Fate of antigen-binding cells in unresponsive and immune mice.

Antigen-binding cells (ABC) to the antigen human gamma globulin (HGG) were quantitated in lymphoid tissues of A/J mice at various times after the injection of deaggregated HGG (tolerogen), aggregated HGG (immunogen), or saline. The reaction of lymphoid cells with highly labeled HGG was specific to that antigen since binding could be inhibited by excess unlabeled HGG, but not by unrelated non-cross-reacting proteins. Compared with normal mice, there was a marked decrease in the numbers of ABC in the spleens of unresponsive animals evident as early as 12 h after the injection of tolerogen. A marked increase in ABC was observed in the spleens of immunogen-injected mice, beginning at 24 h and reaching a peak at 3 days. In bone marrow, no difference in the number of ABC was found among the three experimental groups until day 20, when a reduction in ABC was observed only in tolerogen-injected mice. No quantitative difference in the thymuses in the experimental groups could be determined because of the paucity of ABC displayed by normal thymus cells.