FIG. 5.

Second-generation promoter constructs tested for long-term gene expression. The LAT region and relevant restriction sites are shown, indicating the positions at which the cassettes below were inserted into the HSV genome. These cassettes were inserted into the LAT regions of viruses already deficient in ICP34.5 and vmw65 (virus strain 1764) and are thus present twice per virus genome due to the diploid nature of the LAT region. LAP1 and LAP2 refer to the sequences identified by Goins et al. (15), with LAT P2 being the region used later in this study by us. The pR19 series of cassettes referred to in the text is indicated, together with a summary of the results obtained following footpad inoculation of mice with these viruses (see Materials and Methods).