[Construction and characterization of reverse genetic system for H9N2 avian influenza].

ABSTRACT

OBJECTIVE: To provide a technology platform for vaccine development as well as the research on transmission and pathogenesis, the reverse genetic system for H9N2 avian influenza virus was established. METHODS: Eight full-length cDNAs of avian influenza virus A/Guangzhou/333/99 (H9N2) were amplified by RT-PCR and separately cloned into the transcription/expression vector, pCI-polI. The 8 plasmids DNA was cotransfected into 293T cell, the cell supernatant was collected and inoculated into embryonated eggs, the rescued virus from the allantoic fluid was identified by hemagglutinination assay. RESULTS: The avian influenza H9N2 virus was successfully rescued by 8 plasmids co-transfection in 293T cells. The hemagglutinination titer of the rescued virus is up to 2(9)/50 microl and its growth curve remained relatively as to the wild-type virus. CONCLUSION: The reverse genetic for avian influenza H9N2 subtype virus has been established successfully.