Comparison of efficacy of antisense oligomers directed toward TNF-alpha in helper T and macrophage cell lines

The authors investigated the use of antisense oligomers specific for TNF-alpha (AS-2) and nonsense control oligomers (NS) in T cells (HT2) and macrophages (RAW264.7), comparing three distinct chemical formulations, Phosphorothioate antisense (S-AS) caused sequence-specific inhibition of TNF-alpha, production by activated HT2s (0.5 mu M S-AS 2 vs S-NS: 31.4 +/- 1.2%, 4.2 +/- 3.2% inhibition, respectively), In contrast, S-AS were ineffective in RAW264.7, despite greater uptake as measured with fluorescent S-oligonucleotides. Furthermore, differences in efficacy of S-AS (HT2 > RAW) were not attributable to differences in the pinocytic (HT2 = RAW) or adsorptive endocytic (RAW > HT2) pathways implicated in oligonucleotide uptake, suggesting an important role for intracellular events after antisense uptake, Morpholino oligomers (M-AS), in contrast, were more effective in RAW264.7 than in HT2 (32.6 +/- 2.6% vs 12.3 +/- 0.5% inhibition), consistent with uptake experiments using fluorescent M-oligomers. Phosphodiester oligonucleotides were ineffective in both cell types, It was concluded that antisense efficacy in leukocytes varies according to type of oligomer, cell target and intracellular processing event(s). (C) 1997 Academic Press Limited.