Characterization of cytotoxic T-lymphocyte epitopes and immune responses to SARS coronavirus spike DNA vaccine expressing the RGD-integrin-binding motif.
Integrins are critical for initiating T-cell activation events. The integrin-binding motif Arg-Gly-Asp (RGD) was incorporated into the pcDNA 3.1 mammalian expression vector expressing the codon-optimized extracellular domain of SARS coronavirus (SARS-CoV) spike protein, and tested by immunizing C57BL/6 mice. Significant cell-mediated immune responses were characterized by cytotoxic T-lymphocyte (51)Cr release assay and interferon-gamma secretion ELISPOT assay against RMA-S target cells presenting predicted MHC class I H2-Kb epitopes, including those spanning residues 884-891 and 1116-1123 within the S2 subunit of SARS-CoV spike protein. DNA vaccines incorporating the Spike-RGD/His motif or the Spike-His construct generated robust cell-mediated immune responses. Moreover, the Spike-His DNA vaccine construct generated a significant antibody response. Immunization with these DNA vaccine constructs elicited significant cellular and humoral immune responses. Additional T-cell epitopes within the SARS-CoV spike protein that may contribute to cell-mediated immunity in vivo were also identified.
Poh
W P
WP
Department of Physiology, Yong Loo Lin School of Medicine, National University of Singapore, Kent Ridge, Singapore, Singapore.
Narasaraju
T
T
Pereira
N A
NA
Zhong
F
F
Phoon
M C
MC
Macary
P A
PA
Wong
S H
SH
Lu
J
J
Koh
D R
DR
Chow
Vincent T K
VT
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D003602:Cytotoxicity, Immunologic; D018984:Epitopes, T-Lymphocyte; D005260:Female; D007371:Interferon-gamma / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008810:Mice, Inbred C57BL; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics / Q000276:immunology*; D064370:Spike Glycoprotein, Coronavirus; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology*; D019444:Vaccines, DNA / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*; D014765:Viral Vaccines / Q000276:immunology*
D000914:Antibodies, Viral; D018984:Epitopes, T-Lymphocyte; D008562:Membrane Glycoproteins; D064370:Spike Glycoprotein, Coronavirus; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins; D014765:Viral Vaccines; C578557:spike glycoprotein, SARS-CoV; D007371:Interferon-gamma