We have engineered a helper-dependent mini-EBV, with minimal cis-EBV elements for episomal replication, viral amplification and packaging, for use as a gene delivery system. The therapeutic potential of this system was established by stably transducing B-lymphoblastoid cells from several human diseases patients with a mini-EBV constitutively expressing the normal cDNAs and showing in vitro correction of the diseases phenotype. Currently, we are focusing on the delivery of very large functional genes ( i.e. genomic DNA ) as infectious HAECs in human cells.
Schematic life cycle of infectious mini-EBV: During the lytic phase, mini-EBV DNA replicates in the presence of helper virus via a rolling circle mechanism to generate head to tail concatemeric molecules, which are then cleaved and packaged into infectious EBV virions. After infection of human B-cells, the mini-EBV virions recircularize the packaged DNA and episomal replication occurs.