猪伪狂犬病病毒ZJ01ΔgI/gE/TK株种子批的免疫原性鉴定

Identification of immunogenicity of a porcine pseudorabies virus strain with deletion of TK/gE/gI genes in seed batch

本研究选用30头28~30日龄猪伪狂犬病病毒(PRV)阴性仔猪,随机分为6组,每组5头,第1~5组分别接种F1、F5、F20、F30、F35代次PRV TK/gE/gI基因缺失毒株ZJ01R病毒液,接种剂量为每头106.0 TCID50,第6组为非免疫对照组。接种后第28天用PRV ZJ01株攻击,结果显示,5个代次疫苗病毒免疫组猪PRV gB血清抗体均为阳性,gE抗体均为阴性,PRV ZJ01特异性中和抗体效价可达1∶32以上。用PRV ZJ01株强毒滴鼻攻击后,非免疫攻毒对照组猪出现严重的临床症状,表现明显的呼吸道症状与神经症状,3/5头猪死亡。5个代次ZJ01R免疫组猪攻毒后均无明显临床症状,脑组织PRV载量均明显低于攻毒对照组(P<0.05),免疫保护效力达100%。证明该疫苗毒株免疫原性稳定,可用于疫苗研制。

The 28—30 days-old piglets free of pseudorabies virus(PRV)infection were randomly divided into 5 groups each with 5.Group 1—5 were individually inoculated with the F1,F5,F20,F30 and F35 generation of PRV ZJ01R strain from ZJ01 by deletion of TK/gE/gI genes at dose of 106.0 TCID50 for one piece,and Group 6 was inoculated with DMEM as negative control.The immunological efficacy was observed by challenged with PRV ZJ01 strain at 28 days post vaccination.The results showed that all the piglets immunized with the ZJ01R strain produced higher levels of anti-gB antibodies.And anti-PRV ZJ01 neutralizing antibodies titers were more than 1∶32.After challenge with the virulent strain ZJ01 nasally,all the piglets in the no vaccination control group showed serve respiratory clinical signs and neurological symptoms,and 3 out of 5 piglets died.But the piglets in the ZJ01R immunized groups had no abnormal clinical symptoms and was able to resist the attack of virulent strains effectively.The viral loads in brain were significantly lower than those in the challenge control group(P<0.05),and the protective effect was 100%.It indicted that PRV ZJ01R strain is stable in immunogenicity,and can be used for the development of vaccine in the future.