Objective: To express human Vascular endothelial growth factor121(VEGF121) in insect cells. Methods: A gene construct containing VEGF was cloned in the p Fast Bac-HTA vector, followed by transformation in DH10 BAC. Th...Objective: To express human Vascular endothelial growth factor121(VEGF121) in insect cells. Methods: A gene construct containing VEGF was cloned in the p Fast Bac-HTA vector, followed by transformation in DH10 BAC. The recombinant bacmid was then extracted, and transfected into Sf9 insect cells. The transfected cells were harvested, and then VEGF expression was confirmed by Western blotting using specific antibodies. The tube formation assay was used for functional assessment of VEGF. Results: Our results showed that VEGF could be successfully expressed in the baculovirus system. Purified VEGF was able to stimulate in vitro tube formation of human endothelial cells. Conclusions: Results from this study demonstrated that the recombinantly-produced VEGF can be considered as a promising candidate for therapeutic purposes.展开更多
The microsporidian spore wall proteins, as the main components of the spore wall, play a key role in spore adherence to host cells and in recognition of the parasite by the host during the invasion process. In this st...The microsporidian spore wall proteins, as the main components of the spore wall, play a key role in spore adherence to host cells and in recognition of the parasite by the host during the invasion process. In this study, we used the Bac-to-Bac baculovirus expression system to express the spore wall protein SWP26, fused to enhanced green fluorescent protein (EGFP), in the silkworm BmN cell line. The SWP26 and EGFP genes were inserted into the baculovirus transfer vector pFastBac1. The transfer vector pFastBac1-swp26-egfp was transformed into the bacterium Escherichia coli DHl0Bac/Bombyx mori nucleopolyhedrovirus (BmNPV) to construct the recombinant vBmswp26-egfp bacmid. The vBmswp26-egfp bacmid DNA was then used to transfect BmN cells to obtain the recombinant baculovirus. Western blotting analysis of total protein lysates in BmN cells infected by the recombinant virus showed a protein band of approximately 51 kDa, which corresponded to the deduced molecular weight of the swp26-egfp fusion protein. In addition, a fluorescence signal was observed in the cytoplasm and nucleoplasm of transfected cells, indicating that SWP26 had been successfully expressed in BmN cells. The SWP26 expression system established in this study lays the foundation for additional molecular and cellular studies, especially those focused on the interaction between the SWP26 protein of Nosema bombycis and the proteins of the silkworm, Bombyx mori.展开更多
This paper describes a rapid method of constructing homologous recombinant baculovirus in E. coli with PCR-amplified fragments. By using this method, the traditional steps of constructing transfer vector are omitted. ...This paper describes a rapid method of constructing homologous recombinant baculovirus in E. coli with PCR-amplified fragments. By using this method, the traditional steps of constructing transfer vector are omitted. The method is based on phage l red system which can promote the recombination between the homologous fragments with the length above 36 bp. Taking HaSNPV as an example, this paper describes the rapid recombination process by using chloramphenicol resistance gene (CmR) to replace orf135 in HaSNPV genome. A pair of primers with length of 60 bp was synthesized, in which 40 bp was homologous to the each end sequence of orf135, and the rest 20 bp was homologous to the each end sequence of CmR. By using these primers, a linear fragment containing the complete CmR gene between 40 bp of homologous arms of orf135 was generated by PCR with the plasmid pKD3 which contains CmR as the template. By transforming the linear fragment into the E. coli containing the bacterial artificial chromosome of HaSNPV and with the help of a plasmid expressing l recombinase, the recombinants on which the homologue replacement had taken place were selected by chloramphenicol resistance. This method greatly shortens the process of constructing recombinant baculovirus since the process was performed in E. coli and does not need to construct transfer vectors. It can be further used for gene replacement and gene deletion of other large viral genomes.展开更多
基金supported financially by Iran National Science Foundation(INSF)grant number 91004026
文摘Objective: To express human Vascular endothelial growth factor121(VEGF121) in insect cells. Methods: A gene construct containing VEGF was cloned in the p Fast Bac-HTA vector, followed by transformation in DH10 BAC. The recombinant bacmid was then extracted, and transfected into Sf9 insect cells. The transfected cells were harvested, and then VEGF expression was confirmed by Western blotting using specific antibodies. The tube formation assay was used for functional assessment of VEGF. Results: Our results showed that VEGF could be successfully expressed in the baculovirus system. Purified VEGF was able to stimulate in vitro tube formation of human endothelial cells. Conclusions: Results from this study demonstrated that the recombinantly-produced VEGF can be considered as a promising candidate for therapeutic purposes.
文摘The microsporidian spore wall proteins, as the main components of the spore wall, play a key role in spore adherence to host cells and in recognition of the parasite by the host during the invasion process. In this study, we used the Bac-to-Bac baculovirus expression system to express the spore wall protein SWP26, fused to enhanced green fluorescent protein (EGFP), in the silkworm BmN cell line. The SWP26 and EGFP genes were inserted into the baculovirus transfer vector pFastBac1. The transfer vector pFastBac1-swp26-egfp was transformed into the bacterium Escherichia coli DHl0Bac/Bombyx mori nucleopolyhedrovirus (BmNPV) to construct the recombinant vBmswp26-egfp bacmid. The vBmswp26-egfp bacmid DNA was then used to transfect BmN cells to obtain the recombinant baculovirus. Western blotting analysis of total protein lysates in BmN cells infected by the recombinant virus showed a protein band of approximately 51 kDa, which corresponded to the deduced molecular weight of the swp26-egfp fusion protein. In addition, a fluorescence signal was observed in the cytoplasm and nucleoplasm of transfected cells, indicating that SWP26 had been successfully expressed in BmN cells. The SWP26 expression system established in this study lays the foundation for additional molecular and cellular studies, especially those focused on the interaction between the SWP26 protein of Nosema bombycis and the proteins of the silkworm, Bombyx mori.
基金supported partly by the National Natural Science Foundation of China(Grant Nos.30025003&30070034)the Hundreds-Talent Program and Knowledge Innovation Program(Grant No.kscx2-1-02,kscx2-SW-301-09)of the Chinese Academy of Sciences.
文摘This paper describes a rapid method of constructing homologous recombinant baculovirus in E. coli with PCR-amplified fragments. By using this method, the traditional steps of constructing transfer vector are omitted. The method is based on phage l red system which can promote the recombination between the homologous fragments with the length above 36 bp. Taking HaSNPV as an example, this paper describes the rapid recombination process by using chloramphenicol resistance gene (CmR) to replace orf135 in HaSNPV genome. A pair of primers with length of 60 bp was synthesized, in which 40 bp was homologous to the each end sequence of orf135, and the rest 20 bp was homologous to the each end sequence of CmR. By using these primers, a linear fragment containing the complete CmR gene between 40 bp of homologous arms of orf135 was generated by PCR with the plasmid pKD3 which contains CmR as the template. By transforming the linear fragment into the E. coli containing the bacterial artificial chromosome of HaSNPV and with the help of a plasmid expressing l recombinase, the recombinants on which the homologue replacement had taken place were selected by chloramphenicol resistance. This method greatly shortens the process of constructing recombinant baculovirus since the process was performed in E. coli and does not need to construct transfer vectors. It can be further used for gene replacement and gene deletion of other large viral genomes.
