Synthetic peptide studies on the severe acute respiratory syndrome (SARS) coronavirus spike glycoprotein: perspective for SARS vaccine development.
BACKGROUND
The S (spike) protein of the etiologic coronavirus (CoV) agent of severe acute respiratory syndrome (SARS) plays a central role in mediating viral infection via receptor binding and membrane fusion between the virion and the host cell. We focused on using synthetic peptides for developing antibodies against SARS-CoV, which aimed to block viral invasion by eliciting an immune response specific to the native SARS-CoV S protein.


METHODS
Six peptide sequences corresponding to the surface regions of SARS-CoV S protein were designed and investigated by use of combined bioinformatics and structural analysis. These synthetic peptides were used to immunize both rabbits and monkeys. Antisera collected 1 week after the second immunization were analyzed by ELISA and tested for antibody specificity against SARS-CoV by immunofluorescent confocal microscopy.


RESULTS
Four of our six synthetic peptides (S2, S3, S5, and S6) elicited SARS-CoV-specific antibodies, of which S5 (residues 788-820) and S6 (residues 1002-1030) exhibited immunogenic responses similar to those found in a parallel investigation using truncated recombinant protein analogs of the SARS-CoV S protein. This suggested that our S5 and S6 peptides may represent two minimum biologically active sequences of the immunogenic regions of the SARS-CoV S protein.


CONCLUSIONS
Synthetic peptides can elicit specific antibodies to SARS-CoV. The study provides insights for the future development of SARS vaccine via the synthetic-peptide-based approach.
Choy
Wai-Yan
WY
Molecular Biotechnology Program, Department of Biology, The Chinese University of Hong Kong, Shatin, Hong Kong, China.
Lin
Shu-Guang
SG
Chan
Paul Kay-Sheung
PK
Tam
John Siu-Lun
JS
Lo
Y M Dennis
YM
Chu
Ida Miu-Ting
IM
Tsai
Sau-Na
SN
Zhong
Ming-Qi
MQ
Fung
Kwok-Pui
KP
Waye
Mary Miu-Yee
MM
Tsui
Stephen Kwok-Wing
SK
Ng
Kai-On
KO
Shan
Zhi-Xin
ZX
Yang
Min
M
Wu
Yi-Long
YL
Lin
Zhan-Yi
ZY
Ngai
Sai-Ming
SM
D000595:Amino Acid Sequence; D000818:Animals; D004797:Enzyme-Linked Immunosorbent Assay; D000882:Haplorhini; D008562:Membrane Glycoproteins / Q000737:chemistry / Q000276:immunology*; D018613:Microscopy, Confocal; D008856:Microscopy, Fluorescence; D008969:Molecular Sequence Data; D010455:Peptides / Q000138:chemical synthesis / Q000737:chemistry / Q000276:immunology*; D011817:Rabbits; D045473:Severe acute respiratory syndrome-related coronavirus / Q000276:immunology*; D064370:Spike Glycoprotein, Coronavirus; D014611:Vaccination; D014759:Viral Envelope Proteins / Q000737:chemistry / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*
D008562:Membrane Glycoproteins; D010455:Peptides; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus