ABSTRACT
Objective To produce human papillomavirus type 6(HPV-6)virus-like particles with Escherichia coli expression system and study its immunogenicity.Methods HPV-6 L1 gene was inserted into pmkaryotic expression vector pTO-T7 and then expressed in Escherichia coli ER2566.The HPV-6 L1 protein was purified by ammonium sulfate precipitation,ion-exchange chromatography,and hydrophobic interaction chromatography.Then the purified HPV-6 L1 self-assembled into virus-like particle after removing 1,4dithiothreitol(DTr).The morphology of the virus-like particles was investigated with dynamic light scatter and transmission electron microscopy,and the immunogenicity was determined with in vitro pseudownons neutralization as8ay.Results HPV-6 L1 was expressed in soluble form in Escherichia coli.Following the removal of DTT,purified HPV-6 L1 protein could assemble into virus-like particles as 25 am in the radius.And the animal immunization test showed HPV-6 virus-like particles can elite hish titer neutralizing antibodies.Conclusion The bacterially expressed HPV-6 L1 VLP is highly immunogenieity and easy to produce.And it can be good candidate of HPV-6 vaccine.
ABSTRACT
The immune effect of two recombinant protein fragments of spike protein in severe acute respiratory syndrome coronavirus (SARS CoV) was investigated in Balb/c mice. Two partial spike gene fragments S1 (322 1464 bp) and S2 (2170 2814 bp) of SARS coronavirus were amplified by RT-PCR, and cloned into pET-23a prokaryotic expression vector, then transformed into competent Escherichia E. coli BL21 (DE3)(pLysS) respectively. Recombinant proteins were expressed and purified by Ni2+ immobilized metal ion affinity chromatography. The purified proteins mixed with complete Freund adjuvant were injected into Balb/c mice three times at a two-week interval. High titer antibody was detected in the serum of immunized Balb/c mice, and mice immunized with S1 protein produced high titer IgG1, IgG2a, IgG2b and IgG3, while those immunized with S2 protein produced high titer IgG1, IgG2a, but lower titer IgG2b and IgG3. Serum IFN-concentration was increased significantly but the concentrations of Il-2, IL-4 and IL-10 had no significant change. And a marked increase was observed in the number of spleen CD8+ T cells. The results showed that recombinant proteins of SARS coronavirus spike protein induced hormonal and cellular immune response in Balb/c mice.
ABSTRACT
The immune effect of two recombinant protein fragments of spike protein in severe acute respiratory syndrome coronavirus (SARS CoV) was investigated in Balb/c mice. Two partial spike gene fragments S1 (322-1464 bp) and S2 (2170-2814 bp) of SARS coronavirus were amplified by RT-PCR, and cloned into pET-23a prokaryotic expression vector, then transformed into competent Escherichia E.coli BL21 (DE3)(pLysS) respectively. Recombinant proteins were expressed and purified by Ni2+ immobilized metal ion affinity chromatography. The purified proteins mixed with complete Freund adjuvant were injected into Balb/c mice three times at a two-week interval. High titer antibody was detected in the serum of immunized Balb/c mice, and mice immunized with S1 protein produced high titer IgG1, IgG2a, IgG2b and IgG3, while those immunized with S2 protein produced high titer IgG1, IgG2a, but lower titer IgG2b and IgG3. Serum IFN-γ concentration was increased significantly but the concentrations of IL-2, IL-4 and IL-10 had no significant change. And a marked increase was observed in the number of spleen CD8+ T cells. The results showed that recombinant proteins of SARS coronavirns spike protein induced hormonal and cellular immune response in Balb/c mice.
ABSTRACT
To construct a recombinant plasmid Pet23a-M, the gene encoding severe acute respiratory syndrome (SARS) coronavirus membrane protein was amplified by RT-PCR and cloned into the expression plasmid Pet23a. Results of restriction endonuclease analysis, PCR detection and DNA sequencing analysis revealed that the cloned DNA sequence was the same as that reported. The recombinants were transformed into Escherichia coli (E. Coli) BL21 (DE3) and induced by Isopropyl-beta-D-thiogalactopyranoside (IPTG). The expression of 27 kD (1 kD=0.992 1 ku) protein was detected by SDS-PAGE and pured by metal chelated chromatography. Results of Western-blot showed that this expressed protein could react with antibodies in sera of SARS patients during convalescence. This provided the basis for the further study on SARS virus vaccine and diagnostic agents.
Subject(s)
Cloning, Molecular , Escherichia coli/genetics , Escherichia coli/metabolism , Membrane Proteins/biosynthesis , Membrane Proteins/genetics , Membrane Proteins/isolation & purification , Plasmids/biosynthesis , Plasmids/genetics , Recombinant Proteins/biosynthesis , Recombinant Proteins/genetics , Recombinant Proteins/isolation & purification , Reverse Transcriptase Polymerase Chain Reaction , Severe acute respiratory syndrome-related coronavirus/chemistry , Severe acute respiratory syndrome-related coronavirus/genetics , Viral Vaccines/biosynthesisABSTRACT
To construct a recombinant plasmid Pet23a-M, the gene encoding severe acute respiratory syndrome (SARS) coronavirus membrane protein was amplified by RT-PCR and cloned into the expression plasmid Pet23a. Results of restriction endonuclease analysis, PCR detection and DNA sequencing analysis revealed that the cloned DNA sequence was the same as that reported. The recombinants were transformed into Escherichia coli (E. Coli) BL21 (DE3) and induced by Isopropyl-beta-D-thiogalactopyranoside (IPTG). The expression of 27 kD (1 kD=0.992 1 ku) protein was detected by SDS-PAGE and pured by metal chelated chromatography. Results of Western-blot showed that this expressed protein could react with antibodies in sera of SARS patients during convalescence. This provided the basis for the further study on SARS virus vaccine and diagnostic agents.
Subject(s)
Humans , Cloning, Molecular , Escherichia coli , Genetics , Metabolism , Membrane Proteins , Genetics , Plasmids , Genetics , Recombinant Proteins , Genetics , Reverse Transcriptase Polymerase Chain Reaction , Severe acute respiratory syndrome-related coronavirus , Chemistry , Genetics , Viral VaccinesABSTRACT
Objective To construct a prokaryotic expression system containing the dense granule protein 4(GRA4) of Toxoplasma gondii,purify the expressed protein and detect its immunogenicity.Methods The specific fragment of GRA4 gene was amplified by PCR.After subcloning the prokaryotic expression recombinant pET,GRA4,the expressed product was purified with His?BindTM affinity chromatography and analyzed by Western blot.BALB/c mice were immunized with the GRA4 recombinant protein,and the antibody IgG titer was detected by ELISA.Results The pET,GRA4 prokaryotic expression system was obtained.The MW of the expressed protein was Mr 40 000 and formed in inclusion body.After purification,the recombinant protein could be specifically recognized by the T.gondii infected rabbit serum.Mice immunized with the purified recombinant protein elicited high titer of IgG antibody.Conclusion The pET,GRA4 recombinant protein was successfully expressed and purified,which shows the immunogenicity.