title: A high-temperature passaging attenuated Pseudorabies vaccine protects piglets completely against emerging PRV variant.
abstract: Emerging variant of pseudorabies virus (PRV) have evaded the antiviral immunity of commercially available PRV vaccine and have led to PRV outbreaks in Chinese pig farms. Here, we attenuated a PRV variant strain by serial passages in vitro and evaluate the protective efficacy of the attenuated strain as a vaccine candidate. The virulent PRV variant strain JS-2012 was continuously passaged in Vero cells at 40°C and attenuated rapidly. After 90 passages in Vero cells, the passaged virus lost its ability to cause death in 2-week-old piglets. The 120th passage virus was avirulent in the sucking piglets. An attenuated strain, JS-2012-F120 derived from the 120th passage virus by three rounds of plaque cloning grew better than its parent strain JS-2012 in Vero cells and showed notably different cytopathic effects and plaque morphology from JS-2012. PCR combined with sequence analysis showed that JS-2012-F120 contained a 2307-bp deletion covering nucleotide 487 of gE gene to 531 of US2 gene. After inoculation with JS-2012-F120, young piglets were completely protected from challenge with the classical and emerging virulent PRVs. Moreover, the piglets did not develop specific gE antibodies. Thus, JS-2012-F120 appears to be a promising marker vaccine to control PRV variant circulating in Chinese pig farms, and the high-temperature passaging in vitro was an efficient method to attenuated alphaherpesvirus.
authors.affiliation: College of Veterinary Medicine, Northwest A & F University, Yangling 712100, Shaanxi, China; Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Chao
authors.initials: C
authors.lastname: Liang
authors.affiliation: Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China.
authors.forename: Wu
authors.initials: W
authors.lastname: Tong
authors.affiliation: Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China.
authors.forename: Hao
authors.initials: H
authors.lastname: Zheng
authors.affiliation: Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China.
authors.forename: Jiqiang
authors.initials: J
authors.lastname: Wu
authors.affiliation: Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China.
authors.forename: Guoxin
authors.initials: G
authors.lastname: Li
authors.affiliation: College of Veterinary Medicine, Northwest A & F University, Yangling 712100, Shaanxi, China. Electronic address: zhouem@nwsuaf.edu.cn.
authors.forename: En-Min
authors.initials: EM
authors.lastname: Zhou
authors.affiliation: Department of Swine Infectious Diseases, Shanghai Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Shanghai 200241, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou 225009, Jiangsu, China. Electronic address: gztong@shvri.ac.cn.
authors.forename: Guangzhi
authors.initials: G
authors.lastname: Tong
mesh_terms: D000818:Animals; D000914:Antibodies, Viral / Q000097:blood; D004196:Disease Outbreaks; D011558:Herpesvirus 1, Suid / Q000235:genetics*; D011557:Pseudorabies / Q000517:prevention & control*; D022421:Pseudorabies Vaccines / Q000276:immunology*; D013552:Swine; D013553:Swine Diseases / Q000517:prevention & control* / Q000821:virology; D013696:Temperature; D014611:Vaccination; D014613:Vaccines, Attenuated / Q000276:immunology; D014759:Viral Envelope Proteins / Q000235:genetics
chemical_list: D000914:Antibodies, Viral; D022421:Pseudorabies Vaccines; D014613:Vaccines, Attenuated; D014759:Viral Envelope Proteins
keywords: High-temperature passaging; Marker vaccine; Pseudorabies virus