Epstein-Barr virus-derived vectors for transient and stable expression of recombinant proteins

The transient expression level of foreign proteins in primate cells can be enhanced by incorporating the replication elements derived from Epstein-Barr virus (EBV). Specifically, we have constructed expression plasmids with the replication origin region (OriP) from EBV and an adenovirus-transformed cell line that expresses the EBV nuclear antigens-1 (EBNA-1). As EBV vectors can replicate as episomes in the nuclei, such vectors can have a stable transfection efficiency as high as 25% and provide a straightforward way of obtaining large amounts of recombinant proteins transiently or stably.