Studies on antigenic competition. I. Antigenic competition between the Fc and Fab fragments of rabbit IgG in mice.

In the antibody response to rabbit IgG in BALB/c mice, antigenic competition has been demonstrated between Fc and Fab'. Similar competition was found when a mixture of Fc and Fab' was used as antigen. In both cases the presence of Fc suppressed the antibody response to Fab'. Competition was demonstrable only in the primary antibody response. The effect on competition of varying the routes and the time course of administration of the antigens was investigated.