猪瘟病毒E2基因真核表达载体表达效率和免疫效果的比较

Comparisons of the expression efficiencies and immune effects of two eukaryotic vectors encoding CFSV E2 gene

比较猪瘟病毒E2基因的真核表达质粒proVAX-E2n和pVP22-E2n体外表达效率以及体内的免疫效果,以从中选出高效的猪瘟病毒核酸疫苗.将上述表达载体转染Hela细胞进行体外表达后,用RT-PCR和间接ELISA法检测Hela细胞体内和体外表达产物;免疫6～8周龄昆明白小鼠, 用间接ELISA法和MTS法检测小鼠血清中CSFV特异性IgG抗体水平以及脾脏中淋巴细胞增殖功能.结果表明2种E2重组质粒均能在Hela细胞中正确表达,且proVAX-E2n的E2蛋白表达量(OD值为0.575 4)明显高于pVP22-E2n(OD值为0.306 05)(P<0.05);proVAX-E2n刺激机体产生的抗体水平(最高抗体滴度为1:2 200)显著高于pVP22-E2n免疫组(最高抗体滴度1:1 600);淋巴细胞增殖结果显示proVAX-E2n(刺激指数4.073)与pVP22-E2n(刺激指数2.205)相比,能诱发小鼠产生更强的CSFV的特异性淋巴细胞增殖反应.本研究表明proVAX真核表达载体对E2基因体外表达效率和小鼠免疫效果均高于pVP22真核表达载体.

In order to get a high efficiency CSFV DNA vaccine, the expression efficiencies in vitro and immune effects in vivo of proVAX-E2n and pVP22-E2n were compared.,. After transfected into Hela cells, both expressed products in vitro were accessed by indirect ELISA and RT-PCR. The results showed that proVAX-E2n （OD = 0.575 4） expressed significantly higher E2 protein than pVP22-E2n （OD= 0. 306 05）. To investigate their immune effects the KunMing White mice were immunized with both plasmids intramuscularly, The specific antibody of CSFV in serum of mice was detected by indirect ELISA, and the lymphocytes proliferation in spleen was detected by MTS, The results showed that the anti- body level （the highest titer= 1：2 200） and the lymphocytes proliferation （the stimulation index = 4.073） of the group immunized with the proVAX-E2n were significantly higher than that with pVP22-E2n （the highest titer= 1：1 600, the stimulation index = 2.205）. This study demonstrated that efficiency of in vitro expression and immune responses in mice of proVAX was better than that of pVP22.