Construction Of DNA Vaccine Against SARS Coronavirus Infection And Its Immune Characteristics

Objective: To construct DNA vaccine against C region gene of SARS coronavirus (SARS-CoV) S protein, and observe the immune response induced by DNA vaccine injection.Methods: A recombinant plasmid was constructed by cloning SARS-CoV Sc gene fragment into pcDNA3.1(-), which could induce SARS-CoV specific antibodies in mice. After mice immunized with the recombinant DNA vaccine by injection, the SARS-CoV antibodies in the sera of mice were detected by ELISA, the lymphocyte phenotypes were detected by FCM, the distribution of the plasmids was detected by PCR method.Results: It can induce potent humoral and cellular immune response in mice. 15 days after injection special antibodies against SARS-CoV can be detected in the sera, and its quantity was directly increased as time went by; 30 days after injection it reached a plate 1:1000. There were dramatic leaps in the quantity of CD8~+T cells: CD4%:41.44±1.20 CD8%:10.96±1.33 CD3%:59.71±0.99 CD4/CD8:3.78±3.65; as for control group,CD4%:38.25±2.00 CD8%:7.63±0.32 CD3%: 43.57±2.23 CD4/ CD8:5.17± 1.36. No immune response could be observed in the control group. Result drawn from PCR showed that the plasmid is not equally distributed in the tissues, only in the muscle and the liver had we found distinct trace of the plasmid.Conclusions: S gene of SARS-CoV can be used as a candidated antigen of DNA vaccine to induce SARS-CoV specific antibodies, it can induce potent humoral and cellular immune response in mice.