[Action of a yeast dsRNA preparation on the humoral immune response and the delayed hypersensitivity reaction].

The studies showed that yeast dsRNA in a dose of 2.5 mg/kg had a stimulating effect on the humoral immune response. When the preparation was administered soon after sensitization of experimental animals by the thymus-dependent antigen (sheep red blood cells, SRBC), there were observed a more than two-fold increase in the AFC count in the spleen and increased titers of hemolysins in blood serum. With the use of higher doses of the preparation (up to 10 mg/kg) the level of the immunostimulating effect remained unchanged. The efficacy of the preparation in CBA and C57BL/6 mice with high and low reactivity to the antigen was the same. Delayed-type hypersensitivity in the animals sensitized by SRBC was inhibited by yeast dsRNA in a dose of 10 mg/kg.