EFFICACY OF A NEW ANTI-TNF ALPHA AGENT

Antisense oligonucleotides show promise as agents for controlling the expression of specific genes. However, the standard method of delivery of modified oligonucleotides has several difficulties: Toxicity of phosphorothioate and other derivaties is of concern, cell-specific delivery is difficult, and dose levels can only be controlled by frequency of injection. Delivery of RNA, directly or by in situ transcription from regulatable promoters (gene therapy approach), offers potential solutions to the above problems. However, mRNA sequences in coding regions cannot be blocked by simple RNA oligos due to disruption of complexes by ribosomes during translation. In the proposed research we test the efficacy of a new antisense agent, targeted against tumor necrosis factor (TNF) alpha, that is designed to lock onto its target mRNA so as to prevent dissociation during translation. Control of TNF alpha shows promise as a therapy for sepsis and arthritis. We will rely on a proven method of delivery to machrophages. If successful, this locking approach, which can be extended to any antisense target, is likely to increase both the effectiveness of antisense therapy in general and the number of sequences that can be targeted. Constructs will be tested for efficacy in down-regulating TNF alpha expression in mouse macrophages in vitro and in vivo. The approach is suitable for delivery of antisense constructs using lipid vehicles as well as by a gene therapy approach. The technique can also be adapted to antigene strategies.