Glucose conjugation of anti-HIV-1 oligonucleotides containing unmethylated CpG motifs reduces their immunostimulatory activity

Antisense oligodeoxynucleotides (ODNs) are short synthetic DNA polymers complementary to a target RNA sequence. They are commonly designed to halt a biological event, such as translation or splicing. ODNs are potentially useful therapeutic agents for the treatment of different human diseases. Carbohydrate–ODN conjugates have been reported to improve the cell-specific delivery of ODNs through receptor mediated endocytosis. We tested the anti-HIV activity and biochemical properties of the 5′-end glucose-conjugated GEM 91 ODN targeting the initiation codon of the gag gene of HIV-1 RNA in cell-based assays. The conjugation of a glucose residue significantly reduces the immunostimulatory effect without diminishing its potent anti-HIV-1 activity. No significant effects were observed in either ODN stability in serum, in vitro degradation of antisense DNA–RNA hybrids by RNase H, cell toxicity, cellular uptake and ability to interfere with genomic HIV-1 dimerisation.