DNA aptamers selected against the HIV-1 RNase H display in vitro antiviral activity

The DNA polymerase of the human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT) is a target widely used to inhibit HIV-1 replication. In contrast, very few inhibitors of the RNase H activity associated with RT have been described, despite the crucial role played by this activity in viral proliferation. DNA ligands with a high affinity for the RNase H domain of HIV-1 RT were isolated by systematic evolution of ligands by an exponential enrichment strategy (SELEX), using recombinant RTs with or without the RNase H domain. The selected oligonucleotides (ODNs) were able to inhibit in vitro the HIV-1 RNase H activity, while no effect was observed on cellular RNase H. We focused our interest on two G-rich inhibitory oligonucleotides. Model studies of the secondary structure of these ODNs strongly suggested that they were able to form G-quartets. In addition to the inhibition of HIV-1 RNase H observed in a cell free system, these ODNs were able to strongly diminish the infectivity of HIV-1 in human infected cells. Oligonucleotides described here may serve as leading compounds for the development of specific inhibitors of this key retroviral enzyme activity.