The ability of tRNA-embedded ribozymes to prevent replication of HIV-1 in cell culture

A trans-acting tRNA-embedded ribozyme targeted to HIV-1 RNA is flanked by cis-acting ribozymes at both its 5 ’ and its 3 ’ end so that, upon transcription, the trans-acting ribozyme is trimmed at both its 5 ’ and its 3 ’ end, with resultant liberation of a small tRNA-embedded ribozyme. The trans-acting ribozymes targeted to a different site in HIV-1 RNA were expressed under the control of the SR promoter and were examined in cell culture in a co-transfection transient assay with an HIV-1 infectious molecular clone, pNL4-3, for their ability to suppress HIV-1 replication. Although the extent of inhibition depended on the target site, all constructs caused significant inhibition of the HIV-1 p24 antigen production in culture supernatant. The ribozyme targeted to either 5 ’ SS (5’ major splicing site) or tat1 site within tat-coding region had the highest inhibitory effect (>80%) when the molar ratio of template DNA for the target HIV-1 RNA to that for the ribozyme was 1:8. I