Modified adenovirus penton base protein (UTARVE) as a nonreplicating vector for delivery of antisense oligonucleotides with antiviral and/or antineoplastic activity

Antisense oligonucleotides that selectively inhibit gene expression are a g enetic approach for disease treatment and prevention. However, their use as therapeutic agents is complicated by their low rate of transport across ce llular membranes and their sequestration within endocytic-like vesicles. We report that the adenovirus type-2 penton base protein modified to include the fusogenic peptide of the influenza virus hemagglutinin protein is a non -replicating vector (designated UTARVE) that improves delivery of antisense oligonucleotides. Approximately 10-18% of the input vector was internalize d by A549 and HeLa cells as determined by immunoblotting. It was cleared by proteolysis within 48 h. The vector had endosome disruptive potential as e videnced by erythrocyte lysis activity at low pH and a primarily diffuse cy toplasmic distribution in treated cells. Despite concentration and time-dep endent cell detachment, UTARVE was not cytotoxic in the dye release assay. We used R1T1, an antisense oligonucleotide that inhibits expression of the multifunctional herpes simplex virus type-2 (HSV-2) R1 protein, HSV-2 growt h and the proliferation of R1 PK transformed cells to examine vector-mediat ed delivery. Conjugated FITC-labeled R1T1 was rapidly (15-30 min) internali zed by all cells treated at low (80 nM) concentration and the oligomer was intracellularly dissociated from the vector. This compares to 65-83% of cel ls internalizing the unconjugated R1T1 when treated for 24 h. In antiviral assays, the IC50 and time required to inhibit HSV-2 growth were significant ly lower for the conjugated (2 nM; 30 min) as compared to unconjugated (100 nM; 24 h) R1T1. The data indicate that the bioavailability and biological activity of R1T1 were significantly increased by its delivery with UTARVE.