Passive transfer of the idiotypically suppressed state by serum from suppressed mice and transfer of suppression from mothers to offspring.

Mice that are suppressed with respect to an idiotype (CRIA) present in A/J anti-p-azophenylarsonate antibodies, hyperimmunized, and allowed to rest were previously found to possess high concentrations of suppressor T cells with anti-idiotypic receptors. We have now observed that the sera of such mice contain soluble factors that can selectively suppress the CRIA component of a humoral response when passively transferred to adult or neonatal recipients. When T cells from suppressed, hyperimmunized mice were transferred into female mice before mating, their offspring, upon immunization, produced anti-Ar antibodies that lacked CRIA. A state of idiotypic suppression was also produced in offspring when the mother was inoculated with serum from suppressed mice a few days before parturition. The results indicate that the suppressor factor is not an immunoglobulin.