The role of antibody feedback inhibition in the regulation of the secondary antibody response after high and low dose priming.

Spleen cells from mice immunized with a low dose of SRBC produce a greater secondary response to subsequent antigenic challenge in vivo than spleen cells from mice initially immunized with a larger dose. However, when the spleen cells are removed from the mice and given a secondary challange in tissue culture, a greater response is produced by cells from animals primed with the larger dose. Serum from the mice receiving the high dose of antigen contains low, but significant levels of specific antibody, and can inhibit further antibody production by lymphoid cells in vivo and in vitro. The characteristics of this suppression are similar to those known for passively administered specific antibody. Thus, antibody produced as a result of primary immunization may act through an inhibitory feedback mechanism in specifically limiting the magnitude of the secondary response to subsequent antigenic challenge in the normal animal