The region of the HSV-1 latency-associated transcript required for epinephrine-induced reactivation in the rabbit does not include the 2.0-kb intron.

Previous studies have localized the region of the latency-associated transcript (LAT) of HSV-1 responsible for epinephrine-induced reactivation in the rabbit eye model to the first 1.5 kb of the primary transcript. This region extends from the 5prime prime or minute exon of the primary LAT transcript through the 5prime prime or minute half of the LAT 2.0-kb intron. To determine whether the 5prime prime or minute end of the LAT intron contributes to the induced reactivation phenotype, three recombinant viruses containing deletions within this portion of the LAT intron were constructed. The three recombinants, containing deletions spanning a combined region of 969 bp at the 5prime prime or minute end of the LAT intron, reactivated with the wild-type frequency of 17syn+. These results indicate that the elements governing induced reactivation reside within the first 699 bp of the primary LAT transcript encoding the 5prime prime or minute LAT exon.