Induction of human leukocyte interferon by heat-treated poly I: poly C.

Synthetic double stranded RNA (poly I: poly C) was prepared from polyinosinic acid (poly I) and polycytidylic acid (poly C) by heat-treated followed by gradual cooling, and was used for induction of human leukocyte interferon (IFN). When poly I: poly C solution was heated at 37 - 65 degrees C for 30 minutes, high activity of human IFN (10,000 - 60,000 i. u./ml) was obtained. In this system, the optimum molecular weight of poly I: poly C to induce IFN was 12.6 - 17.6 S. The properties of induced IFN were heat- and acid- stable, and it was neutralized with anti-IFN alpha serum. So, it was confirmed that it was IFN alpha.