Zhao Ping, Ke Jin-Shan, Qin Zhao-Lin, Ren Hao, Zhao Lan-Juan, Yu Jian-Guo, Gao Jun, Zhu Shi-Ying, Qi Zhong-Tian
Department of Microbiology, Second Military Medical University, Shanghai 200433, China.
Acta Biochim Biophys Sin (Shanghai). 2004 Jan;36(1):37-41. doi: 10.1093/abbs/36.1.37.
The spike (S) protein, a main surface antigen of SARS-coronavirus (SARS-CoV), is one of the most important antigen candidates for vaccine design. In the present study, three fragments of the truncated S protein were expressed in E.coli, and analyzed with pooled sera of convalescence phase of SARS patients. The full length S gene DNA vaccine was constructed and used to immunize BALB/c mice. The mouse serum IgG antibody against SARS-CoV was measured by ELISA with E. coli expressed truncated S protein or SARS-CoV lysate as diagnostic antigen. The results showed that all the three fragments of S protein expressed by E.coli was able to react with sera of SARS patients and the S gene DNA candidate vaccine could induce the production of specific IgG antibody against SARS-CoV efficiently in mice with seroconversion ratio of 75% after 3 times of immunization. These findings lay some foundations for further understanding the immunology of SARS-CoV and developing SARS vaccines.
刺突（S）蛋白是严重急性呼吸综合征冠状病毒（SARS-CoV）的主要表面抗原之一，是疫苗设计中最重要的抗原候选物之一。在本研究中，截短的S蛋白的三个片段在大肠杆菌中表达，并用SARS患者恢复期的混合血清进行分析。构建了全长S基因DNA疫苗并用于免疫BALB/c小鼠。以大肠杆菌表达的截短S蛋白或SARS-CoV裂解物作为诊断抗原，通过ELISA法检测小鼠血清中抗SARS-CoV的IgG抗体。结果表明，大肠杆菌表达的S蛋白的所有三个片段都能与SARS患者的血清发生反应，S基因DNA候选疫苗能在小鼠中有效诱导产生抗SARS-CoV的特异性IgG抗体，三次免疫后血清转化率为75%。这些发现为进一步了解SARS-CoV的免疫学和开发SARS疫苗奠定了一定基础。
