To obtain the P8 protein of Rice gall dwarf virus (RGDV) with biological activity,its outer coat protein gene S8 was expressed in Spodoptera frugiperda (Sf9) insect cells using the baculovirus expression system.The S8...To obtain the P8 protein of Rice gall dwarf virus (RGDV) with biological activity,its outer coat protein gene S8 was expressed in Spodoptera frugiperda (Sf9) insect cells using the baculovirus expression system.The S8 gene was subcloned into the pFastBacTM1 vector,to produce the recombinant baculovirus transfer vector pFB-S8.After transformation,pFB-S8 was introduced into the competent cells (E.coli DH10Bac) containing a shuttle vector,Bacmid,generating the recombinant bacmid rbpFB-S8.After being infected by recombinant baculovirus rvpFB-S8 at different multiplicities of infection,Sf9 cells were collected at different times and analyzed by SDS-PAGE,Western blotting and immunofluorescence microscopy.The expression level of the P8 protein was highest between 48-72 h after transfection of Sf9 cells.Immunofluorescence microscopy showed that P8 protein of RGDV formed punctate structures in the cytoplasm of Sf9 cells.展开更多
The polyhedrin (polh) gene is often used to analyse evolution of baculovirus. In this report, the polh of Antheraea pernyi nucleopolyhedro-virus (AnpeNPV) was cloned and sequenced. The Open reading frame (ORF) of the ...The polyhedrin (polh) gene is often used to analyse evolution of baculovirus. In this report, the polh of Antheraea pernyi nucleopolyhedro-virus (AnpeNPV) was cloned and sequenced. The Open reading frame (ORF) of the AnpeNPV consists of 738 nucleotides encoding 245 amino acids with molecular masses of 29 kDa. The deduced amino acids were significant homol-ogy with other baculoviruses, such as Attacus ricini NPV (ArNPV) and Autographa californica NPV (AcNPV). A strongly hydrophilic region was predicted at positions from 30 to 50 of the An-peNPV Polh protein by bioinformatics analysis. Expression of the polh gene of AnpeNPV in E. coli was examined by SDS–PAGE, Western blot and Mass-spectrum analysis. The result showed that the bacterium expression system was suitable for the virus gene expression. It indi-cated that the products of the polh gene ex-pressed in this system can be easier to use for raising antibodies.展开更多
In the baculovirus shuttle vector(bacmid) system, a helper plasmid and a donor plasmid are employed to insert heterologous genes into a cloned baculovirus genome via Tn7 transposition in Escherichia coli. The helper a...In the baculovirus shuttle vector(bacmid) system, a helper plasmid and a donor plasmid are employed to insert heterologous genes into a cloned baculovirus genome via Tn7 transposition in Escherichia coli. The helper and donor plasmids are usually cotransfected with constructed bacmids into insect cells, which will lead to integration of these plasmids into the viral genome,and hence to the production of defective virions. In this study, to facilitate the preparation of plasmid-free recombinant bacmids, we modified a set of helper and donor plasmids by replacing their replication origins with that of a temperature-sensitive(ts) plasmid, p SIM6. Using the resulting ts helper plasmid p MON7124 ts and the ts donor plasmid p FB1ts-PH-GFP, a recombinant bacmid,b Ac WT-PG(-), was constructed, and the transposition efficiency was found to be 33.1%. The plasmids were then removed by culturing at 37 °C. For b Ac WT-PG(-), the infectious progeny virus titer and the protein expression level under the control of the polyhedrin promoter were similar to those of a bacmid constructed with unmodified helper and donor plasmids. These ts plasmids will be useful for obtaining plasmid-free bacmids for both heterologous protein production and fundamental studies of baculovirus biology.展开更多
AcNPV (Autographa californica nuclear polyhedrosis virus) and BmNPV(Bombyx mori nuclear polyhedrosis virus) are two principal insect-baculovirus expression systems, each having different characteristics. AcNPV has a w...AcNPV (Autographa californica nuclear polyhedrosis virus) and BmNPV(Bombyx mori nuclear polyhedrosis virus) are two principal insect-baculovirus expression systems, each having different characteristics. AcNPV has a wider host range and can infect a series of cell lines thus making it suitable for cell suspension culture expression, but the small size of the host insect, A. californica, makes AcNPV less suitable for large scale protein synthesis. In contrast, BmNPV can only infect the silkworm, Bombyx mori, which is well-known for its easy rearing and large size. These characteristics make the BmNPV system especially suitable for large-scale industrial ex-pression. To utilize the advantages of both AcNPV and BmNPV, we tried to expand their host range through homologous recombination and successfully constructed a hybrid baculovirus of AcNPV and BmNPV, designated as HyNPV. The hybrid baculovirus can infect the hosts of both AcNPV and BmNPV. Taking the human basic fibroblast growth factor (bFGF) gene as an appli-cation example, we constructed a recombinant, HyNPV-bFGF. This construct is able to express the bFGF protein both in silkworm larvae and in common-use cell lines, sf21, sf9 and High-five. Moreover, to reduce the loss of recombinant protein due to degradation by proteases that are simultaneously expressed by the baculovirus, we knocked out the cysteinase gene coding for one of the most important baculovirus proteases. This knockout mutation improves the produc-tion efficiency of the bFGF recombinant protein.展开更多
将中和性流行性感冒 (流感 )病毒基因工程抗体IV 2、IV 6的轻链和重链Fd段基因 ,分别克隆入全抗体表达载体 pAC L Fc ,构建成杆状病毒表达载体pAC L Fc Ⅳ 2和 pAC L Fc Ⅳ 6 ,转染昆虫Sf9细胞 ,利用杆状病毒 /昆虫细胞系统实现抗体...将中和性流行性感冒 (流感 )病毒基因工程抗体IV 2、IV 6的轻链和重链Fd段基因 ,分别克隆入全抗体表达载体 pAC L Fc ,构建成杆状病毒表达载体pAC L Fc Ⅳ 2和 pAC L Fc Ⅳ 6 ,转染昆虫Sf9细胞 ,利用杆状病毒 /昆虫细胞系统实现抗体的分泌型表达 ,表达产物进行亲和层析分离纯化。SDS PAGE电泳和Westernblot法证实有完整免疫球蛋白的表达 ,免疫印迹法证实它们能与流感病毒血凝素蛋白特异性结合。经间接竞争性抑制ELISA法测定 ,抗体与流感病毒抗原结合的解离常数KD 值分别为 2 5× 10 -9M和 3 0× 10 -9M。流感病毒基因工程全抗体经在昆虫细胞中的表达、纯化和抗体特性鉴定 ,获得了两株纯化的全抗体 ,可用于以后的动物模型呼吸道粘膜被动免疫抗感染的研究。展开更多
基金supported by the National Science Foundation of China (30970135)The Key Project of Genetically Modified Organisms Breeding(2009ZX08009-044B)+1 种基金the Natural Science Foundation of Fujian Province of China (No.2006J0065)the Public-interest Scientific Institution Basal Research Fund of Fujian Province (2009R10029-3)
文摘To obtain the P8 protein of Rice gall dwarf virus (RGDV) with biological activity,its outer coat protein gene S8 was expressed in Spodoptera frugiperda (Sf9) insect cells using the baculovirus expression system.The S8 gene was subcloned into the pFastBacTM1 vector,to produce the recombinant baculovirus transfer vector pFB-S8.After transformation,pFB-S8 was introduced into the competent cells (E.coli DH10Bac) containing a shuttle vector,Bacmid,generating the recombinant bacmid rbpFB-S8.After being infected by recombinant baculovirus rvpFB-S8 at different multiplicities of infection,Sf9 cells were collected at different times and analyzed by SDS-PAGE,Western blotting and immunofluorescence microscopy.The expression level of the P8 protein was highest between 48-72 h after transfection of Sf9 cells.Immunofluorescence microscopy showed that P8 protein of RGDV formed punctate structures in the cytoplasm of Sf9 cells.
文摘The polyhedrin (polh) gene is often used to analyse evolution of baculovirus. In this report, the polh of Antheraea pernyi nucleopolyhedro-virus (AnpeNPV) was cloned and sequenced. The Open reading frame (ORF) of the AnpeNPV consists of 738 nucleotides encoding 245 amino acids with molecular masses of 29 kDa. The deduced amino acids were significant homol-ogy with other baculoviruses, such as Attacus ricini NPV (ArNPV) and Autographa californica NPV (AcNPV). A strongly hydrophilic region was predicted at positions from 30 to 50 of the An-peNPV Polh protein by bioinformatics analysis. Expression of the polh gene of AnpeNPV in E. coli was examined by SDS–PAGE, Western blot and Mass-spectrum analysis. The result showed that the bacterium expression system was suitable for the virus gene expression. It indi-cated that the products of the polh gene ex-pressed in this system can be easier to use for raising antibodies.
基金supported by the National Nature Science Foundation of China (31370188)Shenzhen Municipal Development and Reform Commission (Shenzhen Research and Development Center,Code:[2012]318)
文摘In the baculovirus shuttle vector(bacmid) system, a helper plasmid and a donor plasmid are employed to insert heterologous genes into a cloned baculovirus genome via Tn7 transposition in Escherichia coli. The helper and donor plasmids are usually cotransfected with constructed bacmids into insect cells, which will lead to integration of these plasmids into the viral genome,and hence to the production of defective virions. In this study, to facilitate the preparation of plasmid-free recombinant bacmids, we modified a set of helper and donor plasmids by replacing their replication origins with that of a temperature-sensitive(ts) plasmid, p SIM6. Using the resulting ts helper plasmid p MON7124 ts and the ts donor plasmid p FB1ts-PH-GFP, a recombinant bacmid,b Ac WT-PG(-), was constructed, and the transposition efficiency was found to be 33.1%. The plasmids were then removed by culturing at 37 °C. For b Ac WT-PG(-), the infectious progeny virus titer and the protein expression level under the control of the polyhedrin promoter were similar to those of a bacmid constructed with unmodified helper and donor plasmids. These ts plasmids will be useful for obtaining plasmid-free bacmids for both heterologous protein production and fundamental studies of baculovirus biology.
文摘AcNPV (Autographa californica nuclear polyhedrosis virus) and BmNPV(Bombyx mori nuclear polyhedrosis virus) are two principal insect-baculovirus expression systems, each having different characteristics. AcNPV has a wider host range and can infect a series of cell lines thus making it suitable for cell suspension culture expression, but the small size of the host insect, A. californica, makes AcNPV less suitable for large scale protein synthesis. In contrast, BmNPV can only infect the silkworm, Bombyx mori, which is well-known for its easy rearing and large size. These characteristics make the BmNPV system especially suitable for large-scale industrial ex-pression. To utilize the advantages of both AcNPV and BmNPV, we tried to expand their host range through homologous recombination and successfully constructed a hybrid baculovirus of AcNPV and BmNPV, designated as HyNPV. The hybrid baculovirus can infect the hosts of both AcNPV and BmNPV. Taking the human basic fibroblast growth factor (bFGF) gene as an appli-cation example, we constructed a recombinant, HyNPV-bFGF. This construct is able to express the bFGF protein both in silkworm larvae and in common-use cell lines, sf21, sf9 and High-five. Moreover, to reduce the loss of recombinant protein due to degradation by proteases that are simultaneously expressed by the baculovirus, we knocked out the cysteinase gene coding for one of the most important baculovirus proteases. This knockout mutation improves the produc-tion efficiency of the bFGF recombinant protein.
