Immunization of mice with a DNA vaccine based on severe acute respiratory syndrome coronavirus spike protein fragment 1.
According to data in GenBank, a gene encoding SARS spike protein fragment 1 (S1) was synthesized. After recombination with an immunostimulatory sequence (ISS), the gene was cloned into the plasmid pIRES to produce pIRES-ISS-S1. On confirmation of the expression of S1 protein by indirect immunofluorescence assay (IFA), after the transfection of pIRES-ISS-S1 into BHK-21 cells, the DNA vaccine was repeatedly administrated to BALB/c mice. CD4+ and CD8+ spleen T lymphocytes were analyzed by flow cytometry (FCM) to evaluate T cell-mediated immune responses, the antigen-specific responses of T cells were evaluated by cytotoxic T lymphocyte (CTL) assay, and the level of IgG in antisera from immunized mice was determined by enzyme-linked immunosorbent assay. Results showed that the counts of spleen CD4+ and CD8+ T lymphocytes were increased, that the T cell-mediated immune responses showed antigen specificity, and that IgG was significantly induced with DNA vaccines pIRES-ISS-S1 and pIRES-S1 at titers of 1:320 and 1:160, respectively. These results are promising for the protective immunization of humans.
Zhao
Bo
B
Key Laboratory for Molecular Enzymology and Engineering of Ministry of Education, Jilin University [corrected] Changchun, China.
Jin
Ning-Yi
NY
Wang
Rui-Lin
RL
Zhang
Li-Shu
LS
Zhang
Ying-Jiu
YJ
D000595:Amino Acid Sequence; D000818:Animals; D000914:Antibodies, Viral; D001483:Base Sequence; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D002460:Cell Line; D006224:Cricetinae; D005260:Female; D007114:Immunization; D007074:Immunoglobulin G / Q000097:blood; D008562:Membrane Glycoproteins / Q000008:administration & dosage / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*; D051379:Mice; D008807:Mice, Inbred BALB C; D008969:Molecular Sequence Data; D045473:Severe acute respiratory syndrome-related coronavirus / Q000276:immunology*; D045169:Severe Acute Respiratory Syndrome / Q000276:immunology* / Q000517:prevention & control; D064370:Spike Glycoprotein, Coronavirus; D013602:T-Lymphocytes, Cytotoxic / Q000276:immunology; D019444:Vaccines, DNA / Q000008:administration & dosage* / Q000276:immunology; D014759:Viral Envelope Proteins / Q000008:administration & dosage / Q000737:chemistry* / Q000235:genetics / Q000276:immunology*
D000914:Antibodies, Viral; D007074:Immunoglobulin G; D008562:Membrane Glycoproteins; D064370:Spike Glycoprotein, Coronavirus; D019444:Vaccines, DNA; D014759:Viral Envelope Proteins