Receptor ligand-facilitated cationic liposome delivery of anti-HIV-1 Rev-binding aptamer and ribozyme DNAs

We examined whether HIV-1 gene expression could be inhibited by the anti-HIV Rev-binding aptamer [RBE(apt)], and whether the antiviral effect of the aptamer could be enhanced by a ribozyme directed against the HIV-1 city gene. Since cationic liposomes are relatively safe and non-immunogenic for in vivo gene delivery, we tested the effectiveness of the aptamer and ribozyme DNAs in HeLa cells, using Lipofectin reagent in a transient transfection assay. To increase the transfection efficiency, lipofectin was mixed with transferrin before subsequent addition of DNA, Co-transfection of HeLa cells with the RBE(apt) and the proviral HIV clone, HXB Delta Bgl, resulted in inhibition of virus production. Specific inhibition of viral p24 production following co-transfection of the RBE(apt) and HIV proviral DNAs was observed. These data provide strong support for the use of in vitro evolved ligands as potential anti-HIV agents. The addition of the anti-env ribozyme to the aptamer construct did not further enhance the antiviral activity, suggesting either that we had reached the limits of inhibition in this assay, or that the ribozyme was not able to access its target site with Rev bound to the RBE aptamer. The observed inhibition of p24 production could not be attributed to the non-specific toxicity of the transfection procedure, because no difference in viability was observed between the RBE(apt)- and the vector control-treated cells. All of the aptamer-ribozyme constructs as well as the RBE(apt) were similarly effective.