title: A recombinant field strain of Marek's disease (MD) virus with reticuloendotheliosis virus long terminal repeat insert lacking the meq gene as a vaccine against MD.
abstract: Marek's disease virus (MDV) GX0101, which is a field strain with a naturally occurring insertion of the reticuloendotheliosis virus (REV) long terminal repeat (LTR) fragment, shows distinct biological activities. Deletion of the meq gene in GX0101 contributes to its complete loss of pathogenicity and oncogenicity in SPF chickens, but this virus has a kanamycin resistance gene (kan(r)) residual at the site of meq gene. In the present study, the kan(r) was knocked out and a meq-null virus with a good replicative ability termed SC9-1 was selected. In vivo studies showed that SC9-1 had no pathogenicity or tumorigenicity to chickens. There were no obvious impacts on chicken weight, immune organ index or antibody levels induced by avian influenza virus (AIV)/newcastle disease virus (NDV) inactivated vaccines compared with the control group. The SC9-1 virus provided superior protection than CVI988/Rispens vaccine in both SPF chickens and Hy-line brown chickens when challenged with a very virulent MDV (rMd5 strain). There was no obvious change in SC9-1 protection against MDV rMd5 in SPF chickens after 20 passages in chicken embryonic fibroblast cells (CEFs). In conclusion, SC9-1 is a safe and effective vaccine candidate for the prevention of Marek's disease.
authors.affiliation: College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong 271018, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Su
authors.affiliation: College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong 271018, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Cui
authors.affiliation: Institute of Animal Husbandry and Veterinary, Beijing Academy of Agriculture and Forestry Sciences, Beijing 100097, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhou
authors.affiliation: College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong 271018, China.
authors.forename: Zimeng
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Biotechnology Research Institute, Chinese Academy of Agricultural Sciences, Beijing 100081, China.
authors.forename: Yanpeng
authors.initials: Y
authors.lastname: Li
authors.affiliation: China Institute of Veterinary Drug Control, Beijing 100081, China.
authors.forename: Jiabo
authors.initials: J
authors.lastname: Ding
authors.affiliation: College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong 271018, China.
authors.forename: Yixin
authors.initials: Y
authors.lastname: Wang
authors.affiliation: College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong 271018, China.
authors.forename: Luntao
authors.initials: L
authors.lastname: Duan
authors.affiliation: College of Veterinary Medicine, Shandong Agricultural University, Tai'an, Shandong 271018, China. Electronic address: zzcui@sdau.edu.cn.
authors.forename: Zhizhong
authors.initials: Z
authors.lastname: Cui
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D002645:Chickens; D005347:Fibroblasts / Q000821:virology; D017353:Gene Deletion; D005814:Genes, Viral; D042822:Genomic Instability; D025922:Mardivirus / Q000235:genetics* / Q000276:immunology*; D008380:Marek Disease / Q000517:prevention & control*; D022501:Marek Disease Vaccines / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology* / Q000302:isolation & purification; D011995:Recombination, Genetic; D001356:Reticuloendotheliosis virus / Q000235:genetics*; D020079:Terminal Repeat Sequences; D014614:Vaccines, Synthetic / Q000008:administration & dosage / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification; D014776:Virus Cultivation
chemical_list: D022501:Marek Disease Vaccines; D014614:Vaccines, Synthetic
keywords: Cell culture passage; Marek's disease virus; Meq gene; REV LTR; Recombinant MDV; Vaccine safety and efficacy