A state resembling tolerance arising in mice under the influence of antigen of lysed erythrocytes

Abstract

A lysate obtained by treating sheep's erythrocytes with distilled water, purified by ultracentri-fugation in the cold, was shown to possess weak immunogenicity. Its injection into mice caused a state of hyporeactivity to sheep's erythrocytes (the level of the immune response was depressed to 10–25% of the control). The ability of mouse spleen cells to give an immune response to erythrocytes was undisturbed after adaptive transfer. In the early stages after injection of the lysate the spleen cells of the mice had weak suppressive activity when transplanted into intact animals. Blood serum of mice treated with the lysate possessed weak blocking activity which disappeared after absorption of the serum with sheep's erythrocytes. It is concluded that the hyporeactivity arising in the mice after injection of the lysate is due to the presence of antibodies inhibiting the immune response in the serum.