Safety and immunogenicity of an attenuated Chinese pseudorabies variant by dual deletion of TK&gE genes

作者：Jichun Wang, Zengcai Song, Aimin Ge, Rongli Guo, Yongfeng Qiao, Mengwei Xu, Zhisheng Wang, Yamei Liu, Yating Zheng, Hongjie Fan, Jibo Hou · 发表于：BMC Veterinary Research · 年份：2018 · DOI：10.1186/s12917-018-1536-7 · 被引用次数：46 · 研究领域：Herpesvirus Infections and Treatments、Animal Disease Management and Epidemiology、Viral Infections and Immunology Research

Since the outbreak of a new emerging virulent pseudorabies virus mutant in Chinese pig herds, intensive research has been focused on the construction of novel gene deletion vaccine based on the variant virulent viruses. An ideal vaccine candidate is expected to have a balanced safety and immunogenicity. From the infectious clone of PRV AH02LA strain, a TK deletion mutant was generated through two-step Red mutagenesis. After homologous recombination with a transfer vector, a TK&gE dual deficient mutant PRV (PRV ΔTK&gE-AH02 ) was generated, and its structure verified by PCR, RFLP and sequencing. Growth kinetics test showed that PRV ΔTK&gE-AH02 reached a titer of 10 7.5 TCID 50 /mL on ST cells. The PRV ΔTK&gE-AH02 at a dose of 10 6.0 TCID 50 /animal was not virulent in mice or 1-day-old piglets with maternal PRV antibodies. No clinical signs or virus shedding were detected in 28~ 35-day-old piglets without maternal PRV antibodies after nasal or intramuscular administration with a dose of 10 6.0 TCID 50 , although it caused one death of four 1-day-old piglets without maternal PRV antibodies. In the efficiency test of PRV ΔTK&gE-AH02 , all four 28~ 35-day-old piglets without PRV antibody in the challenge control showed typical clinical symptoms and virus shedding, and two died at 4~ 5 days post challenge. All piglets in 10 5.0 , 10 4.0 and 10 3.0 TCID 50 /dose PRV ΔTK&gE-AH02 groups provided complete protection against challenge at only 7 days post intramuscular vaccination. More ...