Application of baculovirus as a delivery vehicle for study of transcription and translation mechanism of parvovirus in non-permissive mammalian cells

Human bocavirus (HBoV) is a parvovirus associated with respiratory and gastrointestinal diseases in humans. Recombinant baculoviruses have been used widely for many years to transduce transiently and stably a variety of mammalian cell types at high frequencies. In this study, to explore further the use of baculovirus as a gene delivery vehicle for study of transcription and translation mechanism of human bocavirus which lacks susceptible cell culture system, two recombinant baculoviruses were constructed: Bac-BoV-EGFP in which the EGFP gene was under the control of the HBoV1 promoter, and Bac-HBoV1 encompassing the nearly whole HBoV1 genome without both termini. The data demonstrated that efficient gene delivery and expression were observed in numerous mammalian cells transduced by Bac-BoV-EGFP and the transduction rate was much greater than that in plasmid-based transfected cells. The analysis of transcription and translation in Bac-HBoV1 transduced A549 cells showed that two transcripts from NP1 gene were detected by RT-PCR and the NP1 was localized in the nucleus, suggesting that the Bac-HBoV1 recombinant baculovirus delivered efficiently the HBoV1 genome into A549 cells. In summary, this system provides a useful tool for analysis of the transcription and translation of some viruses lacking a virus-cell replication system.