Immunologic tolerance to heterologous immunoglobulin: its relation to in vitro filtration by macrophages.

The cellular and molecular basis for the difference in ability of BCG to induce tolerance in BALB/c and DBA/2 mice has been examined by in vitro biofiltration. It was found that incubation with the adherent cells from BALB/c but not DBA/2 spleens could remove the material from BGG which inhibited tolerance induction in BALB/c mice. This material was shown to represent only a trace component in BGG, was present in only certain commercial batches of BGG, and was apparently unrelated to the presence of aggregates or endotoxin.