Transcriptional trans-activation of HIV-1 genome by HIV-1 TAT protein requires the presence, in cis, of the TAT activation region or TAR element. The approach we have used to suppress HIV-1 gene expression is based on the overexpression of a multimerized TAR sequence to sequester one or more components involved in the TAT response. Co-transfection of multiple TAR expression plasmid with LTR-TAT and LTR-CAT plasmids suppresses the level of indicator gene activity (CAT) by as much as 97 percent. The downregulation observed is dependent on the quantity of transfected poly-TAR as well as a number of transfected TAR repeats expressed per unit transcript.
