Inhibition of HIV-1 in cell culture by oligonucleotide-loaded nanoparticles

Purpose. To investigate the potential use of polymeric nanoparticles for th e delivery of antisense oligonucleotides in HIV-1-infected cell cultures. Methods. Phosphorothioate oligonucleotides were encapsulated into poly (D,L -lactic acid) nanoparticles. Two models of infected cells were used to test the ability of nanoparticles to deliver them. HeLa P4-2 CD4+ cells, stably transfected with the P-galactosidase reporter gone, were first used to eva luate the activity of the oligonucleotides on a single-round infection cycl e. The acutely infected lymphoid CEM cells were then used to evaluate the i nhibition of the viral production of HIV-1 by the oligonucleotides. Results. The addition to infected CENT cells of nanoparticles containing ga g antisense oligonucleotides in the nanomolar range led to strong inhibitio n of the viral production in a concentration-dependent manner. Similar resu lts were previously observed in HeLa P4-2 CD4+ cells. Nanoparticle-entrappe d random-order gag oligonucleotides had similar effects on reverse transcri ption. However, the reverse transcriptase activity of infected cells treate d with nanomolar concentrations of free antisense and random oligonucleotid es was not affected. Conclusions. These results suggest that poly (D,L-lactic acid) nanoparticle s may have great potential as an efficient delivery system for oligonucleot ides in HIV natural target cells, i.e., lymphocytic cells.