Elicitation of immunity in mice after immunization with the S2 subunit of the severe acute respiratory syndrome coronavirus.
The S2 domain of the severe acute respiratory syndrome coronavirus (SARS-CoV) spike (S) protein is responsible for fusion between virus and target cell membranes, and is expected to be immungenic. In this study, we investigated the immune responses against the S2 subunit in BALB/c mice, which were vaccinated either with plasmid DNA encoding the S2 domain (residues 681-1120), the recombinant S2 fragment (residues 681-980) in incomplete Freund's adjuvant, or with inactivated SARS-CoV. The increased number of specific cytotoxic cells (CTLs) and the high titer of specific antibody showed stimulation of both arms of the immune system in these groups. The shift in cytokines suggested that Th1-polarized immune response was induced by plasmid pCoVS2, meanwhile the Th2-dominant response was induced by recombinant S2 fragment and inactivated vaccine. However, the titer of neutralizing antibodies was only detectable in mice immunized with inactivated virus, but not with pCoVS2 plasmid. Taken together, the S2 domain could induce specific cellular immune response and a high level of total IgG but little neutralizing antibodies against infection by SARSCoV.
Guo
Yingjun
Y
Department of Medical Genetics, The Second Military Medical University, Shanghai, People's Republic of China.
Sun
Shuhan
S
Wang
Kaiyu
K
Zhang
Shu
S
Zhu
Weijia
W
Chen
Ze
Z
D000818:Animals; D000914:Antibodies, Viral / Q000097:blood*; D019556:COS Cells; D002522:Chlorocebus aethiops; D005260:Female; D006801:Humans; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood; D007371:Interferon-gamma / Q000096:biosynthesis; D015847:Interleukin-4 / Q000096:biosynthesis; D008562:Membrane Glycoproteins / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D010446:Peptide Fragments / Q000235:genetics / Q000276:immunology; D011994:Recombinant Proteins / Q000276:immunology; D045473:Severe acute respiratory syndrome-related coronavirus / Q000276:immunology*; D064370:Spike Glycoprotein, Coronavirus; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D014709:Vero Cells; D014759:Viral Envelope Proteins / Q000235:genetics / Q000276:immunology*
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; D010446:Peptide Fragments; D011994:Recombinant Proteins; D064370:Spike Glycoprotein, Coronavirus; D014759:Viral Envelope Proteins; C578557:spike glycoprotein, SARS-CoV; C578553:spike protein, mouse hepatitis virus; D015847:Interleukin-4; D007371:Interferon-gamma