RT Journal Article
SR Electronic
T1 Cross-Neutralization of Human and Palm Civet Severe Acute Respiratory Syndrome Coronaviruses by Antibodies Targeting the Receptor-Binding Domain of Spike Protein
JF The Journal of Immunology
JO J. Immunol.
FD American Association of Immunologists
SP 6085
OP 6092
DO 10.4049/jimmunol.176.10.6085
VO 176
IS 10
A1 He, Yuxian
A1 Li, Jingjing
A1 Li, Wenhui
A1 Lustigman, Sara
A1 Farzan, Michael
A1 Jiang, Shibo
YR 2006
UL http://www.jimmunol.org/content/176/10/6085.abstract
AB The spike (S) protein of severe acute respiratory syndrome coronavirus (SARS-CoV) is considered as a protective Ag for vaccine design. We previously demonstrated that the receptor-binding domain (RBD) of S protein contains multiple conformational epitopes (Conf I-VI) that confer the major target of neutralizing Abs. Here we show that the recombinant RBDs derived from the S protein sequences of Tor2, GD03, and SZ3, the representative strains of human 2002–2003 and 2003–2004 SARS-CoV and palm civet SARS-CoV, respectively, induce in the immunized mice and rabbits high titers of cross-neutralizing Abs against pseudoviruses expressing S proteins of Tor2, GD03, and SZ3. We also demonstrate that the Tor2-RBD induced-Conf I-VI mAbs can potently neutralize both human SARS-CoV strains, Tor2 and GD03. However, only the Conf IV-VI, but not Conf I-III mAbs, neutralize civet SARS-CoV strain SZ3. All these mAbs reacted significantly with each of the three RBD variants (Tor2-RBD, GD03-RBD, and SZ3-RBD) that differ at several amino acids. Regardless, the Conf I-IV and VI epitopes were completely disrupted by single-point mutation of the conserved residues in the RBD (e.g., D429A, R441A, or D454A) and the Conf III epitope was significantly affected by E452A or D463A substitution. Interestingly, the Conf V epitope, which may overlap the receptor-binding motif and induce most potent neutralizing Abs, was conserved in these mutants. These data suggest that the major neutralizing epitopes of SARS-CoV have been apparently maintained during cross-species transmission, and that RBD-based vaccines may induce broad protection against both human and animal SARS-CoV variants.