A novel coronavirus, severe acute respiratory syndrome (SA RS)-associated coronavirus (SARS-CoV), has been identified as the causal agent of SARS. Spike (S) protein is a major structural glycoprotein of the SARS virus...A novel coronavirus, severe acute respiratory syndrome (SA RS)-associated coronavirus (SARS-CoV), has been identified as the causal agent of SARS. Spike (S) protein is a major structural glycoprotein of the SARS virus and a potential target for SARS-specific cell-mediated immune responses. A pa nel of S protein-derived peptides was tested for their binding affinity to HLA -A *0201 molecules. Peptides with high affinity for HLA-A *0201 were then as se ssed for their capacity to elicit specific immune responses mediated by cytotoxi c T lymphocytes (CTLs) both in vivo, in HLA-A2.1/K b transgenic mice, a nd in vitro, from peripheral blood lymphocytes (PBLs) harvested from healthy HLA-A 2.1 + donors. SARS-CoV protein-derived peptide-1 (SSp-1 RLNEVAKNL), induced pepti de-specific CTLs both in vivo (transgenic mice) and in vitro (human PBL s), which specifically released interferon-gamma (IFN-gamma) upon stimulation with SSp-1-pulsed autologous dendritic cells (DCs) or T2 cells. SSp-1-specif ic CTLs also lysed major histocompatibility complex (MHC)-matched tumor cell lines engineered to express S proteins. HLA-A *0201-SSp-1 tetramer staining re vealed the presence of significant populations of SSp-1-specific CTLs in SSp- 1-induced CD8 + T cells. We propose that the newly identified epitope SSp-1 w ill help in the characterization of virus control mechanisms and immunopathology in SARS-CoV infection, and may be relevant to the development of immunotherape utic approaches for SARS.展开更多
AIM： To find a soluble and functional recombinant receptor-binding domain of severe acute respiratory syndrome-associated coronavirus （SARS-Cov）, and to analyze its receptor binding ability. METHODS： Three fusion ...AIM： To find a soluble and functional recombinant receptor-binding domain of severe acute respiratory syndrome-associated coronavirus （SARS-Cov）, and to analyze its receptor binding ability. METHODS： Three fusion tags （glutathione S-transferase, GST; thioredoxin, Trx; maltose-binding protein, MBP）, which preferably contributes to increasing solubility and to facilitating the proper folding of heteroprotein, were used to acquire the soluble and functional expression of RBD protein in Escherichia coli （BL21（DE3） and Rosetta-gamiB （DE3） strains）. The receptor binding ability of the purified soluble RBD protein was then detected by ELISA and flow cytometry assay. RESULTS： RBD of SARS-Cov spike protein was expressed as inclusion body when fused as TrxA tag form in both BL21 （DE3） and Rosetta-gamiB （DE3） under many different cultures and induction conditions. And there was no visible expression band on SDS-PAGE when RBD was expressed as MBP tagged form. Only GST tagged RBD was soluble expressed in BL21（DE3）, and the protein was purified by AKTA Prime Chromatography system. The ELISA data showed that GST.RBD antigen had positive reaction with anti-RBD mouse monoclonal antibody 1A5. Further flow cytometry assay demonstrated the high efficiency of RBD＇s binding ability to ACE2 （angiotensin-converting enzyme 2） positive Vero E6 cell. And ACE2 was proved as a cellular receptor that meditated an initial-affinity interaction with SARS-Cov spike protein. The geometrical mean of GST and GST.RBD binding to Vero E6 cells were 77.08 and 352.73 respectively. CONCLUSION： In this paper, we get sufficient soluble N terminal GST tagged RBD protein expressed in EcoliBL21 （DE3）; data from ELISA and flow cytometry assay demonstrate that the recombinant protein is functional and binding to ACE2 positive Vero E6 cell efficiently. And the recombinant RBD derived from E.coli can be used to developing subunit vaccine to block S protein binding with receptor and to neutralizing SARS-Cov infection.展开更多
Objective Expressing and purifying the segment of SARS-CoV spike protein in E.Coli. Methods The target gene was obtained by RT-PCR. The PCR product was cloned into pEGM- T Easy Vector, sequencing and double restrict...Objective Expressing and purifying the segment of SARS-CoV spike protein in E.Coli. Methods The target gene was obtained by RT-PCR. The PCR product was cloned into pEGM- T Easy Vector, sequencing and double restriction digestion ( BamHⅠ,PstⅠ) were performed. The target gene was subcloned into PQE30 expression vector. The gene was expressed in the E.coli strain M15 cells induced by IPTG. The protein was purified with a nickel HiTrap chelating metal affinity column. Results The recombinant expression plasmid was successfully constructed and the protein was well expressed in E. coli strain M15 cells. The ideal pure protein was obtained by purification. Western blotting analysis suggested the protein could act with the convalescent sera of lab confirmed SARS patients. Conclusion The segment of SARS-CoV spike protein was well expressed and purified, and can be applied in diagnosis and immunological research of SARS.展开更多
SARS coronavirus （SARS-CoV） is the etiologic agent of severe acute respiratory syndrome. The aim of this study was to construct Sars-CoV membrane （M）, nucleocapsid （N） and spike 2 （$2） gene eukaryotic expressi...SARS coronavirus （SARS-CoV） is the etiologic agent of severe acute respiratory syndrome. The aim of this study was to construct Sars-CoV membrane （M）, nucleocapsid （N） and spike 2 （$2） gene eukaryotic expression plasmids, and identify their expression in vitro. Gene fragments encoding N protein, M protein and $2 protein of SARS-CoV were amplified by PCR using cDNA obtained from lung samples of SARS patients as template, and subcloned into pcDNA3.1 vector to form eukaryotic expression plasmids. SARS-CoV protein eukaryotic expression plasmids were transfected respectively into CHO cells. Immunohistochemistry was employed to detect the expression of the structural proteins of SARS-CoV in transfected cells. SARS-CoV protein eukaryotic expression plasmids were successfully constructed by identification with digestion of restriction enzymes and sequencing. M, N and S2 proteins of SARS-CoV were detected in the cytoplasm of transfected CHO cells. It was concluded that these recombinant eukaryotic expression plasmids were constructed successfully, and SARS-CoV encoding proteins could activate transcription and expression of hfgl2 gene.展开更多
文摘A novel coronavirus, severe acute respiratory syndrome (SA RS)-associated coronavirus (SARS-CoV), has been identified as the causal agent of SARS. Spike (S) protein is a major structural glycoprotein of the SARS virus and a potential target for SARS-specific cell-mediated immune responses. A pa nel of S protein-derived peptides was tested for their binding affinity to HLA -A *0201 molecules. Peptides with high affinity for HLA-A *0201 were then as se ssed for their capacity to elicit specific immune responses mediated by cytotoxi c T lymphocytes (CTLs) both in vivo, in HLA-A2.1/K b transgenic mice, a nd in vitro, from peripheral blood lymphocytes (PBLs) harvested from healthy HLA-A 2.1 + donors. SARS-CoV protein-derived peptide-1 (SSp-1 RLNEVAKNL), induced pepti de-specific CTLs both in vivo (transgenic mice) and in vitro (human PBL s), which specifically released interferon-gamma (IFN-gamma) upon stimulation with SSp-1-pulsed autologous dendritic cells (DCs) or T2 cells. SSp-1-specif ic CTLs also lysed major histocompatibility complex (MHC)-matched tumor cell lines engineered to express S proteins. HLA-A *0201-SSp-1 tetramer staining re vealed the presence of significant populations of SSp-1-specific CTLs in SSp- 1-induced CD8 + T cells. We propose that the newly identified epitope SSp-1 w ill help in the characterization of virus control mechanisms and immunopathology in SARS-CoV infection, and may be relevant to the development of immunotherape utic approaches for SARS.
文摘AIM： To find a soluble and functional recombinant receptor-binding domain of severe acute respiratory syndrome-associated coronavirus （SARS-Cov）, and to analyze its receptor binding ability. METHODS： Three fusion tags （glutathione S-transferase, GST; thioredoxin, Trx; maltose-binding protein, MBP）, which preferably contributes to increasing solubility and to facilitating the proper folding of heteroprotein, were used to acquire the soluble and functional expression of RBD protein in Escherichia coli （BL21（DE3） and Rosetta-gamiB （DE3） strains）. The receptor binding ability of the purified soluble RBD protein was then detected by ELISA and flow cytometry assay. RESULTS： RBD of SARS-Cov spike protein was expressed as inclusion body when fused as TrxA tag form in both BL21 （DE3） and Rosetta-gamiB （DE3） under many different cultures and induction conditions. And there was no visible expression band on SDS-PAGE when RBD was expressed as MBP tagged form. Only GST tagged RBD was soluble expressed in BL21（DE3）, and the protein was purified by AKTA Prime Chromatography system. The ELISA data showed that GST.RBD antigen had positive reaction with anti-RBD mouse monoclonal antibody 1A5. Further flow cytometry assay demonstrated the high efficiency of RBD＇s binding ability to ACE2 （angiotensin-converting enzyme 2） positive Vero E6 cell. And ACE2 was proved as a cellular receptor that meditated an initial-affinity interaction with SARS-Cov spike protein. The geometrical mean of GST and GST.RBD binding to Vero E6 cells were 77.08 and 352.73 respectively. CONCLUSION： In this paper, we get sufficient soluble N terminal GST tagged RBD protein expressed in EcoliBL21 （DE3）; data from ELISA and flow cytometry assay demonstrate that the recombinant protein is functional and binding to ACE2 positive Vero E6 cell efficiently. And the recombinant RBD derived from E.coli can be used to developing subunit vaccine to block S protein binding with receptor and to neutralizing SARS-Cov infection.
文摘Objective Expressing and purifying the segment of SARS-CoV spike protein in E.Coli. Methods The target gene was obtained by RT-PCR. The PCR product was cloned into pEGM- T Easy Vector, sequencing and double restriction digestion ( BamHⅠ,PstⅠ) were performed. The target gene was subcloned into PQE30 expression vector. The gene was expressed in the E.coli strain M15 cells induced by IPTG. The protein was purified with a nickel HiTrap chelating metal affinity column. Results The recombinant expression plasmid was successfully constructed and the protein was well expressed in E. coli strain M15 cells. The ideal pure protein was obtained by purification. Western blotting analysis suggested the protein could act with the convalescent sera of lab confirmed SARS patients. Conclusion The segment of SARS-CoV spike protein was well expressed and purified, and can be applied in diagnosis and immunological research of SARS.
基金supported by a grant from National Key Project of Science and Technology Ministry of China for 973-SARS (No. 2003CB514112)SARS funding first granted from Ministry of education of China ([2003]64)The National 10th Five-Year Plan Key Project of China (2004BA720A01)
文摘SARS coronavirus （SARS-CoV） is the etiologic agent of severe acute respiratory syndrome. The aim of this study was to construct Sars-CoV membrane （M）, nucleocapsid （N） and spike 2 （$2） gene eukaryotic expression plasmids, and identify their expression in vitro. Gene fragments encoding N protein, M protein and $2 protein of SARS-CoV were amplified by PCR using cDNA obtained from lung samples of SARS patients as template, and subcloned into pcDNA3.1 vector to form eukaryotic expression plasmids. SARS-CoV protein eukaryotic expression plasmids were transfected respectively into CHO cells. Immunohistochemistry was employed to detect the expression of the structural proteins of SARS-CoV in transfected cells. SARS-CoV protein eukaryotic expression plasmids were successfully constructed by identification with digestion of restriction enzymes and sequencing. M, N and S2 proteins of SARS-CoV were detected in the cytoplasm of transfected CHO cells. It was concluded that these recombinant eukaryotic expression plasmids were constructed successfully, and SARS-CoV encoding proteins could activate transcription and expression of hfgl2 gene.
