Genetic Analysis and Gene Expression with Mini-Epstein-Barr Virus Plasmids

Upon infection with Epstein-Barr virus (EBV), primary human B-lymphocytes are efficiently immortalized and give rise to lymphoblastoid cell lines in vitro. Four of the 11 viral genes expressed in the immortalized B cells have been found to be essential genetically for the process of immortalization: the EBV nuclear antigens EBNA2, EBNA3a, and EBNA3c, and the latent membrane protein 1 (LMP1) (1 –5 ). Since EBNA1 maintains the status of the EBV genomes in the proliferating B cells, it might also be indispensable (6 ).