Interferon induction by a tumoral DNA in an homologous culture system.

The interferon induction by Rous sarcoma DNA in an homologous culture system and a further insight of its kinetics and antimetabolites action were the principal aim of the present study. There was a direct relation between the dose of the inducer and the protection against the cytoplathogenic effect of the challenging virus (VSV) reaching the highest activity (68-75% CPE inhibition) with 100 mug RS-DNA. The kinetics of the induction revealed a peak inhibition by 18 hours after the inducer. Treatment with Actinomycin D evidenced that both interferon production and activity are modified. Its early addition resulted in a poor protection; but an accentuated interferon release was observed when antimetabolite was added 18 hours after the inducer. Similar results were obtained when its effect was studied on the activity of exogenous interferon. Interferon induction by Rous sarcoma DNA in an homologous system, allows the detection of a difference between tumoral and normal DNA at a biological level.