The Experts below are selected from a list of 1596 Experts worldwide ranked by ideXlab platform
Ziguo Yuan - One of the best experts on this subject based on the ideXlab platform.
-
recombinant Canine Adenovirus type 2 expressing tgrop16 provides partial protection against acute toxoplasma gondii infection in mice
Infection Genetics and Evolution, 2016Co-Authors: Xu Zhang, Xiuxiang Zhang, Xiaohu Wang, Kenneth Yongabi Anchang, Auwalu Yusuf Abdullahi, Lijun Xia, Weili Feng, Ziguo YuanAbstract:Abstract We previously demonstrated that the survival time of BALB/c mice challenged with Toxoplasma gondii RH strain was prolonged by immunising the mice with a eukaryotic vector expressing the protein ROP16 of T. gondii. Building upon previous findings, we are exploring improved vaccination strategies to enhance protection. In this work, a novel recombinant Canine Adenovirus type 2 expressing ROP16 (CAV-2-ROP16) of T. gondii was constructed and identified to express ROP16 in Madin-Darby Canine kidney cells (MDCK) cells by western blot (WB) and indirect immunofluorescence (IFA) assays. Intramuscular immunisation of BALB/c mice with CAV-2-ROP16 was performed to evaluate the humoral and cellular immune responses. This vaccination triggered significant humoral and cellular responses, including ROP16-stimulated lymphoproliferation (P 0.05), revealing that a predominant Th1-type response had developed. The cell-mediated cytotoxic activity with high levels of IFN-γ and TNF-α was significantly increased in both CD4+ and CD8+ T-cell compartments in the mice immunised with CAV-2-ROP16 (P
-
generation of e3 deleted Canine Adenovirus type 2 expressing the gc glycoprotein of seoul virus by gene insertion or deletion of related terminal region sequences
Journal of General Virology, 2010Co-Authors: Ziguo Yuan, Xiaohu Wang, Shengjun Luo, Liguo Yuan, Xiuxiang ZhangAbstract:Seoul virus (SEOV) is one of the four hantaviruses known to cause haemorrhagic fever with renal syndrome. The medium genome segment encodes the Gn/Gc glycoproteins of SEOV, which form the major structural part of the virus envelope. Gc and/or Gn are the candidate antigens of hantavirus for induction of a highly immunogenic response for hantavirus vaccine. In this study, the immune response induced by a replication-competent recombinant Canine Adenovirus type 2 expressing the Gc protein of SEOV was evaluated in BALB/c mice. Sera from immunized mice contained neutralizing antibodies that could specifically recognize SEOV and neutralize its infectivity in vitro. Moreover, the recombinant virus induced complete protection against an intensive infectious challenge with ∼1000 50 % infective doses for SEOV strain CC-2. Protective-level neutralizing antibodies were maintained for at least 20 weeks. This recombinant virus is therefore a potential alternative to the inactivated vaccine.
-
a single immunization with a recombinant Canine Adenovirus type 2 expressing the seoul virus gn glycoprotein confers protective immunity against seoul virus in mice
Vaccine, 2009Co-Authors: Ziguo Yuan, Xiuxiang Zhang, Xiaohu Wang, Yasser S MahmmodAbstract:Seoul virus (SEOV), a member of hantavirus genus, is one of the causative agents of hemorrhagic fever with renal syndrome (HFRS) and afflicts tens of thousands of people annually. In this paper, we evaluate the immune response induced by a replication-competent recombinant Canine Adenovirus type 2 expressing the Gn protein of SEOV (rCAV-2-Gn) in BALB/c mice. Sera from immunized mice contained neutralizing antibodies that could specifically recognize SEOV and neutralize its infectivity in vitro. Moreover, the recombinant virus induced complete protection against a lethal challenge with the highly virulent SEOV strain CC-2. Protective level neutralizing antibodies were maintained for at least 20 weeks. The efficacy of the recombinant was similar to that induced by a currently available inactivated HFRS vaccine. This recombinant virus is therefore a potential alternative to the inactivated vaccine.
-
development of recombinant Canine Adenovirus type 2 expressing the gn glycoprotein of seoul virus
Biologicals, 2008Co-Authors: Ziguo Yuan, Y. Liu, Xiuxiang Zhang, Shoufeng Zhang, Shengyan Gao, Fei Zhang, Xiaohu WangAbstract:Seoul virus glycoprotein Gn is a major structural protein and candidate antigen of hantavirus that induces a highly immunogenic response for hantavirus vaccine. In this study, a replication-competent recombinant Canine Adenovirus type-2 expressing Gn was constructed by the in vitro ligation method. The Gn expression cassette, including the human cytomegalovirus (hCMV) promoter/enhancer and the SV40 early mRNA polyadenylation signal, was cloned into the SspI site of the E3 region which is not essential for proliferation of CAV-2. Expression of Gn was confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.
Xiuxiang Zhang - One of the best experts on this subject based on the ideXlab platform.
-
recombinant Canine Adenovirus type 2 expressing tgrop16 provides partial protection against acute toxoplasma gondii infection in mice
Infection Genetics and Evolution, 2016Co-Authors: Xu Zhang, Xiuxiang Zhang, Xiaohu Wang, Kenneth Yongabi Anchang, Auwalu Yusuf Abdullahi, Lijun Xia, Weili Feng, Ziguo YuanAbstract:Abstract We previously demonstrated that the survival time of BALB/c mice challenged with Toxoplasma gondii RH strain was prolonged by immunising the mice with a eukaryotic vector expressing the protein ROP16 of T. gondii. Building upon previous findings, we are exploring improved vaccination strategies to enhance protection. In this work, a novel recombinant Canine Adenovirus type 2 expressing ROP16 (CAV-2-ROP16) of T. gondii was constructed and identified to express ROP16 in Madin-Darby Canine kidney cells (MDCK) cells by western blot (WB) and indirect immunofluorescence (IFA) assays. Intramuscular immunisation of BALB/c mice with CAV-2-ROP16 was performed to evaluate the humoral and cellular immune responses. This vaccination triggered significant humoral and cellular responses, including ROP16-stimulated lymphoproliferation (P 0.05), revealing that a predominant Th1-type response had developed. The cell-mediated cytotoxic activity with high levels of IFN-γ and TNF-α was significantly increased in both CD4+ and CD8+ T-cell compartments in the mice immunised with CAV-2-ROP16 (P
-
generation of e3 deleted Canine Adenovirus type 2 expressing the gc glycoprotein of seoul virus by gene insertion or deletion of related terminal region sequences
Journal of General Virology, 2010Co-Authors: Ziguo Yuan, Xiaohu Wang, Shengjun Luo, Liguo Yuan, Xiuxiang ZhangAbstract:Seoul virus (SEOV) is one of the four hantaviruses known to cause haemorrhagic fever with renal syndrome. The medium genome segment encodes the Gn/Gc glycoproteins of SEOV, which form the major structural part of the virus envelope. Gc and/or Gn are the candidate antigens of hantavirus for induction of a highly immunogenic response for hantavirus vaccine. In this study, the immune response induced by a replication-competent recombinant Canine Adenovirus type 2 expressing the Gc protein of SEOV was evaluated in BALB/c mice. Sera from immunized mice contained neutralizing antibodies that could specifically recognize SEOV and neutralize its infectivity in vitro. Moreover, the recombinant virus induced complete protection against an intensive infectious challenge with ∼1000 50 % infective doses for SEOV strain CC-2. Protective-level neutralizing antibodies were maintained for at least 20 weeks. This recombinant virus is therefore a potential alternative to the inactivated vaccine.
-
a single immunization with a recombinant Canine Adenovirus type 2 expressing the seoul virus gn glycoprotein confers protective immunity against seoul virus in mice
Vaccine, 2009Co-Authors: Ziguo Yuan, Xiuxiang Zhang, Xiaohu Wang, Yasser S MahmmodAbstract:Seoul virus (SEOV), a member of hantavirus genus, is one of the causative agents of hemorrhagic fever with renal syndrome (HFRS) and afflicts tens of thousands of people annually. In this paper, we evaluate the immune response induced by a replication-competent recombinant Canine Adenovirus type 2 expressing the Gn protein of SEOV (rCAV-2-Gn) in BALB/c mice. Sera from immunized mice contained neutralizing antibodies that could specifically recognize SEOV and neutralize its infectivity in vitro. Moreover, the recombinant virus induced complete protection against a lethal challenge with the highly virulent SEOV strain CC-2. Protective level neutralizing antibodies were maintained for at least 20 weeks. The efficacy of the recombinant was similar to that induced by a currently available inactivated HFRS vaccine. This recombinant virus is therefore a potential alternative to the inactivated vaccine.
-
development of recombinant Canine Adenovirus type 2 expressing the gn glycoprotein of seoul virus
Biologicals, 2008Co-Authors: Ziguo Yuan, Y. Liu, Xiuxiang Zhang, Shoufeng Zhang, Shengyan Gao, Fei Zhang, Xiaohu WangAbstract:Seoul virus glycoprotein Gn is a major structural protein and candidate antigen of hantavirus that induces a highly immunogenic response for hantavirus vaccine. In this study, a replication-competent recombinant Canine Adenovirus type-2 expressing Gn was constructed by the in vitro ligation method. The Gn expression cassette, including the human cytomegalovirus (hCMV) promoter/enhancer and the SV40 early mRNA polyadenylation signal, was cloned into the SspI site of the E3 region which is not essential for proliferation of CAV-2. Expression of Gn was confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and Western blotting.
H U Rongliang - One of the best experts on this subject based on the ideXlab platform.
-
construction of recombinant Canine Adenovirus type 2 expressing rabies virus glycoprotein
Virologica Sinica, 2005Co-Authors: Zhang Shoufeng, H U Rongliang, Xiao Yueqiang, Tian Xiangyang, Xia XianzhuAbstract:To construct a new type of vaccine for dog Rabies prevention, Canine Adenovirus type-2 was developed for Rabies virus glycoprotein expression. A 1044bp fragment of the E3 region of Canine Adenovirus type-2 in plasmid pVAX-E3(7.86kb) was deleted by Dra Ⅲ/SspⅠdouble digestion, and an expression cassette of 2424bp in length, composed of the cytomegalovirus immediately early promoter, Rabies virus strain SRV_9 glycoprotein cDNA and SV40 polyadenylation signal, was cloned into the deleted site. The NruⅠ-SalⅠfragment of pPolyⅡ-CAV-2 excluding the E3 region and the NruⅠ-SalⅠfragment of pVAX-E3 containing the expression cassette of the Rabies virus glycoprotein were recombined into pPolyⅡ-CAV2-CGS. The recombinant CAV-2 genome was released by AscⅠ/ClaⅠdigestion and was transfected into MDCK cells by Lipofectamine~(TM) 2000. Canine Adenovirus typical CPE and the recombinant virus, CAV-2-CGS, were observed 8 d after transfection. Rabies virus glycoprotein expression was confirmed by Western blotting analysis. ˎ,Verdana,Arial; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">Preliminary immunization trial in dogs showed that the recombinant virus could stimulate specific immune response to both vector virus and Rabies virus .
-
construction of deleted e3 vector of Canine Adenovirus type 2 expressin g foreign genes
Chinese journal of veterinary science, 2003Co-Authors: H U RongliangAbstract:To construct E3 expression vectors of Canine ad enovirus for engineered vaccine recombination,2 pairs of primers each containing a BglⅡ site at the beginning and at the end of E3 were designed and synthesize d.PCR based quick mutations were performed,resulting in a recombinant plasmid pB E3 M.The region between the two BglⅡ sites was deleted,producing a plasmid pBE 3Δ.Multiple clonal sites were introduced into pBE3Δ at BglⅡ site,giving rise to a plasmid pBE3L.Using these base vectors,two candidate expression vectors of green fluorescent protein(GFP) with and without foreign promoters were construct ed,an d named as pBE3LGFP and pBE3LCGFP,respectively.Expression of the two candidate e xpression vectors was identified by transfecting them into DK cells.The results showed that pBE3LCGFP was expressive by fluorescent microscope observation.While pBE3LGFP could not be expressed.It is demonstrated that foreign promoter was ne cessary for gene expression in deleted E3 region of Canine Adenovirus type 2.
-
cloning and identification of the full length infectious genome of Canine Adenovirus type 2
Chinese journal of veterinary science, 2002Co-Authors: H U RongliangAbstract:A 1 013 bp fragment (U) at the left end and a 972 bp fragment(D) at the right end of the genome of Canine Adenovirus type-2(CAV-2) strain YCA18 were separately amplified by PCR.They were then cloned into plamid pPoly2 with direction from left fragment to right fragment,resulting in a rescue plasmid pPoly2-UD.The pPoly2-UD was linearized by HindⅢ and BstBⅠ digestion and was cotransformed with the purified CAV-2 genome into competent E.coli Sure TM.Recombinant plasmids harboring the full CAV-2 genome were obtained after bacterial intermolecular homologous recombination.One of the recombinant plasmids,pPoly2-CAV-2,was further identified by enzyme digestion analysis and sequencing.The cloned CAV-2 genome was amplified in plasmid form,released by ClaⅠ/AscⅠ double digestion,and transfected into MDCK cells by Lipofectamine mediated transformation.Retransfection of the transfected MDCK cells was performed after three passages.Typical cytopathogenic effect was observed 4 days after retransfection.The virus Heamagglutination to human red blood cell can be inhibited by anti-CAV-2 sera.All above demonstrated that an infectious CAV-2 genome in plasmid form was gained and this laid a solid foundation for further manipulating the genome as a live vaccine vector.
Xia Xianzhu - One of the best experts on this subject based on the ideXlab platform.
-
construction of recombinant Canine Adenovirus type 2 expressing rabies virus glycoprotein
Virologica Sinica, 2005Co-Authors: Zhang Shoufeng, H U Rongliang, Xiao Yueqiang, Tian Xiangyang, Xia XianzhuAbstract:To construct a new type of vaccine for dog Rabies prevention, Canine Adenovirus type-2 was developed for Rabies virus glycoprotein expression. A 1044bp fragment of the E3 region of Canine Adenovirus type-2 in plasmid pVAX-E3(7.86kb) was deleted by Dra Ⅲ/SspⅠdouble digestion, and an expression cassette of 2424bp in length, composed of the cytomegalovirus immediately early promoter, Rabies virus strain SRV_9 glycoprotein cDNA and SV40 polyadenylation signal, was cloned into the deleted site. The NruⅠ-SalⅠfragment of pPolyⅡ-CAV-2 excluding the E3 region and the NruⅠ-SalⅠfragment of pVAX-E3 containing the expression cassette of the Rabies virus glycoprotein were recombined into pPolyⅡ-CAV2-CGS. The recombinant CAV-2 genome was released by AscⅠ/ClaⅠdigestion and was transfected into MDCK cells by Lipofectamine~(TM) 2000. Canine Adenovirus typical CPE and the recombinant virus, CAV-2-CGS, were observed 8 d after transfection. Rabies virus glycoprotein expression was confirmed by Western blotting analysis. ˎ,Verdana,Arial; mso-font-kerning: 1.0pt; mso-bidi-font-family: 'Times New Roman'; mso-fareast-font-family: 宋体; mso-ansi-language: EN-US; mso-fareast-language: ZH-CN; mso-bidi-language: AR-SA">Preliminary immunization trial in dogs showed that the recombinant virus could stimulate specific immune response to both vector virus and Rabies virus .
-
construction and packaging of recombinant Canine Adenovirus type 2 expression nucleocapsid protein of Canine distemper virus
Journal of Jilin Agricultural University, 2005Co-Authors: Ju Huiyan, Xia Xianzhu, Gao Yuwei, Li Yanfang, Yang SongtaoAbstract:The expression cassette of the Canine distemper virus nucleocapsid(CDV N) was released from pVAXLPN plasmid by digestion with MluⅠand SphⅠin order to construct recombinant Canine Adenovirus type-2(CAV-2) expression nucleocapsid protein of Canine distempter virus.Then the CDV N expression cassette was blunted and ligated into(SspⅠ) site of pVAXΔE3 plasmid so that transferring vector plasmid pVAXΔE3LPN was constructed.After pVAXΔE3LPN plasmid was digested with NruⅠ and(SalⅠ),the objective fragment containing the CDV N expression cassette and some of Adenovirus E3 regions were extracted and cloned into ppoly2-CAV-2 plasmid which was digested with the same enzyme in order to generate recombinant plasmid pCAV-2-CDVLPN.The linearization genosome CAV-2-CDVLPN was obtained after recombinant plasmid pCAV-2-CDVLPN was digested with AscⅠ.The CAV-2-CDVLPN was mixed with the segments of CAV-2 SY genosome digested with SalⅠand NruⅠ.Then the mixture was co-transfected into MDCK cells by Lipofectamine.After three transfections,typical CAV-2 cytopathic effect(CPE) was observed by microscope.It was proved that recombinant Canine Adenovirus type-2 expression nucleocapsid protein of Canine distemper virus was successfully packed by electr on microscope observation and enzyme digestion.
E J Kremer - One of the best experts on this subject based on the ideXlab platform.
-
Evaluation of helper-dependent Canine Adenovirus vectors in a 3D human CNS model
Gene Therapy, 2016Co-Authors: D Simão, P Fernandes, S. Salinas, C. Pinto, C.j. Peddie, S. Piersanti, L.m. Collinson, I. Saggio, G. Schiavo, E J KremerAbstract:Gene therapy is a promising approach with enormous potential for treatment of neurodegenerative disorders. Viral vectors derived from Canine Adenovirus type 2 (CAV-2) present attractive features for gene delivery strategies in the human brain, by preferentially transducing neurons, are capable of efficient axonal transport to afferent brain structures, have a 30-kb cloning capacity and have low innate and induced immunogenicity in preclinical tests. For clinical translation, in-depth preclinical evaluation of efficacy and safety in a human setting is primordial. Stem cell-derived human neural cells have a great potential as complementary tools by bridging the gap between animal models, which often diverge considerably from human phenotype, and clinical trials. Herein, we explore helper-dependent CAV-2 (hd-CAV-2) efficacy and safety for gene delivery in a human stem cell-derived 3D neural in vitro model. Assessment of hd-CAV-2 vector efficacy was performed at different multiplicities of infection, by evaluating transgene expression and impact on cell viability, ultrastructural cellular organization and neuronal gene expression. Under optimized conditions, hd-CAV-2 transduction led to stable long-term transgene expression with minimal toxicity. hd-CAV-2 preferentially transduced neurons, whereas human Adenovirus type 5 (HAdV5) showed increased tropism toward glial cells. This work demonstrates, in a physiologically relevant 3D model, that hd-CAV-2 vectors are efficient tools for gene delivery to human neurons, with stable long-term transgene expression and minimal cytotoxicity.
-
bioprocess development for Canine Adenovirus type 2 vectors
Gene Therapy, 2013Co-Authors: P Fernandes, C Peixoto, V M Santiago, E J Kremer, A S Coroadinha, P M AlvesAbstract:Canine Adenovirus type 2 (CAV-2) vectors overcome many of the clinical immunogenic concerns related to vectors derived from human Adenoviruses (AdVs). In addition, CAV-2 vectors preferentially transduce neurons with an efficient traffic via axons to afferent regions when injected into the brain. To meet the need for preclinical and possibly clinical uses, scalable and robust production processes are required. CAV-2 vectors are currently produced in E1-transcomplementing dog kidney (DK) cells, which might raise obstacles in regulatory approval for clinical grade material production. In this study, a GMP-compliant bioprocess was developed. An MDCK-E1 cell line, developed by our group, was grown in scalable stirred tank bioreactors, using serum-free medium, and used to produce CAV-2 vectors that were afterwards purified using column chromatographic steps. Vectors produced in MDCK-E1 cells were identical to those produced in DK cells as assessed by SDS-PAGE and dynamic light scatering measurements (diameter and Zeta potential). Productivities of ∼10(9) infectious particles (IP) ml(-1) and 2 × 10(3) IP per cell were possible. A downstream process using technologies transferable to process scales was developed, yielding 63% global recovery. The total particles to IP ratio in the purified product (<20:1) was within the limits specified by the regulatory authorities for AdV vectors. These results constitute a step toward a scalable process for CAV-2 vector production compliant with clinical material specifications.
-
SGSH gene transfer in mucopolysaccharidosis type IIIA mice using Canine Adenovirus vectors
Molecular Genetics and Metabolism, 2010Co-Authors: A. A. Lau, E J Kremer, J. J. Hopwood, K. M. HemsleyAbstract:Many viral backbones have been used as gene transfer vectors. However, the efficacy of therapy based on human-derived vectors may be limited by the high incidence of pre-existing humoral and cellular memory immunity. To circumvent some of the clinical disadvantages of vectors derived from common human pathogens, we have used an E1-deleted vector derived from a xenogenic Adenovirus, Canine Adenovirus serotype 2 (CAV-2) to ameliorate neuropathological changes associated with the lysosomal storage disorder, mucopolysaccharidosis type IIIA (MPS IIIA). This presently untreatable condition is caused by N-sulfoglucosamine sulfohydrolase (SGSH) deficiency and is characterized by heparan sulfate accumulation and progressive neurodegeneration. Injection of CAV-SGSH-GFP into the thalamus of adult MPS IIIA mouse brain resulted in short-term gene expression. In contrast, intra-ventricular injection of newborn mice yielded dose-dependent transgene expression which persisted for at least 20-weeks and improved neuropathology. Together, these studies suggest that this E1-deleted CAV-2 vector is capable of mediating regional medium-term gene expression and facilitating improvements in neuropathology in MPS IIIA mice.
-
An update on Canine Adenovirus type 2 and its vectors
Viruses, 2010Co-Authors: T. Bru, S. Salinas, E J KremerAbstract:Adenovirus vectors have significant potential for long- or short-term gene transfer. Preclinical and clinical studies using human derived Adenoviruses (HAd) have demonstrated the feasibility of flexible hybrid vector designs, robust expression and induction of protective immunity. However, clinical use of HAd vectors can, under some conditions, be limited by pre-existing vector immunity. Pre-existing humoral and cellular anti-capsid immunity limits the efficacy and duration of transgene expression and is poorly circumvented by injections of larger doses and immuno-suppressing drugs. This review updates Canine Adenovirus serotype 2 (CAV-2, also known as CAdV-2) biology and gives an overview of the generation of early region 1 (E1)-deleted to helper-dependent (HD) CAV-2 vectors. We also summarize the essential characteristics concerning their interaction with the anti-HAd memory immune responses in humans, the preferential transduction of neurons, and its high level of retrograde axonal transport in the central and peripheral nervous system. CAV-2 vectors are particularly interesting tools to study the pathophysiology and potential treatment of neurodegenerative diseases, as anti-tumoral and anti-viral vaccines, tracer of synaptic junctions, oncolytic virus and as a platform to generate chimeric vectors.
-
Structural and mutational analysis of human Ad37 and Canine Adenovirus 2 fiber heads in complex with the D1 domain of coxsackie and Adenovirus receptor.
Journal of Biological Chemistry, 2006Co-Authors: Elena Seiradake, E J Kremer, Hugues Lortat-jacob, Olivier Billet, Stephen CusackAbstract:Adenovirus fibers from most serotypes bind the D1 domain of coxsackie and Adenovirus receptor (CAR), although the binding residues are not strictly conserved. To understand this further, we determined the crystal structures of Canine Adenovirus serotype 2 (CAV-2) and the human Adenovirus serotype 37 (HAd37) in complex with human CAR D1 at 2.3 and 1.5A resolution, respectively. Structure comparison with the HAd12 fiber head-CAR D1 complex showed that the overall topology of the interaction is conserved but that the interfaces differ in number and identity of interacting residues, shape complementarity, and degree of conformational adaptation. Using surface plasmon resonance, we characterized the binding affinity to CAR D1 of wild type and mutant CAV-2 and HAd37 fiber heads. We found that CAV-2 has the highest affinity but fewest direct interactions, with the reverse being true for HAd37. Moreover, we found that conserved interactions can have a minor contribution, whereas serotype-specific interactions can be essential. These results are discussed in the light of virus evolution and design of Adenovirus vectors for gene transfer.
