[Prokaryotic expression of SARS coronavirus spike protein and construction of its DNA vaccine].
OBJECTIVE
To study the immunological characteristics of the spike (S) protein of SARS coronavirus (SARS-CoV) and analyze the feasibility of using this protein as the component for SARS vaccine development.


METHODS
The two truncated fragments of S gene were separately cloned into the prokaryotic expression vector pET-15b and expressed in E.coli. The resulting recombinant proteins, rS(a) and rS(b), were purified by affinity chromatography. The full-length S gene was cloned into the eukaryotic expression plasmid pSecTagB to prepare recombinant plasmid pSecS as the DNA vaccine to immunize BALB/c mice for inducing the secretion of anti-SARS-CoV protein. The immunological effect of anti-SARS-CoV antibody was tested with purified rS(a) and rS(b) proteins by enzyme-linked immunosorbent assay (ELISA).


RESULTS
Both the truncated recombinant proteins were expressed in soluble forms and reacted specifically with the sera from immunized pSecS mice and clinically diagnosed SARS patients. The prokaryotically expressed recombinant truncated S protein had similar antigenicity with SARS-CoV S protein.


CONCLUSIONS
The recombinant protein could be used as an antigen for detecting the serum of SARS CoV-infected patients. The SARS-CoV S gene vaccine could induce the production of specific antibody, which offers clues for the research of SARS DNA vaccine.
Li
Jian-na
JN
Southern China University of Tropical Agriculture, Danzhou 571737, China. christina0125@163.com
Xiang
Kai-jun
KJ
Zhou
Rong
R
Huang
Chun-hua
CH
Ding
Yong-qiang
YQ
Zeng
Qi-yi
QY
Zhong
Qiu-ping
QP
D000818:Animals; D004926:Escherichia coli / Q000235:genetics / Q000378:metabolism; D005822:Genetic Vectors; D006801:Humans; D008562:Membrane Glycoproteins / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D051379:Mice; D008807:Mice, Inbred BALB C; D011387:Prokaryotic Cells / Q000378:metabolism*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000276:immunology; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics*; D045169:Severe Acute Respiratory Syndrome / Q000517:prevention & control; D064370:Spike Glycoprotein, Coronavirus; D019444:Vaccines, DNA / Q000096:biosynthesis* / Q000276:immunology; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000235:genetics* / Q000276:immunology; D014765:Viral Vaccines / Q000096:biosynthesis* / Q000276:immunology
D008562:Membrane Glycoproteins; D011994:Recombinant Proteins; D064370:Spike Glycoprotein, Coronavirus; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus