The augmenting effect of antibody on the induction of an immune response.

Primary and secondary antigenic stimuli were given in the presence of antibody in order to study the role of antibody in the induction of the subsequent immune response. Primed cells immunized with crystalline bacterial α-amylase (BαA) and crystalline Taka-amylase A (TAA) were more effectively stimulated by antigen bearing cells which had been previously prepared by exposure to the two antigens in the presence of anti-BαA or anti-TAA than in the absence of the antibodies. The augmenting effect of the antibody was specific in relation to the antibody added. The primary antibody responses to BαA and TAA were also specifically augmented by the presence of the corresponding antibody, when two antigens were mixed with the antibody and injected intravenously into normal mice. When dinitrophenyl (DNP) residues were introduced to BaA, the immune response stimulated by DNP-BαA was also augmented by anti-DNP antibody. Although specificity of the response augmented by anti-hapten or anti-carrier antibody may be determined on a cellular level, the specificity of response augmented by either of these antibodies extended to the hapten as well as the carrier-determinants. Thus, the presence of antibody directed against any of determinants on an antigen, might result in widening the spectrum of responsiveness of the animal to other antigenic determinants.