title: Comparative pathogenicity and immunogenicity of triple and double gene-deletion pseudorabies virus vaccine candidates.
abstract: Pseudorabies (PR) outbreaks have re-emerged in many pig farms with vaccination coverage in China, which suggests that current vaccine strains provide poor protection against novel, epidemic strains. In this study, based on the highly virulent PRV ZJ01 variant, a PR virus (PRV) thymidine kinase (TK)/gE/gI deleted strain-rZJ01ΔTK/gE/gI-was generated, which showed similar growth features in vitro compared to the parent strain PRV ZJ01 and its gE/gI deleted strain rZJ01ΔgE/gI. The results of a piglet experiment (with 10 piglets each group) showed that the rZJ01ΔTK/gE/gI vaccine generated similar levels of neutralizing antibodies against ZJ01 compared to the rZJ01ΔgE/gI vaccine (p>0.05). However, rZJ01ΔgE/gI inoculation resulted in slight inflammatory cell infiltrations, hemorrhages, and congestion in the brain and lungs. After a ZJ01 challenge, all animals in the rZJ01ΔTK/gE/gI- and rZJ01ΔgE/gI-vaccinated groups survived without exhibiting any clinical symptoms, whereas all non-vaccinated control animals died within 7days post-challenge. Furthermore, microscopic lesions and virus loads in the brains and lungs in the two vaccinated groups were significantly lower than those in the control group. Meanwhile, the virus levels in the brains of piglets in the rZJ01ΔTK/gE/gI group were significantly lower than those in the rZJ01ΔgE/gI group. These results indicate that the triple gene-deleted PRV rZJ01ΔTK/gE/gI strain has lower pathogenicity and higher protective efficacy against variant PRV challenge compared with the double gene-deleted PRV rZJ01ΔgE/gI strain. Together, all these data indicate that the PRV rZJ01ΔTK/gE/gI strain should be an ideal vaccine candidate for the prevention of PR in China.
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Dong
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Juan
authors.initials: J
authors.lastname: Bai
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Sun
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Zhenqing
authors.initials: Z
authors.lastname: Gu
authors.affiliation: National Veterinary Biological Medicine Engineering Research Center, Nanjing 210014, China.
authors.forename: Jichun
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Haifeng
authors.initials: H
authors.lastname: Sun
authors.affiliation: Key Laboratory of Animal Diseases Diagnostic and Immunology, Ministry of Agriculture, College of Veterinary Medicine, Nanjing Agricultural University, Nanjing 210095, China; Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonoses, Yangzhou, China. Electronic address: jiangp@njau.edu.cn.
authors.forename: Ping
authors.initials: P
authors.lastname: Jiang
mesh_terms: D000818:Animals; D017353:Gene Deletion; D011558:Herpesvirus 1, Suid / Q000276:immunology* / Q000472:pathogenicity*; D000071497:Immunogenicity, Vaccine; D022421:Pseudorabies Vaccines / Q000276:immunology*; D034421:Sus scrofa; D013552:Swine; D013553:Swine Diseases / Q000517:prevention & control* / Q000821:virology; D014774:Virulence
chemical_list: D022421:Pseudorabies Vaccines
keywords: Highly virulent; Pseudorabies virus; Recombinant virus vaccine; Swine