The Kinetics of in Vivo Tolerance Introduction in Mice

C57BL/6 mice were rendered immunologically tolerant by an intraperitoneal injection of 200 μg of bovine γ globulin (BGG). An intraperitoneal injection of 1 mg of polyornithine (poly-O) given from 24 hr before to 5 hr after the injection of BGG produced immunity rather than tolerance. After 8 hr the induction of tolerance by BGG was no longer reversible by the poly-O. In a further test of the induction period of tolerance, washed spleen cells were transferred to x-irradiated recipients which were then immunized. If spleen cells were removed from donor mice as little as 4 hr after they had been injected with 2 mg of BGG, significant loss of ability to produce immunity in recipients was seen.