Studies on the Mechanism of the Suppression of Active Antibody Synthesis by Passively Administered Antibody

F(ab′)2 and Fab′ anti-DNP antibody fragments suppressed anti-DNP antibody formation. The fraction of anti-DNP antibody elutable from a specific precipitate by p-nitrophenyl-ε-aminocaproic acid (p-NP-EACA) suppressed anti-DNP antibody formation but did not alter the percentage of the anti-DNP antibody that could be eluted with p-NP-EACA. The data are consistent with the concept that passively tranferred antibody causes suppression by binding antigen thus preventing it from stimulating potential antibody-forming cells.