Inhibition of HIV-1 Replication in Cultured Cells with Antisense Oligonucleotides Encapsulated in Immunoliposomes

Abstract

Antisense oligonucleotides inhibit HIV replication in vitro, but their activity is limited by their sensitivity to nucleases and low cellular uptake. To see whether these problems could be circumvented, we compared effects of HIV-1 rev and tat gene-specific antisense phosphodiester or phosphorothioate oligonucleotides, either free in solution or encapsulated in antibody-targeted liposomes (immunoliposomes), on acutely or chronically infected cells. Phosphodiester antisense oligonucleotides were inactive in their free form in acutely and chronically infected cells (up to a concentration of 50 microM). When encapsulated in immunoliposomes directed to HLA class I molecules expressed by targeted cells, they inhibited viral replication (at a concentration of 0.5 microM) in acutely infected cells in a sequence-specific manner. The same phosphodiester antisense oligonucleotides in liposomes had no antiviral activity in chronically infected cells. In acutely infected cells, phosphorothioate oligonucleotides free in solution inhibited the replication of HIV without sequence specificity and had slightly greater activity, also nonspecific, when encapsulated in liposomes. Phosphorothioate antisense (anti-rev) oligonucleotides specifically blocked HIV replication in chronically infected cells. When encapsulated in targeted liposomes the efficiency of inhibition for these cells was increased by at least 60-fold relative to the same oligonucleotide free in solution.