EFFECT OF ION-PAIRING ON THE CELLULAR-TRANSPORT OF ANTISENSE OLIGONUCLEOTIDE

Antisense oligonucleotide represents an interesting tool for selective inhibition of gene expression. However, their low efficiency of intro duction within intact cells remains to be overcome. Antisense-TGF beta (25 mer) and antisense-TNF alpha (18 mer) were used to study the cell ular transport and biological function of antisense oligonucleotide in vitro. Since TGF and TNF play on important role in regulating the nit ric oxide production from macrophages, the action of the above antisen se oligonucleotides was easily monitored by the determination of nitri te. Poly-L-lysine, benzalkonium chloride and tetraphenylphosphonium ch loride were used as polycations, which neutralize the negative charge of antisense oligonucleotide. The production of nitric oxide mediated by gamma-IFN in mouse peritoneal macrophage was increased by antisense -TGF beta in a dose-dependent manner. Antisense-TNF alpha reduced the nitric oxide release from activated RAW 264.7 cells. Significant enhan cement in the nitric oxide production was investigated by the cotreatm ent of poly-L-lysine with antisense-TGF beta. On the meanwhile, inhibi tion effect of antisense-TNF alpha is not changed by the addition of p oly-L-lysine. These results demonstrate that control of expression of TGF beta and TNF alpha gene is achieved using antisense technology and the cellular uptake of antisense oligonucleotide could be enhanced by ion-pairing.