| 摘要 |
The present invention relates to an in vivo system for expression and packaging of recombinant RNA into pseudovirus particles. The invention is based on the discovery that plant viral coat proteins (CPs) may be efficiently expressed in E. coli, and that these recombinant coat proteins will function to assemble in vivo and package recombinant chimeric RNA, containing an operatively linked origin-of-assembly (OAS) sequence, to form mature viral particles containing a foreign RNA. The present invention thus provides for packaging of RNA into a ribonuclease-resistant form that is easily purified and stored, and which overcomes the prior art problems associated with degradation of RNA by ribonucleases. Significantly, the method of the invention is RNA sequence- and length-independent. The components of the invention include a source in the bacterial host of viral coat proteins, and a source in the bacterial host to direct the transcription of a DNA molecule comprising an OAS-encoding DNA and a foreign DNA, which DNA molecule can be transcribed in the host cell to produce an RNA molecule comprising an OAS operatively linked to an RNA of interest. The CPs and OAS are from a plant virus having a rod-shaped helical particle and a single-stranded RNA genome, most preferably tobacco mosaic virus. |
