[Potent neutralization antibody elicited in mice by SARS-associated coronavirus spike protein S1 domain].
OBJECTIVE
To study the antigenicity of SARS associated coronavirus (CoV) spike S1 (12-672Aa) domain.


METHODS
BALB/c mice were immunized with a plasmid bearing codon-optimized SARS-CoV (Tor2 strain) S1 domain and then boosted with purified S1 protein; the SARS-CoV specific IgG antibody was tested by ELISA and neutralization antibody was determined by in vitro microneutralization assay.


RESULTS
S1 domain of SARS-CoV spike, which has been demonstrated harboring the receptor binding domain, successfully elicited SARS-CoV specific IgG antibody in mouse after combined immunization with DNA and purified S1 protein; the antibody elicited solely by S1 could potently neutralize SARS-CoV (HKU-39849) in vitro, 50% of 1 000 TCID50 SARS-CoV challenged cells were protected from viral infection by a 1:1499.68 dilution of mice sera immunized with S1 protein, but negative control sera showed no protection.


CONCLUSIONS
S1 domain of SARS-CoV spike protein, which is responsible for receptor binding, can efficiently and sufficiently induce highly potent neutralizing antibody in mice. This result suggested that S1 domain could be an effective subunit vaccines against SARS-CoV.
Zhang
Yun
Y
Department of Etiology, Institute of Basic Medical Science, CAMS and PUMC, Beijing 100005, China.
Yang
Fan
F
Li
Yan-han
YH
Li
Wen-hui
WH
Tu
Xin-ming
XM
Wei
Qiang
Q
Zhu
Hua
H
Liu
Li
L
Wang
Heng
H
Qin
Chuan
C
Yuan
Guo-yong
GY
He
Wei
W
Wang
Shu-hui
SH
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D002460:Cell Line; D004622:Embryo, Mammalian; D004847:Epithelial Cells / Q000378:metabolism; D005260:Female; D006801:Humans; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood; D007668:Kidney / Q000166:cytology; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism; D051379:Mice; D008807:Mice, Inbred BALB C; D009500:Neutralization Tests; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics / Q000276:immunology*; D045169:Severe Acute Respiratory Syndrome / Q000276:immunology / Q000821:virology; D064370:Spike Glycoprotein, Coronavirus; D014162:Transfection; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology* / Q000378:metabolism
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins