An OriP/EBNA-1-based baculovirus vector with prolonged and enhanced transgene expression

Area of Science:

• Biotechnology
• Molecular Biology
• Virology

Background:

• Autographa californica multiple nucleopolyhedrovirus (AcMNPV) is a potential gene delivery vector for mammalian cells.
• Limitations include transient expression and low transduction efficiency due to lack of replication in mammalian cells.

Purpose of the Study:

• To enhance baculovirus gene delivery by enabling sustained transgene expression in mammalian cells.
• To investigate the role of Epstein-Barr virus (EBV) elements (OriP and EBNA-1) in baculovirus vector maintenance and transgene expression.

Main Methods:

• Constructed recombinant baculovirus vectors with EBV's OriP and EBNA-1 genetic elements.
• Tested vector persistence and transgene (enhanced green fluorescence protein - EGFP) expression in mammalian cell lines (HEK293, Vero, Cos-7, Hone-1).

Main Results:

• Recombinant baculovirus with OriP and EBNA-1 demonstrated persistence in mammalian cells without selective pressure.
• Sustained EGFP expression for up to 60 days in HEK293 cells with enhanced expression levels.
• Baculovirus genome persistence correlated with EBNA-1 protein expression.

Conclusions:

• The improved baculovirus vector facilitates prolonged and enhanced foreign gene expression in mammalian cells.
• Sufficient EBNA-1 protein levels are crucial for maintaining the OriP-containing baculovirus genome.
• This novel vector holds potential for gene therapy applications.