摘要
目的研究SARS冠状病毒(SARS-CoV)靶细胞受体结合区所构建之DNA疫苗的免疫效果,为进一步的SARS-CoV免疫机理研究及疫苗研制奠定基础。方法选取SARS-CoVS基因包含靶细胞受体结合区和S1亚单位C端2个基因片段作为目的基因,构建真核表达质粒pVAX-RBD(receptor binding domain)、pVAX-S1C作为DNA疫苗免疫BALB/c小鼠,检测其特异性体液免疫及细胞免疫情况。结果体液免疫方面,以SARS全病毒裂解产物和原核表达的RBD蛋白作为诊断抗原,用ELISA均可检测到高滴度的小鼠血清抗体IgG的产生。而且,血清中和试验显示pVAX-RBD质粒激发了小鼠保护性中和抗体的产生。通过流式细胞分析和酶联免疫斑点实验(ELISPOT)检测,pVAX-RBD和pVAX-S1C两组质粒均诱导免疫小鼠产生了特异性细胞免疫反应。结论证明SARS-CoVS蛋白受体结合区上中和表位的存在;体液免疫在抗SARS-CoV感染方面起到重要作用。
Objective To investigate immune response of the DNA vaccine encoding receptor-binding domain of SARS-coronavirus （SARS-CoV） and its immune effects for exploring the immune mechanisms of SARS-CoV and developing vaccines. Methods Two kinds of truncated S protein gene fragments were cloned into eukazyotie expression domain （RBD） and S1 subunit C terminal （S1C）, respectively. Balb/ e mice were immunized with the two DNA vaccines pVAX-RBD and pVAX-S1C and the speeific humoral and cell-mediated immune responses were detected by flow cytometry （FCM） and enzyme-linked immunosopt （ELSPOT）. Results Mouse sere IgG antibodies with high titer were detected by enzyme-linked imnmnosorbent assay （ ELISA）, with E. coli-expressed protein RBD or SARS-CoV lysate as diagnostic antigen. Furthennore, neutralizing antibodies were also detected in mice vaccinated with the plasmid pVAX-RBD containing the receptor-binding domain. The two expression plasmids could induce some speeiiie cell-mediated immune responses. Conclusion It is proved that the existence of neutralizing epitope in S protein receptor-binding domain; in addition, humoml immunity plays a significant role in preventing virus infection, while the effect of ceil-mediated immune is uncertain and need to be further study.
出处
《免疫学杂志》
CAS
CSCD
北大核心
2007年第2期131-134,共4页
Immunological Journal
基金
北京科委中英SARS免疫病理学研究基金项目资助(H030230100130)
关键词
SARS冠状病毒
S蛋白
受体结合区
中和抗体
DNA疫苗
Severe acute respiratory syndrome-coronavirus
Spike protein
Receptor-binding domain
Neutralizing antibody
DNA vaccine
