[Expression of SARS coronavirus nucleocapsid protein and construction of its DNA vaccine].
OBJECTIVE
To express the nucleocapsid (N) protein of SARS coronavirus (SARS-CoV) in E. coli and construct its DNA vaccine.


METHODS
The prokaryotic expression vector pQEN containing N gene was constructed and transformed into the E. coli. The recombinant N protein was then expressed and purified by Ni(2+)-NTA affinity resin. In addition, the N gene was cloned into the eukaryotic expression plasmid pSecTagB and the eukaryotic recombinant expression vector pSecN was obtained. The DNA vaccine pSecN was injected to immunize the BALB/c mice to produce the antiserum against N protein of SARS-CoV. Subsequently, the reactivity of the antiserum with recombinant N protein and SARS-CoV particles was assayed by ELISA.


RESULTS
Recombinant N protein reacted strongly and specifically with the sera from immunized mice and SARS patients. Similarly, the sera of immunized mice could also react specifically with SARS-CoV particles.


CONCLUSIONS
The recombinant N protein could be used as a good antigen to detect SARS. The DNA vaccine pSecN could also efficiently induce the production of IgG against N protein of SARS-CoV, which offered clues to the development of a potential DNA vaccine.
Xiang
Kai-jun
KJ
Guangzhou Huayin Genetic Science and Technology Co., Ltd., Guangzhou 510150, China.
Zeng
Qi-yi
QY
Ding
Yong-qiang
YQ
Zhu
Bing
B
Zhou
Rong
R
D000086462:Coronavirus Nucleocapsid Proteins; D004591:Electrophoresis, Polyacrylamide Gel; D004797:Enzyme-Linked Immunosorbent Assay; D019590:Nucleocapsid Proteins / Q000235:genetics* / Q000276:immunology* / Q000302:isolation & purification / Q000378:metabolism; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics* / Q000276:immunology*; D019444:Vaccines, DNA / Q000235:genetics* / Q000276:immunology*
D000086462:Coronavirus Nucleocapsid Proteins; D019590:Nucleocapsid Proteins; D019444:Vaccines, DNA