Characterisation of a human herpesvirus 6 variant A 'amplicon' and replication modulation by U94-Rep 'latency gene'.
The human herpesvirus 6 (HHV-6) variant A genome has conserved sequences which are signals for initiating lytic replication (origin, 'ori-lyt') and DNA packaging into the virion (pac2/1). Here these are functionally characterised and used to construct a gene-expression amplifiable-vector, an 'amplicon', with applications for gene delivery to lymphoid-myeloid cells or their progenitor stem cells. A minimal efficient ori-lyt for replication was identified which was enhanced in the presence of the imperfect direct repeated DNA domain (IDR). In A variant strains these are arranged as three adjacent repeats with the most divergence in IDR3. Addition of the pac2/1 sequences also enhanced detection of ori-lyt replication and conferred DNA packaging properties, thus, the amplicon could be packaged with 'helper' virus. An HHV-6 specific factor, which inhibits amplicon replication was identified by trans replication assays. This is the U94-Rep 'latency' gene product, which can modulate efficiency of such amplifiable vectors, based on the lytic origin. It could also affect maintenance of viral genomes or vectors during latency.
Turner
Simon
S
Department of Infectious and Tropical Diseases, London School of Hygiene and Tropical Medicine, University of London, Keppel St., London WC1E 7HT, UK.
DiLuca
Dario
D
Gompels
Ursula
U
D001483:Base Sequence; D017931:DNA Primers; D005784:Gene Amplification; D014644:Genetic Variation; D015654:Herpesvirus 6, Human / Q000145:classification* / Q000235:genetics* / Q000302:isolation & purification; D006801:Humans; D019169:Jurkat Cells; D010957:Plasmids; D016133:Polymerase Chain Reaction / Q000379:methods; D015183:Restriction Mapping / Q000379:methods; D013601:T-Lymphocytes / Q000821:virology; D014779:Virus Replication / Q000502:physiology*
D017931:DNA Primers