Characterization of humoral responses in mice immunized with plasmid DNAs encoding SARS-CoV spike gene fragments.
The immunological characteristics of SARS-CoV spike protein were investigated by administering mice with plasmids encoding various S gene fragments. We showed that the secreting forms of S1, S2 subunits and the N-terminus of S1 subunit (residues 18-495) were capable of eliciting SARS-CoV specific antibodies and the region immediate to N-terminus of matured S1 protein contained an important immunogenic determinant for elicitation of SARS-CoV specific antibodies. In addition, mice immunized with plasmids encoding S1 fragment developed a Th1-mediated antibody isotype switching. Another interesting finding was that mouse antibodies elicited separately by plasmids encoding S1 and S2 subunits cooperatively neutralized SARS-CoV but neither the S1 nor S2 specific antibodies did, suggesting the possible role of both S1 and S2 subunits in host cell docking and entry. These results provide insights into understanding the immunological characteristics of spike protein and the development of subunit vaccines against SARS-CoV.
Department of Zoology, The University of Hong Kong, Pokfulam Rd, Hong Kong, SAR, China.
Fanya
F
Zeng
Ken Yan Ching
KY
Chow
Chung Chau
CC
Hon
Ka Man
KM
Law
Chi Wai
CW
Yip
Kwok Hung
KH
Chan
Joseph S Malik
JS
Peiris
Frederick Chi Ching
FC
Leung
D000818:Animals; D000906:Antibodies / Q000276:immunology; D000917:Antibody Formation / Q000187:drug effects; D015870:Gene Expression; D007111:Immunity, Cellular; D007114:Immunization; D007074:Immunoglobulin G / Q000276:immunology; D008562:Membrane Glycoproteins / Q000235:genetics* / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010957:Plasmids / Q000235:genetics / Q000276:immunology*; D021122:Protein Subunits / Q000276:immunology; D011994:Recombinant Proteins / Q000235:genetics / Q000276:immunology; D045473:Severe acute respiratory syndrome-related coronavirus / Q000235:genetics* / Q000276:immunology; D064370:Spike Glycoprotein, Coronavirus; D019444:Vaccines, DNA / Q000235:genetics / Q000276:immunology*; D014759:Viral Envelope Proteins / Q000235:genetics* / Q000276:immunology*
D000906:Antibodies; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; D021122:Protein Subunits; D011994:Recombinant Proteins; D064370:Spike Glycoprotein, Coronavirus; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins