The Effect of Antibody on the Induction of Tolerance to Human γ-Globulin in Icr Albino Mice

Abstract

Summary Tolerance to human γ-globulin (HGG) was achieved in neonate and adult random-bred ICR mice following a single intraperitoneal injection of 1 to 10 mg of HGG. The duration of tolerance depended on the amount injected and the age of the animal at the time of injection. Antibody production occurred at times, following antigenic challenge, when detectable amounts of antigen were still present in the serum of the once tolerant animals. Following recovery from unresponsiveness the initial antibody response had the characteristics of a primary response and antibody levels of the once tolerant mice remained lower than those of immunized mice for several months. Spontaneous antibody production (without prior antigenic challenge) was only rarely observed and it was always transient. Antiserum had an effect on hastening the loss of tolerance of an older group of adult tolerant mice, but it did not enhance the immune response of younger mice. When small amounts of high-titered antiserum were administered to neonate tolerant mice at birth, it affected the induction of tolerance, and antibody levels of these mice were higher than those of tolerant mice not injected with antibody. There was no effect on neonate tolerant mice when antiserum was administered during the tolerant state up to the time of recovery. Since antibody levels were comparable in both the serum and the ascites fluid (obtained by the injection of sarcoma 37 tumor cells), ascites fluid served as the source of antibody. No precipitating antibody was formed by either immunized mice or those which had lost tolerance. Hence, all antibody levels were tested by the passive tanned cell hemagglutination method.