The Experts below are selected from a list of 201 Experts worldwide ranked by ideXlab platform
Gaiping Zhang - One of the best experts on this subject based on the ideXlab platform.
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unravelling the receptor binding property of egg drop syndrome virus edsv from the crystal structure of edsv fiber head
International Journal of Biological Macromolecules, 2019Co-Authors: Yapeng Song, Qiang Wei, Yunchao Liu, Hua Feng, Yumei Chen, Yanwei Wang, Yilin Bai, Guangxu Xing, Ruiguang Deng, Gaiping ZhangAbstract:Abstract Egg drop syndrome virus (EDSV) is an Avian Adenovirus that causes markedly decrease in egg production, and in the quality of the eggs when it infects chickens. Until now, EDSV virus-cell interactions are poorly understood, and the cellular receptor is still unknown. In the present study, we determined the atomic structure of the fiber head of EDSV (residues 377–644) at 2.74 A resolution. Structure comparison with the (chick embryo lethal orphan) CELO long fiber head and human Adenovirus fiber heads reveals that the Avian Adenovirus may interact with the same attachment factor in a unique fashion. Based on the previous studies of CELO virus, we assumed that the chicken coxsackievirus and Adenovirus receptor (CAR) may be the attachment factor. We then demonstrate that the chicken CAR serves as a cellular attachment factor for EDSV based on three lines of evidences. Taken together, the results presented here are helpful for further exploring the pathogenesis related to the interaction between EDSV and host cells, and may be used for vaccine development and intervention strategies against EDSV infection.
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development of novel subunit vaccine based on truncated fiber protein of egg drop syndrome virus and its immunogenicity in chickens
Virus Research, 2019Co-Authors: Yapeng Song, Qiang Wei, Yunchao Liu, Yilin Bai, Guangxu Xing, Ruiguang Deng, Gaiping ZhangAbstract:Abstract Egg-drop syndrome virus (EDSV) is an Avian Adenovirus that causes markedly decrease in egg production and in the quality of the eggs when it infects chickens. In this report, we engineered truncated fiber protein containing the entire knob domain and part of the shaft region as a vaccine candidate. The protein was obtained in the soluble fraction in Escherichia coli (E. coli), and expression level after nickel-affinity purification was 126 mg/L. By means of multiple characterization methods, it is demonstrated that the recombinant protein retains the native trimeric structure. A single inoculation with the structure-stabilized recombinant protein, even at the lowest dose of 2 μg, stimulated hemagglutination inhibition (HI) antibody responses in chickens, for at least 16 weeks. Neutralizing titers in sera from the protein immunized groups was similar to that of inactivated vaccine immunized group. The lymphocyte proliferation response and cytokine secretion were also induced in immunized SPF chickens. In addition, immunization with the fiber protein also significantly reduced the viral load in the liver. Taken together, these results suggest the truncated fiber protein as an effective single dose, long lasting and rapidly effective vaccine to protect against EDSV.
Matthew Cotten - One of the best experts on this subject based on the ideXlab platform.
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defining car as a cellular receptor for the Avian Adenovirus celo using a genetic analysis of the two viral fibre proteins
Journal of General Virology, 2001Co-Authors: Poi Kiang Tan, Anneisabelle Michou, Jeffrey M Bergelson, Matthew CottenAbstract:The coxsackievirus and Adenovirus receptor (CAR) is a high affinity receptor used by Adenoviruses, including Adenovirus type 5 (Ad5). The Adenovirus fibre molecule bears the high affinity cell binding domain of Ad5, allowing virions to attach to CAR. The Avian Adenovirus CELO displays two fibre molecules on its capsid and it was logical to expect that the cell binding functions of CELO might also reside in one or both of these fibres. We had previously shown that the cell binding properties of CELO resemble Ad5, suggesting that the two viruses use similar receptors. Experiments with CAR-deficient CHO cells and CHO cells modified to express CAR demonstrated that CELO has CAR-dependent transduction behaviour like Ad5. Mutations were introduced into the CELO genome to disrupt either the long fibre 1 or the short fibre 2. A CELO genome with fibre 2 disrupted did not generate virus, demonstrating that fibre 2 is essential for some stage in virus growth, assembly or spread. However, a CELO genome with disrupted fibre 1 gene produced virus (CELOdF1) that was capable of entering chicken cells, but had lost both the ability to efficiently transduce human cells and the CAR-specific transduction displayed by wild-type CELO. The ability of CELOdF1 to transduce chicken cells suggests that CELOdF1 may still bind, probably via fibre 2, to a receptor expressed on Avian but not mammalian cells. CELOdF1 replication was dramatically impaired in chicken embryos, demonstrating that fibre 1 is important for the in vivo biology of CELO.
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mutational analysis of the Avian Adenovirus celo which provides a basis for gene delivery vectors
Journal of Virology, 1999Co-Authors: Anneisabelle Michou, Heike Lehrmann, Mediyha Saltik, Matthew CottenAbstract:The Avian Adenovirus CELO is being developed as a gene transfer tool. Using homologous recombination in Escherichia coli, the CELO genome was screened for regions that could be deleted and would tolerate the insertion of a marker gene (luciferase or enhanced green fluorescent protein). For each mutant genome, the production of viable virus able to deliver the transgene to target cells was monitored. A series of mutants in the genome identified a set of open reading frames that could be deleted but which must be supplied in trans for virus replication. A region of the genome which is dispensable for viral replication and allows the insertion of an expression cassette was identified and a vector based on this mutation was evaluated as a gene delivery reagent. Transduction of Avian cells occurs at 10- to 100-fold greater efficiency (per virus particle) than with an Adenovirus type 5 (Ad5)-based vector carrying the same expression cassette. Most important for gene transfer applications, the CELO vector transduced mammalian cells as efficiently as an Ad5 vector. The CELO vector is exceptionally stable, can be grown inexpensively in chicken embryos, and provides a useful alternative to Ad5-based vectors.
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the complete dna sequence and genomic organization of the Avian Adenovirus celo
Journal of Virology, 1996Co-Authors: Susanna Chiocca, Robert Kurzbauer, Gotthold Schaffner, Adam Baker, Vivien Mautner, Matthew CottenAbstract:The complete DNA sequence of the Avian Adenovirus chicken embryo lethal orphan (CELO) virus (FAV-1) is reported here. The genome was found to be 43,804 bp in length, approximately 8 kb longer than those of the human subgenus C Adenoviruses (Ad2 and Ad5). This length is supported by pulsed-field gel electrophoresis analysis of genomes isolated from several related FAV-1 isolates (Indiana C and OTE). The genes for major viral structural proteins (Illa, penton base, hexon, pVI, and pVIII), as well as the 52,000-molecular-weight (52K) and 100K proteins and the early-region 2 genes and IVa2, are present in the expected locations in the genome. CELO virus encodes two fiber proteins and a different set of the DNA-packaging core proteins, which may be important in condensing the longer CELO virus genome. No pV or pIX genes are present. Most surprisingly, CELO virus possesses no identifiable E1, E3, and E4 regions. There is 5 kb at the left end of the CELO virus genome and 15 kb at the right end with no homology to Ad2. The sequences are rich in open reading frames, and it is likely that these encode functions that replace the missing El, E3, and E4 functions.
Patrick Langlois - One of the best experts on this subject based on the ideXlab platform.
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crystallization of the c terminal head domain of the Avian Adenovirus celo long fibre
Acta Crystallographica Section F-structural Biology and Crystallization Communications, 2006Co-Authors: Pablo Guardado Calvo, Patrick Langlois, Antonio L Llamassaiz, Mark J Van RaaijAbstract:Avian Adenovirus CELO contains two different fibres: fibre 1, the long fibre, and fibre 2, the short fibre. The short fibre is responsible for binding to an unknown Avian receptor and is essential for infection of birds. The long fibre is not essential, but is known to bind the coxsackievirus and Adenovirus receptor protein. Both trimeric fibres are attached to the same penton base, of which each icosahedral virus contains 12 copies. The short fibre extends straight outwards, while the long fibre emerges at an angle. The carboxy-terminal amino acids 579–793 of the Avian Adenovirus long fibre have been expressed with an amino-terminal hexahistidine tag and the expressed trimeric protein has been purified by nickel-affinity chromatography and crystallized. Crystals were grown at low pH using PEG 10 000 as precipitant and belonged to space group C2. The crystals diffracted rotating-anode Cu Kα radiation to at least 1.9 A resolution and a complete data set was collected from a single crystal to 2.2 A resolution. Unit-cell parameters were a = 216.5, b = 59.2, c = 57.5 A, β = 101.3°, suggesting one trimer per asymmetric unit and a solvent content of 46%. The long fibre head does not have significant sequence homology to any other protein of known structure and molecular-replacement attempts with known fibre-head structures were unsuccessful. However, a map calculated using SIRAS phasing shows a clear trimer with a shape similar to known Adenovirus fibre-head structures. Structure solution is in progress.
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deletion of open reading frames 9 10 and 11 from the Avian Adenovirus celo genome effect on biodistribution and humoral responses
Journal of General Virology, 2005Co-Authors: Frederick Le Goff, Andre Jestin, Isabelle Mederlemangeot, Patrick LangloisAbstract:In this study, the in vivo effect of the 3.6 kbp deletion of the three open reading frames (ORF) 9, 10 and 11 found at the right end of the CELO genome was examined. Groups of chickens were inoculated oronasally with 10(5)-10(7) p.f.u. per animal of wild-type virus and two recombinant CELO strains (rCELO) expressing luciferase and secreted alkaline phosphatase (SEAP). The tissue biodistribution, assessed by PCR, was similar for both wild-type and recombinant viruses. The infectious viral particle titre was determined by a p.f.u. counting method and the antibody responses to the CELO vector and the SEAP antigen were evaluated by ELISA. Infectious particle titres in tissues from chickens inoculated with the wild-type CELO virus increased up to 6 days post-inoculation, and declined until 11 days while titres in organs from chickens inoculated with the rCELO strain were low and only detectable at 4 days post-inoculation. Moreover, although anti-CELO antibody levels were three times lower in sera from chickens inoculated with rCELO, antibodies directed to the heterologous SEAP antigen were detected. Based on these results, no differences in tropism were observed, but the level of production of viral particles and the humoral responses appeared to decrease. Viruses replicate less efficiently with a deletion performed at the right end of the CELO genome. Nevertheless, the presence of antibodies directed to heterologous antigens makes the CELO virus an advantageous candidate for Avian vaccination.
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Avian Adenovirus celo recombinants expressing vp2 of infectious bursal disease virus induce protection against bursal disease in chickens
Vaccine, 2004Co-Authors: Achille Francois, Nicolas Eterradossi, Bernard Delmas, Christophe Chevalier, Didier Toquin, G Rivallan, Patrick LangloisAbstract:To develop a CELO virus vector that can induce protection against infectious bursal disease, CELO viruses expressing the host-protective antigen VP2 of infectious bursal disease virus (IBDV) were constructed. In the engineered recombinants, the VP2 gene (the 441-first codons of the IBDA polyprotein) was placed under the control of the CMV promoter. Two positions in the CELO genome were chosen to insert the VP2 expression cassette. The recombinants were found apathogenic, when inoculated by different routes and even at high doses (up to 10(8) per animal). Chickens vaccinated oro-nasally with these different recombinants and challenged with very virulent IBDV were found to be poorly protected. In contrast, when inoculated with one or two (subcutaneous or intradermic) injections of CELOa-VP2, the chickens showed no clinical signs and no mortality after challenge. In the vaccinated chickens, the titers of neutralization antibody reached 7-9 values, showing that protection could be explained by the induction of a sufficient humoral response. After challenge, the weight ratio Bursa of Fabricius/body was about 2.5 per thousand, a value similar to that obtained with the commercial Bur706 vaccine. However, histological lesions in the Bursa of Fabricius were observed, showing that a complete protection was not totally achieved. Contact transmission was evidenced. Protection was also obtained when inoculation of CELOa-VP2 was carried out in ovo. Prime-boost strategies were also tested with the CELOa-VP2 vector used in association with the purified VP2 antigen, or DNA encoding VP2 or a CELO vector expressing chicken myeloid growth factor (cMGF). None of these regimens were shown to substantially increase the level of protection when compared to double CELOa-VP2 inoculations. These results indicate that CELO-based vectors are useful to safely induce a strong protective immunity against vvIBDV in chickens.
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construction of Avian Adenovirus celo recombinants in cosmids
Journal of Virology, 2001Co-Authors: Achille Francois, Vincent Payet, Nicolas Eterradossi, Bernard Delmas, Patrick LangloisAbstract:The Avian Adenovirus CELO is a promising vector for gene transfer applications. In order to study this potentiality, we developed an improved method for construction of Adenovirus vectors in cosmids that was used to engineer the CELO genome. For all the recombinant viruses constructed by this method, the ability to produce infectious particles and the stability of the genome were evaluated in a chicken hepatocarcinoma cell line (LMH cell line). Our aim was to develop a replication-competent vector for vaccination of chickens, so we first generated knockout point mutations into 16 of the 22 unassigned CELO open reading frames (ORFs) to determine if they were essential for virus replication. As the 16 independent mutant viruses replicated in our cellular system, we constructed CELO genomes with various deletions in the regions of these nonessential ORFs. An expression cassette coding for the enhanced green fluorescent protein (eGFP) was inserted in place of these deletions to easily follow expression of the transgene and propagation of the vector in cell monolayers. Height-distinct GFP-expressing CELO vectors were produced that were all replication competent in our system. We then retained the vector backbone with the largest deletion (i.e., 3.6 kb) for the construction of vectors carrying cDNA encoding infectious bursal disease virus proteins. These CELO vectors could be useful for vaccination in the chicken species.
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transcriptional organization of the Avian Adenovirus celo
Journal of Virology, 1998Co-Authors: Vincent Payet, Claire Arnauld, Jeanpaul Picault, Andre Jestin, Patrick LangloisAbstract:A detailed map of the transcriptional organization of the CELO virus genome was produced. Recent computer analysis of CELO virus has indicated the presence of 38 putative open reading frames (ORFs). This study, based on analysis of the transcriptional products of CELO in vitro, confirmed the presence of RNAs for 26 of these 38 ORFs. All of the results were obtained by cDNA isolation or specific reverse transcriptase PCR. Observation of ORF transcription kinetics postinfection revealed the existence of early and late expression, with the earliest starting at 2 h postinfection. The 5′ untranslated regions of some RNAs were also studied, and this revealed the existence of a bipartite leader sequence, comparable in structure to the tripartite leader of mastAdenovirus. The leader most probably involved in transcriptional activity was observed in most of the structural protein genes of the CELO virus genome. This suggests some homology in transcriptional organization between the Avian Adenovirus CELO and known mastAdenoviruses such as human Adenovirus.
D Goldberg - One of the best experts on this subject based on the ideXlab platform.
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the complete dna sequence and genome organization of the Avian Adenovirus hemorrhagic enteritis virus
Virology, 1998Co-Authors: J Pitcovski, M Mualem, Z Reikoren, S Krispel, E Shmueli, Y Peretz, B Gutter, G Gallili, Amnon Michael, D GoldbergAbstract:Hemorrhagic enteritis virus (HEV) belongs to the Adenoviridae family, a subgroup of Adenoviruses (Ads) that infect Avian species. In this article, the complete DNA sequence and the genome organization of the virus are described. The full-length of the genome was found to be 26,263 bp, shorter than the DNA of any other Ad described so far. The G + C content of the genome is 34.93%. There are short terminal repeats (39 bp), as described for other Ads. Genes were identified by comparison of the DNA and predicted amino acid sequences with published sequences of other Ads. The organization of the genome in respect to late genes (52K, IIIa, penton base, core protein, hexon, endopeptidase, 100K, pVIII, and fiber), early region 2 genes (polymerase, terminal protein, and DNA binding protein), and intermediate gene IVa2 was found to be similar to that of other human and Avian Ad genomes. No sequences similar to E1 and E4 regions were found. Very low similarity to ovine E3 region was found. Open reading frames were identified with no similarity to any published Ad sequence.
Yapeng Song - One of the best experts on this subject based on the ideXlab platform.
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unravelling the receptor binding property of egg drop syndrome virus edsv from the crystal structure of edsv fiber head
International Journal of Biological Macromolecules, 2019Co-Authors: Yapeng Song, Qiang Wei, Yunchao Liu, Hua Feng, Yumei Chen, Yanwei Wang, Yilin Bai, Guangxu Xing, Ruiguang Deng, Gaiping ZhangAbstract:Abstract Egg drop syndrome virus (EDSV) is an Avian Adenovirus that causes markedly decrease in egg production, and in the quality of the eggs when it infects chickens. Until now, EDSV virus-cell interactions are poorly understood, and the cellular receptor is still unknown. In the present study, we determined the atomic structure of the fiber head of EDSV (residues 377–644) at 2.74 A resolution. Structure comparison with the (chick embryo lethal orphan) CELO long fiber head and human Adenovirus fiber heads reveals that the Avian Adenovirus may interact with the same attachment factor in a unique fashion. Based on the previous studies of CELO virus, we assumed that the chicken coxsackievirus and Adenovirus receptor (CAR) may be the attachment factor. We then demonstrate that the chicken CAR serves as a cellular attachment factor for EDSV based on three lines of evidences. Taken together, the results presented here are helpful for further exploring the pathogenesis related to the interaction between EDSV and host cells, and may be used for vaccine development and intervention strategies against EDSV infection.
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development of novel subunit vaccine based on truncated fiber protein of egg drop syndrome virus and its immunogenicity in chickens
Virus Research, 2019Co-Authors: Yapeng Song, Qiang Wei, Yunchao Liu, Yilin Bai, Guangxu Xing, Ruiguang Deng, Gaiping ZhangAbstract:Abstract Egg-drop syndrome virus (EDSV) is an Avian Adenovirus that causes markedly decrease in egg production and in the quality of the eggs when it infects chickens. In this report, we engineered truncated fiber protein containing the entire knob domain and part of the shaft region as a vaccine candidate. The protein was obtained in the soluble fraction in Escherichia coli (E. coli), and expression level after nickel-affinity purification was 126 mg/L. By means of multiple characterization methods, it is demonstrated that the recombinant protein retains the native trimeric structure. A single inoculation with the structure-stabilized recombinant protein, even at the lowest dose of 2 μg, stimulated hemagglutination inhibition (HI) antibody responses in chickens, for at least 16 weeks. Neutralizing titers in sera from the protein immunized groups was similar to that of inactivated vaccine immunized group. The lymphocyte proliferation response and cytokine secretion were also induced in immunized SPF chickens. In addition, immunization with the fiber protein also significantly reduced the viral load in the liver. Taken together, these results suggest the truncated fiber protein as an effective single dose, long lasting and rapidly effective vaccine to protect against EDSV.
