Antibody formation: reduced responses after administration of excessive amounts of nonspecific stimulators.

Enhancement of antibody formation in vitro and in vivo by poly(A.U), cyclic AMP, dibutyryl cyclic AMP, or any one of these agents in combination with theophylline or caffeine, is usually limited to certain dose ranges. High doses of these nonspecific stimulators can produce less or no enhancement, or may actually inhibit antibody formation. Such dose-response relationships may be pertinent to an understanding of phenomena of specific immunological nonresponsiveness and certain types of antigenic competition.