H5N1亚型禽流感病毒HA基因DNA疫苗的构建和活体电击免疫试验初报

Construction and Immune Assay of HA DNA Vaccine of H5N1 Subtype Avian Influenza Viruses

将高致病力禽流感病毒A/Goose/GuangDong/1/96(H5N1)的HA基因克隆到质粒pcDNA4/His鄄Max和pRc/CMV上得到真核表达质粒pC4H5和pCMVH5。将pC4H5和pCMVH5经活体电击和肌肉注射接种于3周龄SPF鸡的右腿内侧,并设空白质粒对照。二次免疫后第二周用104.2ELD50的同源病毒进行攻击。结果pC4H5和pCMVH5活体电击免疫SPF鸡能诱导产生持续表达的高水平特异性抗体,可产生100%的保护率,并能有效地阻止H5N1病毒攻击后病毒在泄殖腔的排出,而肌肉注射组和空白对照组在攻毒后全部发病并死亡。结果表明活体电击免疫是一条可以与基因枪免疫相媲美甚至优于基因枪免疫的有效免疫途径。

The H5 gene of AIV, A/Goose/GuangDong/1/96(H5N1), was subcloned into eukaryotic expressing vectors pcDNA4/ HisMax and pRc/ CMV, and these construct were designated pC4H5 and pCMVH5. SPF chickens were immunized using electroporation by two injections, 3 weeks apart, of 30μg /ck or 50μg/ck into the right quadriceps muscle. A couple of weeks after the secondary immunization, the chickens were challenged with lethal dose of 104.2 ELD50 of HPAIV GD/96(H5N1) by intramuscular injection. The data show that immunized by E.P. with 50 μg/chicken can provide 100 percent of protection for either pC4H5 or pCMVH5 plasmids, and were effectively inhibited to shed viruses in cloaca when chanllenge with H5N1, while the chickens vaccinated by intramuscular injection or with blank plasmid controls experience 100% mortality respectively following challenge. And these protections were companied by the high levels of specific antibody to H5N1 AIV. The above results indicated that electroporation is as good as or better than intramuscular in immune ways.