FIG. 1.

Schematic representation of the gene inserts used to construct each of the vaccine plasmids. Plasmids expressing HIV-1_YU-2 envelope gene inserts sgp120_YU-2 (A), sgp140_YU-2 (B), and sgp140_YU-2(−/FT) (C), were constructed, and a representative of how the individual Envs assemble as either monomers or trimers is shown. A schematic representation of the addition of one, two, and three copies of mC3d fused to the 3′ end of each HIV-1_YU-2 envelope gene insert, sgp120_YU-2 (A), sgp140_YU-2 (B), or sgp140_YU-2(−/FT) (C), is shown. Each of the gene inserts was cloned into the previously described eukaryotic vaccine vector pTR600 (30, 50, 51). The vector contains the CMV immediate-early promoter (CMV promoter) plus intron A for efficiently initiating transcription of eukaryotic inserts and the bovine growth hormone polyadenylation terminator for efficient termination of transcription. This vector also contains the Col E1 origin of replication for prokaryotic replication as well as the kanamycin resistance (Kan^r) gene for selection in antibiotic media.