MODIFIED ANTISENSE OLIGONUCLEOTIDES DIRECTED AGAINST TUMOR-NECROSIS-FACTOR RECEPTOR-TYPE-I INHIBIT TUMOR-NECROSIS-FACTOR ALPHA-MEDIATED FUNCTIONS

Tumor necrosis factor alpha (TNF alpha), a polypeptide produced by act ivated macrophages, is a highly pleiotropic cytokine which elicits inf lammatory and immunological reactions. The binding of TNF alpha to tum or necrosis factor receptor type I (TNFRI) is considered the initial s tep responsible for some of the multiple biological functions mediated by TNF alpha. The role of TNF alpha as an inflammatory mediator throu gh human TNFRI makes TNFRI an attractive target for intervention in bo th acute and chronic inflammatory diseases. In this study, we have ide ntified partial phosphorothioate oligodeoxyribonucleotides (ODNs) cont aining C-5 propynyl or hexynyl derivatives of 2'-deoxyuridine which sp ecifically inhibited TNFRI and subsequently inhibited the functions of TNF alpha mediated through TNFRI. The most active ODNs were directed against the 3'-poly adenylation signal site on the TNFRI mRNA, and in a cellular assay, gene-specific antisense inhibition occurred in a dos e-dependent fashion at submicromolar concentrations, in the presence o f Cellfectin. The inhibition of gene expression correlated with the bi nding affinity of the ODN for the target mRNA. The ODNs lowered TNFRI protein levels and TNF alpha-mediated functions by specifically reduci ng levels of TNFRI mRNA. These anti-TNFRI ODNs offer a novel approach for controlling biological functions of TNF alpha and may be useful as human therapeutic agents for treating diseases in which TNF alpha has been implicated.