Antigen-antibody complexes suppress antibody production by mouse plasmacytoma cells in vitro.

Preformed complexes of 2,4-dinitrophenylated keyhole limpet hemocyanin (DNP-KLH) and anti-DNP or anti-KLH antibodies selectively, suppressed the production of anti-DNP IgA by the plasmacytoma cell line, MOPC 315, in vitro. Compexes made with DNP8.5KLH (8.5 moles DNP/10(5) daltons carrier) inhibited the secretion of IgA but not its synthesis, whereas complexes prepared with the more highly substituted DNP20KLH inhibited synthesis as well. Moreover, complexes of DNP-KLH and anti-DNP F(ab')2 fragments were as suppressive as those made with IgG antibodies, suggesting that the mode of presentation of antigenic determinants and not surface Fe receptors may play a major role in this phenomenon.