TARGETED ANTISENSE MODULATION OF INFLAMMATORY CYTOKINE RECEPTORS

Antisense technology is potentially a powerful means by which to selec tively control gene expression. We have used antisense oligonucleotide s to modulate the response of the hepatoma cell line, HepG2, to the in flammatory cytokine, IL-6, by inhibiting the expression of its multifu nctional signal transducer, gp130. HepG2 cells respond to IL-6 by upre gulating acute phase proteins, such as haptoglobin, by five- to tenfol d. Gp130 is central to this response, as the upregulation of haptoglob in is almost completely blocked by the addition of high concentrations (similar to 100 mu g/mL) of a monoclonal antibody to gp130. Antisense oligodeoxynucleotides complementary to the mRNA encoding gp130 inhibi ted the upregulation of haptoglobin by IL-6-stimulated HepG2 cells by about 50%. However, a nonsense sequence also inhibited haptoglobin sec retion by about 20%. To improve the specificity and efficiency of acti on, we targeted the antisense oligonucleotides to HepG2 cells using a conjugate of asialoglycoprotein-poly-L-lysine. The targeted antisense reduced the binding of IL-6 to HepG2 cells, virtually eliminating high affinity binding. In addition, it inhibited haptoglobin upregulation by over 70%. Furthermore, the dose of targeted antisense required for biological effect was reduced by about an order of magnitude as compar ed with unconjugated antisense. These results demonstrate the potentia l of antisense oligonucleotides as a means to control the acute phase response as well as the need for a greater understanding of the mechan ism and dynamics of antisense molecules as they are developed toward t herapeutic application. (C) 1997 John Wiley & Sons, Inc.