Construction of a Novel Infectious Clone of Recombinant Herpesvirus of Turkey Fc-126 Expressing VP2 of IBDV
Abid Ullah Shah,
Zhisheng Wang,
Yating Zheng,
Rongli Guo,
Saisai Chen,
Mengwei Xu,
Chuanjian Zhang,
Yamei Liu,
Jichun Wang
Affiliations
Abid Ullah Shah
National Research Center of Engineering and Technology for Veterinary Biologicals/Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Zhisheng Wang
National Research Center of Engineering and Technology for Veterinary Biologicals/Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Yating Zheng
National Research Center of Engineering and Technology for Veterinary Biologicals/Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Rongli Guo
Institute of Veterinary Medicine, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Saisai Chen
National Research Center of Engineering and Technology for Veterinary Biologicals/Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Mengwei Xu
National Research Center of Engineering and Technology for Veterinary Biologicals/Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Chuanjian Zhang
National Research Center of Engineering and Technology for Veterinary Biologicals/Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Yamei Liu
National Research Center of Engineering and Technology for Veterinary Biologicals/Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
Jichun Wang
National Research Center of Engineering and Technology for Veterinary Biologicals/Institute of Veterinary Immunology and Engineering, Jiangsu Academy of Agricultural Sciences, Nanjing 210014, China
The increased virulence of infectious bursal disease virus (IBDV) is a threat to the chicken industry. The construction of novel herpesvirus of turkey-vectored (HVT) vaccines expressing VP2 of virulent IBDV may be a promising vaccine candidate for controlling this serious disease in chickens. We generated a novel infectious clone of HVT Fc-126 by inserting mini-F sequences in lieu of the glycoprotein C (gC) gene. Based on this bacterial artificial chromosome (BAC), a VP2 expression cassette containing the pMCMV IE promoter and a VP2 sequence from the virulent IBDV NJ09 strain was inserted into the noncoding area between the UL55 and UL56 genes to generate the HVT vector VP2 recombinant, named HVT-VP2-09. The recovered vectored mutant HVT-VP2-09 exhibited higher titers (p = 0.0202 at 36 h) or similar growth kinetics to the parental virus HVT Fc-126 (p = 0.1181 at 48 h and p = 0.1296 at 64 h). The high reactivation ability and strong expression of VP2 by HVT-VP2-09 in chicken embryo fibroblasts (CEFs) were confirmed by indirect immunofluorescence (IFA) and Western blotting. The AGP antibodies against IBDV were detected beginning at 3 weeks post-inoculation (P.I.) of HVT-VP2-09 in 1-day-old SPF chickens. Seven of ten chickens immunized with HVT-VP2-09 were protected post-challenge (P.C.) with the virulent IBDV NJ09 strain. In contrast, all chickens in the challenge control group showed typical IBD lesions in bursals, and eight of ten died P.C. In this study, we demonstrated that (i) a novel HVT BAC with the whole genome of the Fc-126 strain was obtained with the insertion of mini-F sequences in lieu of the gC gene; (ii) HVT-VP2-09 harboring the VP2 expression cassette from virulent IBDV exhibited in vitro growth properties similar to those of the parental HVT virus in CEF cells; and (iii) HVT-VP2-09 can provide efficient protection against the IBDV NJ09 strain.
