COVALENT PROTEIN-OLIGONUCLEOTIDE CONJUGATES FOR EFFICIENT DELIVERY OFANTISENSE MOLECULES

Antisense oligonucleotides have been covalently attached to asialoglyc oprotein (ASGP) via disulfide bond conjugation chemistry. These conjug ates were characterized extensively by an array of chemical, chromatog raphic, and spectroscopic means. Multiple (approximately six) oligonuc leotides can be conjugated to each ASGP molecule. The molecular conjug ates were used to deliver antisense oligonucleotides complementary to the mRNA of the interleukin 6 signal transduction protein (gp130) to m odulate the acute phase response of hepatoma (HepG2) cells in vitro. T hese conjugates were biologically active, as measured by inhibition of the cytokine-stimulated up-regulation of the acute phase protein hapt oglobin. The level of inhibition was comparable to that found with pre vious technology featuring noncovalent complexes of ASGP-poly(L-lysine ) and oligonucleotide. Because of the ability to control the stoichiom etry of the conjugate and its unimolecular nature (as opposed to bimol ecular for the noncovalent conjugates), this methodology holds great p romise for further development and application.