Generation of VP5 deficient mutant of infectious bursal disease virus strain HZ2

摘要

Infectious bursal disease virus (IBDV) is a bi-segmented, dsRNA virus of the Birnaviridae family. The nonstructural protein VPS has been reported to be associated with virus-induced cell apoptosis and pathogenicity, but its role in viral replication has not been unequivocally identified. Based on a PCR introduced mutagenesis strategy, the 33 bp of 96-129 bp located between ORF Aland ORF A2 of genomic segment A of IBDV strain HZ2 were deleted, and an Nhe I (GcTaGc) site was inserted at 96-102 bp simultaneously. The mutated segment A was ligated into pCi, resulting in pCI-ANhe3. A chi-meric and deficient IBDV strain, named strain ANheS, was recovered from chicken embryo fibroblast (CEF) cells by co-transfection with pCI-ANhe3 and pCl-mB, derived from the genomic segment B strain HZ2. The indirect fluorescent assay identified that strain ANhe3 could replicate on CEF cells without expression of VPS. Further examination showed that the patho-genesis of strain ANheS replicating on SPF chicken embryos was attenuated compared to strain HZ2. This paper provides a new rapid rescue strategy for gene-deleted virus. This strategy lays a basis for gene-deleted vaccine of IBDV.