Polyvalent epitope inhibits but added with anti-idiotype antibody enhances idiotype suppression.

When BALB/c spleen cell cultures were preincubated with polyvalent PC-antigens, regardless of their immunogenicity, cultures became resistant to id suppression induced by subsequent treatment with anti-id antibody and immunogenic PC-antigen. In addition, incubation with both anti-id and any of these antigens assisted the induction of rapid, irreversible B cell tolerance. These results suggest that B cells bearing receptors for an epitope undergo an initial triggering in response to polyvalent epitope regardless of the T dependence and/or immunogenicity of the antigen. An additional signal must then facilitate the differentiation of the partially activated B cells to produce antibody. Therefore, a nonimmunogenic polyvalent epitope-bearing molecule can deliver either an initial triggering signal or a tolerogenic signal, depending on the presence of anti-id antibody, and it is as efficient as a complete immunogen.