编码SARS-CoV S1和S2蛋白的DNA疫苗对小鼠的免疫应答

目的构建编码SARS-CoVS蛋白亚单位S1和S2的核酸疫苗,并检测其对小鼠的免疫应答。方法依据GenBank中SARS-CoV基因组序列,人工合成SARS-CoVS1和S2亚单位基因,分别与CTL表位基因重组后,克隆至表达载体pIRES1neo中,构建DNA疫苗pIRCTL-S1和pIRCTL-S2。将构建的DNA疫苗转染BHK-21细胞,采用间接免疫荧光试验检测其在真核细胞中的表达。免疫小鼠后,用流式细胞仪测定CD4+、CD8+T淋巴细胞亚类数,用ELISA试剂盒检测免疫小鼠血清中抗SARS-CoV抗体水平。结果所构建的DNA疫苗pIRCTL-S1和pIRCTL-S2转染BHK-21细胞后,均能表达抗原蛋白,免疫小鼠后可有效地刺激淋巴细胞增殖,并诱导产生抗SARS-CoV特异性抗体。结论所构建的两种DNA疫苗在小鼠体内均产生了体液和细胞免疫应答,为SARS核酸疫苗的研制奠定了基础。

Immune Response Induced by DNA Vaccine Encoding SARS-CoV S1 and S2 Proteins in Mice

Objective To construct DNA vaccine encoding SARS-CoV S1 and S2 proteins and induce immune response in mice.Methods Synthesize the genes encoding S1 and S2 subunits of SARS-CoV according to the SARS-CoV genome sequence reported in GenBank and recombine with CTL epitope gene,then clone into expression vector pIRESlneo.Transfect BHK-21 cells with the constructed recombinant plasmids pIRCTL-S1 and pIRCTL-S2 respectively and determine the expressed product by IFA.Immunize mice with pIRCTL-S1 and pIRCTL-S2 respectively,and determine the CD4 and CD8 T cell subgroups by flow cytometry,and serum antibody against SARS-CoV by ELISA.Results Both pIRCTL-S1 and pIRCTL-S2 were expressed in BHK-21 cells.The expressed proteins stimulated the proliferation of lymphocytes and induced specific antibody against SARS-CoV in mice.Conclusion The constructed DNA vaccines pIRCTL-S1 and pIRCTL-S2 induced both humoral and cellular immune responses in mice,which laid a foundation of development of SARS DNA vaccine.