SPECIFIC-INHIBITION OF IN-VITRO REVERSE TRANSCRIPTION USING ANTISENSEOLIGONUCLEOTIDES TARGETED TO THE TAR REGIONS OF HIV-1 AND HIV-2

Antisense oligonucleotides (ODNs) overlapping the stem-loop structure of the trans-activating responsive (TAR) element at the 5' end of HIV- 1 and HIV-2 viral RNAs were tested for their inhibitory effect on cDNA synthesis by HIV-1 and HIV-2 reverse transcriptases (RT). Inhibition of reverse transcription is sequence-specific and enhanced by the pres ence of the RT-associated RNase H activity. The degree of inhibition o btained with the anti-TAR antisense is significantly higher than with other HIV-1 targeted antisense ODNs used before [1]. Gel retardation s howed a stable specific complex between the 16- and 25-mer anti-TAR HI V-1 selected ODNs and the target region. No complex was observed with a non-inhibitor 22-mer anti-TAR ODN and with the corresponding control sequences. Targeting of the first stem-loop in the 5' region of HIV-2 RNA by anti-TAR ODNs inhibited very strongly reverse transcription by HIV-2 RT. The structure of the antisense and the target sequence affe ct annealing efficiency and hence the degree of inhibition of reverse transcription. (C) 1997 Elsevier Science B.V.