[Immunodepressive activity of glycoproteins].

Glycoprotein fraction of the blood serum of cattle depressed both the primary and the secondary immune response in case of mouse inoculation 24 hours before the immunization with sheep erythrocytes. The use of this fraction coincidently with the antigenic stimulus or after it was ineffective. Analogous fractions from the thymus and the liver of cattle produced a similar action. Glycoprotein fraction of the serum, thymus and liver depressing the immunological reactions possessed a marked ribonuclease activity.