Inhibition of IL-6 in mice by anti-NF-kappa B oligodeoxyribonucleotide N3 ' -> P5 ' phosphoramidates

Oligonucleotide N3' --> P5' Phosphoramidates (PN) may confer advantages ove r unmodified phosphodiester compounds for therapeutic applications (I). Pre vious in vitro data demonstrated that PN Oligodeoxynucleotides (ODNs) posse ss several advantageous features, including RNase H-independence, an improv ed resistance to nuclease degradation, decreased protein binding, and high affinity sequence-specific binding to complementary RNAs (1, 2). Consequent ly, we undertook a study to investigate the effects of PN antisense (AS) ol igos targeted against the p65 subunit of the Nuclear Factor Kappa beta (NF- kappa B) transcription factor in vivo, in mice. The ability of the antisens e molecules to inhibit IL-6 elevation induced by lipopolysaccharide (LPS) i n mice, was studied. A 16 mer uniformly modified PN and a chimeric phosphor amidate-phosphodiester oligodeoxynucleotide complementary to the region sur rounding the starting codon, (PN-PO-PN) of the NK-kappa B p65 subunit, mRNA , both caused a sequence specific reduction of the serum IL-6 level in mice . A scrambled oligodeoxynucleotide showed much lower IL-6 inhibition in mic e. These results show that the p65 PN-AS can modulate expression of IL-6 in mice without uptake enhancers and therefore may be a useful prototype for RNAse-H independent therapeutic agents.