以乳酸杆菌为载体的口蹄疫病毒VP1基因 DNA疫苗猪体免疫试验

给猪口服和肌肉注射以乳酸杆菌为载体的口蹄疫病毒VP1基因DNA疫苗(L.acido SFMD-1),以正向间接血凝试验(IHA)和MTT方法分别检测了免疫后FMDV VP1抗体的动态变化和特异性T细胞增殖反应情况,并与商用FMD油佐剂疫苗、裸质粒FMDV VP1基因DNA疫苗诱导的特异性免疫抗体水平进行了比较。结果显示,口服组猪在免疫后第21d抗体效价达到了1∶2~(7.7),而肌肉注射组猪为1∶2~(3.3)。加强免疫后2周,口服免疫组抗体水平下降到1∶2~(5.3),到第3周快速上升到1∶2~8；与此相对应,肌肉途径免疫组猪抗体效价缓慢地从1∶2~(5.3)上升到1∶2~(6.7)。口服途径和肌肉注射途径的刺激指数(SI)分别为1.93和2.00,2种免疫途径都可以诱导特异性T细胞增殖反应。证实,该疫苗能够在猪体诱发VP1特异性T细胞和B细胞反应,以乳酸杆菌为载体是DNA免疫和预防猪口蹄疫的一种极有前景的方法。

Vaccination of pigs against foot-and-mouth disease virus with a DNA vaccine containing VP1 gene using Lactobacillus acidophilus as carrier

Pigs were inoculated with a DNA vaccine encoding FMDV VP1 gene using Lactobacillus aci- dophilus as carrier(L.acido SFMD-1).Anti-FMDV VP1-specific antibody and T cell proliferation re- sponse were measured by the indirect haemagglutination test and the MTT assay,respectively.Compared with the intramuscular injection routes,the oral administration group showed a significant higher antibody level on day 21,and the titer reached 1:2~(7.7),whereas the titer in the intramuscular injection route was 1:2~(3.3).On week 2 post booster,the titer of the oral administration group decreased to 1:2~(5.3),and then rose rapidly to 1:2~8 on next week; whereas the counterpart route from 1:2~(5.3)to 2~(6.7).The stimulation in- dex for immunization via oral and the intramuscular routes reached 1.93 and 2.00,respectively.The re- suits demonstrated clearly that vaccine could elicit VPl-specific T cell and B cell response in swine,and L. acidophilus as a carrier was a potent tool for DNA immunization and defense against FMDV.