BVDV-E2截短基因重组卡介苗对牛的免疫效果评价

为评价牛病毒性腹泻病毒(BVDV)E2截短基因重组卡介苗对牛的免疫效果,将BVDV抗原抗体阴性牛随机分为rBCG-pMV361-E2-1(1 aa-297aa)、rBCG-pMV361-E2-2(1 aa-345 aa)、rBCG-pMV361-E2-3(1 aa-374 aa)、rBCG-pMV361-E2-4(45 aa-297 aa)、rBCG-pMV361-E2-5(45 aa-345 aa)、rBCG-pMV361-E2-6(45 aa-374 aa)、BVDV对照组、BCG对照组和PBS对照组,各组牛免疫相应疫苗后通过特异性抗体检测、淋巴细胞增殖试验、淋巴细胞亚群检测和细胞因子检测分析疫苗的免疫效果。结果显示,BVDV E2截短基因重组卡介苗均可诱导BVDV特异性抗体的产生,rBCG-pMV361-E2-1组抗体水平高于其他重组卡介苗试验组和BVDV对照组。淋巴细胞增殖试验结果显示,rBCG-pMV361-E2-2组SI为2.038±0.21,显著高于其他重组卡介苗试验组(P<0.01)。牛外周血CD4^+、CD8^+T淋巴细胞亚群检测结果显示,rBCG-pMV361-E2-5组牛外周血中CD4^+和CD8^+ T淋巴细胞亚群含量与PBS组比较,差异极显著(P<0.01)。IFN-γ检测结果显示,rBCG-pMV361-E2-1的IFN-γ水平显著高于其他试验组和对照组(P<0.01)。研究表明,rBCG-pMV361-E2-1可诱导接种牛产生较好的体液免疫应答,rBCG-pMV361-E2-1、rBCG-pMV361-E2-2和rBCG-pMV361-E2-5在诱导细胞免疫应答上效果较好。

Evaluation of Immune Efficacy of Recombinant BCG Expressing E2 Truncated Gene of Bovine Viral Diarrhea Virus in Cattle

To evalutedthe immunogenicity of recombinant BCG(rBCG) expressing BVDV E2 truncated gene,the cattle were randomly diviede into rBCG-pMV361-E2-1(1 aa-297 aa),rBCG-pMV361-E2-2(1 aa-345 aa),rBCG-pMV361-E2-3(1 aa-374 aa),rBCG-pMV361-E2-4( 45 aa-297 aa),rBCG-pMV361-E2-5(45 aa-345 aa),rBCG-pMV361-E2-6(45 aa-374 aa),BVDV control group,BCG control group and PBS control group.The immunogenicity of rBCGs were evaluated by BVDV antibody test,lymphocyte proliferation test,T lymphocyte subgroup test and cytokine assay.The results showed that rBCG effectively induced immunity system to generate anti BVDV antibodies.The antibody level of rBCG-pMV361-E2-1 group was increased significantly than that of other rBCG groups.The peripheral lymphocyte stimulus index was 2.038±0.21 in the rBCG-pMV361-E2-2 group at week 12 post boost immunization,showing a significantly difference(P<0.01) compared to the rBCGs and PBS groups.The result of CD4^+ and CD8^+ T lymphocyte test indicated that the level of CD4^+ and CD8^+ expression in cattle immunized with rBCG-pMV361-E2-5 were increased significantly than that of PBS group(P<0.01).The detection of IFN-gamma showed that the level of IFN-gamma of rBCG-pMV361-E2-1 was significantly higher than that of other experimental groups and control groups(P<0.01).rBCGs were mediated induced Th2 cellular immunity.This study demonstrated that rBCG-pMV361-E2-1 can effectively induce humoral immune response,rBCG-pMV361-E2-1,rBCG-pMV361-E2-2 and rBCG-pMV361-E2-5 have elicited greater cellular immune responses in cattle against BVDV.