[Interferon-inducing activity of liposome-incorporated double-stranded polynucleotides and the means for its...

Natural double-stranded RNA (dsRNA) incorporated into liposomes upon parenteral inoculation induces 4 times as much amounts of interferon as inoculation of the equal amount of dsRNA without liposomes. Oral administration of liposome-incorporated dsRNA induces in animals serum interferon in amounts similar to those induced by parenteral inoculation of dsRNA without liposomes (320-640 units/ml). When liposome-incorporated dsRNA is used, interferon induction is prolonged to 24 hours. The prolongation period increases to 5 days after preliminary treatment of animals with "empty" liposomes. In M-19 cell culture, 2-hour treatment with liposome-incorporated dsRNA in a dose of 5-10 micrograms/ml induces a yield of 640-1280 units/ml interferon and 100% antiviral effect. The L-929 culture is more sensitive to dsRNA in liposomes. Even its minimal amounts (0.1-1 microgram/ml) after 2-3-hour contact produce a 100% antiviral effect in the presence of low amounts of interferon in the culture fluid (20-40 units/ml) or in its complete absence.