this aspect of the viral life cycle crucial. Vaccinia virus (VV) has been widely cited as a helper virus for AAV. However, to date, there are no detailed analyses of its helper function. Here, the helper role of VV was studied in detail. In contrast to common belief, we demonstrated that VV was not a sufficient helper virus for AAV replication. Vaccinia failed to produce rAAV and activate AAV promoters. While this virus could not support rAAV production, Vaccinia could initiate AAV replication and packaging when AAV promoter activation is not necessary. This activity is due to the ability of Vaccinia-driven Rep78 to transcribe in the cytoplasm and subsequently translate in the nucleus and undergo typical functions in the AAV life cycle. As such, VV is subhelper for AAV compared to complete helper functions of adenovirus.
Roymans, Dirk; Alnajjar, Sarhad S; Battles, Michael B; Sitthicharoenchai, Panchan; Furmanova-Hollenstein, Polina; Rigaux, Peter; Berg, Joke Van den; Kwanten, Leen; Ginderen, Marcia Van; Verheyen, Nick; Vranckx, Luc; Jaensch, Steffen; Arnoult, Eric; Voorzaat, Richard; Gallup, Jack M; Larios-Mora, Alejandro; Crabbe, Marjolein; Huntjens, Dymphy; Raboisson, Pierre; Langedijk, Johannes P; Ackermann, Mark R; McLellan, Jason S; Vendeville, Sandrine; Koul, Anil
Respiratory syncytial virus is a major cause of acute lower respiratory tract infection in young children, immunocompromised adults, and the elderly. Intervention with small-molecule antivirals specific for respiratory syncytial virus presents an important therapeutic opportunity, but no such compounds are approved today. Here we report the structure of JNJ-53718678 bound to respiratory syncytial virus fusion (F) protein in its prefusion conformation, and we show that the potent nanomolar activity of JNJ-53718678, as well as the preliminary structure-activity relationship and the pharmaceutical optimization strategy of the series, are consistent with the binding mode of JNJ-53718678 and other respiratory syncytial virus fusion inhibitors. Oral treatment of neonatal lambs with JNJ-53718678, or with an equally active close analog, efficiently inhibits established acute lower respiratory tract infection in the animals, even when treatment is delayed until external signs of respiratory syncytial virus illness have become visible. Together, these data suggest that JNJ-53718678 is a promising candidate for further development as a potential therapeutic in patients at risk to develop respiratory syncytial virus acute lower respiratory tract infection.Respiratory syncytial virus causes lung infections in children, immunocompromised adults, and in the elderly. Here the authors show that a chemical inhibitor to a viral fusion protein is effective in reducing viral titre and ameliorating infection in rodents and neonatal lambs.
Andersen, Kristian G.; Shapiro, B. Jesse; Matranga, Christian B.; Sealfon, Rachel; Lin, Aaron E.; Moses, Lina M.; Folarin, Onikepe A.; Goba, Augustine; Odia, Ikponmwonsa; Ehiane, Philomena E.; Momoh, Mambu; England, Eleina M.; Winnicki, Sarah; Branco, Luis M.; Gire, Stephen K.; Phelan, Eric; Tariyal, Ridhi; Tewhey, Ryan; Omoniwa, Omowunmi; Fullah, Mohammed; Fonnie, Richard; Fonnie, Mbalu; Kanneh, Lansana; Jalloh, Simbirie; Gbakie, Michael; Saffa, Sidiki; Karbo, Kandeh; Gladden, Adrianne D.; Qu, James; Stremlau, Matthew; Nekoui, Mahan; Finucane, Hilary K.; Tabrizi, Shervin; Vitti, Joseph J.; Birren, Bruce; Fitzgerald, Michael; McCowan, Caryn; Ireland, Andrea; Berlin, Aaron M.; Bochicchio, James; Tazon-Vega, Barbara; Lennon, Niall J.; Ryan, Elizabeth M.; Bjornson, Zach; Milner, Danny A.; Lukens, Amanda K.; Broodie, Nisha; Rowland, Megan; Heinrich, Megan; Akdag, Marjan; Schieffelin, John S.; Levy, Danielle; Akpan, Henry; Bausch, Daniel G.; Rubins, Kathleen; McCormick, Joseph B.; Lander, Eric S.; Günther, Stephan; Hensley, Lisa; Okogbenin, Sylvanus; Schaffner, Stephen F.; Okokhere, Peter O.; Khan, S. Humarr; Grant, Donald S.; Akpede, George O.; Asogun, Danny A.; Gnirke, Andreas; Levin, Joshua Z.; Happi, Christian T.; Garry, Robert F.; Sabeti, Pardis C.
Summary The 2013-2015 West African epidemic of Ebola virus disease (EVD) reminds us how little is known about biosafety level-4 viruses. Like Ebola virus, Lassa virus (LASV) can cause hemorrhagic fever with high case fatality rates. We generated a genomic catalog of almost 200 LASV sequences from clinical and rodent reservoir samples. We show that whereas the 2013-2015 EVD epidemic is fueled by human-to-human transmissions, LASV infections mainly result from reservoir-to-human infections. We elucidated the spread of LASV across West Africa and show that this migration was accompanied by changes in LASV genome abundance, fatality rates, codon adaptation, and translational efficiency. By investigating intrahost evolution, we found that mutations accumulate in epitopes of viral surface proteins, suggesting selection for immune escape. This catalog will serve as a foundation for the development of vaccines and diagnostics. PMID:26276630
Mohan, K; Weiss, G A
Specific detection of circulating tumor cells and characterization of their aggressiveness could improve cancer diagnostics and treatment. Metastasis results from such tumor cells, and causes the majority of cancer deaths. Chemically modified viruses could provide an inexpensive and efficient approach to detect tumor cells and quantitate their cell surface biomarkers. However, non-specific adhesion between the cell surface receptors and the virus surface presents a challenge. This report describes wrapping the virus surface with different PEG architectures, including as fusions to oligolysine, linkers, spacers and scaffolded ligands. The reported PEG wrappers can reduce by >75% the non-specific adhesion of phage to cell surfaces. Dynamic light scattering verified the non-covalent attachment by the reported wrappers as increased sizes of the virus particles. Further modifications resulted in specific detection of prostate cancer cells expressing PSMA, a key prostate cancer biomarker. The approach allowed quantification of PSMA levels on the cell surface, and could distinguish more aggressive forms of the disease.
Andersen, Kristian G; Shapiro, B Jesse; Matranga, Christian B; Sealfon, Rachel; Lin, Aaron E; Moses, Lina M; Folarin, Onikepe A; Goba, Augustine; Odia, Ikponmwonsa; Ehiane, Philomena E; Momoh, Mambu; England, Eleina M; Winnicki, Sarah; Branco, Luis M; Gire, Stephen K; Phelan, Eric; Tariyal, Ridhi; Tewhey, Ryan; Omoniwa, Omowunmi; Fullah, Mohammed; Fonnie, Richard; Fonnie, Mbalu; Kanneh, Lansana; Jalloh, Simbirie; Gbakie, Michael; Saffa, Sidiki; Karbo, Kandeh; Gladden, Adrianne D; Qu, James; Stremlau, Matthew; Nekoui, Mahan; Finucane, Hilary K; Tabrizi, Shervin; Vitti, Joseph J; Birren, Bruce; Fitzgerald, Michael; McCowan, Caryn; Ireland, Andrea; Berlin, Aaron M; Bochicchio, James; Tazon-Vega, Barbara; Lennon, Niall J; Ryan, Elizabeth M; Bjornson, Zach; Milner, Danny A; Lukens, Amanda K; Broodie, Nisha; Rowland, Megan; Heinrich, Megan; Akdag, Marjan; Schieffelin, John S; Levy, Danielle; Akpan, Henry; Bausch, Daniel G; Rubins, Kathleen; McCormick, Joseph B; Lander, Eric S; Günther, Stephan; Hensley, Lisa; Okogbenin, Sylvanus; Schaffner, Stephen F; Okokhere, Peter O; Khan, S Humarr; Grant, Donald S; Akpede, George O; Asogun, Danny A; Gnirke, Andreas; Levin, Joshua Z; Happi, Christian T; Garry, Robert F; Sabeti, Pardis C
The 2013-2015 West African epidemic of Ebola virus disease (EVD) reminds us of how little is known about biosafety level 4 viruses. Like Ebola virus, Lassa virus (LASV) can cause hemorrhagic fever with high case fatality rates. We generated a genomic catalog of almost 200 LASV sequences from clinical and rodent reservoir samples. We show that whereas the 2013-2015 EVD epidemic is fueled by human-to-human transmissions, LASV infections mainly result from reservoir-to-human infections. We elucidated the spread of LASV across West Africa and show that this migration was accompanied by changes in LASV genome abundance, fatality rates, codon adaptation, and translational efficiency. By investigating intrahost evolution, we found that mutations accumulate in epitopes of viral surface proteins, suggesting selection for immune escape. This catalog will serve as a foundation for the development of vaccines and diagnostics. VIDEO ABSTRACT. Copyright © 2015 Elsevier Inc. All rights reserved.
Komarova, Natalia L; Anghelina, Daniela; Voznesensky, Igor; Trinité, Benjamin; Levy, David N; Wodarz, Dominik
Human immunodeficiency virus can spread through target cells by transmission of cell-free virus or directly from cell-to-cell via formation of virological synapses. Although cell-to-cell transmission has been described as much more efficient than cell-free infection, the relative contribution of the two transmission pathways to virus growth during multiple rounds of replication remains poorly defined. Here, we fit a mathematical model to previously published and newly generated in vitro data, and determine that free-virus and synaptic transmission contribute approximately equally to the growth of the virus population.
Hyman, Paul; Abedon, Stephen T.
Life forms can be roughly differentiated into those that are microscopic versus those that are not as well as those that are multicellular and those that, instead, are unicellular. Cellular organisms seem generally able to host viruses, and this propensity carries over to those that are both microscopic and less than truly multicellular. These viruses of microorganisms, or VoMs, in fact exist as the world's most abundant somewhat autonomous genetic entities and include the viruses of domain Bacteria (bacteriophages), the viruses of domain Archaea (archaeal viruses), the viruses of protists, the viruses of microscopic fungi such as yeasts (mycoviruses), and even the viruses of other viruses (satellite viruses). In this paper we provide an introduction to the concept of viruses of microorganisms, a.k.a., viruses of microbes. We provide broad discussion particularly of VoM diversity. VoM diversity currently spans, in total, at least three-dozen virus families. This is roughly ten families per category—bacterial, archaeal, fungal, and protist—with some virus families infecting more than one of these microorganism major taxa. Such estimations, however, will vary with further discovery and taxon assignment and also are dependent upon what forms of life one includes among microorganisms. PMID:24278736
Dennehy, John J
The cross-species transmission of viruses into new host populations, termed virus emergence, is a significant issue in public health, agriculture, wildlife management, and related fields. Virus emergence requires overlap between host populations, alterations in virus genetics to permit infection of new hosts, and adaptation to novel hosts such that between-host transmission is sustainable, all of which are the purview of the fields of ecology and evolution. A firm understanding of the ecology of viruses and how they evolve is required for understanding how and why viruses emerge. In this paper, I address the evolutionary mechanisms of virus emergence and how they relate to virus ecology. I argue that, while virus acquisition of the ability to infect new hosts is not difficult, limited evolutionary trajectories to sustained virus between-host transmission and the combined effects of mutational meltdown, bottlenecking, demographic stochasticity, density dependence, and genetic erosion in ecological sinks limit most emergence events to dead-end spillover infections. Despite the relative rarity of pandemic emerging viruses, the potential of viruses to search evolutionary space and find means to spread epidemically and the consequences of pandemic viruses that do emerge necessitate sustained attention to virus research, surveillance, prophylaxis, and treatment. © 2016 New York Academy of Sciences.
Full Text Available Life forms can be roughly differentiated into those that are microscopic versus those that are not as well as those that are multicellular and those that, instead, are unicellular. Cellular organisms seem generally able to host viruses, and this propensity carries over to those that are both microscopic and less than truly multicellular. These viruses of microorganisms, or VoMs, in fact exist as the world’s most abundant somewhat autonomous genetic entities and include the viruses of domain Bacteria (bacteriophages, the viruses of domain Archaea (archaeal viruses, the viruses of protists, the viruses of microscopic fungi such as yeasts (mycoviruses, and even the viruses of other viruses (satellite viruses. In this paper we provide an introduction to the concept of viruses of microorganisms, a.k.a., viruses of microbes. We provide broad discussion particularly of VoM diversity. VoM diversity currently spans, in total, at least three-dozen virus families. This is roughly ten families per category—bacterial, archaeal, fungal, and protist—with some virus families infecting more than one of these microorganism major taxa. Such estimations, however, will vary with further discovery and taxon assignment and also are dependent upon what forms of life one includes among microorganisms.
Debing, Yannick; Winton, James; Neyts, Johan; Dallmeier, Kai
Hepatitis E virus (HEV) is one of the most important causes of acute hepatitis worldwide. Although most infections are self-limiting, mortality is particularly high in pregnant women. Chronic infections can occur in transplant and other immune-compromised patients. Successful treatment of chronic hepatitis E has been reported with ribavirin and pegylated interferon-alpha, however severe side effects were observed. We employed the cutthroat trout virus (CTV), a non-pathogenic fish virus with remarkable similarities to HEV, as a potential surrogate for HEV and established an antiviral assay against this virus using the Chinook salmon embryo (CHSE-214) cell line. Ribavirin and the respective trout interferon were found to efficiently inhibit CTV replication. Other known broad-spectrum inhibitors of RNA virus replication such as the nucleoside analog 2′-C-methylcytidine resulted only in a moderate antiviral activity. In its natural fish host, CTV levels largely fluctuate during the reproductive cycle with the virus detected mainly during spawning. We wondered whether this aspect of CTV infection may serve as a surrogate model for the peculiar pathogenesis of HEV in pregnant women. To that end the effect of three sex steroids on in vitro CTV replication was evaluated. Whereas progesterone resulted in marked inhibition of virus replication, testosterone and 17β-estradiol stimulated viral growth. Our data thus indicate that CTV may serve as a surrogate model for HEV, both for antiviral experiments and studies on the replication biology of the Hepeviridae.
Lowery, D Thomas; Vickers, Patricia M; Bittner, Lori A; Stobbs, Lorne W; Foottit, Robert G
Utilization of timed virus acquisition access probes in studies of plum pox virus (PPV) transmission by aphids demonstrated that endemic species transmitted the virus readily from plum, Prunus domestica (L.) Batsch; peach, P. persica (L.); or dwarf flowering almond, P. glandulosa Thunberg., to peach seedlings. The green peach aphid, Myzus persicae (Sulzer), was shown to be the most efficient vector. Acquisition of virus by green peach aphids from infected peach leaves resulted in 18-28% infected peach seedlings, while aphids previously fed on infected leaves of plum transferred virus to 36% of peach seedlings. Although the spirea aphid, Aphis spiraecola (Patch), was a less efficient vector than M. persicae it is perhaps more important for the spread of PPV due to its greater abundance and occurrence earlier in the season when peach trees are thought to be more susceptible to infection. Virus transmission rates varied depending on the virus source and healthy test plant species. In contrast to many previous studies, aphid inoculation of the experimental host Nicotiana benthamiana Domin occurred at a low rate, never exceeding 4%. Acquisition of PPV by M. persicae from infected peach fruit was greatly reduced compared with acquisition from leaves. The results of this research indicate that the Ontario isolate of PPV-D is readily transmissible by aphids to peach and natural spread of the virus needs to be considered in future management or eradication programs. © Her Majesty in Right of Canada, as represented by the Minister of Agriculture and Agri-Food Canada. Published by Oxford University Press on behalf of Entomological Society of America.
Takamatsu, Yuki; Uchida, Leo; Morita, Kouichi
West Nile virus (WNV) and Japanese encephalitis virus (JEV) are important causes of human encephalitis cases, which result in a high mortality ratio and neurological sequelae after recovery. Understanding the mechanism of neuropathogenicity in these viral infections is important for the development of specific antiviral therapy. Here, we focused on human-derived neuronal and glial cells to understand the cellular responses against WNV and JEV infection. It was demonstrated that early IFN-β induction regulated virus replication in glioblastoma tbl98G cells, whereas delayed IFN-β induction resulted in efficient virus replication in neuroblastoma SK-N-SH cells. Moreover, the concealing of viral dsRNA in the intracellular membrane resulted in the delayed IFN response in SK-N-SH cells. These results, which showed different IFN responses between human neuronal and glial cells after WNV or JEV infection, are expected to contribute to our understanding of the molecular mechanisms for neuropathology in these viral infections.
... Pandemic Other Avian Influenza A Virus Infections in Humans Language: English (US) Español Recommend on Facebook Tweet ... A Viruses Avian Influenza A Virus Infections in Humans Although avian influenza A viruses usually do not ...
Picone, O; Vauloup-Fellous, C; D'Ortenzio, E; Huissoud, C; Carles, G; Benachi, A; Faye, A; Luton, D; Paty, M-C; Ayoubi, J-M; Yazdanpanah, Y; Mandelbrot, L; Matheron, S
A Zika virus epidemic is currently ongoing in the Americas. This virus is linked to congenital infections with potential severe neurodevelopmental dysfunction. However, incidence of fetal infection and whether this virus is responsible of other fetal complications are still unknown. National and international public health authorities recommend caution and several prevention measures. Declaration of Zika virus infection is now mandatory in France. Given the available knowledge on Zika virus, we suggest here a review of the current recommendations for management of pregnancy in case of suspicious or infection by Zika virus in a pregnant woman. Copyright © 2016 Elsevier Masson SAS. All rights reserved.
Full Text Available Viruses are known to be abundant, ubiquitous, and to play a very important role in the health and evolution of life organisms. However, most biologists have considered them as entities separate from the realm of life and acting merely as mechanical artifacts that can exchange genes between different organisms. This article reviews some definitions of life organisms to determine if viruses adjust to them, and additionally, considers new discoveries to challenge the present definition of viruses. Definitions of life organisms have been revised in order to validate how viruses fit into them. Viral factories are discussed since these mini-organelles are a good example of the complexity of viral infection, not as a mechanical usurpation of cell structures, but as a driving force leading to the reorganization and modification of cell structures by viral and cell enzymes. New discoveries such as the Mimivirus, its virophage and viruses that produce filamentous tails when outside of their host cell, have stimulated the scientific community to analyze the current definition of viruses. One way to be free for innovation is to learn from life, without rigid mental structures or tied to the past, in order to understand in an integrated view the new discoveries that will be unfolded in future research. Life processes must be looked from the complexity and trans-disciplinarity perspective that includes and accepts the temporality of the active processes of life organisms, their interdependency and interrelation among them and their environment. New insights must be found to redefine life organisms, especially viruses, which still are defined using the same concepts and knowledge of the fifties. Rev. Biol. Trop. 59 (3: 993-998. Epub 2011 September 01.