Inhibition by interferon of delayed-type hypersensitivity in the mouse.

The effect of interferon on delayed-type by persensitivity to picryl chloride and sheep erythrocytes was examined in the mouse. When administered to sensitized animals on the day before or the day of challenge, tissue culture interferon inhibited both the ear swelling induced by pieryl chloride and footpad swelling induced by sheep erythrocytes. Newcastle disease virus, when injected into sensitized If-1l or If-1h congenic mice a few hours before challenge, caused an inhibition of delayed-type hypersensitivity which could be related to the amount of serum interferon induced by the virus. These results indicate that interferon production may represent one of the factors responsible for the depression of cell-mediated immune reactions during virus infection.