Abstract: The invention provides a recombinant vector comprising a DNA segment having a synthetic origin of DNA synthesis that binds EBNA-1 and is capable of initiating DNA synthesis of sequences linked to the synthetic origin of DNA synthesis and maintaining the linked sequences when in the presence of EBNA-1. The synthetic origin of DNA synthesis comprises at least two binding sites for EBNA-1, wherein the two EBNA-1 binding sites are flanked by at least two half-binding sites for TRF2 or at least two binding sites for a protein that enhances the affinity of EBNA-1 for the synthetic origin of DNA synthesis. Further provided are host cells with the vector and methods of using the vector, for instance, ex vivo or in vivo.

Abstract: The invention provides a recombinant vector comprising a DNA segment having a synthetic origin of DNA synthesis that binds EBNA-1 and is capable of initiating DNA synthesis of sequences linked to the synthetic origin of DNA synthesis and maintaining the linked sequences when in the presence of EBNA-1. The synthetic origin of DNA synthesis comprises at least two binding sites for EBNA-1, wherein the two EBNA-1 binding sites are flanked by at least two half-binding sites for TRF2 or at least two binding sites for a protein that enhances the affinity of EBNA-1 for the synthetic origin of DNA synthesis. Further provided are host cells with the vector and methods of using the vector, for instance, ex vivo or in vivo.

Abstract: The invention provides a vector encoding a derivative of EBNA-1 that is not cytotoxic when expressed efficiently in cells, which supports extrachromosomal replication, maintenance and transcription from extrachromosomal oriP containing vectors but does not substantially activate transcription from host cell genes. Also provided is a vector having oriP and encoding a derivative of EBNA-1. The vectors of the invention may be employed in vitro and in gene therapy.

Abstract: A method of inhibiting viral gene activities (and cellular gene activities) is disclosed. In one embodiment, the method comprises the step of delivering an effective amount of an inhibitor of a viral looping/linking factor to an infected patient.

Abstract: A method of assaying potential inhibitors of EBNA-1 is disclosed. In one aspect, this invention comprises the steps of (a) obtaining an EBV-positive cell line and an EBV-negative cell line; (b) exposing the cell lines to a test compound, and (c) observing the effect of the compound on induction of apoptosis in the cell lines, wherein significant apoptosis in the EBV-positive cell line and lack of significant apoptosis in the EBV-negative cell line indicates a compound that specifically inhibits EBNA-1.

Abstract: A method of assaying potential inhibitors of EBNA-1 is disclosed. In one aspect, this invention comprises the steps of (a) obtaining an EBV-positive cell line and an EBV-negative cell line; (b) exposing the cell lines to a test compound, and (c) observing the effect of the compound on induction of apoptosis in the cell lines, wherein significant apoptosis in the EBV-positive cell line and lack of significant apoptosis in the EBV-negative cell line indicates a compound that specifically inhibits EBNA-1.

Abstract: A method of inhibiting viral gene activities (and cellular gene activities) is disclosed. In one embodiment, the method comprises the step of delivering an effective amount of an inhibitor of a viral looping/linking factor to an infected patient.

Abstract: The invention provides lymphotrophic herpes virus (preferably EBV) recombinants. The portions of the virus that are responsible for the packaging and lytic phase replication have been isolated and cloned. When used with vectors and hosts containing a segment that controls plasmid replication, they provide a means of carrying foreign genes into B-lymphocytes.

Abstract: A recombinant vector and a eukaryotic host transformed thereby are disclosed. In one embodiment, there is a eukaryotic host that has a recombinant plasmid comprising a plasmid backbone, a foreign eukaryotic gene component, and a first gene segment from a lymphotrophic herpes virus. There is also provided in the host a second gene segment from a lymphotrophic herpes virus. The first and second gene segments interact to assist the plasmid in maintaining itself as a plasmid when inserted into a eukaryotic host, and permit stable replication of the host. The preferred virus is the Epstein-Barr virus, and the two preferred viral segments are the EBV origin of replication and the segment coding for EBNA protein.