title: Evaluation of two strains of Marek's disease virus serotype 1 for the development of recombinant vaccines against very virulent infectious bursal disease virus.
abstract: Attenuated strains of Marek's disease virus serotype 1 (MDV1), and the closely related herpesvirus of turkeys, are among the most potent vectors for development of recombinant vaccines for poultry. To investigate the effects of MDV1 strain characteristics on the protective efficacy of the recombinant vaccines, we developed two recombinant MDV1 vaccines for expressing the VP2 gene of infectious bursal disease virus (IBDV) based on two different MDV1 strains, the attenuated strain 814 and the Meq gene-deleted recombinant MDV1 strain rLMS△Meq, as the viral vectors. The r814-VP2 virus based on the 814 strain exhibited higher replication efficiency in cell culture while lower viral titers in chickens, compared to rLMS△Meq-VP2 derived from the rLMS△Meq strain. Further studies indicated that r814-VP2 produced higher levels of VP2 protein in cells and elicited stronger immune responses against IBDV in chickens than rLMS△Meq-VP2. After IBDV challenge, rLMS△Meq-VP2 provided 50% protection against mortality, and the birds that survived developed bursal atrophy and gross lesions. In contrast, r814-VP2 conferred complete protection not only against development of clinical signs and mortality, but also against the formation of bursal lesions. The results indicate that different MDV1 vector influences the protective efficacy of recombinant MDV1 vaccines. The r814-VP2 has the potential to serve as a bivalent vaccine against two important lethal pathogens of chickens.
authors.affiliation: Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, PR China.
authors.forename: Kai
authors.initials: K
authors.lastname: Li
authors.affiliation: Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, PR China.
authors.forename: Yongzhen
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, PR China.
authors.forename: Changjun
authors.initials: C
authors.lastname: Liu
authors.affiliation: Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Gao
authors.affiliation: Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, PR China.
authors.forename: Yulong
authors.initials: Y
authors.lastname: Gao
authors.affiliation: Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, PR China.
authors.forename: Yanping
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, PR China.
authors.forename: Hongyu
authors.initials: H
authors.lastname: Cui
authors.affiliation: Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, PR China.
authors.forename: Xiaole
authors.initials: X
authors.lastname: Qi
authors.affiliation: Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, PR China.
authors.forename: Li
authors.initials: L
authors.lastname: Zhong
authors.affiliation: Avian Immunosuppressive Diseases Division, State Key Laboratory of Veterinary Biotechnology, Harbin Veterinary Research Institute, Chinese Academy of Agricultural Sciences, Harbin 150069, PR China. Electronic address: xmw@hvri.ac.cn.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Wang
mesh_terms: D000818:Animals; D000914:Antibodies, Viral; D018175:Birnaviridae Infections / Q000276:immunology / Q000517:prevention & control*; D002645:Chickens; D005822:Genetic Vectors; D008381:Herpesvirus 2, Gallid / Q000235:genetics*; D007243:Infectious bursal disease virus / Q000276:immunology* / Q000472:pathogenicity; D011201:Poultry Diseases / Q000517:prevention & control; D065288:Serogroup; D016019:Survival Analysis; D019444:Vaccines, DNA / Q000276:immunology; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000276:immunology; D015678:Viral Structural Proteins / Q000008:administration & dosage / Q000235:genetics* / Q000276:immunology; D014765:Viral Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology*
chemical_list: D000914:Antibodies, Viral; C082513:VP2 protein, infectious bursal disease virus; D019444:Vaccines, DNA; D014614:Vaccines, Synthetic; D015678:Viral Structural Proteins; D014765:Viral Vaccines
keywords: Infectious bursal disease virus; MDV1 vaccine strains; Marek's disease virus; Protective efficacy; VP2 gene